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Antigen-presenting cells (APCs) play an important role in virus infection control by bridging innate and adaptive immune responses. Macrophages and dendritic cells (DCs) possess various surface receptors to recognize/internalize antigens, and antibody binding can enhance pathogen-opsonizing uptake by these APCs via interaction of antibody fragment crystallizable (Fc) domains with Fc receptors, evoking profound pathogen control in certain settings. Here, we examined phagocytosis-enhancing potential of Fc domains directly oriented on a retroviral virion/virus-like particle (VLP) surface. We generated an expression vector coding a murine Fc fragment fused to the transmembrane region (TM) of a retroviral envelope protein, deriving expression of the Fc-TM fusion protein on the transfected cell surface and production of virions incorporating the chimeric Fc upon co-transfection. Incubation of Fc-displaying simian immunodeficiency virus (SIV) with murine J774 macrophages and bone marrow-derived DCs derived Fc receptor-dependent enhanced uptake, being visualized by imaging cytometry. Alternative preparation of a murine leukemia virus (MLV) backbone-based Fc-displaying VLP loading an influenza virus hemagglutinin (HA) antigen resulted in enhanced HA internalization by macrophages, stating antigen compatibility of the design. Results show that the Fc-TM fusion molecule can be displayed on certain viruses/VLPs and may be utilized as a molecular adjuvant to facilitate APC antigen uptake., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Background: Person with human immunodeficiency virus type-1 (PWH) are prone to chronic inflammation due to residual viral production, even with antiretroviral therapy (ART), which increases the risk of age-related diseases. There is also limited information on changes in the intestinal environment of PWH during ART. In this longitudinal study, we investigated changes in the gut microbiota, persistence of chronic inflammation, interactions between the gut environment and inflammation, and metabolic changes in PWH using long-term ART., Results: We analyzed changes in clinical parameters and gut microbiota in 46 PWH over a mean period of 4 years to understand the influence of gut dysbiosis on inflammation. Overall, changes in the gut microbiota included a decrease in some bacteria, mainly involved in short-chain fatty acid (SCFA) production, and an increase in certain opportunistic bacteria. Throughout the study period, an increase in bacterial-specific metabolic activity was observed in the intestinal environment. Continued decline in certain bacteria belonging to the Clostridia class and metabolic changes in gut bacteria involved in glucose metabolism. Additionally, patients with a low abundance of Parabacteroides exhibited low bacterial alpha diversity and a significant increase in body mass index (BMI) during the study period. Monocyte chemoattractant protein 1, a marker of macrophage activation in the plasma, continued to increase from baseline (first stool collection timepoint) to follow-up (second stool collection timepoint), demonstrating a mild correlation with BMI. Elevated BMI was mild to moderately correlated with elevated levels of plasma interleukin 16 and chemokine ligand 13, both of which may play a role in intestinal inflammation and bacterial translocation within the gut microbiota. The rate of BMI increase correlated with the rate of decrease in certain SCFA-producing bacteria, such as Anaerostipes and Coprococcus 3., Conclusion: Our data suggest that despite effective ART, PWH with chronic inflammation exhibit persistent dysbiosis associated with gut inflammation, resulting in a transition to an intestinal environment with metabolic consequences. Moreover, the loss of certain bacteria such as Parabacteroides in PWH correlates with weight gain and may contribute to the development of metabolic diseases., (© 2024. The Author(s).)

Human T cell leukemia/T-lymphotropic virus type 1 (HTLV-1) infection occurs by cell-to-cell transmission and can induce fatal adult T cell leukemia. Vaccine development is critical for the control of HTLV-1 transmission. However, determining whether vaccine-induced anti-Env antibodies can prevent cell-to-cell HTLV-1 transmission is challenging. Here, we examined the protective efficacy of a vaccine inducing anti-Env antibodies against HTLV-1 challenge in cynomolgus macaques. Eight of 10 vaccinated macaques produced anti-HTLV-1 neutralizing antibodies (NAbs) and were protected from an intravenous challenge with 10 8 HTLV-1-producing cells. In contrast, the 2 vaccinated macaques without NAb induction and 10 unvaccinated controls showed HTLV-1 infection with detectable proviral load after challenge. Five of the eight protected macaques were administered with an anti-CD8 monoclonal antibody, but proviruses remained undetectable and no increase in anti-HTLV-1 antibodies was observed even after CD8 + cell depletion in three of them. Analysis of Env-specific T cell responses did not suggest involvement of vaccine-induced Env-specific T cell responses in the protection. These results indicate that anti-Env antibody induction by vaccination can result in functionally sterile HTLV-1 protection, implying the rationale for strategies aimed at anti-Env antibody induction in prophylactic HTLV-1 vaccine development., Competing Interests: Declaration of interests T.M. is an inventor on Patent Cooperation Treaty (PCT) application for SeV-NVP-EnvF vaccine., (Copyright © 2024 The Author(s). Published by Elsevier Inc. All rights reserved.)

Persistent inflammation in chronic HIV infection may affect immune responses against SARS-CoV-2 infection. Plasma levels of multiple proinflammatory cytokines during acute SARS-CoV-2 infection were assessed in people with HIV (PWH) with effective cART. There were no significant differences in any of the tested cytokines between COVID-19 severity in PWH, while most of them were significantly higher in individuals with severe disease in HIV-uninfected individuals, suggesting that excess cytokines release by hyper-inflammatory responses does not occur in severe COVID-19 with HIV infection. The strong associations between the cytokines observed in HIV-uninfected individuals, especially between IFN-α/TNF-α and other cytokines, were lost in PWH. The steady state plasma levels of IP-10, ICAM-1, and CD62E were significantly higher in PWH, indicating that PWH are in an enhanced inflammatory state. Loss of the several inter-cytokine correlations were observed in in vitro LPS stimuli-driven cytokines production in PWH. These data suggest that inflammatory responses during SARS-CoV-2 infection in PWH are distinct from those in HIV-uninfected individuals, partially due to the underlying inflammatory state and/or impairment of innate immune cells.

Dengue virus (DENV) represents a significant global health burden, with 50% of the world's population at risk of infection, and there is an urgent need for next-generation vaccines. Virus-like particle (VLP)-based vaccines, which mimic the antigenic structure of the virus but lack the viral genome, are an attractive approach. Here, we describe a dengue VLP (DENVLP) vaccine which generates a neutralizing antibody response against all four DENV serotypes in 100% of immunized non-human primates for up to 1 year. Additionally, DENVLP vaccination produced no ADE response against any of four DENV serotypes in vitro . DENVLP vaccination reduces viral replication in a non-human primate challenge model. We also show that transfer of purified IgG from immunized monkeys into immunodeficient mice protects against subsequent lethal DENV challenge, indicating a humoral mechanism of protection. These results indicate that this DENVLP vaccine is immunogenic and can be considered for clinical evaluation. Immunization of non-human primates with a tetravalent DENVLP vaccine induces high levels of neutralizing antibodies and reduces the severity of infection for all four dengue serotypes.IMPORTANCEDengue is a viral disease that infects nearly 400 million people worldwide and causes dengue hemorrhagic fever, which is responsible for 10,000 deaths each year. Currently, there is no therapeutic drug licensed to treat dengue infection, which makes the development of an effective vaccine essential. Virus-like particles (VLPs) are a safe and highly immunogenic platform that can be used in young children, immunocompromised individuals, as well as healthy adults. In this study, we describe the development of a dengue VLP vaccine and demonstrate that it induces a robust immune response against the dengue virus for over 1 year in monkeys. The immunity induced by this vaccine reduced live dengue infection in both murine and non-human primate models. These results indicate that our dengue VLP vaccine is a promising vaccine candidate., Competing Interests: D.T., K.Ma., A.U., Y.W., and M.I are employees of VLP Therapeutics, Inc.; J.F.S. is an employee of and holds stocks in VLP Therapeutics, Inc. W.A. is a board member and employee of and holds stocks in VLP Therapeutics, Inc. W.A. is an inventor on a related vaccine patent. The remaining authors declare no competing interest.

BACKGROUND: Vaccination against mpox (formerly known as monkeypox), an infectious disease caused by the monkeypox virus (MPXV), is needed to prevent outbreaks and consequent public health concerns. The LC16m8 vaccine, a dried cell-cultured proliferative live attenuated vaccinia virus–based vaccine, was approved in Japan against smallpox and mpox. However, its immunogenicity and efficacy against MPXV have not been fully assessed. We assessed the safety and immunogenicity of LC16m8 against MPXV in healthy adults. METHODS: We conducted a single-arm study that included 50 participants who were followed up for 168 days postvaccination. The primary end point was the neutralizing antibody seroconversion rate against MPXVs, including the Zr599 and Liberia strains, on day 28. The secondary end points included the vaccine “take” (major cutaneous reaction) rate, neutralizing titer kinetics against MPXV and vaccinia virus (LC16m8) strains, and safety outcomes. RESULTS: Seroconversion rates on day 28 were 72% (36 of 50), 70% (35 of 50), and 88% (44 of 50) against the Zr599 strain, the Liberia strain, and LC16m8, respectively. On day 168, seroconversion rates decreased to 30% (15 of 50) against the Zr599 and Liberia strains and to 76% (38 of 50) against LC16m8. The vaccine “take” (broad definition) rate on day 14 was 94% (46 of 49). Adverse events (AEs), including common solicited cutaneous reactions, occurred in 98% (45 of 48) of participants; grade 3 severity AEs occurred in 16% (8 of 50). No deaths, serious AEs, or mpox onset incidences were observed up to day 168. CONCLUSIONS: The LC16m8 vaccine generated neutralizing antibody responses against MPXV in healthy adults. No serious safety concerns occurred with LC16m8 use. (Funded by the Ministry of Health, Labour and Welfare of Japan; Japan Registry of Clinical Trials number, jRCTs031220171.)

Objectives　In response to the steady rise in the number of cases of mpox in nonendemic countries, starting with an outbreak in the United Kingdom in May 2022, the World Health Organization declared a public health emergency of international concern on July 23, 2022. As of November 13, 2022, seven cases of mpox have been reported in Japan.Methods　A community engagement approach was applied to prevent the spread of mpox in Japan.Results　A tripartite partnership between academia, community, and government (ACG) was established to promote multisectoral communication between vulnerable communities, medical personnel involved in diagnosis and treatment, public health specialists at public health centers, epidemiologists at the National Institute of Infectious Diseases (NIID), and government and public administration. Through information sharing, this ACG partnership can translate accurate information into effective infection control measures.Conclusion　By developing and maintaining the ACG partnership, an environment will be created that allows an immediate response to future public health crises affecting vulnerable communities. This Practice Report describes the process of establishing an ACG partnership.

Unspliced HIV-1 RNAs function as messenger RNAs for Gag or Gag-Pol polyproteins and progeny genomes packaged into virus particles. Recently, it has been reported that fate of the RNAs might be primarily determined, depending on transcriptional initiation sites among three consecutive deoxyguanosine residues (GGG tract) downstream of TATA-box in the 5' long terminal repeat (LTR). Although HIV-1 RNA transcription starts mostly from the first deoxyguanosine of the GGG tract and often from the second or third deoxyguanosine, RNAs beginning with one guanosine (G1-form RNAs), whose transcription initiates from the third deoxyguanosine, were predominant in HIV-1 particles. Despite selective packaging of G1-form RNAs into virus particles, its biological impact during viral replication remains to be determined. In this study, we revealed that G1-form RNAs are primarily selected as a template for provirus DNA rather than other RNAs. In competitions between HIV-1 and lentiviral vector transcripts in virus-producing cells, approximately 80% of infectious particles were found to generate provirus using HIV-1 transcripts, while lentiviral vector transcripts were conversely selected when we used HIV-1 mutants in which the third deoxyguanosine in the GGG tract was replaced with deoxythymidine or deoxycytidine (GGT or GGC mutants, respectively). In the other analyses of proviral sequences after infection with an HIV-1 mutant in which the GGG tract in 3' LTR was replaced with TTT, most proviral sequences of the GGG-tract region in 5' LTR were found to be TTG, which is reasonably generated using the G1-form transcripts. Our results indicate that the G1-form RNAs serve as a dominant genome to establish provirus DNA.IMPORTANCESince the promoter for transcribing HIV-1 RNA is unique, all viral elements including genomic RNA and viral proteins have to be generated by the unique transcripts through ingenious mechanisms including RNA splicing and frameshifting during protein translation. Previous studies suggested a new mechanism for diversification of HIV-1 RNA functions by heterogeneous transcriptional initiation site usage; HIV-1 RNAs whose transcription initiates from a certain nucleotide were predominant in virus particles. In this study, we established two methods to analyze heterogenous transcriptional initiation site usage by HIV-1 during viral infection and showed that RNAs beginning with one guanosine (G1-form RNAs), whose transcription initiates from the third deoxyguanosine of the GGG tract in 5' LTR, were primarily selected as viral genome in infectious particles and thus are used as a template to generate provirus for continuous replication. This study provides insights into the mechanism for diversification of unspliced RNA functions and requisites of lentivirus infectivity., Competing Interests: The authors declare no conflict of interest.

Human immunodeficiency virus (HIV) 1 infection is known to cause gut microbiota dysbiosis. Among the causes is the direct infection of HIV-1 in gut-resident CD4 + T cells, causing a cascade of phenomena resulting in the instability of the gut mucosa. The effect of HIV infection on gut microbiome dysbiosis remains unresolved despite antiretroviral therapy. Here, we show the results of a longitudinal study of microbiome analysis of people living with HIV (PLWH). We contrasted the diversity and composition of the microbiome of patients with HIV at the first and second time points (baseline_case and six months later follow-up_case, respectively) with those of healthy individuals (baseline_control). We found that despite low diversity indices in the follow-up_case, the abundance of some genera was recovered but not completely, similar to baseline_control. Some genera were consistently in high abundance in PLWH. Furthermore, we found that the CD4 + T-cell count and soluble CD14 level were significantly related to high and low diversity indices, respectively. We also found that the abundance of some genera was highly correlated with clinical features, especially with antiretroviral duration. This includes genera known to be correlated with worse HIV-1 progression ( Achromobacter and Stenotrophomonas ) and a genus associated with gut protection ( Akkermansia ). The fact that a protector of the gut and genera linked to a worse progression of HIV-1 are both enriched may signify that despite the improvement of clinical features, the gut mucosa remains compromised., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2024 Runtuwene, Parbie, Mizutani, Ishizaka, Matsuoka, Abana, Kushitor, Bonney, Ofori, Kiyono, Ishikawa, Ampofo and Matano.)

Human T-cell leukemia virus type 1 (HTLV-1) induces chronic asymptomatic latent infection with a substantial proviral load but without significant viral replication in vivo . Cumulative studies have indicated involvement of CD8-positive (CD8 + ) cells, including virus-specific CD8 + T cells in the control of HTLV-1 replication. However, whether HTLV-1 expression from latently infected cells in vivo occurs in the absence of CD8 + cells remains unclear. Here, we examined the impact of CD8 + cell depletion by monoclonal anti-CD8 antibody administration on proviral load in HTLV-1-infected cynomolgus macaques. Five cynomolgus macaques were infected with HTLV-1 by inoculation with HTLV-1-producing cells. Administration of monoclonal anti-CD8 antibody in the chronic phase resulted in complete depletion of peripheral CD8 + T cells for approximately 2 months. All five macaques showed an increase in proviral load following CD8 + cell depletion, which peaked just before the reappearance of peripheral CD8 + T cells. Tax-specific CD8 + T-cell responses were detected in these recovered CD8 + T cells. Importantly, anti-HTLV-1 antibodies also increased after CD8 + cell depletion, indicating HTLV-1 antigen expression. These results provide evidence indicating that HTLV-1 can proliferate from the latent phase in the absence of CD8 + cells and suggest that CD8 + cells are responsible for the control of HTLV-1 replication. IMPORTANCE HTLV-1 can cause serious diseases such as adult T-cell leukemia (ATL) in humans after chronic asymptomatic latent infection with substantial proviral load. Proviruses are detectable in peripheral lymphocytes in HTLV-1 carriers, and the association of a higher proviral load with a higher risk of disease progression has been observed. However, neither substantial viral structural protein expression nor viral replication was detectable in vivo . Cumulative studies have indicated involvement of CD8 + cells, including virus-specific CD8 + T cells in the control of HTLV-1 replication. In the present study, we showed that CD8 + cell depletion by monoclonal anti-CD8 antibody administration results in HTLV-1 expression and an increase in proviral load in HTLV-1-infected cynomolgus macaques. Our results indicate that HTLV-1 can proliferate in the absence of CD8 + cells, suggesting that CD8 + cells are responsible for the control of HTLV-1 replication. This study provides insights into the mechanism of virus-host immune interaction in latent HTLV-1 infection., Competing Interests: The authors declare no conflict of interest.

T cell immunity is crucial for long-term immunological memory, but the profile of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)-specific memory T cells in individuals who recovered from COVID-19 (COVID-19-convalescent individuals) is not sufficiently assessed. In this study, the breadth and magnitude of SARS-CoV-2-specific T cell responses were determined in COVID-19-convalescent individuals in Japan. Memory T cells against SARS-CoV-2 were detected in all convalescent individuals, and those with more severe disease exhibited a broader T cell response relative to cases with mild symptoms. Comprehensive screening of T cell responses at the peptide level was conducted for spike (S) and nucleocapsid (N) proteins, and regions frequently targeted by T cells were identified. Multiple regions in S and N proteins were targeted by memory T cells, with median numbers of target regions of 13 and 4, respectively. A maximum of 47 regions were recognized by memory T cells for an individual. These data indicate that SARS-CoV-2-convalescent individuals maintain a substantial breadth of memory T cells for at least several months following infection. Broader SARS-CoV-2-specific CD4 + T cell responses, relative to CD8 + T cell responses, were observed for the S but not the N protein, suggesting that antigen presentation is different between viral proteins. The binding affinity of predicted CD8 + T cell epitopes to HLA class I molecules in these regions was preserved for the Delta variant and at 94 to 96% for SARS-CoV-2 Omicron subvariants, suggesting that the amino acid changes in these variants do not have a major impact on antigen presentation to SARS-CoV-2-specific CD8 + T cells. IMPORTANCE RNA viruses, including SARS-CoV-2, evade host immune responses through mutations. As broader T cell responses against multiple viral proteins could minimize the impact of each single amino acid mutation, the breadth of memory T cells would be one essential parameter for effective protection. In this study, breadth of memory T cells to S and N proteins was assessed in COVID-19-convalescent individuals. While broad T cell responses were induced against both proteins, the ratio of N to S proteins for breadth of T cell responses was significantly higher in milder cases. The breadth of CD4 + and CD8 + T cell responses was also significantly different between S and N proteins, suggesting different contributions of N and S protein-specific T cells for COVID-19 control. Most CD8 + T cell epitopes in the immunodominant regions maintained their HLA binding to SARS-CoV-2 Omicron subvariants. Our study provides insights into understanding the protective efficacy of SARS-CoV-2-specific memory T cells against reinfection., Competing Interests: The authors declare no conflict of interest.

Innate immune responses are important in the control of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) replication. We have previously found a lactic acid bacteria species, Lactococcus lactis strain Plasma (LC-Plasma), which possesses specific feature to activate plasmacytoid dendritic cells (pDCs) and thus may affect innate immune responses. Here, we investigated the impact of pDC activation by LC-Plasma on SARS-CoV-2 replication in vitro. Addition of the culture supernatant of pDCs stimulated with LC-Plasma resulted in suppression of SARS-CoV-2 replication in Vero and Calu-3 cells. We confirmed interferon-α (IFN-α) secretion in the supernatant of pDCs stimulated with LC-Plasma and induction of IFN-stimulated genes in cells treated with the pDC supernatant. Anti-IFN-α antibody impaired the suppression of SARS-CoV-2 replication by the supernatant of LC-Plasma-stimulated pDCs, suggesting that IFN-α plays an important role in the SARS-CoV-2 suppression. Our results indicate the potential of LC-Plasma to induce inhibitory responses against SARS-CoV-2 replication through pDC stimulation with IFN-α secretion., Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests. Hiroshi Ishii, Kenta Jounai, Konomi Ohshio, Daisuke Fujiwara, and Tetsuro Matano have patent #PCT/JP2022/40242 pending to Licensee., (Copyright © 2023 Elsevier Inc. All rights reserved.)

Background: The 95-95-95 UNAIDS global strategy was adapted to end the AIDS epidemic by 2030. The target is based on the premise that early detection of HIV-infected persons and linking them to treatment regardless of their CD4 counts will lead to sustained viral suppression. HIV testing strategies to increase uptake of testing in Western and Central Africa remain inadequate. Hence, a high proportion of people living with HIV in this region do not know their status. This report describes the implementation of a community based multi-disease health screening (also known as "Know Your Status" -KYS), as part of basic science research, in a way that contributed to achieving public health goals., Methods: A community based multi-disease health screening was conducted in 7 communities within the Eastern region of Ghana between November 2017 and April 2018, to recruit and match HIV seronegative persons to HIV seropositive persons in a case-control HIV gut microbiota study. Health assessments included blood pressure, body mass index, blood sugar, Hepatitis B virus, syphilis, and HIV testing for those who consented. HIV seronegative participants who consented were consecutively enrolled in an ongoing HIV gut microbiota case-control study. Descriptive statistics (percentages) were used to analyze data., Results: Out of 738 people screened during the exercise, 700 consented to HIV testing and 23 (3%) were HIV positive. Hepatitis B virus infection was detected in 4% (33/738) and Syphilis in 2% (17/738). Co-infection of HIV and HBV was detected in 4 persons. The HIV prevalence of 3% found in these communities is higher than both the national prevalence of 1.7% and the Eastern Regional prevalence of 2.7 in 2018., Conclusion: Community based multi-disease health screening, such as the one undertaken in our study could be critical for identifying HIV infected persons from the community and linking them to care. In the case of HIV, it will greatly contribute to achieving the first two 95s and working towards ending AIDS by 2030., (© 2023. The Author(s).)

Introduction: Late diagnosis of the human immunodeficiency virus (HIV) is a major concern epidemiologically, socially and for national healthcare systems. Although the association of certain demographics with late HIV diagnosis has been reported in several studies, the association of other factors, including clinical and phylogenetic factors, remains unclear. In the present study, we conducted a nationwide analysis to explore the association of demographics, clinical factors, HIV-1 subtypes/circulating recombinant form (CRFs) and genetic clustering with late HIV diagnosis in Japan, where new infections mainly occur among young men who have sex with men (MSM) in urban areas., Methods: Anonymized data on demographics, clinical factors and HIV genetic sequences from 39.8% of people newly diagnosed with HIV in Japan were collected by the Japanese Drug Resistance HIV-1 Surveillance Network from 2003 to 2019. Factors associated with late HIV diagnosis (defined as HIV diagnosis with a CD4 count <350 cells/μl) were identified using logistic regression. Clusters were identified by HIV-TRACE with a genetic distance threshold of 1.5%., Results: Of the 9422 people newly diagnosed with HIV enrolled in the surveillance network between 2003 and 2019, 7752 individuals with available CD4 count at diagnosis were included. Late HIV diagnosis was observed in 5522 (71.2%) participants. The overall median CD4 count at diagnosis was 221 (IQR: 62-373) cells/μl. Variables independently associated with late HIV diagnosis included age (adjusted odds ratio [aOR] 2.21, 95% CI 1.88-2.59, ≥45 vs. ≤29 years), heterosexual transmission (aOR 1.34, 95% CI 1.11-1.62, vs. MSM), living outside of Tokyo (aOR 1.18, 95% CI 1.05-1.32), hepatitis C virus (HCV) co-infection (aOR 1.42, 95% CI 1.01-1.98) and not belonging to a cluster (aOR 1.30, 95% CI 1.12-1.51). CRF07&#95;BC (aOR 0.34, 95% CI 0.18-0.65, vs. subtype B) was negatively associated with late HIV diagnosis., Conclusions: In addition to demographic factors, HCV co-infection, HIV-1 subtypes/CRFs and not belonging to a cluster were independently associated with late HIV diagnosis in Japan. These results imply the need for public health programmes aimed at the general population, including but not limited to key populations, to encourage HIV testing., (© 2023 The Authors. Journal of the International AIDS Society published by John Wiley & Sons Ltd on behalf of the International AIDS Society.)

Objectives: Human Leukocyte Antigen HLA-B*57:01 and B*58:01 are considered anti-HIV-1 protective alleles. HLA-B*57:01/58:01-restricted HIV-1 Gag TW10 (TSTLQEQIGW, Gag residues 240-249) epitope-specific CD8 + T cell responses that frequently select for a Gag escape mutation, T242N, with viral fitness cost are crucial for HIV-1 control. Although this finding has been observed in cohorts where HIV-1 subtype B or C predominates, the protective impact of HLA-B*57:01/58:01 has not been reported in Southeast Asian countries where HIV-1 CRF01&#95;AE is the major circulating strain. Here, the effect of HLA-B*57:01/58:01 on CRF01&#95;AE infection was investigated., Methods: The correlation of HLA-B*57:01/58:01 with viral load and CD4 counts were analyzed in the CRF01&#95;AE-infected Vietnamese cohort (N = 280). The impact of the T242N mutation on CRF01&#95;AE replication capacity was assessed., Results: HLA-B*57:01/58:01-positive individuals mostly had HIV-1 with T242N (62/63) but showed neither a significant reduction in viral load nor increased CD4 counts relative to B*57:01/58:01-negative participants. In vitro and in vivo analyses revealed a significant reduction in viral fitness of CRF01&#95;AE with T242N. In silico analysis indicated reduced presentation of epitopes in the context of CRF01&#95;AE compared to subtype B or C in 10/16 HLA-B*57:01/58:01-restricted HIV-1 epitopes., Conclusion: The protective impact of HLA-B*57:01/58:01 on CRF01&#95;AE infection is impaired despite strong suppressive pressure by TW10-specific CD8 + T cells., Competing Interests: Declaration of competing interest The authors have no competing interests to declare., (Copyright © 2022 The Author(s). Published by Elsevier Ltd.. All rights reserved.)

SARS-CoV-2 continues to spread worldwide. Patients with COVID-19 show distinct clinical symptoms. Although many studies have reported various causes for the diversity of symptoms, the underlying mechanisms are not fully understood. Peripheral blood mononuclear cells from COVID-19 patients were collected longitudinally, and single-cell transcriptome and T cell receptor repertoire analysis was performed. Comparison of molecular features and patients' clinical information revealed that the proportions of cells present, and gene expression profiles differed significantly between mild and severe cases; although even among severe cases, substantial differences were observed among the patients. In one severely-infected elderly patient, an effective antibody response seemed to have failed, which may have caused prolonged viral clearance. Naïve T cell depletion, low T cell receptor repertoire diversity, and aberrant hyperactivation of most immune cell subsets were observed during the acute phase in this patient. Through this study, we provided a better understanding of the diversity of immune landscapes and responses. The information obtained from this study can help medical professionals develop personalized optimal clinical treatment strategies for COVID-19., (© 2023. The Author(s).)

Among western African countries, the Republic of Ghana has maintained an economic growth rate of 5% since the 1980s and is now categorized as a middle-income country. However, as with other developing countries, Ghana still has challenges in the effective implementation of surveillance for infectious diseases. Facing public health emergencies of international concern (PHEIC), it is crucial to establish a reliable sample transportation system to the referral laboratory. Previously, surveillance capacity in Ghana was limited based on Integrated Disease Surveillance and Response, and therefore the "Surveillance and Laboratory Support for Emerging Pathogens of Public Health Importance in Ghana (SLEP)" was introduced to strengthen diarrhea surveillance. The SLEP project started with a sentinel diarrhea survey supported by SATREPS/JICA in collaboration with National Public Health Reference Laboratory (NHPRL) and Noguchi Memorial Institute of Medicine (NMIMR). The base-line survey revealed the limited capacity to detect diarrhea pathogens and to transfer samples from health centers to NHPRL. The involvement of private clinic/hospital facilities into the surveillance network is also crucial to strengthen surveillance in Ghana. The strong and interactive relationship between the two top referral laboratories, NHPRL under the Ministry of Health NMIMR and under the Ministry of Education, enables Ghana Health Services and is critical for the rapid response against PHEIC. In future, we hope that the outcome of the SLEP surveillance project could contribute to building a surveillance network with more timely investigation and transfer of samples to referral labs., (© 2022. The Author(s).)

Objective: In HIV type 1 (HIV-1) infection, virus-specific B-cell and neutralizing antibody (NAb) responses are impaired but exert selective pressure on target viral Envelope (Env) resulting in prominent sequence diversification among geographical areas. The basal induction patterns of HIV Env-specific B cells and their interaction with HIV Env awaits clarification., Design: We investigated the relationship of Env polymorphisms and Env-specific B-cell responses in treatment-naive HIV-1 CRF01&#95;AE-infected Vietnamese., Methods: Samples of 43 HIV-1 CRF01&#95;AE infection-identified individuals were divided into acute-phase ( n  = 12) and chronic-phase ( n  = 31) by combined criteria of serological recent-infection assay and clinical parameters. We quantified subcloning-based polymorphic residue site numbers in plasma-derived Env variable region 1-5 (V1-V5)-coding regions within each individual, designating their summation within each region as variant index. Peripheral blood Env gp 140-specific B-cell responses and plasma neutralizing activity of Env pseudoviruses were examined to analyze their relationship with variant index., Results: HIV-1 CRF01&#95;AE Env gp140-specific total B-cell and plasma cell (CD19 + IgD - CD27 + CD38 + CD138 + ) responses were determined. In chronic-phase samples, significant correlation of variant index in all Env V1-V5 regions with Env-specific plasma cell responses was shown, and V1-V5 total variant index correlated stronger with Env-specific plasma cell as compared with total Env-specific B-cell responses. Env V5 variant index was significantly higher in chronic-phase cross-neutralizers of V5-polymorphic/VRC01-insensitive CRF01&#95;AE Env., Conclusion: Results revealed the association between circulating Env-specific plasma cell responses and Env polymorphisms, implicating selective pressure on Env by plasma cell-derived antibodies and conversely suggests that Env-specific B-cell induction alone is insufficient for exerting Env selective pressure in HIV infection., (Copyright © 2022 Wolters Kluwer Health, Inc. All rights reserved.)

Macaque-tropic HIV-1 (HIV-1mt) variants have been developed to establish preferable primate models that are advantageous in understanding HIV-1 infection pathogenesis and in assessing the preclinical efficacy of novel prevention/treatment strategies. We previously reported that a CXCR4-tropic HIV-1mt, MN4Rh-3, efficiently replicates in peripheral blood mononuclear cells (PBMCs) of cynomolgus macaques homozygous for TRIMCyp (CMs TC ). However, the CMs TC challenged with MN4Rh-3 displayed low viral loads during the acute infection phase and subsequently exhibited short-term viremia. These virological phenotypes in vivo differed from those observed in most HIV-1-infected people. Therefore, further development of the HIV-1mt variant was needed. In this study, we first reconstructed the MN4Rh-3 clone to produce a CCR5-tropic HIV-1mt, AS38. In addition, serial in vivo passages allowed us to produce a highly adapted AS38-derived virus that exhibits high viral loads (up to approximately 10 6 copies ml -1 ) during the acute infection phase and prolonged periods of persistent viremia (lasting approximately 16 weeks postinfection) upon infection of CMs TC . Whole-genome sequencing of the viral genomes demonstrated that the emergence of a unique 15-nt deletion within the vif gene was associated with in vivo adaptation. The deletion resulted in a significant increase in Vpr protein expression but did not affect Vif-mediated antagonism of antiretroviral APOBEC3s, suggesting that Vpr is important for HIV-1mt adaptation to CMs TC . In summary, we developed a novel CCR5-tropic HIV-1mt that can induce high peak viral loads and long-term viremia and exhibits increased Vpr expression in CMs TC .

Determinants of memory T cell longevity following severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection remain unknown. In addition, phenotypes associated with memory T cell longevity, antibody titers, and disease severity are incompletely understood. Here, we longitudinally analyzed SARS-CoV-2-specific T cell and antibody responses of a unique cohort with similar numbers of mild, moderate, and severe coronavirus disease 2019 cases. The half-lives of CD4 + and CD8 + T cells were longer than those of antibody titers and showed no clear correlation with disease severity. When CD4 + T cells were divided into Th1-, Th2-, Th17-, and Tfh-like subsets, the Th17-like subset showed a longer half-life than other subsets, indicating that Th17-like cells are most closely correlated with T cell longevity. In contrast, Th2- and Tfh-like T cells were more closely correlated with antibody titers than other subsets. These results suggest that distinct CD4 + T cell subsets are associated with longevity and antibody responses., Competing Interests: The authors declare no competing interests., (© 2022 The Author(s).)

Expanding access to effective antiretroviral therapy (ART) is a major tool for management of Human Immunodeficiency Virus (HIV) infection. However, rising levels of HIV drug-resistance have significantly hampered the anticipated success of ART in persons living with HIV (PLWH), particularly those from Africa. Though great strides have been made in Ghana toward achieving the UNAIDS "95-95-95" target, a substantial number of PLWH receiving ART have not attained viral suppression. This study investigated patterns of drug resistance mutations in ART naïve as well as ART-experienced PLWH receiving first-line regimen drugs from Ghana. In a cross-sectional study, blood samples were collected from HIV-1 infected adults (≥18 years) attending HIV/AIDS clinic at the Eastern Regional Hospital, Koforidua, Ghana from September to October 2017. Viral RNA isolated from plasma were subjected to genotypic drug resistance testing for Protease Inhibitors (PI), Reverse Transcriptase Inhibitors (RTI), and Integrase Strand Transfer Inhibitors (INSTI). A total of 95 (84 ART experienced, 11 ART naïve) HIV-1 infected participants were sampled in this study. Sixty percent (50/84) of the ART-experienced participants were controlling viremia (viral load < 1,000 copies/ml). Of the 95 patient samples, 32, 34, and 33 were successfully sequenced for protease, reverse-transcriptase, and integrase regions, respectively. The dominant HIV-1 subtypes detected were CRF02&#95;AG (70%), and A3 (10%). Major drug resistance associated mutations were only detected for reverse transcriptase inhibitors. The predominant drug resistance mutations were against nucleos(t)ide reverse transcriptase inhibitors (NRTI)-M184V/I and non-nucleos(t)ide reverse transcriptase inhibitors (NNRTI)-K103N. In the ART-experienced group, M184V/I and K103N were detected in 54% (15/28) and 46% (13/28) of individuals, respectively. Both mutations were each detected in 33% (2/6) of ART naïve individuals. Multiclass resistance to NRTI and NNRTI was detected in 57% of ART-experienced individuals and two ART naïve individuals. This study reports high-level resistance to NNRTI-based antiretroviral therapy in PLWH in Ghana. However, the absence of major PI and INSTI associated-mutations is a good signal that the current WHO recommendation of Dolutegravir in combination with an NRTI backbone will yield maximum benefits as first-line regimen for PLWH in Ghana., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2022 Parbie, Abana, Kushitor, Asigbee, Ntim, Addo-Tetebo, Ansong, Ofori, Mizutani, Runtuwene, Nishizawa, Ishikawa, Kiyono, Ampofo, Matano, Bonney and Kikuchi.)

Accurate monitoring of epidemics is a key strategy for controlling human immunodeficiency virus type-1 (HIV-1) infection. To delineate the characteristics of newly diagnosed cases of HIV-1 infection, we assessed the proportion of recent HIV-1 infections using a recent infection-testing algorithm (RITA). In 2015, 248 cases were newly diagnosed with HIV infection at the Regional Hospital Koforidua, Ghana. Of these, 234 cases (94.4%) were infected with HIV-1 only, four (1.6%) were infected with HIV-2 only, and 10 (4.0%) were co-infected with HIV-1 and HIV-2. All HIV-1 single-seropositive samples were used in the HIV-1 LAg avidity assay for RITA. Our analysis revealed that 18 cases (7.7%) were recently infected, indicating that early diagnosis was not achieved in Ghana. This is the first report to assess the proportion of recent infections in Ghana using a biomarker approach. The accumulation of these data will contribute to the accurate estimation of HIV-1 incidence and prevalence in Ghana.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has been transmitted across all over the world, in contrast to the limited epidemic of genetically- and virologically-related SARS-CoV. However, the molecular basis explaining the difference in the virological characteristics among SARS-CoV-2 and SARS-CoV has been poorly defined. Here we identified that host sialoglycans play a significant role in the efficient spread of SARS-CoV-2 infection, while this was not the case with SARS-CoV. SARS-CoV-2 infection was significantly inhibited by α2-6-linked sialic acid-containing compounds, but not by α2-3 analog, in VeroE6/TMPRSS2 cells. The α2-6-linked compound bound to SARS-CoV-2 spike S1 subunit to competitively inhibit SARS-CoV-2 attachment to cells. Enzymatic removal of cell surface sialic acids impaired the interaction between SARS-CoV-2 spike and angiotensin-converting enzyme 2 (ACE2), and suppressed the efficient spread of SARS-CoV-2 infection over time, in contrast to its least effect on SARS-CoV spread. Our study provides a novel molecular basis of SARS-CoV-2 infection which illustrates the distinctive characteristics from SARS-CoV., Competing Interests: The authors have declared that no competing interests exist.

CD8 + T-cell responses exert strong suppressive pressure on viral replication and select for viral escape mutations in HIV infection. Multiple viral epitopes restricted by major histocompatibility complex class I (MHC-I) are targeted by CD8 + T cells. Sequential selection of viral escape mutations in individual epitope-coding regions could result in failure in CD8 + T cell-based viral control leading to disease progression. However, how this sequential selection of epitope mutations occurs has not fully been determined. Here, we examined sequential selection of viral mutations in seven CD8 + T-cell epitope-coding regions in a macaque AIDS model of simian immunodeficiency virus mac239 (SIVmac239) infection. In seven SIVmac239-infected Burmese rhesus macaques possessing MHC-I haplotype 90-120-Ia, selection of viral mutations was observed in five to seven of the seven 90-120-Ia-associated CD8 + T-cell epitope-coding regions in a year post-infection. Of the seven CD8 + T-cell epitopes, viral mutation selection was detected first at two epitopes, Gag 206-216 and Nef 9-19 , but was found finally at Vif 114-124 epitope in most animals. Viral loads in 6 months were significantly associated with the number of mutated CD8 + T-cell epitope-coding regions 1 year post-infection. Tetramer analysis revealed early induction of Gag 241-249 specific CD8 + T-cell responses, which did not always result in early selection of viral mutations in the Gag 241-249 epitope, suggesting that the order of epitope mutation selection may not be determined only by immunodominance. This SIV infection model using 90-120-Ia-positive macaques would be useful for analysis of the determinants for sequential epitope mutation selection, contributing to our understanding of virus-host CD8 + T-cell interaction in HIV infection., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 The Authors. Published by Elsevier Inc. All rights reserved.)

Polymorphisms in human leukocyte antigen (HLA) class I loci are known to have a great impact on disease progression in HIV-1 infection. Prevailing HIV-1 subtypes and HLA genotype distribution are different all over the world, and the HIV-1 and host HLA interaction could be specific to individual areas. Data on the HIV-1 and HLA interaction have been accumulated in HIV-1 subtype B- and C-predominant populations but not fully obtained in West Africa where HIV-1 subtype CRF02&#95;AG is predominant. In the present study, to obtain accurate HLA typing data for analysis of HLA association with disease progression in HIV-1 infection in West African populations, HLA class I (HLA-A, -B, and -C) four-digit allele typing was performed in treatment-naïve HIV-1 infected individuals in Ghana (n = 324) by a super high-resolution single-molecule sequence-based typing (SS-SBT) using next-generation sequencing. Comparison of the SS-SBT-based data with those obtained by a conventional sequencing-based typing (SBT) revealed incorrect assignment of several alleles by SBT. Indeed, HLA-A*23:17, HLA-B*07:06, HLA-C*07:18, and HLA-C*18:02 whose allele frequencies were 2.5%, 0.9%, 4.3%, and 3.7%, respectively, were not determined by SBT. Several HLA alleles were associated with clinical markers, viral load and CD4+ T-cell count. Of note, the impact of HLA-B*57:03 and HLA-B*58:01, known as protective alleles against HIV-1 subtype B and C infection, on clinical markers was not observed in our cohort. This study for the first time presents SS-SBT-based four-digit typing data on HLA-A, -B, and -C alleles in Ghana, describing impact of HLA on viral load and CD4 count in HIV-1 infection. Accumulation of these data would facilitate high-resolution HLA genotyping, contributing to our understanding of the HIV-1 and host HLA interaction in Ghana, West Africa., Competing Interests: The authors have declared that no competing interests exist.

Diarrheal disease remains a major global health problem particularly in children under 5 years and the emergence of antibiotic-resistant strains of causative pathogens could slow control efforts, particularly in settings where treatment options are limited. This surveillance study conducted in Ghana aimed to determine the prevalence and antimicrobial susceptibility profile of diarrhea-causing bacteria. This was a cross-sectional study carried out in five health facilities in the Ga West Municipality of Ghana between 2017 and 2021. Diarrheic stool samples from patients were collected and cultured on standard differential/selective media and isolates identified by standard biochemical tests, MALDI-TOF assay, and serological analysis. The antibiogram was determined using Kirby-Bauer disk diffusion and Microscan autoScan4 MIC panels which were used for extended-spectrum beta-lactamase (ESBL) detection. Bacteria were isolated from 97.5% (772/792) of stool samples, and 167 of the isolates were diarrheagenic and met our inclusion criteria for antimicrobial resistance (AMR) analysis. These included Escherichia coli (49.1%, 82/167), Salmonella species (23.9%, 40/167), Vibrio species (16.8%, 28/167), and Shigella species (10.2%, 17/167). Among 24 Vibrio species, we observed resistances to cefotaxime (21/24, 87.5%), ceftriaxone (20/24, 83.3%), and ciprofloxacin (6/24, 25%), including four multi-drug resistant isolates. All 13 Vibrio parahaemolyticus isolates were resistant to cefazolin. All 17 Shigella isolates were resistant to tetracycline with resistance to shigellosis drugs such as norfloxacin and ciprofloxacin. Salmonella isolates were highly susceptible to norfloxacin (40/40, 100%) and tetracycline (12/34, 35%). Two ESBL-producing E. coli were also identified with marked susceptibility to gentamicin (66/72, 91.7%) and amikacin (57/72, 79.2%) prescribed in the treatment of E. coli infections. This study showed the different bacteria implicated in diarrhea cases in Ghana and the need for differential diagnoses for better treatment outcomes. Escherichia coli , Shigella , Salmonella , and Vibrio have all been implicated in diarrhea cases in Ghana. The highest prevalence was E. coli and Salmonella with Shigella the least prevalent. Resistance to commonly used drugs found in these isolates may render bacteria infection treatment in the near future nearly impossible. Routine antimicrobial susceptibility testing, effective monitoring, and nationwide surveillance of AMR pathogens should be implemented to curb the increase of antimicrobial resistance in Ghana., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2022 Afum, Asandem, Asare, Asante-Poku, Mensah, Musah, Opare, Taniguchi, Guinko, Aphour, Arhin, Ishikawa, Matano, Mizutani, Asiedu-Bekoe, Kiyono, Anang, Koram and Yeboah-Manu.)

Effective T cell induction is an important strategy in HIV-vaccine development. However, it has been indicated that vaccine-induced HIV-specific CD4 + T cells, the preferential targets of HIV infection, might increase viral acquisition after HIV exposure. We have recently developed an immunogen (CaV11), tandemly connected overlapping 11-mer peptides spanning the simian immunodeficiency virus (SIV) Gag capsid and Vif proteins, to selectively induce Gag- and Vif-specific CD8 + T cells but not CD4 + T cells. Here, we show protective efficacy of a CaV11-expressing vaccine against repeated intrarectal low-dose SIVmac239 challenge in rhesus macaques. Eight of the twelve vaccinated macaques were protected after eight challenges. Kaplan-Meier analysis indicated significant protection in the vaccinees compared to the unvaccinated macaques. Vaccine-induced Gag-specific CD8 + T cell responses were significantly higher in the protected than the unprotected vaccinees. These results suggest that classical CD8 + T cell induction by viral Env-independent vaccination can confer protection from intrarectal SIV acquisition, highlighting the rationale for this immunogen design to induce virus-specific CD8 + T cells but not CD4 + T cells in HIV-vaccine development., Competing Interests: Declaration of interests H.I., T.S., and T. Matano are the inventors on Patent Cooperation Treaty (PCT) application no. PCT/JP2019/1607 concerning the TC11 immunogen. The other authors declare no competing interests., (Copyright © 2022 The Author(s). Published by Elsevier Inc. All rights reserved.)

The role of the intestinal microbiota in coronavirus disease 2019 (COVID-19) is being elucidated. Here, we analyzed the temporal changes in microbiota composition and the correlation between inflammation biomarkers/cytokines and microbiota in hospitalized COVID-19 patients. We obtained stool specimens, blood samples, and patient records from 22 hospitalized COVID-19 patients and performed 16S rRNA metagenomic analysis of stool samples over the course of disease onset compared to 40 healthy individual stool samples. We analyzed the correlation between the changes in the gut microbiota and plasma proinflammatory cytokine levels. Immediately after admission, differences in the gut microbiota were observed between COVID-19 patients and healthy subjects, mainly including enrichment of the classes Bacilli and Coriobacteriia and decrease in abundance of the class Clostridia. The bacterial profile continued to change throughout the hospitalization, with a decrease in short-chain fatty acid-producing bacteria including Faecalibacterium and an increase in the facultatively anaerobic bacteria Escherichia -Shigella . A consistent increase in Eggerthella belonging to the class Coriobacteriia was observed. The abundance of the class Clostridia was inversely correlated with interferon-γ level and that of the phylum Actinobacteria, which was enriched in COVID-19, and was positively correlated with gp130/sIL-6Rb levels. Dysbiosis was continued even after 21 days from onset. The intestines tended to be an aerobic environment in hospitalized COVID-19 patients. Because the composition of the gut microbiota correlates with the levels of proinflammatory cytokines, this finding emphasizes the need to understand how pathology is related to the temporal changes in the specific gut microbiota observed in COVID-19 patients. IMPORTANCE There is growing evidence that the commensal microbiota of the gastrointestinal and respiratory tracts regulates local and systemic inflammation (gut-lung axis). COVID-19 is primarily a respiratory disease, but the involvement of microbiota changes in the pathogenesis of this disease remains unclear. The composition of the gut microbiota of patients with COVID-19 changed over time during hospitalization, and the intestines tended to be an aerobic environment in hospitalized COVID-19 patients. These changes in gut microbiota may induce increased intestinal permeability, called leaky gut, allowing bacteria and toxins to enter the circulatory system and further aggravate the systemic inflammatory response. Since gut microbiota composition correlates with levels of proinflammatory cytokines, this finding highlights the need to understand how pathology relates to the gut environment, including the temporal changes in specific gut microbiota observed in COVID-19 patients.

Induction of antibodies targeting viral glycoproteins is a key for the development of a vaccine against enveloped virus infection. Glycoproteins on the virion exhibiting native multimer structure may be a good immunogen to present antibody epitopes, but it is often difficult to prepare immunogenic inactivated virions. Preparation of soluble glycoprotein multimers has been attempted, while virus-like particles carrying target glycoproteins can be a more immunogenic antigen. In the present study, a target glycoprotein-embedded Sendai virus (SeV) particle was developed for induction of anti-virus antibodies. We constructed a chimeric antigen, HIV-1 EnvF, consisting of HIV-1 Env ectodomain and SeV F transmembrane-cytoplasmic domain, which was shown to be efficiently incorporated into the SeV virion. EnvF was recognized by anti-HIV-1 broadly-neutralizing monoclonal antibodies (bnAbs) including 35O22 that targets an Env trimer-dependent epitope. Analysis revealed that HIV-1 AD8 EnvF can mediate viral entry into the cells, which is inhibited by anti-HIV-1 bnAbs and HIV-1 entry inhibitors, suggesting that the EnvF exhibits an HIV-1 Env native-like functional structure to present bnAb epitopes. Immunization of mice with replication-defective SeVs expressing HIV EnvF and non-infectious SeV particles (NVP) carrying HIV EnvF efficiently induced anti-HIV Env antibodies. HTLV-1 EnvF also showed the potential to efficiently induce anti-HTLV-1 Env antibodies. These results indicate that SeV particles carrying EnvF can be a promising vaccine platform for induction of antibodies targeting enveloped virus glycoproteins., Competing Interests: Declaration of Competing Interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: [Tsugumine Shu and Tetsuro Matano are the inventors on Patent Cooperation Treaty (PCT) application no. PCT/JP2017/41492 concerning NVP-EnvF vaccine.]., (Copyright © 2022 Elsevier Ltd. All rights reserved.)

Persistence of HIV latently infected cells is a barrier to HIV cure. The "kick and kill" strategy for a cure includes clearance of the viral reservoir by HIV-specific cytotoxic T lymphocytes (CTLs). However, exhaustion and senescence of T cells accelerates during HIV infection, and does not fully recover, despite complete viral suppression under antiretroviral therapy. We previously established an induced pluripotent stem cell (iPSC) from a parental HIV-specific CTL clone and generated an iPSC-derived rejuvenated HIV-specific CTL clone (iPSC-CTL), which exhibited an early memory phenotype, high proliferation capacity and effector functions in vitro . Here, we assessed the antiviral efficacy of the HIV-specific iPSC-CTL by single- and multiple-round viral suppression assays (VSAs). The HIV-specific iPSC-CTL suppressed viral replication in an HLA-dependent manner with equivalent efficacy to the parental CTL clone in single-round VSA. In multiple-round VSA, however, the ability of the iPSC-CTL to suppress viral replication was longer than that of the parental CTL clone. These results indicate that HIV-specific iPSC-CTL can sustainably exert suppressive pressure on viral replication, suggesting a novel approach to facilitate clearance of the HIV reservoir via adoptive transfer of rejuvenated CTLs. IMPORTANCE Elimination of latently HIV-infected cells is required for HIV cure. In the "kick and kill" strategy proposed for a cure to HIV, the host immune system, including HIV-specific cytotoxic T lymphocytes (CTLs), play a central role in eliminating HIV antigen-expressing cells following reactivation by latency-reversing agents (LRAs). However, CTL dysfunction due to exhaustion and senescence in chronic HIV infection can be an obstacle to this strategy. Adoptive transfer with effective HIV-specific CTLs may be a solution of this problem. We previously generated an induced pluripotent stem cell (iPSC)-derived rejuvenated HIV-specific CTL clone (iPSC-CTL) with high functional and proliferative capacity. The present study demonstrates that iPSC-CTL can survive and suppress HIV replication in vitro longer than the parental CTL clone, indicating the potential of iPSC-CTL to sustainably exert suppressive pressure on viral replication. Adoptive transfer with rejuvenated HIV-specific CTLs in combination with LRAs may be a new intervention strategy for HIV cure/remission.

Aim: After the hepatitis A virus (HAV) outbreak among men who have sex with men (MSM) around 2018, the importance of HAV vaccination was emphasized, especially for MSM-living with human immunodeficiency virus (MSM-LWHIV). Aimmugen ® is licensed and distributed exclusively in Japan. While administration of three doses is recommended, 85% of recipients in the general population were reported to acquire seroprotection after the second dose. In this study, we evaluated the efficacy of two or three vaccine doses along with predictors associated with the response to Aimmugen ® in MSM-LWHIV., Methods: We retrospectively examined anti-HA-IgG titers of MSM-LWHIV vaccinated with Aimmugen ® in our hospital. Patients' data were collected from medical records., Results: Between January 2018 and October 2019, 141 subjects whose median age was 46 years old, were examined. All the subjects were on antiretroviral therapy (ART) and the median CD4 count was 615/μL. The acquisition rate of protectable anti-HA-IgG titers after the second and third dose was 71.1% and 98.6%, respectively. In 114 subjects whose anti-HA-IgG titers were tested after the second-dose, factors significantly associated with better response were prolonged ART duration and higher CD4 count. The titers of anti-HA-IgG after the third dose were higher in those who became seropositive after the second-dose than those who did not., Conclusions: Three-dose of Aimmugen ® for MSM-LWHIV was effective while two-dose was less effective compared to non-HIV-infected people. People-LWHIV with shorter duration of ART and lesser CD4 cell count achieved lower titers of anti-HA-IgG and might require an additional vaccination., (© 2021 The Authors. Hepatology Research published by John Wiley & Sons Australia, Ltd on behalf of Japan Society of Hepatology.)

Acute-phase neutralizing antibody (NAb) passive immunization in simian immunodeficiency virus (SIV)-infected rhesus macaques (Macaca mulatta) can confer stringent viremia control with T-cell augmentation. In one NAb-infused SIV partial controller, we identify chronic-phase Nef-specific CD107a + CD4 + T-cell response maintenance, implicating that NAb infusion modulates long-term T-cell responses even within viremic control., (© 2021 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

Effective vaccines are essential for the control of the coronavirus disease 2019 (COVID-19) pandemic. Currently developed vaccines inducing severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) spike (S)-antigen-specific neutralizing antibodies (NAbs) are effective, but the appearance of NAb-resistant S variant viruses is of great concern. A vaccine inducing S-independent or NAb-independent SARS-CoV-2 control may contribute to containment of these variants. Here, we investigate the efficacy of an intranasal vaccine expressing viral non-S antigens against intranasal SARS-CoV-2 challenge in cynomolgus macaques. Seven vaccinated macaques exhibit significantly reduced viral load in nasopharyngeal swabs on day 2 post-challenge compared with nine unvaccinated controls. The viral control in the absence of SARS-CoV-2-specific NAbs is significantly correlated with vaccine-induced, viral-antigen-specific CD8 + T cell responses. Our results indicate that CD8 + T cell induction by intranasal vaccination can result in NAb-independent control of SARS-CoV-2 infection, highlighting a potential of vaccine-induced CD8 + T cell responses to contribute to COVID-19 containment., Competing Interests: H.I., K.K., R.S., and T.M. are the inventors on Patent Cooperation Treaty (PCT) application for SeV-NME vaccine. The authors declare no other competing interests., (© 2022 The Author(s).)

Objective: Analysis of the quantity and quality of epitope-specific CD8+ T-cell responses is crucial for understanding the mechanism of HIV/simian immunodeficiency virus (SIV) replication control. We have previously shown that acute-phase passive infusion of neutralizing antibodies (NAbs) results in augmented broad T-cell responses and robust SIVmac239 control in rhesus macaques. Analyzing long-term dynamics of CD8+ T-cell responses in these SIV controllers provides important insights into designing lasting anti-HIV immunity., Design: We analyzed dynamics and metabolic/functional profiles of SIV-specific CD8+ T-cell responses in rhesus macaques that controlled SIVmac239 replication following acute-phase passive NAb infusion., Methods: SIV epitope-specific CD8+ T-cell responses in peripheral blood at multiple chronic-phase time points were investigated in four passive NAb-infused SIV controllers. In particular, expression patterns of Eomesodermin (Eomes), phosphorylated AMP kinase (pAMPK), CD28 and programmed death-1 (PD-1) were examined., Results: In the NAb-infused SIV controllers, a single epitope-specific CD8+ T-cell response detected from acute infection and maintaining low levels up to year 1 showed a surge thereafter, up to year 2 postchallenge. Retention of an effector-skewed and unexhausted Eomes-high/pAMPK-low/CD28-negative/PD-1-low subpopulation in these epitope-specific CD8+ T cells implicated their front-line commitment in residual viral replication control., Conclusion: In long-term SIV control following acute-phase passive NAb infusion, a single-epitope, high-quality CTL response was dominantly induced in the chronic phase. These results likely describe one favorable pattern of immunodominant epitope-specific CD8+ T-cell preservation and suggest the importance of incorporating metabolic marker signatures for understanding NAb/T-cell synergism-based HIV/SIV control., (Copyright © 2021 Wolters Kluwer Health, Inc. All rights reserved.)

Hepatitis A virus (HAV) causes transient acute infection, and little is known of viral shedding via the duodenum and into the intestinal environment, including the gut microbiome, from the period of infection until after the recovery of symptoms. Therefore, in this study, we aimed to comprehensively observe the amount of virus excreted into the intestinal tract, the changes in the intestinal microbiome, and the level of inflammation during the healing process. We used blood and stool specimens from patients with human immunodeficiency virus who were infected with HAV during the HAV outbreak in Japan in 2018. Moreover, we observed changes in fecal HAV RNA and quantified the plasma cytokine level and gut microbiome by 16S rRNA analysis from clinical onset to at least 6 months after healing. HAV was detected from clinical onset up to a period of more than 150 days. Immediately after infection, many pro-inflammatory cytokines were elicited, and some cytokines showed different behaviors. The intestinal microbiome changed significantly after infection (dysbiosis), and the dysbiosis continued for a long time after healing. These observations suggest that the immunocompromised state is associated with prolonged viral shedding into the intestinal tract and delayed recovery of the intestinal environment.

Chronic inflammation is a hallmark of human immunodeficiency virus (HIV) infection and a risk factor for the development and progression of age-related comorbidities. Although HIV-associated gut dysbiosis has been suggested to be involved in sustained chronic inflammation, there remains a limited understanding of the association between gut dysbiosis and chronic inflammation during HIV infection. Here, we investigated compositional changes in the gut microbiome and its role in chronic inflammation in patients infected with HIV. We observed that the gut microbiomes of patients with low CD4 counts had reduced alpha diversity compared to those in uninfected controls. Following CD4 recovery, alpha diversity was restored, but intergroup dissimilarity of bacterial composition remained unchanged between patients and uninfected controls. Patients with HIV had higher abundance of the classes Negativicutes , Bacilli , and Coriobacteriia , as well as depletion of the class Clostridia . These relative abundances positively correlated with inflammatory cytokines and negatively correlated with anti-inflammatory cytokines. We found that gut dysbiosis accompanying HIV infection was characterized by a depletion of obligate anaerobic Clostridia and enrichment of facultative anaerobic bacteria, reflecting increased intestinal oxygen levels and intestinal permeability. Furthermore, it is likely that HIV-associated dysbiosis shifts the immunological balance toward inflammatory Th1 responses and encourages proinflammatory cytokine production. Our results suggest that gut dysbiosis contributes to sustaining chronic inflammation in patients with HIV infection despite effective antiretroviral therapy and that correcting gut dysbiosis will be effective in improving long-term outcomes in patients. IMPORTANCE Chronic inflammation is a hallmark of HIV infection and is associated with the development and progression of age-related comorbidities. Although the gastrointestinal tract is a major site of HIV replication and CD4 + T-cell depletion, the role of HIV-associated imbalance of gut microbiome in chronic inflammation is unclear. Here, we aimed to understand the causal relationship between abnormalities in the gut microbiome and chronic inflammation in patients with HIV. Our results suggest HIV-associated gut dysbiosis presents a more aerobic environment than that of healthy individuals, despite prolonged viral suppression. This dysbiosis likely results from a sustained increase in intestinal permeability, which supports sustained bacterial translocation in HIV patients, despite effective therapy. Additionally, we observed that several bacterial taxa enriched in HIV patients were associated with increased expression of inflammatory cytokines. Collectively, these results suggest that gut dysbiosis plays an important role in chronic inflammation in HIV patients.

Antibody titers against SARS-CoV-2 slowly wane over time. Here, we examined how time affects antibody potency. To assess the impact of antibody maturation on durable neutralizing activity against original SARS-CoV-2 and emerging variants of concern (VOCs), we analyzed receptor binding domain (RBD)-specific IgG antibodies in convalescent plasma taken 1-10 months after SARS-CoV-2 infection. Longitudinal evaluation of total RBD IgG and neutralizing antibody revealed declining total antibody titers but improved neutralization potency per antibody to original SARS-CoV-2, indicative of antibody response maturation. Neutralization assays with authentic viruses revealed that early antibodies capable of neutralizing original SARS-CoV-2 had limited reactivity toward B.1.351 (501Y.V2) and P.1 (501Y.V3) variants. Antibodies from late convalescents exhibited increased neutralization potency to VOCs, suggesting persistence of cross-neutralizing antibodies in plasma. Thus, maturation of the antibody response to SARS-CoV-2 potentiates cross-neutralizing ability to circulating variants, suggesting that declining antibody titers may not be indicative of declining protection., Competing Interests: Declaration of interests The authors declare no competing interests., (Copyright © 2021 The Author(s). Published by Elsevier Inc. All rights reserved.)

SARS-CoV-2 infection presents clinical manifestations ranging from asymptomatic to fatal respiratory failure. Despite the induction of functional SARS-CoV-2-specific CD8+ T-cell responses in convalescent individuals, the role of virus-specific CD8+ T-cell responses in the control of SARS-CoV-2 replication remains unknown. In the present study, we show that subacute SARS-CoV-2 replication can be controlled in the absence of CD8+ T cells in cynomolgus macaques. Eight macaques were intranasally inoculated with 105 or 106 TCID50 of SARS-CoV-2, and three of the eight macaques were treated with a monoclonal anti-CD8 antibody on days 5 and 7 post-infection. In these three macaques, CD8+ T cells were undetectable on day 7 and thereafter, while virus-specific CD8+ T-cell responses were induced in the remaining five untreated animals. Viral RNA was detected in nasopharyngeal swabs for 10-17 days post-infection in all macaques, and the kinetics of viral RNA levels in pharyngeal swabs and plasma neutralizing antibody titers were comparable between the anti-CD8 antibody treated and untreated animals. SARS-CoV-2 RNA was detected in the pharyngeal mucosa and/or retropharyngeal lymph node obtained at necropsy on day 21 in two of the untreated group but undetectable in all macaques treated with anti-CD8 antibody. CD8+ T-cell responses may contribute to viral control in SARS-CoV-2 infection, but our results indicate possible containment of subacute viral replication in the absence of CD8+ T cells, implying that CD8+ T-cell dysfunction may not solely lead to viral control failure., Competing Interests: The authors have declared that no competing interests exist.

Background: This study aimed to clarify how SARS-CoV-2 RNAemia is related to COVID-19 critical condition development and mortality in comparison with other predictive markers and scoring systems., Methods: This is a retrospective cohort study conducted at Yokohama Municipal Citizen's Hospital and National Institute of Infectious Diseases. We recruited adult patients with COVID-19 admitted between March 2020 and January 2021. We compared RNAemia with clinical status on admission including scoring systems such as the 4C Mortality, CURB-65, and A-DROP, as well as the Ct value of the nasopharyngeal PCR, in predicting COVID-19 mortality and critical condition development., Results: Of the 92 recruited patients (median age, 58; interquartile range, 45-71 years), 14 (14.9%) had RNAemia. These patients had an older age (median, 68 years vs. 55.5 years; p = 0.011), higher values of lactated dehydrogenase (median, 381 U/L vs. 256.5 U/L, p < 0.001), C-reactive protein (median, 10.9 mg/dL vs. 3.8 mg/dL; p < 0.001), D-dimer (median, 2.07 μg/mL vs. 1.28 μg/mL; p = 0.015), lower values of lymphocyte (median, 802/μL vs. 1007/μL, p = 0.025) and Ct of the nasopharyngeal PCR assay (median, 20.59 vs. 25.54; p = 0.021) than those without RNAemia. Univariate analysis showed RNAemia was associated with mortality (odds ratio [OR], 18.75; 95% confidence interval [CI], 3.92-89.76; area under the receiver operating characteristic curve [AUC], 0.7851; p = 0.002) and critical condition (OR, 72.00; 95% CI, 12.98-399.29; AUC, 0.8198; p < 0.001). Plus, multivariate analysis also revealed the association of RNAemia with critical condition (adjusted OR, 125.71; 95% CI, 11.47-1377.32; p < 0.001)., Conclusion: On-admission SARS-CoV-2 RNAemia is a potent predictive marker of COVID-19 critical condition and mortality. The adjusted OR for critical condition was as high as 125.71., Competing Interests: The authors have declared that no competing interests exist.

Acute gastroenteritis associated with diarrhea is considered a serious disease in Africa and South Asia. In this study, we examined the trends in the causative pathogens of diarrhea and the corresponding gut microbiota in Ghana using microbiome analysis performed on diarrheic stools via 16S rRNA sequencing. In total, 80 patients with diarrhea and 34 healthy adults as controls, from 2017 to 2018, were enrolled in the study. Among the patients with diarrhea, 39 were norovirus-positive and 18 were rotavirus-positive. The analysis of species richness (Chao1) was lower in patients with diarrhea than that in controls. Beta-diversity analysis revealed significant differences between the two groups. Several diarrhea-related pathogens (e.g., Escherichia-Shigella, Klebsiella and Campylobacter) were detected in patients with diarrhea. Furthermore, co-infection with these pathogens and enteroviruses (e.g., norovirus and rotavirus) was observed in several cases. Levels of both Erysipelotrichaceae and Staphylococcaceae family markedly differed between norovirus-positive and -negative diarrheic stools, and the 10 predicted metabolic pathways, including the carbohydrate metabolism pathway, showed significant differences between rotavirus-positive patients with diarrhea and controls. This comparative study of diarrheal pathogens in Ghana revealed specific trends in the gut microbiota signature associated with diarrhea and that pathogen-dependent dysbiosis occurred in viral gastroenteritis.

HLA-A, -C, -B, and -DRB1 genotypes were analyzed in 178 Japanese COVID-19 patients to investigate the association of HLA with severe COVID-19. Analysis of 32 common HLA alleles at four loci revealed a significant association between HLA-DRB1*09:01 and severe COVID-19 (odds ratio [OR], 3.62; 95% CI, 1.57-8.35; p = 0.00251 [permutation p value = 0.0418]) when age, sex, and other common HLA alleles at the DRB1 locus were adjusted. The DRB1*09:01 allele was more significantly associated with risk for severe COVID-19 compared to preexisting medical conditions such as hypertension, diabetes, and cardiovascular diseases. These results indicate a potential role for HLA in predisposition to severe COVID-19., (© 2021 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

Background: HIV-1 circulating recombinant form (CRF) 01&#95;AE is the second major subtype in Japan. Our previous study indicated that CRF01&#95;AE was predominantly circulating in heterosexuals/injecting drug users (IDUs). With implications of increased CRF01&#95;AE infections among men who have sex with men (MSM), this study sought to investigate whether the transmission dynamics of CRF01&#95;AE infections in Japan have changed., Methods: Sequences from 8032 newly diagnosed HIV-1-infected individuals were analysed. For 614 (7.6%) of CRF01&#95;AE cases, clusters were identified and categorised by transmission risks. Median times to the most recent common ancestors (tMRCA) were estimated., Results: The individuals were predominantly Japanese (64%) and male (72%). MSM became the predominant transmission risk from 2014. Thirty transmission clusters (TCs) and 48 pairs, including 40% of individuals, were identified. MSM were approximately five times more likely to be in a TC compared to heterosexuals, and were the major contributors to TCs. tMRCA data suggest that MSM TCs emerged from 1996 and became predominant around 2000., Conclusions: CRF01&#95;AE has spread among MSM, with frequent and continuous cluster formations, and MSM has become the predominant transmission risk. Our study suggested that CRF01&#95;AE transmission has shifted from heterosexuals/IDUs to MSM. Prevention measures targeting key populations should be considered for controlling CRF01&#95;AE spread., (Copyright © 2021 The Author(s). Published by Elsevier Ltd.. All rights reserved.)

Antibody responses are crucial for the control of virus infection. Understanding of the mechanism of antibody induction is important for the development of a vaccine eliciting effective anti-virus antibodies. Virus-specific B cell receptor (BCR)/antibody repertoires are different among individuals, but determinants for this difference remain largely unclear. We have recently reported that a germline BCR immunoglobulin (IgG) gene polymorphism (VH3.33&#95;ET or VH3.33&#95;VI) in rhesus macaques is the determinant for induction of potent B404-class anti-simian immunodeficiency virus (SIV) neutralizing antibodies in neutralization-sensitive SIVsmH635FC infection. In the present study, we examined whether neutralization-resistant SIVsmE543-3 infection can induce the anti-SIV neutralizing antibodies associated with the germline VH3.33 polymorphism. Anti-SIVsmE543-3 neutralizing antibodies were induced in all the macaques possessing the VH3.33&#95;ET allele, but not in those without VH3.33&#95;ET, in the chronic phase of SIVsmE543-3 infection. Next generation sequencing analysis of BCR VH genes found B404-class antibody sequences only in those with VH3.33&#95;ET. These results indicate that anti-SIVsmE543-3 neutralizing antibody induction associated with the germline BCR IgG gene polymorphism can be triggered by infection with neutralization-resistant SIVsmE543-3. This animal model would be useful for the elucidation of the mechanism of potent antibody induction against neutralization-resistant viruses.

HIV-1 infected individuals under antiretroviral therapy can control viremia but often develop non-AIDS diseases such as cardiovascular and metabolic disorders. Gut microbiome dysbiosis has been indicated to be associated with progression of these diseases. Analyses of gut/fecal microbiome in individual regions are important for our understanding of pathogenesis in HIV-1 infections. However, data on gut/fecal microbiome has not yet been accumulated in West Africa. In the present study, we examined fecal microbiome compositions in HIV-1 infected adults in Ghana, where approximately two-thirds of infected adults are females. In a cross-sectional case-control study, age- and gender-matched HIV-1 infected adults (HIV+; n = 55) and seronegative controls (HIV-; n = 55) were enrolled. Alpha diversity of fecal microbiome in HIV+ was significantly reduced compared to HIV- and associated with CD4 counts. HIV+ showed reduction in varieties of bacteria including Faecalibacterium , the most abundant in seronegative controls, but enrichment of Proteobacteria . Ghanaian HIV+ exhibited enrichment of Dorea and Blautia ; bacteria groups whose depletion has been reported in HIV-1 infected individuals in several other cohorts. Furthermore, HIV+ in our cohort exhibited a depletion of Prevotella , a genus whose enrichment has recently been shown in men having sex with men (MSM) regardless of HIV-1 status. The present study revealed the characteristics of dysbiotic fecal microbiome in HIV-1 infected adults in Ghana, a representative of West African populations., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2021 Parbie, Mizutani, Ishizaka, Kawana-Tachikawa, Runtuwene, Seki, Abana, Kushitor, Bonney, Ofori, Uematsu, Imoto, Kimura, Kiyono, Ishikawa, Ampofo and Matano.)

Antiviral treatments targeting the coronavirus disease 2019 are urgently required. We screened a panel of already approved drugs in a cell culture model of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and identified two new agents having higher antiviral potentials than the drug candidates such as remdesivir and chroloquine in VeroE6/TMPRSS2 cells: the anti-inflammatory drug cepharanthine and human immunodeficiency virus protease inhibitor nelfinavir. Cepharanthine inhibited SARS-CoV-2 entry through the blocking of viral binding to target cells, while nelfinavir suppressed viral replication partly by protease inhibition. Consistent with their different modes of action, synergistic effect of this combined treatment to limit SARS-CoV-2 proliferation was highlighted. Mathematical modeling in vitro antiviral activity coupled with the calculated total drug concentrations in the lung predicts that nelfinavir will shorten the period until viral clearance by 4.9 days and the combining cepharanthine/nelfinavir enhanced their predicted efficacy. These results warrant further evaluation of the potential anti-SARS-CoV-2 activity of cepharanthine and nelfinavir., Competing Interests: The authors declare no competing interests., (© 2021 The Authors.)

Rhesus macaque is one of the most widely used primate model animals for immunological research of infectious diseases including human immunodeficiency virus (HIV) infection. It is well known that major histocompatibility complex (MHC) class I genotypes affect the susceptibility and disease progression to simian immunodeficiency virus (SIV) in rhesus macaques, which is resembling to HIV in humans. It is required to convincingly determine the MHC genotypes in the immunological investigations, that is why several next-generation sequencing (NGS)-based methods have been established. In general, NGS-based genotyping methods using short amplicons are not often applied to MHC because of increasing number of alleles and inevitable ambiguity in allele detection, although there is an advantage of short read sequencing systems that are commonly used today. In this study, we developed a new high-throughput NGS-based genotyping method for MHC class I alleles in rhesus macaques and cynomolgus macaques. By using our method, 95% and 100% of alleles identified by PCR cloning-based method were detected in rhesus macaques and cynomolgus macaques, respectively, which were highly correlated with their expression levels. It was noted that the simulation of new-allele detection step using artificial alleles differing by a few nucleotide sequences from a known allele could be identified with high accuracy and that we could detect a real novel allele from a rhesus macaque sample. These findings supported that our method could be adapted for primate animal models such as macaques to reduce the cost and labor of previous NGS-based MHC genotyping.

An expanded myeloid cell compartment is a hallmark of severe coronavirus disease 2019 (COVID-19). However, data regarding myeloid cell expansion have been collected in Europe, where the mortality rate by COVID-19 is greater than those in other regions including Japan. Thus, characteristics of COVID-19-induced myeloid cell subsets remain largely unknown in the regions with low mortality rates. Here, we analyzed cellular dynamics of myeloid-derived suppressor cell (MDSC) subsets and examined whether any of them correlate with disease severity and prognosis, using blood samples from Japanese COVID-19 patients. We observed that polymorphonuclear (PMN)-MDSCs, but not other MDSC subsets, transiently expanded in severe cases but not in mild or moderate cases. Contrary to previous studies in Europe, this subset selectively expanded in survivors of severe cases and subsided before discharge, but such transient expansion was not observed in non-survivors in Japanese cohort. Analysis of plasma cytokine/chemokine levels revealed positive correlation of PMN-MDSC frequencies with IL-8 levels, indicating the involvement of IL-8 on recruitment of PMN-MDSCs to peripheral blood following the onset of severe COVID-19. Our data indicate that transient expansion of the PMN-MDSC subset results in improved clinical outcome. Thus, this myeloid cell subset may be a predictor of prognosis in cases of severe COVID-19 in Japan., (© The Japanese Society for Immunology. 2021. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

Virus infection induces B cells with a wide variety of B cell receptor (BCR) repertoires. Patterns of induced BCR repertoires are different in individuals, while the underlying mechanism causing this difference remains largely unclear. In particular, the impact of germ line BCR immunoglobulin (Ig) gene polymorphism on B cell/antibody induction has not fully been determined. In the present study, we found a potent antibody induction associated with a germ line BCR Ig gene polymorphism. B404-class antibodies, which were previously reported as potent anti-simian immunodeficiency virus (SIV) neutralizing antibodies using the germ line VH3.33 gene-derived Ig heavy chain, were induced in five of 10 rhesus macaques after SIVsmH635FC infection. Investigation of VH3.33 genes in B404-class antibody inducers ( n  = 5) and non-inducers ( n  = 5) revealed association of B404-class antibody induction with a germ line VH3.33 polymorphism. Analysis of reconstructed antibodies indicated that the VH3.33 residue 38 is the determinant for B404-class antibody induction. B404-class antibodies were induced in all the macaques possessing the B404-associated VH3.33 allele, even under undetectable viremia. Our results show that a single nucleotide polymorphism in germ line VH genes could be a determinant for induction of potent antibodies against virus infection, implying that germ line VH-gene polymorphisms can be a factor restricting effective antibody induction or responsiveness to vaccination. IMPORTANCE Vaccines against a wide variety of infectious diseases have been developed mostly to induce antibodies targeting pathogens. However, small but significant percentage of people fail to mount potent antibody responses after vaccination, while the underlying mechanism of host failure in antibody induction remains largely unclear. In particular, the impact of germ line B cell receptor (BCR)/antibody immunoglobulin (Ig) gene polymorphism on B cell/antibody induction has not fully been determined. In the present study, we found a potent anti-simian immunodeficiency virus neutralizing antibody induction associated with a germ line BCR/antibody Ig gene polymorphism in rhesus macaques. Our results demonstrate that a single nucleotide polymorphism in germ line Ig genes could be a determinant for induction of potent antibodies against virus infection, implying that germ line BCR/antibody Ig gene polymorphisms can be a factor restricting effective antibody induction or responsiveness to vaccination., (Copyright © 2021 American Society for Microbiology.)

A vaccine to ameliorate cytomegalovirus (CMV)-related pathogenicity in transplantation patients is considered a top priority. A therapeutic vaccine must include components that elicit both neutralizing antibodies, and highly effective CD8 T-cell responses. The most important translational model of vaccine development is the captive-bred rhesus macaque (Macaca mulatta) of Indian origin. There is a dearth of information on rhesus cytomegalovirus (rhCMV)-specific CD8 T cells due to the absence of well-defined CD8 T-cell epitopes presented by classical MHC-I molecules. In the current study, we defined two CD8 T-cell epitopes restricted by high-frequency Mamu alleles: the Mamu-A1*002:01 restricted VY9 (VTTLGMALY aa291-299) epitope of protein IE-1, and the Mamu-A1*008:01 restricted NP8 (NPTDRPIP aa96-103) epitope of protein phosphoprotein 65-2. We developed tetramers and determined the level, phenotype, and functional capability of the two epitope-specific T-cell populations in circulation and various tissues. We demonstrated the value of these tetramers for in situ tetramer staining. Here, we first provided critical reagents and established a flow cytometric staining strategy to study rhCMV-specific T-cell responses in up to 40% of captive-bred rhesus macaques. © 2020 The Authors. Cytometry Part A published by Wiley Periodicals LLC on behalf of International Society for Advancement of Cytometry., (© 2020 The Authors. Cytometry Part A published by Wiley Periodicals LLC on behalf of International Society for Advancement of Cytometry.)

Recent studies have indicated an association between gut microbiome composition and various disorders, including infectious diseases. The composition of the microbiome differs among ethnicities and countries, possibly resulting in diversified interactions between host immunity and the gut microbiome. Characterization of baseline microbiome composition in healthy people is an essential step for better understanding of the biological interactions associated with individual populations. However, data on the gut/fecal microbiome have not been accumulated for individuals in West Africa. In the present study, we examined the fecal microbiome composition in healthy adults in Ghana. Toward this, 16S rRNA gene libraries were prepared using bacterial fractions derived from 55 Ghanaian adults, which were then subjected to next-generation sequencing. The fecal microbiome of the Ghanaian adults was dominated by Firmicutes (Faecalibacterium, Subdoligranulum, and Ruminococcaceae UCG-014), Proteobacteria (Escherichia-Shigella and Klebsiella), and Bacteroidetes (Prevotella 9 and Bacteroides), consistent with previous observations in African cohorts. Further, our analysis revealed differences in microbiome composition and a lower diversity of the fecal microbiome in the Ghanaian cohort compared with those reported in non-African countries. This is the first study to describe substantial fecal microbiome data obtained using high-throughput metagenomic tools on samples derived from a cohort in Ghana. The data may provide a valuable basis for determining the association between the fecal microbiome and progression of various diseases in West African populations.