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Objective: To explore the application value of T lymphocyte subsets combined with procalcitonin (PCT), C-reactive protein (CRP), neutrophil to lymphocyte ratio (NLR) and white blood cell count (WBC) in the auxiliary diagnosis and prognosis evaluation of sepsis. Methods: In a retrospective study, seventy-two patients with sepsis diagnosed and treated in Tianjin First Central Hospital from June 2018 to April 2021 were selected as the research objects, and included in the sepsis group were 46 males and 26 females, aged 68 (57.3, 80.3) years. In addition, 111 patients with local infection admitted to hospital during the same period were included in the local infection group, including 62 males and 49 females, aged 68 (51, 77) years. Sepsis patients were divided into survival group (43 cases) and death group (29 cases) according to the 28-day outcome. CD3 + , CD4 + , CD8 + , CD4 + /CD8 + ratio were detected by flow cytometry within 24 h after admission, PCT was detected by ELISA, CRP was detected by immunoturbidimetry, blood routine examination, blood lactic acid (Lac) and oxygen partial pressure (PO 2 ) were detected by instrumental method. Multivariate Logistic regression analysis was used to evaluate the correlation between each indicator and sepsis, and receiver operating characteristic curve (ROC) was drawn to evaluate the diagnostic value of each indicator for sepsis. Multivariate Logistic regression analysis and Kaplan Meier survival analysis were used to evaluate the prognostic value of each index for patients with sepsis. Results: Peripheral blood CD3 + , CD4 + , CD8 + , CD4 + /CD8 + ratio and PLT in sepsis group were significantly lower than those in local infection group( Z =-8.184, P <0.001; Z =-7.210, P <0.001; Z =-5.936, P <0.001; Z =-2.700, P =0.007; Z =-6.381, P <0.001); PCT, CRP, NLR and Lac levels were significantly higher than those in local infection group( Z =-8.262, P <0.001; Z =-3.094, P =0.002; Z =-9.004, P <0.001; Z =-4.770, P <0.001). Multivariate Logistic regression model showed that PCT, NLR, CD3 + , CD8 + , CD4 + /CD8 + were independent risk factors for sepsis. According to ROC curve analysis, AUC of sepsis patients diagnosed by each indicator were 0.862, 0.894, 0.858, 0.760 and 0.618, respectively. The cut-off values were 3.075 ng/ml, 10.715, 44.935×10 9 /L, 27.463×10 9 /L and 0.750, respectively. The NLR sensitivity was 80.6%, and the CD3 + specificity was 94.6%. The AUC of combined detection of PCT and NLR was 0.947, sensitivity was 87.5% and specificity was 91.9%. The combined detection AUC of PCT, NLR, CD3 + , CD4 + /CD8 + was 0.958, the sensitivity and specificity were 90.3% and 91.0% respectively( P <0.001). PCT and Lac in death group were significantly higher than those in survival group( Z =-2.302, P =0.021; Z =-3.095, P =0.002);Peripheral blood CD4 + /CD8 + levels were significantly lower than those in survival group( Z =-3.691, P <0.001),Multivariate Logistic regression model showed that CD4 + /CD8 + ratio was an independent risk factor for 28 d mortality in patients with sepsis ( P <0.001). The ROC curve showed that the AUC was 0.758, and the Youden index reached the maximum when the cut-off value was 1.27, the sensitivity and specificity were 79.3% and 60.5%, respectively. Compared with patients with CD4 + /CD8 + ≥1.27, 28-day mortality was significantly increased in patients with CD4 + /CD8 + <1.27 ( P =0.032). Conclusion: The combined detection of PCT, NLR, CD3 + and CD4 + /CD8 + can improve the auxiliary diagnostic efficiency of sepsis, and the ratio of CD4 + /CD8 + in peripheral blood may have certain predictive value for the prognosis of sepsis.

It is well documented that sporadic Alzheimer's disease (AD) is a multifactorial disease and considered to be a result of several pathological events, both in the periphery and in the brain. The role of the peripheral immune system in the etiology and/or progression of the disease is not fully understood yet, and the results in humans are contradictory so far. Several animal models of AD have been generated and thoroughly characterized to elucidate disease mechanisms and evaluate numerous therapeutic strategies in preclinical studies. In the present study, we carried out a longitudinal evaluation of blood lymphocytes from male and female 3xTg-AD mice to document important immunological abnormalities in the periphery. We documented the age-dependent decrease in the percentage of CD3+ and CD4+ lymphocytes and an increase in the percentage CD3+CD4-CD8- (DN T) cells in the blood of 3xTg-AD mice compared with non-transgenic animals. Severe splenomegaly was observed in 3xTg-AD mice in contrast to wild-type animals. Importantly, all these abnormalities in the peripheral immune system appeared earlier and were more pronounced in males compared with females of the same age, which may account for the shorter lifespan of male mice. We suggest that future research should include the measurement of CD3+ and DN T cells as a potential immunological marker of disease progression in AD patients., (Copyright © 2021 Elsevier B.V. All rights reserved.)

T-cell lymphomas (TCLs) constitute a rare subset of non-Hodgkin lymphomas, with mycosis fungoides/Sézary syndrome (MF/SS) being the most common subtype of cutaneous TCLs (CTCLs). Considered an incurable but treatable disease, MF/SS management presents several challenges including diagnostic delays, debilitating effect on patients' quality of life, need for several lines of therapies, multidisciplinary care and cumulative drug toxicities limiting duration of use. The present review intends to provide an overview of the recent advances in our understanding of the biology of CTCL and how these are being leveraged to provide additional treatment options for management of advanced and recurrent disease. In addition, the discussion of the different modalities of treatment is summarised to further outline the importance of multidisciplinary care and early referral to CTCL centres., (© 2021 British Society for Haematology and John Wiley & Sons Ltd.)

Exhaustion of HIV-1-specific CD8 + T cells prevents optimal control of HIV-1 infection. Identifying unconventional CD8 + T cell subsets to effectively control HIV-1 replication is vital. In this study, the role of CD11c + CD8 + T cells during HIV-1 infection was evaluated. The frequencies of CD11c + CD8 + T cells significantly increased and were negatively correlated with viral load in HIV-1-infected treatment-naïve patients. HIV-1-specific cells were enriched more in CD11c + CD8 + T cells than in CD11c - CD8 + T cells, which could be induced by HIV-1-derived overlapping peptides, marking an HIV-1-specific CD8 + T cell population. This subset expressed higher levels of activating markers (CD38 and HLA-DR), cytotoxic markers (granzyme B, perforin, and CD107a), and cytokines (IL-2 and TNF-α), with lower levels of PD-1 compared to the CD11c - CD8 + T cell subset. In vitro analysis verified that CD11c + CD8 + T cells displayed a stronger HIV-1-specific killing capacity than the CD11c - counterparts. These findings indicate that CD11c + CD8 + T cells have potent immunotherapeutic efficacy in controlling HIV-1 infection., 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 Guo, Zhao, Gao, Huang, Zhang, Zhang, Song, Xu, Fan, Shi, Jiao and Wang.)

Leptomeningeal disease (LMD) in melanoma patients is associated with significant neurological sequela and has a dismal outcome, with survival measured typically in weeks. Despite the therapeutic benefit of targeted therapies and immunotherapies for Stage IV melanoma, patients with LMD do not typically benefit. A deeper understanding of the tumor microenvironment (TME) of LMD may provide more appropriate therapeutic selection. A retrospective analysis of subjects who underwent surgical resection with LMD (n=8) were profiled with seven color multiplex staining to evaluate the expression of the global immune suppressive hub - the signal transducer and activator of transcription 3 (STAT3) and for the presence of CD3+ T cells, CD68+ monocyte-derived cells, CD163+ immune suppressive macrophages, and CD11c+ cells [potential dendritic cells (DCs)] in association with the melanoma tumor marker S100B and DAPI for cellular nuclear identification. High-resolution cellular imaging and quantification was conducted using the Akoya Vectra Polaris. CD11c+ cells predominate in the TME (10% of total cells), along with immunosuppressive macrophages (2%). Another potential subset of DCs co-expressing CD11c+ and the CD163+ immunosuppressive marker is frequently present (8/8 of specimens, 8%). Occasional CD3+ T cells are identified, especially in the stroma of the tumor (p=0.039). pSTAT3 nuclear expression is heterogeneous in the various immune cell populations. Occasional immune cluster interactions can be seen in the stroma and on the edge. In conclusion, the TME of LMD is largely devoid of CD3+ T cells but is enriched in immune suppression and innate immunity., Competing Interests: AH serves on the advisory boards of Caris Life Sciences and WCG Oncology, receives royalties on licensed intellectual property from Celldex Therapeutics and DNAtrix, and received research support from Codiak BioSciences Inc. The remaining 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 Najem, Marisetty, Horbinski, Long, Huse, Glitza Oliva, Ferguson, Kumthekar, Wainwright, Chen, Lesniak, Burks and Heimberger.)

Next-generation tissue-based biomarkers for immunotherapy will likely include the simultaneous analysis of multiple cell types and their spatial interactions, as well as distinct expression patterns of immunoregulatory molecules. Here, we introduce a comprehensive platform for multispectral imaging and mapping of multiple parameters in tumor tissue sections with high-fidelity single-cell resolution. Image analysis and data handling components were drawn from the field of astronomy. Using this "AstroPath" whole-slide platform and only six markers, we identified key features in pretreatment melanoma specimens that predicted response to anti-programmed cell death-1 (PD-1)-based therapy, including CD163 + PD-L1 - myeloid cells and CD8 + FoxP3 + PD-1 low/mid T cells. These features were combined to stratify long-term survival after anti-PD-1 blockade. This signature was validated in an independent cohort of patients with melanoma from a different institution., (Copyright © 2021 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works.)

γδ T cells are the unique T cell subgroup with their T cell receptors composed of γ chain and δ chain. Unlike αβ T cells, γδ T cells are non-MHC-restricted in recognizing tumor antigens, and therefore defined as innate immune cells. Activated γδ T cells can promote the anti-tumor function of adaptive immune cells. They are considered as a bridge between adaptive immunity and innate immunity. However, several other studies have shown that γδ T cells can also promote tumor progression by inhibiting anti-tumor response. Therefore, γδ T cells may have both anti-tumor and tumor-promoting effects. In order to clarify this contradiction, in this review, we summarized the functions of the main subsets of human γδ T cells in how they exhibit their respective anti-tumor or pro-tumor effects in cancer. Then, we reviewed recent γδ T cell-based anti-tumor immunotherapy. Finally, we summarized the existing problems and prospect of this immunotherapy., 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 Li, Li, Zhang, Wu and Chen.)

Intravesical Bacillus Calmette-Guerin (BCG) is an effective immunotherapy for non-muscle invasive bladder cancer (NMIBC). However, recurrence and progression remain frequent warranting deeper insights into its mechanism. We herein comprehensively profiled blood and tissues obtained from NMIBC patients before, during and after BCG treatment using cytometry by time-of-flight (CyTOF) and RNA sequencing to identify the key immune subsets crucial for anti-tumor activity. We observed the temporal changes of peripheral immune subsets including NKT cells, central memory CD4 + T cells, CD8 + T cells and regulatory T cells (Treg) during the course of BCG. Gene expression analysis revealed enriched immune pathways involving in T cell activation and chemotaxis, as well as a more diversified T cell receptor repertoire in post-BCG tissues. Moreover, tissue multiplexed-immunofluorescence (mIF) showed baseline densities of non-Treg and CD8 + PD-1 + T cells were predictive of response and better recurrence-free survival after BCG. Remarkably, post-BCG tissues from responders were found to be infiltrated with more active CD8 + PD-1 - T cells and non-Treg CD4 + FOXP3 - T cells; but increased exhausted CD8 + PD-1 + T cells were found in non-responders. Taken together, we identified predictive biomarkers for response and uncovered the post-treatment expansion of exhausted PD-1 + CD8 + T cells as key to BCG resistance, which could potentially be restored by combining with anti-PD-1 immunotherapy., 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 Lim, Nguyen, Wasser, Kumar, Lee, Nasir, Chua, Lai, Hazirah, Loh, Khor, Yeong, Lim, Low, Albani, Chong and Chew.)

Purpose: To evaluate radiotherapy-induced changes in the expression of programmed death ligand 1 (PD-L1), programmed death 1 (PD-1), and human leukocyte antigen class I (HLA-1) in patients with uterine cervical cancer, as well as infiltration of CD8+ and Forkhead box P3+ (FoxP3+) T lymphocytes into tumor tissue and the prognostic value of these parameters., Materials and Methods: We performed immunohistochemical analysis of pre-radiotherapy biopsies and corresponding post-radiotherapy resected tissues in 104 uterine cervical cancer patients undergoing preoperative chemoradiotherapy or radiotherapy alone. We scored the expression of various proteins to distinguish positive from negative samples., Results: PD-L1-expressing tumor cells (PD-L1 TC) increased significantly after chemoradiotherapy (p = 0.043). CD8+ T cell infiltration (p = 0.002) and FoxP3+ T cell infiltration (p = 0.003) decreased significantly after chemoradiotherapy. Expression of PD‑1, PD-L1-expressing immune cells (PD-L1 IC), and HLA‑1 did not change after chemoradiotherapy. In biopsy specimens obtained before chemoradiotherapy or radiotherapy, greater infiltration of CD8+ T cells (p = 0.001) and FoxP3+ T cells (p = 0.003) were significant predictors of better overall survival (OS). In surgical specimens obtained after chemoradiotherapy or radiotherapy, greater infiltration of PD-L1 TC was the only significant predictor of better OS (p < 0.001) and was related to a significantly lower probability of out-of-field recurrence (p = 0.005)., Conclusion: Chemoradiotherapy induced an immunologic shift that increased PD-L1 TC. Chemoradiotherapy has immunological effects that can influence the results of treatment for uterine cervical cancer.

Background: CD3 and CD19 are the characteristic surface markers of mature T lymphocytes and B lymphocytes of human respectively. A special subset of immune cells that characteristically expressed the surface markers CD19+ of B lymphocytes and CD3+ of T lymphocytes simultaneously (CD19+CD3+ cells, hereinafter referred to as B-T cells) was found in the peripheral blood of human, yet it has not been reported in cancer research before. Our aims were to characterize the expression and possible value of B-T cells in cancer patients., Methods: Flow cytometry was applied to analyse the CD19+CD3+ cells, and laser scanning confocal microscope was utilized to prove co-expressing CD19+ of B lymphocytes and CD3+ of T lymphocytes simultaneously on the surface of the cells. Then a total of 523 patients with malignant tumor were enrolled in this study, and 177 healthy donors were recruited as the control group. The levels of CD19+CD3+ cells in peripheral blood were measured by flow cytometry, and the differences between the two groups were compared., Results: The healthy donors and cancer patients all had B-T cells in their peripheral blood, but the percentage of B-T cells was 0.16 % ± 0.11 % and 0.58 % ± 0.38 % respectively, showing statistically significant (P < 0.0001). There was no significant correlation between the percentage of B-T cells and lymphocyte subsets (P > 0.05). The percentages of B-T cells in different tumor species were different. The proportion of B-T cells was high in esophageal cancer, non-Hodgkin's lymphoma and lung cancer, but it was low in pancreatic cancer, ovarian cancer and kidney cancer. Meanwhile, there was significant difference between esophageal cancer and kidney cancer (P < 0.001). The distribution of B-T cells in pancreatic cancer and kidney cancer was more concentrated, yet more dispersed in other cancers. Although there was a trend of increase in clinical stage Ⅲ+Ⅳ and a trend of decrease in age above 60 years for breast cancer, gastric cancer and liver cancer, there was no significant difference in the percentage of B-T cells in age, gender, different clinical stages, tumor metastasis, lymph node metastasis, and splenomegaly (P > 0.05)., Conclusion: The percentage of B-T cells in cancer patients was significantly higher than that of healthy donors. B-T cells maybe play a very complicated role in tumor, whether it could be a potential tumor immune marker or not and what are the specific phenotypes and functions of it to need be further verified., Competing Interests: Declaration of Competing Interest The authors declare that they have no potential conflicts of interest., (Copyright © 2020 European Federation of Immunological Societies. Published by Elsevier B.V. All rights reserved.)

While investigating the virulence traits of Staphylococcus aureus adhering to the skin of atopic-dermatitis (AD) patients, we identified a novel open reading frame (ORF) with structural similarity to a superantigen from genome sequence data of an isolate from AD skin. Concurrently, the same ORF was identified in a bovine isolate of S. aureus and designated SElY (H. K. Ono, Y. Sato'o, K. Narita, I. Naito, et al., Appl Environ Microbiol 81:7034-7040, 2015, https://doi.org/10.1128/AEM.01873-15). Recombinant SElY bov had superantigen activity in human peripheral blood mononuclear cells. It further demonstrated emetic activity in a primate animal model, and it was proposed that SElY be renamed SEY (H. K. Ono, S. Hirose, K. Narita, M. Sugiyama, et al., PLoS Pathog 15:e1007803, 2019, https://doi.org/10.1371/journal.ppat.1007803). Here, we investigated the prevalence of the sey gene in 270 human clinical isolates of various origins in Japan. Forty-two strains were positive for the sey gene, and the positive isolates were from patients with the skin diseases atopic dermatitis and impetigo/staphylococcal scalded skin syndrome (SSSS), with a detection rate of ∼17 to 22%. There were three variants of SEY (SEY 1 , SEY 2 , and SEY 3 ), and isolates producing SEY variants formed three distinct clusters corresponding to clonal complexes (CCs) 121, 59, and 20, respectively. Most sey + isolates produced SEY in broth culture. Unlike SEY bov , the three recombinant SEY variants exhibited stability against heat treatment. SEY predominantly activated human T cells with a particular T-cell receptor (TCR) Vα profile, a unique observation since most staphylococcal enterotoxins exert their superantigenic activities through activating T cells with specific TCR Vβ profiles. SEY may act to induce localized inflammation via skin-resident T-cell activation, facilitating the pathogenesis of S. aureus infection in disrupted epithelial barriers., (Copyright © 2020 American Society for Microbiology.)

The presence of an extremely stable latent reservoir of HIV-1 is the major obstacle to eradication, despite effective antiretroviral therapy (ART). Recent studies have shown that clonal expansion of latently infected cells without viral reactivation is an important phenomenon that maintains the long-term stability of the reservoir, yet its underlying mechanism remains unclear. Here we report that a subset of CD4 + T cells, characterized by CD161 expression on the surface, is highly permissive for HIV-1 infection. These cells possess a significantly higher survival and proliferative capacity than their CD161-negative counterparts. More importantly, we found that these cells harbor HIV-1 DNA and replication-competent latent viruses at a significantly higher frequency. By using massive single-genome proviral sequencing from ART-suppressed individuals, we confirm that CD161 + CD4 + T cells contain remarkably more identical proviral sequences, indicating clonal expansion of the viral genome in these cells. Taking the results together, our study identifies infected CD161 + CD4 + T cells to be a critical force driving the clonal expansion of the HIV-1 latent reservoir, providing a novel mechanism for the long-term stability of HIV-1 latency. IMPORTANCE The latent reservoir continues to be the major obstacle to curing HIV-1 infection. The clonal expansion of latently infected cells adds another layer maintaining the long-term stability of the reservoir, but its mechanism remains unclear. Here, we report that CD161 + CD4 + T cells serve as an important compartment of the HIV-1 latent reservoir and contain a significant amount of clonally expanded proviruses. In our study, we describe a feasible strategy that may reduce the size of the latent reservoir to a certain extent by counterbalancing the repopulation and dissemination of latently infected cells., (Copyright © 2019 Li et al.)

Transforming growth factor β (TGF-β) has been shown to play a role in immunity against different pathogens in vitro and against parasites in vivo However, its role in viral infections in vivo is incompletely understood. Using a neonatal mouse model of heterologous rhesus rotavirus (RV) vaccination, we show that the vaccine induced rotavirus-specific CD4 T cells, the majority of which lacked expression of KLRG1 or CD127, and a few regulatory rotavirus-specific CD4 T cells that expressed surface latency-associated peptide (LAP)-TGF-β. In these mice, inhibiting TGF-β, with both a neutralizing antibody and an inhibitor of TGF-β receptor signaling (activin receptor-like kinase 5 inhibitor [ALK5i]), did not change the development or intensity of the mild diarrhea induced by the vaccine, the rotavirus-specific T cell response, or protection against a subsequent challenge with a murine EC-rotavirus. However, mice treated with anti-LAP antibodies had improved protection after a homologous EC-rotavirus challenge, compared with control rhesus rotavirus-immunized mice. Thus, oral vaccination with a heterologous rotavirus stimulates regulatory RV-specific CD4 LAP-positive (LAP + ) T cells, and depletion of LAP + cells increases vaccine-induced protection. IMPORTANCE Despite the introduction of several live attenuated animal and human rotaviruses as efficient oral vaccines, rotaviruses continue to be the leading etiological agent for diarrhea mortality among children under 5 years of age worldwide. Improvement of these vaccines has been partially delayed because immunity to rotaviruses is incompletely understood. In the intestine (where rotavirus replicates), regulatory T cells that express latency-associated peptide (LAP) play a prominent role, which has been explored for many diseases but not specifically for infectious agents. In this paper, we show that neonatal mice given a live oral rotavirus vaccine develop rotavirus-specific LAP + T cells and that depletion of these cells improves the efficiency of the vaccine. These findings may prove useful for the design of strategies to improve rotavirus vaccines., (Copyright © 2019 American Society for Microbiology.)

Background: Susceptibility to HIV has been linked to systemic CD4+ T cell activation in cohorts of seronegative individuals with high HIV-exposure risk. We recently described an increased risk of HIV transmission in individuals infected with Wuchereria bancrofti, the causative agent for lymphatic filariasis, in a prospective cohort study. However, the reason for this phenomenon needs further investigation., Methodology/principal Findings: Two-hundred and thirty-five HIV negative adults were tested using Trop Bio ELISA for detection of W. bancrofti infection and Kato Katz urine filtration and stool based RT-PCR for detection of soil transmitted helminths and schistosomiasis. FACS analysis of the fresh peripheral whole blood was used to measure T cell activation markers (HLA-DR, CD38), differentiation markers (CD45, CD27), markers for regulatory T cells (FoxP3, CD25) and the HIV entry receptor CCR5. Frequencies of activated HLA-DRpos CD4 T cells were significantly increased in subjects with W. bancrofti infection (n = 33 median: 10.71%) compared to subjects without any helminth infection (n = 42, median 6.97%, p = 0.011) or those with other helminths (Schistosoma haematobium, S. mansoni, Trichuris trichiura, Ascaris lumbricoides, hookworm) (n = 151, median 7.38%, p = 0.009). Similarly, a significant increase in HLA-DRposCD38pos CD4 T cells and effector memory cells CD4 T cells (CD45ROposCD27neg) was observed in filarial infected participants. Multivariable analyses further confirmed a link between W. bancrofti infection and systemic activation of CD4 T cells independent of age, fever, gender or other helminth infections., Conclusions/significance: W. bancrofti infection is linked to systemic CD4 T cell activation, which may contribute to the increased susceptibility of W. bancrofti infected individuals to HIV infection., Competing Interests: The authors have declared that no competing interests exist.

Cytolytic CD4+ T cells play a prominent role in chronic viral infection. CD4+ CTLs clones specific for HIV-1 Nef and Gag are capable of killing HIV-1 infected CD4+ T cells and macrophages. Additionally, HIV-specific cytolytic CD4+ T cell responses in acute HIV infection are predictive of disease progression. CD57 expression on CD4s identifies cytolytic cells. These cells were dramatically increased in chronic HIV infection. CD57 expression correlated with cytolytic granules, granzyme B and perforin expression. They express lower CCR5 compared to CD57- cells, have less HIV total DNA, and were a minor component of the HIV reservoir. A small percentage of CD57+ CD4+ CTLs from EC were HIV-specific, could upregulate IFNγ with Gag peptide stimulation, express cytolytic granule markers and maintain Tbet high Eomes+ transcription factor phenotype. This was not observed in viraemic controllers. The maintenance of HIV-specific CD4 cytolytic function in Elite controllers together with CD8 CTLs may be important for the control of HIV viraemia and of potential relevance to cure strategies.

Objectives: HIV controllers (HICs) are rare HIV-infected individuals able to maintain undetectable viremia in the absence of antiretroviral treatment. Although HIV-specific cytotoxic T cells have been well deciphered in HIC, γδ T lymphocytes remain largely uncharacterized. The aim of this study was to analyse phenotypic and functional characteristics of γδ T cells and their relationship with immune activation, which remains abnormally elevated and associated with comorbidities in HICs., Methods: Peripheral blood mononuclear cells (PBMCs) were isolated from 16 HICs, 16 patients with untreated chronic HIV infection (UT-CHI) and 20 healthy donors. Surface marker expression and cytokine production by γδ T cells were analysed by flow cytometry., Results: Despite normal frequencies of total γδ T cells, the Vδ2/Vδ2 ratio was significantly reduced in HIC, albeit to a lesser extent than UT-CHI patients. Of note, nine HICs showed elevated Vδ2 γδ T cells, as patients with UT-CHI, which was associated with higher CD8 T-cell activation. Interleukin (IL)-17-production by γδ T cells (Tγδ17) was better preserved in HIC than in UT-CHI patients. Proportion of total γδ T cells positively correlated with CD8 T-cell activation and HIV-DNA, IP-10 and sCD14 levels. Conversely, Tγδ17 cells negatively correlated with CD8 T-cell activation and plasma sCD14 levels. Moreover, transforming growth factor (TGF)-β producing Vδ2 T cells were as dramatically depleted in HIC as in UT-CHI patients., Conclusion: The relative preservation of IL-17-producing γδ T cells in HIC and their negative association with immune activation raise the hypothesis that Tγδ17 cells - potentially through prevention of microbial translocation - may participate in the control of chronic systemic immune activation.

Invasive mould infections (IMI) in immunocompromised patients are difficult to diagnose. Early and targeted treatment is paramount, but minimally invasive tests reliably identifying pathogens are lacking. We previously showed that monitoring pathogen-specific CD4+T cells in peripheral blood using upregulation of induced CD154 positive lymphocytes can be used to diagnose acute IMI. Here, we validate our findings in an independent patient cohort. We stimulated peripheral blood cells from at-risk patients with Aspergillus spp. and Mucorales lysates and quantitated mould-reactive CD4/CD69/CD154 positive lymphocytes via flow cytometry. Mould-reactive lymphocytes were quantitated in 115 at-risk patients. In 38 (33%) patients, the test was not evaluable, mainly due to low T cell counts or non-reactive positive control. Test results were evaluable in 77 (67%) patients. Of these, four patients (5%) had proven IMI and elevated mould-reactive T cell signals. Of 73 (95%) patients without proven IMI, 59 (81%) had mould-reactive T cell signals within normal range. Fourteen (19%) patients without confirmed IMI showed elevated T cell signals and 11 of those received antifungal treatment. The mould-reactive lymphocyte assay identified presence of IMI with a sensitivity of 100% and specificity of 81%. The mould-reactive lymphocyte assay correctly identified all patients with proven IMI. Assay applicability is limited by low T cell counts during bone marrow suppression. The assay has the potential to support diagnosis of invasive mould infection to facilitate tailored treatment even when biopsies are contraindicated or cultures remain negative., (© 2019 Blackwell Verlag GmbH.)

Background : Vitamin D has regulatory effects on different cells of the immune system and low levels are associated with several immune-mediated diseases. Aim : To investigate the association between neonatal 25-hydroxy vitamin D (25-OHD) level and the expression of lymphocyte activation markers (HLA-DR, CD69, CD25, CD45RA) on T-lymphocyte subpopulations and its impact in neonatal infection. Methods : 25-OHD level was measured in the cord blood of 56 neonates and their mothers using an enzyme immune-assay method. Based on the 25-OHD level, infants were categorised into four groups: severe deficiency ( n =  7), moderate deficiency ( n =  21), mild deficiency ( n =  15) and normal 25-OHD level ( n =  13). Mothers were classified into deficient ( n =  18), insufficient ( n =  21) and normal levels ( n =  17). T-lymphocyte subpopulations and lymphocyte activation markers were investigated using flow cytometry. Results : There was a positive correlation between maternal and cord blood 25-OHD levels ( r  = 0.503, p  = 0.001). The group with severe 25-OHD deficiency had the significantly lowest level of total lymphocytes, CD3+ T lymphocytes, CD4+ T-helper and CD8+ T-cytotoxic lymphocytes and CD4+CD45RA+ naïve T-cells compared with the other groups. The frequencies of CD8+CD25+, CD4+CD25+ and CD4+HLA-DR+ activated T-lymphocytes were significantly lower in the severe, moderate and mild deficiency groups than in the normal group. Seven of 43 (16.27%) infants with 25-OHD deficiency were admitted with sepsis to the neonatal intensive care unit and there were no cases of sepsis in the normal 25-OHD group. Conclusion : Vitamin D deficiency is associated with a reduction of lymphocyte subsets and altered T-lymphocyte activation which are considered to be risk factors for neonatal infection.

Latency associated peptide (LAP) is a protein expressed on the membrane of some regulatory T cells (Treg). LAP + Treg have a greater immunomodulatory effect than that of their negative counterparts. In this study, we presented the data on the proportion of LAP + Treg out of CD4 + cells in mice with viral myocarditis, which we believed was more sensitive and specific than that of the ratio of total Treg in CD4 + cells. Comparing with the previously recognized total Treg, LAP + Treg was a better biomarker on myocardial inflammation., (© 2018 Wiley Periodicals, Inc.)

Infection with human papillomavirus (HPV) is the main cause of cervical cancer. Viral persistence is considered the main risk factor for neoplastic progression and evidence suggests that regulatory T cells (Treg) play an important role in the failure of viral elimination. The aim of this study was to detect phenotypic markers of Treg and cytokines interleukin (IL)-10 and transforming growth factor (TGF)-β, in the cervical microenvironment of HPV-infected patients. One hundred and one samples of uterine cervix embedded in paraffin were analyzed. We used immunohistochemistry to examine the coexpression of the CD25/FOXP3 and CD4/TGF-β markers, and the expression of GITR and IL-10 in cells present in the cervical stroma. We detected a microenvironment composed of high proportions of CD25 + FOXP3 + , CD4 + TGFβ + , IL-10 + , and GITR + cells in samples with high viral loads and severe lesions of HPV-infected patients. The abundance of these markers, indicative of the presence of Treg cells and immunosuppressive cytokines, was significantly associated with severe lesions and elevated viral loads in the examined samples. These results suggest that Treg cells may be involved in maintaining a microenvironment favorable for viral persistence and neoplastic progression. Our findings support those of previous studies that suggested that these markers could be used to predict HPV persistence and neoplastic progression, and as potential targets for immune response modulation., (© 2018 Wiley Periodicals, Inc.)

A recent study has pointed out to CD32a as a potential biomarker of HIV-persistent CD4 cells. We have characterized the level and phenotype of CD32+ cells contained in different subsets of CD4 T-cells and its potential correlation with level of total HIV-DNA in thirty HIV patients (10 typical progressors naïve for cART, 10 cART-suppressed patients, and 10 elite controllers). Total HIV-DNA was quantified in different subsets of CD4 T-cells: Trm and pTfh cells. Level and immunephenotype of CD32+ cells were analyzed in these same subsets by flow cytometry. CD32 expression in Trm and pTfh subsets was similar in the different groups, and there was no significant correlation between the level of total HIV-DNA and the level of CD32 expression in these subsets. However, total HIV-DNA level was correlated with expression of CD127 (rho = -0.46, p = 0.043) and of CCR6 (rho = -0.418, p = 0.027) on CD32+ cells. Our results do not support CD32 as a biomarker of total HIV-DNA content. However, analyzing the expression of certain markers by CD32+ cells could improve the utility of this marker in the clinical setting, prompting the necessity of further studies to both validate our results and to explore the potential utility of certain markers expressed by CD32+ cells.

A recent study conducted in blood has proposed CD32 as the marker identifying the "elusive" HIV reservoir. We have investigated the distribution of CD32 + CD4 T cells in blood and lymph nodes (LNs) of HIV-1-uninfected subjects and viremic untreated and long-term-treated HIV-1-infected individuals and their relationship with PD-1 + CD4 T cells. The frequency of CD32 + CD4 T cells was increased in viremic compared to treated individuals in LNs, and a large proportion (up to 50%) of CD32 + cells coexpressed PD-1 and were enriched within T follicular helper (Tfh) cells. We next investigated the role of LN CD32 + CD4 T cells in the HIV reservoir. Total HIV DNA was enriched in CD32 + and PD-1 + CD4 T cells compared to CD32 - and PD-1 - cells in both viremic and treated individuals, but there was no difference between CD32 + and PD-1 + cells. There was no enrichment of latently infected cells with inducible HIV-1 in CD32 + versus PD-1 + cells in antiretroviral therapy (ART)-treated individuals. HIV-1 transcription was then analyzed in LN memory CD4 T cell populations sorted on the basis of CD32 and PD-1 expression. CD32 + PD-1 + CD4 T cells were significantly enriched in cell-associated HIV RNA compared to CD32 - PD-1 - (averages of 5.2-fold in treated individuals and 86.6-fold in viremics), CD32 + PD-1 - (2.2-fold in treated individuals and 4.3-fold in viremics), and CD32 - PD-1 + (2.2-fold in ART-treated individuals and 4.6-fold in viremics) cell populations. Similar levels of HIV-1 transcription were found in CD32 + PD-1 - and CD32 - PD-1 + CD4 T cells. Interestingly, the proportion of CD32 + and PD-1 + CD4 T cells negatively correlated with CD4 T cell counts and length of therapy. Therefore, the expression of CD32 identifies, independently of PD-1, a CD4 T cell population with persistent HIV-1 transcription and coexpression of CD32 and PD-1, the CD4 T cell population with the highest levels of HIV-1 transcription in both viremic and treated individuals. IMPORTANCE The existence of long-lived latently infected resting memory CD4 T cells represents a major obstacle to the eradication of HIV infection. Identifying cell markers defining latently infected cells containing replication-competent virus is important in order to determine the mechanisms of HIV persistence and to develop novel therapeutic strategies to cure HIV infection. We provide evidence that PD-1 and CD32 may have a complementary role in better defining CD4 T cell populations infected with HIV-1. Furthermore, CD4 T cells coexpressing CD32 and PD-1 identify a CD4 T cell population with high levels of persistent HIV-1 transcription., (Copyright © 2018 Noto et al.)

Background: Despite advances made with the highly active antiretroviral therapy (HAART) in the control of the HIV 1 infection, a cure has not been achieved because of the persistence of viral reservoirs. The major HIV reservoirs remain in the lymphoid follicles because of, among other factors, the partial absence of CD8 T-cells in these structures. Recently, lymphoid follicle-confined and circulating CD8 T-cells expressing the C-X-C chemokine receptor type 5 (CXCR5) were described, possessing antiviral mechanisms that could help to control HIV replication., Setting and Methods: By flow cytometry, we characterized the phenotype and function of circulating CXCR5-expressing CD8 T-cells in HIV-infected patients with natural or HAART-induced control of HIV replication., Results: Circulating CXCR5-expressing CD8 T-cells exhibited low or null expression of the C-C chemokine receptor type 7 (CCR7) and had a transitional memory phenotype. Particular redistributions of CXCR5-expressing CD8 T-cells were found in HIV-infected patients, and they were partially restored by HAART. The frequency of CXCR5CCR7 CD8 T-cells was higher in spontaneous HIV controllers and negatively correlated with plasma HIV RNA levels. Total and HIV-specific CXCR5 CD8 T-cells were major producers of interleukin-21, and this function was positively associated with their interferon-γ production., Conclusions: Circulating CXCR5-expressing CD8 T-cells are associated with low-level HIV replication; these cells could be novel correlates of protection, and potentially useful in the eradication of HIV reservoirs.

Interleukin 21 (IL-21) is a pleiotropic common cytokine receptor γ chain cytokine that promotes the effector functions of NK cells and CD8 + T cells and inhibits CD8 + T cell exhaustion during chronic infection. We found that the absolute number of short-lived effector CD8 + T cells (SLECs) (KLRG1 high CD127 low ) decreased significantly in IL-21 receptor-deficient (IL-21R -/- ) mice during Mycobacterium bovis bacillus Calmette-Guérin (BCG) infection. Early effector CD8 + T cells (EECs) (KLRG1 low CD127 low ) were normally generated in IL-21R -/- mice after infection. Exhausted CD8 + T cells (PD-1 high KLRG1 low ) were also normally generated in IL-21R -/- mice after infection. Mixed bone marrow (BM) chimera and transfer experiments showed that IL-21R on CD8 + T cells was essential for the proliferation of EECs, allowing them to differentiate into SLECs after BCG infection. On the other hand, the number of SLECs increased significantly after infection with recombinant BCG (rBCG) that secreted an antigen 85B (Ag85B)-IL-21 fusion protein (rBCG-Ag85B-IL-21), but the number of exhausted CD8 + T cells did not change after rBCG-Ag85B-IL-21 infection. These results suggest that IL-21 signaling drives the differentiation of SLECs from EECs but does not inhibit the exhaustion of CD8 + T cells following BCG infection in mice., (Copyright © 2018 American Society for Microbiology.)

Background: Genital mucosa is the main portal of entry for various incoming pathogens, including human immunodeficiency virus (HIV), hence it is an important site for host immune defenses. Tissue-resident memory T (TRM) cells defend tissue barriers against infections and are characterized by expression of CD103 and CD69. In this study, we describe the composition of CD8+ TRM cells in the ectocervix of healthy and HIV-infected women., Methods: Study samples were collected from healthy Swedish and Kenyan HIV-infected and uninfected women. Customized computerized image-based in situ analysis was developed to assess the ectocervical biopsies. Genital mucosa and blood samples were assessed by flow cytometry., Results: Although the ectocervical epithelium of healthy women was populated with bona fide CD8+ TRM cells (CD103+CD69+), women infected with HIV displayed a high frequency of CD103-CD8+ cells residing close to their epithelial basal membrane. Accumulation of CD103-CD8+ cells was associated with chemokine expression in the ectocervix and HIV viral load. CD103+CD8+ and CD103-CD8+ T cells expressed cytotoxic effector molecules in the ectocervical epithelium of healthy and HIV-infected women. In addition, women infected with HIV had decreased frequencies of circulating CD103+CD8+ T cells., Conclusions: Our data provide insight into the distribution of CD8+ TRM cells in human genital mucosa, a critically important location for immune defense against pathogens, including HIV.

The regulatory function of CCR7 + CD8 + T cells against effector T-cells involved in T-cell mediated rejection (TCMR) in kidney transplant recipients was investigated. In vitro experiments explored the ability of CCR7 + CD8 + T cells to suppress T-cell proliferation under T-cell activation conditions or during coculture with human renal proximal tubular epithelial cells (HRPTEpiC). In an ex vivo experiment, the proportion of CCR7 + /CD8 + , FOXP3 + /CCR7 + CD8 + T and effector T-cell subsets were compared between the normal biopsy control (NC, n = 17) and TCMR group (n = 17). The CCR7 + CD8 + T cells significantly suppressed the proliferation of CD4 + T cells and significantly decreased the proportion of IFN-γ + and IL-17 + /CD4 + T cells and inflammatory cytokine levels (all p < 0.05). After coculturing with HRPTEpiC, CCR7 + CD8 + T cells also suppressed T-cell differentiation into IL-2 + , IFN-γ + , and IL-17 + /CD4 + T cells (all p < 0.05). The TCMR group had significantly fewer CCR7 + /CD8 + and FOXP3 + /CCR7 + CD8 + T in comparison with the NC group, but the proportions of all three effector T-cell subsets were increased in the TCMR group (all p < 0.05). The proportion of CCR7 + /CD8 + T was inversely correlated with those of effector T-cell subsets. The results indicate that CCR7 + CD8 + T cells may regulate effector T-cells involved in TCMR in an in vitro and in an ex vivo transplant model.

The gut microbiota in chicken has long been studied, mostly from the perspective of growth performance. However, there are some immunological studies regarding gut homeostasis in chicken. Although CD4 + CD25 + T cells are reported to act as regulatory T cells (Tregs) in chicken, there have been no studies showing the relationship between gut microbiota and Tregs. Therefore, we established a model for 'antibiotics (ABX)-treated chickens' through administration of an antibiotic cocktail consisting of ampicillin, gentamycin, neomycin, metronidazole, and vancomycin in water for 7 days. CD4 + CD8 - CD25 + and CD4 + CD8 + CD25 + T cells in cecal tonsils were significantly decreased in this model. Gram-positive bacteria, especially Clostridia, was responsible for the changes in CD4 + CD8 - CD25 + or CD4 + CD8 + CD25 + T cells in cecal tonsils. Feeding ABX-treated chickens with acetate recovered CD4 + CD8 - CD25 + and CD4 + CD8 + CD25 + T cells in cecal tonsils. GPR43, a receptor for acetate, was highly expressed in CD4 + CD8 - CD25 + T cells. In conclusion, our study demonstrated that the gut microbiota can regulate the population of CD4 + CD8 - CD25 + and CD4 + CD8 + CD25 + T cells, and that acetate is responsible for the induction of CD4 + CD8 - CD25 + T cells in cecal tonsils via GPR43.

Background: Recently, CD32 has been described to be a specific surface marker of latently HIV-infected CD4 T cells, but little is known about the frequency and distribution of CD32 expression on naive and memory CD8 and CD4 T cell populations in HIV patients and healthy individuals., Methods: We studied peripheral blood samples of 36 HIV-1-infected patients [23 viremic patients / 13 antiretroviral therapy(ART)-treated] and healthy individuals (n = 14) as well as cells from lymph nodes (8 HIV infected, 5 controls) using a multiparametric flow cytometry panel determining surface expression of CD3, CD8, CD4, CD45RA, CCR7, CD27, CD25, CD127, CCR5, CCR6, CXCR4, CD38, HLA-DR, TIGIT, and PD-1., Results: Overall, expression of CD32 on total peripheral CD4 T cells between viremic HIV patients, ART-treated and healthy individuals only slightly differed (mean values 1.501%, 0.2785%, and 0.2343%, respectively). However, the level of expression was significantly higher in peripheral and lymph nodal memory CD4 T cell subpopulations of viremic patients compared with ART-treated patients and healthy controls. CD32 CD4 T cells showed higher immune activation and higher expression of CXCR4 than their CD32 counterparts. Furthermore, expression of CD32 on total CD4 T cells and memory T cell populations correlated with general immune activation regardless of the infection status., Conclusions: Follow-up studies will have to further evaluate CD32 as marker of latently HIV-infected CD4 T cells since other host-related variables such as immune activation seem to influence CD32 expression regardless of the infection status.

Objective: Immunoglobulin (Ig) G4-related aortic aneurysms (IgG4-AAs) are a special aortic aneurysm among IgG4-related diseases (IgG4-RDs), which are inflammatory and fibrous conditions characterized by tumorous swelling of affected organs and high serum IgG4 concentrations. Recently, IgG4-RD pathogenesis was shown to be associated with T-helper-2 (Th2) and regulatory T (Treg) dominant cytokine production, such as interleukin (IL)-4, IL-10, and IL-13. IL-6 is a key proinflammatory cytokine contributing to lymphocyte and plasmacyte maturation and to atherosclerosis and aneurysm development. We serologically and histopathologically evaluated the cytokine profile in IgG4-AA patients., Methods: Patients with IgG4-AAs (n = 10), non-IgG4-related inflammatory abdominal aortic aneurysms (non-IgG4-AAAs; n = 5), atherosclerotic AAAs (aAAAs; n = 10), and normal aortas without dilatation (n = 10) were examined for serum IL-10, IL-13, and IL-6 levels. Resected aortic tissues were evaluated for cluster of differentiation (CD) 34 (in the endothelial cells and mesenchymal cells) and CD163 (by macrophages) expression using immunohistochemistry and in situ hybridization., Results: Serum IL-10 levels were rather higher in IgG4-AA patients (median, 1.3 pg/mL) than in non-IgG4-AAA and aAAA patients and in patients with normal aortas. Elevated serum IL-13 levels relative to standard values were detected in two IgG4-AA patients but not in the other groups. Cells immunopositive for IL-10 and IL-13 were more frequent in IgG4-AAs and significantly correlated with serum IgG4 levels. Serum IL-6 levels (median, 78.5 pg/mL) were also significantly higher in IgG4-AA patients than in non-IgG4-AAA and aAAA patients and control patients with normal aortas (P = .01, P = .001, and P = .004, respectively). They positively correlated with serum IgG4 levels and adventitial thickness, but other cytokines did not. The number of IL-6-immunopositive cells in the adventitia was significantly higher in IgG4-AA patients (median, 17.8/high-power field) than in aAAA patients or patients with normal aortas (P =.001 and P = .002, respectively). In situ hybridization confirmed frequent IL-6 messenger (m)RNA expression in the endothelium, mesenchymal cells, and histiocytes in IgG4-AA adventitia. In the same cells of IgG4-AAs, coexpression of IL-6 and CD34 mRNA or CD163 mRNA was detected., Conclusions: The cytokine profiles of IgG4-AA patients had two characteristics: local IL-10 and IL-13 upregulation in IgG4-AAs was related to Th2 and Treg-predominant cytokine balance, similar to other IgG4-RDs, and IL-6 upregulation in the adventitia was characterized by activated immune reactions in IgG4-AA patients. IL-6 synthesis, through contributions of mesenchymal cells and macrophages in the adventitia, is strongly involved in IgG4-AA pathogenesis or progression, or both., (Copyright © 2017 Society for Vascular Surgery. Published by Elsevier Inc. All rights reserved.)

Introduction: Despite major progress in controlling HIV disease through antiretroviral therapy, changes in immune phenotype and function persist in individuals with chronic HIV, raising questions about accelerated aging of the immune system., Methods: We conducted a cross-sectional study (2005-2007) of HIV-infected (n = 111) and uninfected (n = 114) men from the Veterans Aging Cohort Study. All HIV-infected subjects were on antiretroviral therapy with VL <400 copies/mL for at least 3 years. T-cell markers were examined using flow cytometry. We evaluated the impact of HIV serostatus and age on T-cell phenotypes (expressed as percentages of the total CD4 and CD8 T-cell population) using multivariate linear regression, adjusted for smoking, alcohol, and race/ethnicity. We tested for interactions between HIV and age by including interaction terms., Results: Among both HIV-infected and uninfected subjects, increasing age was associated with a decreased proportion of naive CD4 T cells (P = 0.014) and CD8 T cells (P < 0.0001). Both HIV infection and increasing age were associated with higher proportions of effector memory CD4 T cells (P < 0.0001 for HIV; P = 0.04 for age) and CD8 T cells (P = 0.0001 for HIV; P = 0.0004 for age). HIV infection, but not age, was associated with a higher proportion of activated CD8 T cells (P < 0.0001). For all T-cell subsets tested, there were no significant interactions between HIV infection and age., Conclusions: Age and HIV status independently altered the immune system, but we found no conclusive evidence that HIV infection and advancing age synergistically result in accelerated changes in age-associated T-cell markers among virally suppressed individuals.

Background: Adverse viral and medication effects on adipose tissue contribute to the development of metabolic disease in HIV-infected persons, but T cells also have a central role modulating local inflammation and adipocyte function. We sought to characterize potentially proinflammatory T-cell populations in adipose tissue among persons on long-term antiretroviral therapy and assess whether adipose tissue CD8 T cells represent an expanded, oligoclonal population., Methods: We recruited 10 HIV-infected, non-diabetic, overweight or obese adults on efavirenz, tenofovir, and emtricitabine for >4 years with consistent viral suppression. We collected fasting blood and subcutaneous abdominal adipose tissue to measure the percentage of CD4 and CD8 T cells expressing activation, exhaustion, late differentiation/senescence, and memory surface markers. We performed T-cell receptor (TCR) sequencing on sorted CD8 cells. We compared the proportion of each T-cell subset and the TCR repertoire diversity, in blood versus adipose tissue., Results: Adipose tissue had a higher percentage of CD3CD8 T cells compared with blood (61.0% vs. 51.7%, P < 0.01) and was enriched for both activated CD8HLA-DR T cells (5.5% vs. 0.9%, P < 0.01) and late-differentiated CD8CD57 T cells (37.4% vs. 22.7%, P < 0.01). Adipose tissue CD8 T cells displayed distinct TCRβ V and J gene usage, and the Shannon Entropy index, a measure of overall TCRβ repertoire diversity, was lower compared with blood (4.39 vs. 4.46; P = 0.05)., Conclusions: Adipose tissue is enriched for activated and late-differentiated CD8 T cells with distinct TCR usage. These cells may contribute to tissue inflammation and impaired adipocyte fitness in HIV-infected persons.

Introduction: Rheumatoid arthritis (RA) is a chronic autoimmune disease that is characterized by the presence of different autoantibodies such as rheumatoid factor (RF) and anti-citrullinated protein antibodies. CD4T cells expressing CXCR5, referred as follicular helper T cells (Tfh), collaborate with B cells to produce antibodies. Differential expression of CXCR3 and CCR6 within CD4 + CXCR5 + T cells defines three mayor subsets: CXCR3 + CCR6 - (Tfh1), CXCR3 - CCR6 - (Tfh2) and CXCR3 - CCR6 + (Tfh17). The aim of the study was to assess whether there is an association between the percentage of these cells and RA and whether there is a correlation with disease activity., Material and Methods: Twenty-four RA patients, 22 healthy controls (HC) and 16 undifferentiated arthritis (UA) patients were included. Percentage of CD4 + CXCR5 + T cells and their subsets were analyzed by flow cytometry., Results: No differences were found in the percentages of CD4 + CXCR5 + T cells in the comparison of RA vs HC or RA vs UA patients. Tfh1, Tfh2 and Tfh17 subsets showed no differences either. There was no correlation between CD4 + CXCR5 + T cells, Tfh1, Tfh2 and Tfh17, and Disease Activity Score in twenty-eight joints (DAS28) or erythrocyte sedimentation rate. Surprisingly, there was a positive correlation between Tfh17 cells and C-reactive protein. Finally, there was no correlation between CD4 + CXCR5 + T cells, or their subsets, and anti-mutated citrullinated vimentin, or between the cells and RF., Conclusion: There were no differences between the percentages of CD4 + CXCR5 + T cells and their subsets in peripheral blood of RA patients and the percentages of cells in the control groups. This finding does not rule out a pathogenic role of these cells in the development and activity of RA., (Copyright © 2016 Elsevier España, S.L.U. and Sociedad Española de Reumatología y Colegio Mexicano de Reumatología. All rights reserved.)

The study was carried out to study expression of Toll like receptors 2 (TLR2), natural/inducible Treg and Interferon-γ alongside oxidative stress and understand their significance in pediatric samples. Influence of oxidative stress on Celiac Disease was analysed by evaluating lipid peroxidation, reduced glutathione, Glutathione peroxidase, etc. A comparison was performed among CD patients, CD patients on gluten free diet (GFD), and healthy controls. Peripheral nTregs exhibited a similar pattern of reduced numbers in CD and GFD cases when compared to healthy controls. On the other hand, inducible Tregs were much lower in GFD patients as compared to CD patients. Expression of TLR2 on iTregs was elevated in CD and GFD, however, expression on nTregs was unaltered in all the three groups. The inflammatory cytokine IFN-γ positive Treg cells were found to be elevated in CD as compared to control group. Oxidative stress was elevated in CD as compared to healthy controls while that in GFD samples was lower in comparison to CD. The levels of LPO, activities of enzymes SOD and Catalase were higher in CD and GFD samples when compared to controls. However, enzyme Glutathione peroxidase and reduced glutathione levels declined in both CD and GFD groups as compared to controls. This report highlights the effect of elevated oxidative stress in CD on reduced traffic of iTregs toward periphery. A strong correlation was observed between the cytokine IFN-γ and TLR2 expression in movement of iTregs in CD patients., (© 2017 APMIS. Published by John Wiley & Sons Ltd.)

The functional heterogeneity of T cell responses to diverse antigens expressed at different stages of Mycobacterium tuberculosis (Mtb) infection, in particular early secreted versus dormancy related latency antigens expressed later, that distinguish subjects with latent (LTBI), pulmonary (PTB) or extrapulmonary (EPTB) tuberculosis remains unclear. Here we show blood central memory CD4 T-cell responses specific to Mtb dormancy related (DosR) latency, but not classical immunodominant secretory antigens, to clearly differentiate LTBI from EPTB and PTB. The polyfunctionality score integrating up to 31 DosR-specific CD4 T-cell functional profiles was significantly higher in LTBI than EPTB or PTB subjects. Further analysis of 256 DosR-specific T-cell functional profiles identified regulatory IL10  +  Th17 cells (IL10 + IL17A + IL17F + IL22 + ) to be significantly enriched in LTBI; in contrast to pro-inflammatory Th17 cells (IFNγ + IL17A + /IL10 - ) in the blood and lung of EPTB and PTB subjects respectively. A blood polyfunctional, Mtb DosR latency antigen specific, regulatory, central memory response is therefore a novel functional component of T-cell immunity in latent TB and potential correlate of protection.

CD8 + T lymphocytes are critical for the control of gammaherpesvirus latency. To determine how memory CD8 + T cells generated during latency differ from those primed during acute or chronic viral infection, we adoptively transferred naive P14 CD8 + T cells into uninfected recipients, and examined surface proteins, cytokines and transcription factors following infection with the Armstrong (acute) or Clone 13 (chronic) strains of lymphocytic choriomeningitis virus (LCMV), or murine gammaherpesvirus 68 (MHV68) expressing the LCMV epitope D b GP33-41. By performing k-means clustering and generating self organizing maps (SOM), we observed increased short-lived effector-like, CD27 l o CD62L l o and Bcl-6 l o CD8 + T cells following latent infection. In addition, we found that memory CD8 + T cells from latent primed mice underwent less expansion following adoptive transfer and antigen rechallenge. Data from cluster models were combined and visualized by principal component analysis (PCA) demonstrating memory CD8 + T cells from latent infection occupy an intermediate differentiation space., (Copyright © 2017. Published by Elsevier Inc.)

In a recent unit in this series, protocols for the isolation, cryopreservation, thawing, and immunophenotyping of HPBMC isolated from peripheral whole blood using cell surface marker (CSM) staining and multi-color flow cytometry analysis were presented. The current procedure describes the detection and quantification of CSM and intracellular markers (ICM), including transcription factors and cytokines, following activation and differentiation of CD4+ T-cells using multi-color flow cytometry. Results indicated that repeatable and robust detection of ICM could be obtained in surface marker-defined T cells that identify functional subsets of cells. There were no observed differences between fresh and cryopreserved HPBMC in eight phenotypes analyzed (T-CD3, Th-CD4, Tmem-CD45RO, activated T-CD3/CD25, Treg- Foxp3/CD25, Th1-IFNγ, Th2- IL-4, Th17-IL-17A). There was an observed difference in activated T- CD3/CD69 in the short term (30-90 days) cryopreserved samples as compared to the freshly isolated samples, which may have resulted from the variance in controls or small sample size. © 2017 by John Wiley & Sons, Inc., (Copyright © 2017 John Wiley & Sons, Inc.)

iNKT cells are a unique lineage of T cells that recognize glycolipid presented by CD1d. In the thymus, they differentiate into iNKT1, iNKT2 and iNKT17 effector subsets, characterized by preferential expression of Tbet, Gata3 and ROR-γt and production of IFN-γ, IL-4 and IL-17, respectively. We demonstrate that the transcriptional regulator Runx1 is essential for the generation of ROR-γt expressing iNKT17 cells. PLZF-cre Runx1 cKO mice lack iNKT17 cells in the thymus, spleen and liver. Runx1-deficient iNKT cells have altered expression of several genes important for iNKT17 differentiation, including decreased expression of IL-7Rα, BATF and c-Maf and increased expression of Bcl11b and Lef1. However, reduction of Lef1 expression or introduction of an IL-7Rα transgene is not sufficient to correct the defect in iNKT17 differentiation, demonstrating that Runx1 is a key regulator of several genes required for iNKT17 differentiation. Loss of Runx1 leads to a severe decrease in iNKT cell numbers in the thymus, spleen and liver. The decrease in cell number is due to a combined decrease in proliferation at Stage 1 during thymic development and increased apoptosis. Thus, we describe a novel role of Runx1 in iNKT cell development and differentiation, particularly in orchestrating iNKT17 differentiation.

Signal transducer and activator of transcription 3 (STAT3) is a key signaling protein in the skeletal system as well as in the immune system. Accumulating evidence demonstrates that the inflammatory response is deeply involved in the healing process of bone fractures, but how the immune system is regulated during this process is unclear. In this study, we examined STAT3-mediated regulation of immunity in adult patients with closed tibia fracture. In all patients, the expression and activation of STAT3 peaked at around day 7 to day 14 after surgery, and gradually decreased during the rest of the healing period. At day 7 (peak STAT3 expression and phosphorylation), the CD4 + CD25 + T cells from bone fracture patients presented the highest level of STAT3 activation among lymphocyte subsets. Therefore, we investigated the role of STAT3 in CD4 + CD25 + T cells. The level of FOXP3 expression by CD4 + CD25 + T cells was directly correlated with the level of STAT3 phosphorylation in these cells. The level of STAT3 phosphorylation in CD4 + CD25 + T cells was also inversely correlated with the level of IFN-γ and TNF-α secretion in peripheral blood mononuclear cells. Inhibition of STAT3 significantly suppressed FOXP3 and IL-10 expression by CD4 + CD25 + T cells, as well as the ability of CD4 + CD25 + T cells to suppress T-cell IFN-γ and TNF-α secretion. Furthermore, early healers patients presented significantly higher STAT3 expression and phosphorylation than late healers, possibly due to the higher IL-6 and IL-10 levels in the serum of early healing patients. Together, these data demonstrated that STAT3 was beneficial to bone fracture healing, possibly by enhancing Treg-mediated suppression of counteracting inflammations, and suggested that STAT3 could be used as a prognostic marker to identify otherwise undistinguishable patients at risk of developing delayed union or nonunion., (© 2017 APMIS. Published by John Wiley & Sons Ltd.)

Several studies have shown an association of alcohol dependence with DNA methylation (DNAm), suggesting that environmentally-induced changes on epigenomic variation may play an important role in alcohol dependence. In the present study, we analysed genome-wide DNAm profiles of purified CD3 + T-cells from pre- and post-treatment alcohol dependent patients, as well as closely matched healthy controls. We identified 59 differentially methylated CpG sites comparing patients prior to treatment with healthy controls and were able to confirm 8 of those sites in additional analyses for differentially methylated regions. Comparing patients before and after a 3-week alcohol treatment program we revealed another unique set of 48 differentially methylated CpG sites. Additionally, we found that the mean global DNAm was significantly lower in patients prior to treatment compared to controls, but reverted back to levels similar to controls after treatment. We validated top-ranked hits derived from the epigenome-wide analysis by pyrosequencing and further replicated two of them in an independent cohort and confirmed differential DNAm of HECW2 and SRPK3 in whole blood. This study is the first to show widespread DNAm variation in a disease-relevant blood cell type and implicates HECW2 and SRPK3 DNAm as promising blood-based candidates to follow up in future studies.

The differential recognition of fungal cell wall polysaccharides that program innate and adaptive immunity to the human opportunistic fungal pathogen Aspergillus fumigatus has been a focus of considerable interest. In a mouse model of fungal conidia aspiration, decreased relative levels of cell wall core carbohydrates β-1,3-glucan to chitin in A. fumigatus isolates and mutant strains were correlated with increased airway eosinophil recruitment. In addition, an increase in fungal surface chitin exposure induced by the β-1,3-glucan synthesis-targeting drug caspofungin was associated with increased murine airway eosinophil recruitment after a single challenge of conidia. The response to increased A. fumigatus chitin was associated with increased transcription of IL-17A after a single aspiration, although this cytokine was not required for eosinophil recruitment. Rather, both RAG1 and γδ T cells were required, suggesting that this subset of innate-like lymphocytes may be an important regulator of potentially detrimental type 2 immune responses to fungal inhalation and infection., (Copyright © 2017 Institut Pasteur. Published by Elsevier Masson SAS. All rights reserved.)

Glycosylation of Env defines pathogenic properties of simian immunodeficiency virus (SIV). We previously demonstrated that pathogenic SIVmac239 and a live-attenuated, quintuple deglycosylated Env mutant (Δ5G) virus target CD4 + T cells residing in different tissues during acute infection. SIVmac239 and Δ5G preferentially infected distinct CD4 + T cells in secondary lymphoid organs (SLOs) and within the lamina propria of the small intestine, respectively (C. Sugimoto et al., J Virol 86:9323-9336, 2012, https://doi.org/10.1128/JVI.00948-12). Here, we studied the host responses relevant to SIV targeting of CXCR3 + CCR5 + CD4 + T cells in SLOs. Genome-wide transcriptome analyses revealed that Th1-polarized inflammatory responses, defined by expression of CXCR3 chemokines, were distinctly induced in the SIVmac239-infected animals. Consistent with robust expression of CXCL10, CXCR3 + T cells were depleted from blood in the SIVmac239-infected animals. We also discovered that elevation of CXCL10 expression in blood and SLOs was secondary to the induction of CD14 + CD16 + monocytes and MAC387 + macrophages, respectively. Since the significantly higher levels of SIV infection in SLOs occurred with a massive accumulation of infiltrated MAC387 + macrophages, T cells, dendritic cells (DCs), and residential macrophages near high endothelial venules, the results highlight critical roles of innate/inflammatory responses in SIVmac239 infection. Restricted infection in SLOs by Δ5G also suggests that glycosylation of Env modulates innate/inflammatory responses elicited by cells of monocyte/macrophage/DC lineages. IMPORTANCE We previously demonstrated that a pathogenic SIVmac239 virus and a live-attenuated, deglycosylated mutant Δ5G virus infected distinct CD4 + T cell subsets in SLOs and the small intestine, respectively (C. Sugimoto et al., J Virol 86:9323-9336, 2012, https://doi.org/10.1128/JVI.00948-12). Accordingly, infections with SIVmac239, but not with Δ5G, deplete CXCR3 + CCR5 + CD4 + T (Th1) cells during the primary infection, thereby compromising the cellular immune response. Thus, we hypothesized that distinct host responses are elicited by the infections with two different viruses. We found that SIVmac239 induced distinctly higher levels of inflammatory Th1 responses than Δ5G. In particular, SIVmac239 infection elicited robust expression of CXCL10, a chemokine for CXCR3 + cells, in CD14 + CD16 + monocytes and MAC387 + macrophages recently infiltrated in SLOs. In contrast, Δ5G infection elicited only modest inflammatory responses. These results suggest that the glycosylation of Env modulates the inflammatory/Th1 responses through the monocyte/macrophage subsets and elicits marked differences in SIV infection and clinical outcomes., (Copyright © 2017 American Society for Microbiology.)

The pro-inflammatory cytokine interleukin 17 (IL-17) is critically involved in immunity and inflammation. T-helper 17 and γδ T cells are the predominant sources of IL-17 in the immune system. However, the mechanisms by which the expression of IL-17 is regulated in T cells remain elusive. Here, we demonstrate that loss of histone deacetylase 6 (HDAC6) in mice does not affect the generation of CD4 + or CD8 + T cells, but stimulates the development of IL-17-producing γδ T cells. Our data further show that HDAC6 deficiency increases the production of IL-17 by Vγ4 + γδ T cells in the spleen and lymph nodes. Consistent with these observations, small-molecule inhibition of HDAC6 activity in γδ T cells promotes the expression of IL-17 in vitro . These data thus reveal that HDAC6 represses IL-17 production in T cells, providing novel insights into the role of HDAC6 in the immune system. These findings also have important implications for the clinical investigation of HDAC6-targeted therapies., Competing Interests: Competing Interests: The authors have declared that no competing interest exists.

Fungal specific CD154 + T-cells have been described as a biomarker in invasive aspergillosis. The influence of sample storage on the detection of these cells was assessed. Six-hour delay prior to PBMC isolation is associated with an 18% decrease of cell viability and alterations of the cellular composition of the sample. This results in 87% reduction of CD154 + A. fumigatus specific cells due to reduced assay sensitivity and increased background values in unstimulated samples. If prompt cell measurement is not feasible, isolated PBMCs can be frozen (at -20°C and -80°C) and processed later with comparable assay reliability (mean value fresh vs. thawing: 0.126, 0.133; Pearson-Coefficient: 0.962)., (© The Author 2016. Published by Oxford University Press on behalf of The International Society for Human and Animal Mycology. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

We investigated the effect of combination antiretroviral therapy (cART) on immune recovery, particularly on the percentages of PD-1-positive cells within the major leukocyte subsets. Cryopreserved peripheral blood mononuclear cells and plasma samples collected longitudinally from a subset of 13 children and adolescents (between 9.7 and 18.2 years old) who were enrolled in the International Maternal Pediatric Adolescent AIDS Clinical Trials (IMPAACT) P1066 were used for this study. Immunophenotyping by flow cytometry was performed to determine the effect of raltegravir-containing cART regimen on the distribution of leukocyte populations, on the expression of PD-1 on T cell subpopulations, and on the expression of well-established markers of T cell activation (CD38 and HLA-DR) on CD8 T cells. C reactive protein (CRP), lipopolysaccharide (LPS), IL-6, and soluble CD163 were assayed in plasma samples by an enzyme-linked immunosorbent assay. Plasma viral loads were decreased in all subjects (by an average of 2.9 log units). The cART regimen, including raltegravir, induced changes in CD8 T cell subsets, consistent with an effective antiretroviral outcome and improved immunologic status, including increased percentages of CD8 stem cell memory T cells (Tscm). The percentages of CD8 PD-1-positive cells decreased significantly as compared with baseline levels. Among the proinflammatory markers measured in plasma, sCD163 showed a decline that was associated with cART. cART therapy, including raltegravir, over 48 weeks in children is associated with immune restoration, consistent with effective antiretroviral therapy, namely decreased percentages of PD-1 + CD8 + T cells, an increase in CD8 Tscm cells, and decreased levels of sCD163.

Objective(s): To assess the frequency and function of HIV-1-specific HLA-G (histocompatibility antigen class I, G) CD8 T cells in HIV-1 controllers and progressors., Design: We performed an observational cross-sectional cohort analysis in untreated (n = 47) and treated (n = 17) HIV-1 patients with different rates of disease progression and n = 14 healthy individuals., Methods: We evaluated the frequency, the proportion and the function of total and virus-specific HLA-G CD8 T cells by tetramer or intracellular cytokine staining, followed by flow cytometric analysis. Cytokine secretion of sorted CD8 T-cell subsets was evaluated by Luminex assays., Results: The proportion and the absolute frequency of HLA-G HIV-1-specific CD8 T cells were directly associated with CD4 T-cell counts and inversely correlated with viral loads, whereas total or HLA-G-negative HIV-1-specific CD8 T cells were not. In functional assays, HLA-G CD8 T cells from HIV-1-negative individuals had higher abilities to produce the antiviral (C-C chemokine receptor type 5) ligands MIP-1β (macrophage inflammatory protein-1ß), MIP-1α and Rantes., Conclusion: HLA-G HIV-1-specific CD8 T cells may represent a previously unrecognized correlate of HIV-1 immune control., Competing Interests: Potential conflicts of interest. None of the authors have reported conflicts of interest.

Objectives: The objective of this article is to investigate the contribution of colon and blood CD4 T-cell subsets expressing the chemokine receptor CCR6 to HIV persistence during antiretroviral therapy., Design: Matched sigmoid biopsies and blood samples (n = 13) as well as leukapheresis (n = 20) were collected from chronically HIV-infected individuals receiving antiretroviral therapy. Subsets of CD4 T cells with distinct differentiation/polarization profiles were identified using surface markers as follows: memory (TM, CD45RA), central memory (TCM; CD45RACCR7), effector (TEM/TM; CD45RACCR7), Th17 (CCR6CCR4), Th1Th17 (CCR6CXCR3), Th1 (CCR6CXCR3), and Th2 (CCR6CCR4)., Methods: We used polychromatic flow cytometry for cell sorting, nested real-time PCR for HIV DNA quantification, ELISA and flow cytometry for HIV p24 quantification. HIV reactivation was induced by TCR triggering in the presence/absence of all-trans retinoic acid., Results: Compared with blood, the frequency of CCR6 TM was higher in the colon. In both colon and blood compartments, CCR6 TM were significantly enriched in HIV DNA when compared with their CCR6 counterparts (n = 13). In blood, integrated HIV DNA levels were significantly enriched in CCR6 versus CCR6 TCM of four of five individuals and CCR6 versus CCR6 TEM of three of five individuals. Among blood TCM, Th17 and Th1Th17 contributed the most to the pool of cells harboring integrated HIV DNA despite their reduced frequency compared with Th2, which were infected the least. HIV reactivation was induced by TCR triggering and/or retinoic acid exposure at higher levels in CCR6 versus CCR6 TM, TCM, and TEM., Conclusion: CCR6 is a marker for colon and blood CD4 T cells enriched for replication-competent HIV DNA. Novel eradication strategies should target HIV persistence in CCR6CD4 T cells from various anatomic sites.

Peripheral CD4+CXCR5+PD-1+ T cells are a putative circulating counterpart to germinal center T follicular helper (TFH) cells. They show both phenotypic and functional similarities to TFH cells, which provide necessary help for the differentiation of B cells to antibody-secreting plasmablasts. In this study, we evaluated the frequency, phenotypes, and responses of peripheral TFH-like (pTFH) cells to superantigen and recall antigen stimulation in 10 healthy and 34 chronically infected treatment-naive HIV-1+ individuals. There was no difference in the frequency of pTFH cells between HIV+ and HIV- individuals. Surface expression of ICOS, but not CD40L, was higher on pTFH cells at baseline in HIV+ individuals. Compared with HIV- individuals, pTFH cells from HIV+ individuals had decreased maximal expression of ICOS and CD40L in response to in vitro superantigen stimulation. This decreased response did not correlate with viral control, CD4 T-cell count, duration of infection, or the degree of neutralizing antibody breadth. Despite a decreased maximal response, pTFH responses to HIV Gag and tetanus toxoid recall antigens were preserved., Competing Interests: All authors declare no competing financial interests.

Introduction: This study investigates the influence of Mycobacterium tuberculosis infection on immune activation biomarkers, both in HIV-infected and -uninfected subjects., Methods: Forty-eight treatment-naive HIV-infected patients and 74 HIV-uninfected subjects were recruited and divided into groups according to their M. tuberculosis infection status: latent tuberculosis infection (LTBI), active tuberculosis (TB), and no evidence of M. tuberculosis infection. The expression of cellular markers CD38 and HLA-DR on circulating CD8 T lymphocytes and the plasmatic levels of soluble markers interleukin-6, sCD14, and D-Dimer were measured and compared between groups. The HIV-infected patients with no evidence of M. tuberculosis or with LTBI who initiated antiretroviral treatment were tested again for these biomarkers once viral suppression was reached., Results: In both HIV-infected and -uninfected groups, patients with TB had higher levels of immune activation markers than subjects with LTBI and with no evidence of M. tuberculosis. Among the HIV-uninfected subjects, no significant difference in biomarker level was found between those presenting LTBI and those with no evidence of M. tuberculosis. The effect of LTBI on activation biomarkers in the HIV-infected groups was inconclusive because of the small number of individuals in the HIV+/LTBI group. sCD14 and D-Dimer levels were significantly higher in the TB-only group than in the HIV-only group., Discussion: Although TB is associated with an increase in biomarkers of immune activation, the effect of LTBI is less evident. Further investigation is warranted, and according to our results, soluble markers may offer greater sensitivity for the evaluation of M. tuberculosis-associated immune activation than cellular markers.