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Asthma is a chronic inflammatory disease of the airways long known for phenotypic heterogeneity. Phenotyping studies in asthma have led to a better characterization of disease pathogenesis, yet further work is needed to pair available treatments with disease endotypes. In this review, the biology of targeted pathways is discussed along with the efficacy of biologic therapies targeting those pathways. Results of asthma clinical trials are included, as well as results of trials in related diseases. This review then analyzes how biologics help to inform the complex immunobiology of asthma and further guide their use while identifying areas for future research.

Preexisting anti-interferon-α (anti-IFN-α) autoantibodies in blood are associated with susceptibility to life-threatening COVID-19. However, it is unclear whether anti-IFN-α autoantibodies in the airways, the initial site of infection, can also determine disease outcomes. In this study, we developed a multiparameter technology, FlowBEAT, to quantify and profile the isotypes of anti-severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and anti-IFN-α antibodies in longitudinal samples collected over 20 months from the airways and blood of 129 donors spanning mild to severe COVID-19. We found that nasal IgA1 anti-IFN-α autoantibodies were induced after infection onset in more than 70% of mild and moderate COVID-19 cases and were associated with robust anti-SARS-CoV-2 immunity, fewer symptoms, and efficient recovery. Nasal anti-IFN-α autoantibodies followed the peak of host IFN-α production and waned with disease recovery, revealing a regulated balance between IFN-α and anti-IFN-α response. In contrast, systemic IgG1 anti-IFN-α autoantibodies appeared later and were detected only in a subset of patients with elevated systemic inflammation and worsening symptoms. These data reveal a protective role for nasal anti-IFN-α in the immunopathology of COVID-19 and suggest that anti-IFN-α autoantibodies may serve a homeostatic function to regulate host IFN-α after viral infection in the respiratory mucosa.

Background: Biologic therapies inhibiting the IL-4 or IL-5 pathways are very effective in the treatment of asthma and other related conditions. However, the cytokines IL-4 and IL-5 also play a role in the generation of adaptive immune responses. Although these biologics do not cause overt immunosuppression, their effect in primary severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) immunization has not been studied completely., Objective: Our aim was to evaluate the antibody and cellular immunity after SARS-CoV-2 mRNA vaccination in patients on biologics (PoBs)., Methods: Patients with severe asthma or atopic dermatitis who were taking benralizumab, dupilumab, or mepolizumab and had received the initial dose of the 2-dose adult SARS-CoV-2 mRNA vaccine were enrolled in a prospective, observational study. As our control group, we used a cohort of immunologically healthy subjects (with no significant immunosuppression) who were not taking biologics (NBs). We used a multiplexed immunoassay to measure antibody levels, neutralization assays to assess antibody function, and flow cytometry to quantitate Spike-specific lymphocytes., Results: We analyzed blood from 57 patients in the PoB group and 46 control subjects from the NB group. The patients in the PoB group had lower levels of SARS-CoV-2 antibodies, pseudovirus neutralization, live virus neutralization, and frequencies of Spike-specific B and CD8 T cells at 6 months after vaccination. In subgroup analyses, patients with asthma who were taking biologics had significantly lower pseudovirus neutralization than did subjects with asthma who were not taking biologics., Conclusion: The patients in the PoB group had reduced SARS-CoV-2-specific antibody titers, neutralizing activity, and virus-specific B- and CD8 T-cell counts. These results have implications when considering development of a more individualized immunization strategy in patients who receive biologic medications blocking IL-4 or IL-5 pathways., Competing Interests: Disclosure statement Supported by the National Institutes of Health (NIH)/National Institute of Allergy and Infectious Diseases (NIAID) (grants NIH/NHLBI T32HL116271 [to M.C.R., P.A.L., and N.S.]; the National Center for Advancing Translational Sciences of the NIH (UL1TR002378 [to N.S.]; P01AI125180 [to I.S. and F.E.L.]; U54CA260563 [to I.S. and F.E.L.]; R01AI121252 [to F.E.L.]; R01AI172254 [to F.E.L.]; U01AI141993 [to F.E.L.]; and NIH P51OD011132, 1U54CA260563, and the NIH/NIAID Centers of Excellence for Influenza Research and Response (under contract 75N93021C00017 to Emory University). This work does not necessarily represent the views of the US government or Department of Veterans Affairs. Disclosure of potential conflict of interest: N. S. Haddad is employed by MicroB-plex, Inc, but did not receive any payments for this article. C. Swenson receives compensation and consulting fees from Insmed, Inc, that are unrelated to this article. F. Holguin is a member of the adjudication committee of the ASPEN (A Study to Assess the Efficacy, Safety, and Tolerability of Brensocatib in Participants With Non-Cystic Fibrosis Bronchiectasis) trial at Insmed, Inc. J. D. Roback received funding from an NIH grant in the past 36 months. I. Sanz receives royalties from BLI INC for plasma cell survival media; consulting fees from GSK, Pfizer, Kayverna, Johnson & Johnson, Celgene, Bristol-Myer Squibb, and Visterra; and honoraria for presentations from Yale and Harvard Universities. In addition, I. Sanz has a patent on plasma cell survival media. F. Eun-Hyung Lee receives or has received research grants from Genentech and the Gates Foundation; royalties from BLI INC for plasma cell survival media; consulting fees from Be Bio Pharma; honoraria for presentations at the University of Pennsylvania, the University of Cincinnati, and the Gerontological Advanced Practice Nurses Association; has patents on plasma cell survival media and media of elaborated newly synthesized antibodies (MENSA); and is the founder and owner of MicroB-plex, Inc. The rest of the authors declare that they have no relevant conflicts of interest., (Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.)

Post-acute sequelae of SARS-CoV-2 (SARS2) infection (PASC) is a heterogeneous condition, but the main viral drivers are unknown. Here, we use MENSA, Media Enriched with Newly Synthesized Antibodies, secreted exclusively from circulating human plasmablasts, to provide an immune snapshot that defines the underlying viral triggers. We provide proof-of-concept testing that the MENSA technology can capture the new host immune response to accurately diagnose acute primary and breakthrough infections when known SARS2 virus or proteins are present. It is also positive after vaccination when spike proteins elicit an acute immune response. Applying the same principles for long-COVID patients, MENSA is positive for SARS2 in 40% of PASC vs none of the COVID recovered (CR) patients without any sequelae demonstrating ongoing SARS2 viral inflammation only in PASC. Additionally, in PASC patients, MENSAs are also positive for Epstein-Barr Virus (EBV) in 37%, Human Cytomegalovirus (CMV) in 23%, and herpes simplex virus 2 (HSV2) in 15% compared to 17%, 4%, and 4% in CR controls respectively. Combined, a total of 60% of PASC patients have a positive MENSA for SARS2, EBV, CMV, and/or HSV2. MENSA offers a unique antibody snapshot to reveal the underlying viral drivers in long-COVID thus demonstrating the persistence of SARS2 and reactivation of viral herpes in 60% of PASC patients., Competing Interests: Declaration of Potential Conflicts of Interest FEL is the founder of MicroB-plex, Inc. and serves on the scientific board of Be Biopharma, is a recipient of grants from the BMGF and Genentech, Inc., and has served as a consultant for Astra Zeneca. NSH and AMP were scientists at MicroB-plex, Inc., Atlanta, GA and JLD is a scientist at MicroB-plex, Inc., Atlanta, GA. IS has consulted for GSK, Pfizer, Kayverna, Johnson & Johnson, Celgene, Bristol Myer Squibb, and Visterra. FEL, DN, and IS are inventors of the patents concerning the plasma cell survival media related to this work (issued 9/21/21, US 11,124766 B2 PCT/US2016/036650; and issued 9/21/21, US 11,125757 B2). FEL & JLD are inventors of MENSA patent U.S. Patent No. 10,247,729. April 2, 2019. FEL, NSH, JLD, & IS are inventors of the MENSA PASC diagnostic provisional patent, March 28, 2024. All other authors have declared that no conflict of interest exists.

Although significant strides have been made in the understanding of pulmonary immunology, much work remains to be done to comprehensively explain coordinated immune responses in the lung. The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic only served to highlight the inadequacy of current models of host-pathogen interactions and reinforced the need for current and future generations of immunologists to unravel complex biological questions. As part of that effort, the 64th Annual Thomas L. Petty Aspen Lung Conference was themed "Bridging the Gap between Innate and Adaptive Immunity in the Lung" and featured exciting work from renowned immunologists. This report summarizes the proceedings of the 2022 Aspen Lung Conference, which was convened to discuss the roles played by innate and adaptive immunity in disease pathogenesis, evaluate the interface between the innate and adaptive immune responses, assess the role of adaptive immunity in the development of autoimmunity and autoimmune lung disease, discuss lessons learned from immunologic cancer treatments and approaches, and define new paradigms to harness the immune system to prevent and treat lung diseases.

While immunologic correlates of COVID-19 have been widely reported, their associations with post-acute sequelae of COVID-19 (PASC) remain less clear. Due to the wide array of PASC presentations, understanding if specific disease features associate with discrete immune processes and therapeutic opportunities is important. Here we profile patients in the recovery phase of COVID-19 via proteomics screening and machine learning to find signatures of ongoing antiviral B cell development, immune-mediated fibrosis, and markers of cell death in PASC patients but not in controls with uncomplicated recovery. Plasma and immune cell profiling further allow the stratification of PASC into inflammatory and non-inflammatory types. Inflammatory PASC, identifiable through a refined set of 12 blood markers, displays evidence of ongoing neutrophil activity, B cell memory alterations, and building autoreactivity more than a year post COVID-19. Our work thus helps refine PASC categorization to aid in both therapeutic targeting and epidemiological investigation of PASC., (© 2023. The Author(s).)

Background: Type 1 (T1) inflammation (marked by IFN-γ expression) is now consistently identified in subsets of asthma cohorts, but how it contributes to disease remains unclear., Objective: We sought to understand the role of CCL5 in asthmatic T1 inflammation and how it interacts with both T1 and type 2 (T2) inflammation., Methods: CCL5, CXCL9, and CXCL10 messenger RNA expression from sputum bulk RNA sequencing, as well as clinical and inflammatory data were obtained from the Severe Asthma Research Program III (SARP III). CCL5 and IFNG expression from bronchoalveolar lavage cell bulk RNA sequencing was obtained from the Immune Mechanisms in Severe Asthma (IMSA) cohort and expression related to previously identified immune cell profiles. The role of CCL5 in tissue-resident memory T-cell (TRM) reactivation was evaluated in a T1 high murine severe asthma model., Results: Sputum CCL5 expression strongly correlated with T1 chemokines (P < .001 for CXCL9 and CXCL10), consistent with a role in T1 inflammation. CCL5 high participants had greater fractional exhaled nitric oxide (P = .009), blood eosinophils (P < .001), and sputum eosinophils (P = .001) in addition to sputum neutrophils (P = .001). Increased CCL5 bronchoalveolar lavage expression was unique to a previously described T1 high /T2 variable /lymphocytic patient group in the IMSA cohort, with IFNG trending with worsening lung obstruction only in this group (P = .083). In a murine model, high expression of the CCL5 receptor CCR5 was observed in TRMs and was consistent with a T1 signature. A role for CCL5 in TRM activation was supported by the ability of the CCR5 inhibitor maraviroc to blunt reactivation., Conclusion: CCL5 appears to contribute to TRM-related T1 neutrophilic inflammation in asthma while paradoxically also correlating with T2 inflammation and with sputum eosinophilia., (Copyright © 2023 American Academy of Allergy, Asthma & Immunology. Published by Elsevier Inc. All rights reserved.)

Immunoglobulin (Ig) E is central to the pathogenesis of allergic conditions, including allergic fungal rhinosinusitis. However, little is known about IgE antibody secreting cells (ASCs). We performed single-cell RNA sequencing from cluster of differentiation (CD)19 + and CD19 - ASCs of nasal polyps from patients with allergic fungal rhinosinusitis (n = 3). Nasal polyps were highly enriched in CD19 + ASCs. Class-switched IgG and IgA ASCs were dominant (95.8%), whereas IgE ASCs were rare (2%) and found only in the CD19 + compartment. Through Ig gene repertoire analysis, IgE ASCs shared clones with IgD - CD27 - "double-negative" B cells, IgD + CD27 + unswitched memory B cells, and IgD - CD27 + switched memory B cells, suggesting ontogeny from both IgD + and memory B cells. Transcriptionally, mucosal IgE ASCs upregulate pathways related to antigen presentation, chemotaxis, B cell receptor stimulation, and survival compared with non-IgE ASCs. Additionally, IgE ASCs have a higher expression of genes encoding lysosomal-associated protein transmembrane 5 (LAPTM5) and CD23, as well as upregulation of CD74 (receptor for macrophage inhibitory factor), store-operated Calcium entry-associated regulatory factor (SARAF), and B cell activating factor receptor (BAFFR), which resemble an early minted ASC phenotype. Overall, these findings reinforce the paradigm that human ex vivo mucosal IgE ASCs have a more immature plasma cell phenotype than other class-switched mucosal ASCs and suggest unique functional roles for mucosal IgE ASCs in concert with Ig secretion., (Copyright © 2023. Published by Elsevier Inc.)

Troubling disparities in COVID-19-associated mortality emerged early, with nearly 70% of deaths confined to Black/African American (AA) patients in some areas. However, targeted studies on this vulnerable population are scarce. Here, we applied multiomics single-cell analyses of immune profiles from matching airways and blood samples of Black/AA patients during acute SARS-CoV-2 infection. Transcriptional reprogramming of infiltrating IFITM2+/S100A12+ mature neutrophils, likely recruited via the IL-8/CXCR2 axis, leads to persistent and self-sustaining pulmonary neutrophilia with advanced features of acute respiratory distress syndrome (ARDS) despite low viral load in the airways. In addition, exacerbated neutrophil production of IL-8, IL-1β, IL-6, and CCL3/4, along with elevated levels of neutrophil elastase and myeloperoxidase, were the hallmarks of transcriptionally active and pathogenic airway neutrophilia. Although our analysis was limited to Black/AA patients and was not designed as a comparative study across different ethnicities, we present an unprecedented in-depth analysis of the immunopathology that leads to acute respiratory distress syndrome in a well-defined patient population disproportionally affected by severe COVID-19., (© 2023 by The American Society of Hematology. Licensed under Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International (CC BY-NC-ND 4.0), permitting only noncommercial, nonderivative use with attribution. All other rights reserved.)

Severe SARS-CoV-2 infection 1 has been associated with highly inflammatory immune activation since the earliest days of the COVID-19 pandemic 2-5 . More recently, these responses have been associated with the emergence of self-reactive antibodies with pathologic potential 6-10 , although their origins and resolution have remained unclear 11 . Previously, we and others have identified extrafollicular B cell activation, a pathway associated with the formation of new autoreactive antibodies in chronic autoimmunity 12,13 , as a dominant feature of severe and critical COVID-19 (refs. 14-18 ). Here, using single-cell B cell repertoire analysis of patients with mild and severe disease, we identify the expansion of a naive-derived, low-mutation IgG1 population of antibody-secreting cells (ASCs) reflecting features of low selective pressure. These features correlate with progressive, broad, clinically relevant autoreactivity, particularly directed against nuclear antigens and carbamylated proteins, emerging 10-15 days after the onset of symptoms. Detailed analysis of the low-selection compartment shows a high frequency of clonotypes specific for both SARS-CoV-2 and autoantigens, including pathogenic autoantibodies against the glomerular basement membrane. We further identify the contraction of this pathway on recovery, re-establishment of tolerance standards and concomitant loss of acute-derived ASCs irrespective of antigen specificity. However, serological autoreactivity persists in a subset of patients with postacute sequelae, raising important questions as to the contribution of emerging autoreactivity to continuing symptomology on recovery. In summary, this study demonstrates the origins, breadth and resolution of autoreactivity in severe COVID-19, with implications for early intervention and the treatment of patients with post-COVID sequelae., (© 2022. The Author(s).)

Within 8 weeks of primary Clostridioides difficile infection (CDI), as many as 30% of patients develop recurrent disease with the associated risks of multiple relapses, morbidity, and economic burden. There are no clear clinical correlates or validated biomarkers that can predict recurrence during primary infection. This study demonstrated the potential of a simple test for identifying hospitalized CDI patients at low risk for disease recurrence. Forty-six hospitalized CDI patients were enrolled at Emory University Hospitals. Samples of serum and a novel matrix from circulating plasmablasts called "medium-enriched for newly synthesized antibodies" (MENSA) were collected during weeks 1, 2, and 4. Antibodies specific for 10 C. difficile antigens were measured in each sample. Among the 46 C. difficile-infected patients, 9 (19.5%) experienced recurrence within 8 weeks of primary infection. Among the 37 nonrecurrent patients, 23 (62%; 23/37) had anti-C. difficile MENSA antibodies specific for any of the three toxin antigens: TcdB-CROP, TcdBvir-CROP, and/or CDTb. Positive MENSA responses occurred early (within the first 12 days post-symptom onset), including six patients who never seroconverted. A similar trend was observed in serum responses, but they peaked later and identified fewer patients (51%; 19/37). In contrast, none (0%; 0/9) of the patients who subsequently recurred after hospitalization produced antibodies specific for any of the three C. difficile toxin antigens. Thus, patients with a negative early MENSA response against all three C. difficile toxin antigens had a 19-fold greater relative risk of recurrence. MENSA and serum levels of immunoglobulin A (IgA) and/or IgG antibodies for three C. difficile toxins have prognostic potential. These immunoassays measure nascent immune responses that reduce the likelihood of recurrence thereby providing a biomarker of protection from recurrent CDI. Patients who are positive by this immunoassay are unlikely to suffer a recurrence. Early identification of patients at risk for recurrence by negative MENSA creates opportunities for targeted prophylactic strategies that can reduce the incidence, cost, and morbidity due to recurrent CDI.

Due to the severity of COVID-19 disease, the U.S. Centers for Disease Control and Prevention and World Health Organization recommend that manipulation of active viral cultures of SARS-CoV-2 and respiratory secretions from COVID-19 patients be performed in biosafety level (BSL)3 laboratories. Therefore, it is imperative to develop viral inactivation procedures that permit samples to be transferred to lower containment levels (BSL2), while maintaining the fidelity of complex downstream assays to expedite the development of medical countermeasures. In this study, we demonstrate optimal conditions for complete viral inactivation following fixation of infected cells with commonly used reagents for flow cytometry, UVC inactivation in sera and respiratory secretions for protein and Ab detection, heat inactivation following cDNA amplification for droplet-based single-cell mRNA sequencing, and extraction with an organic solvent for metabolomic studies. Thus, we provide a suite of viral inactivation protocols for downstream contemporary assays that facilitate sample transfer to BSL2, providing a conceptual framework for rapid initiation of high-fidelity research as the COVID-19 pandemic continues., (Copyright © 2022 The Authors.)

Objectives: Allergic fungal rhinosinusitis (AFRS) is an eosinophilic subtype of chronic rhinosinusitis with nasal polyposis (CRSwNP). This study aimed to investigate the transcriptome of AFRS nasal polyp epithelium., Methods: Sinonasal epithelial cells were harvested from healthy nasal mucosa and polyp tissue collected from participants undergoing elective sinonasal surgery. Primary epithelial cells were subsequently grown in air/liquid interface and subjected to RNA-seq analysis, RT-qPCR, immunoblotting, and immunostaining., Results: A total of 19 genes were differentially expressed between healthy and AFRS sample epithelium. The second top candidate gene, ranked by adjusted p-value, was prostaglandin E receptor 2 (PTGER2). The upregulation of PTGER2 was confirmed by RT-qPCR and immunoblot. The presence of the EP2 receptor, encoded by the PTGER2 gene, was confirmed by immunocytochemistry., Conclusion: PTGER2 is a potential novel therapeutic target for AFRS. EP2 dysregulation is associated with aspirin-exacerbated respiratory disease, potentially giving insight into common mechanisms of disease in severe CRSwNP., Level of Evidence: NA Laryngoscope, 2024., (© 2024 The Author(s). The Laryngoscope published by Wiley Periodicals LLC on behalf of The American Laryngological, Rhinological and Otological Society, Inc. This article has been contributed to by U.S. Government employees and their work is in the public domain in the USA.)

The humoral immune system comprises B cells and plasma cells, which play important roles in organ transplantation, ranging from the production of both protective and injurious antibodies as well as cytokines that can promote operational tolerance. Recent data from conditions outside of transplantation have identified a novel human B-cell subset that expresses the transcription factor T-bet and exerts pleiotropic functions by disease state. Here, we review the generation, activation, and functions of the T-bet + B-cell subset outside of allotransplantation, and consider the relevance of this subset as mediators of allograft injury., Competing Interests: The authors declare no conflicts of interest., (Copyright © 2023 The Author(s). Published by Wolters Kluwer Health, Inc.)

Introduction: Allergic rhinitis (AR) is one of the leading allergic diseases worldwide. Allergen immunotherapy (AIT) induces persistent specific allergen tolerance to achieve remission of the symptoms in AR patients. We creatively conducted the intra-cervical lymphatic immunotherapy (ICLIT) for AR patients. However, the underlying molecular mechanism of immune cell response of AIT in AR remains elusive., Method: To investigate the transcriptome profile in AR patients who underwent ICLIT, we comprehensively investigated the transcriptional changes in B cells from peripheral blood mononuclear cells of AR patient by single-cell RNA sequencing. Immunoglobulins and relative key gene, which influences the B cell differentiation, was demonstrated. The biomarkers' association with different types of tumors was investigated., Results: Naive B cells, germinal center B cells, activated memory B cells, and memory B cells constituted the B cells subsets. The expression of IGHE, IGHGs, IGHA, IGHD, and IGHM from memory B cells was validated. Pseudotime analysis further indicated the dynamic change from the expression of the immunoglobulins in the memory B cells, suggesting that ITGB1 may contribute to the differentiation procedure of memory B cells. The cell-cell communication among these immune cells demonstrated the significantly enhanced CD23, BTLA signaling after ICLIT in AR patient. ITGB1 was upregulated in 13 tumors and downregulated in six others. High ITGB1 expression was linked to poor prognosis in eight types of tumors. ITGB1 expression showed correlations with tumor mutation burden, tissue purity, and microsatellite instability in different types of tumors., Discussion: ITGB1 was demonstrated as a potential biomarker for AR patients after ICLIT and is significant in identifying immune infiltration in tumor tissue and predicting tumor prognosis., (© 2024 Wiley Periodicals LLC.)

The essential role of B cells is to produce protective immunoglobulins (Ig) that recognize, neutralize, and clear invading pathogens. This results from the integration of signals provided by pathogens or vaccines and the stimulatory microenvironment within sites of immune activation, such as secondary lymphoid tissues, that drive mature B cells to differentiate into memory B cells and antibody (Ab)-secreting plasma cells. In this context, B cells undergo several molecular events including Ig class switching and somatic hypermutation that results in the production of high-affinity Ag-specific Abs of different classes, enabling effective pathogen neutralization and long-lived humoral immunity. However, perturbations to these key signaling pathways underpin immune dyscrasias including immune deficiency and autoimmunity or allergy. Inborn errors of immunity that disrupt critical immune pathways have identified non-redundant requirements for eliciting and maintaining humoral immune memory but concomitantly prevent immune dysregulation. Here, we will discuss our studies on human B cells, and how our investigation of cytokine signaling in B cells have identified fundamental requirements for memory B-cell formation, Ab production as well as regulating Ig class switching in the context of protective versus allergic immune responses., (© 2023 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

Introduction: Acute COVID-19 infection causes significant alterations in the innate and adaptive immune systems. While most individuals recover naturally, some develop long COVID (LC) syndrome, marked by persistent or new symptoms weeks to months after SARS-CoV-2 infection. Despite its prevalence, there are no clinical tests to distinguish LC patients from those fully recovered. Understanding the immunological basis of LC is essential for improving diagnostic and treatment approaches. Methods: We performed deep immunophenotyping and functional assays to examine the immunological profiles of LC patients, individuals with active COVID-19, recovered patients, and healthy donors. This analysis assessed both innate and adaptive immune features, identifying potential biomarkers for LC syndrome. A Binomial Generalized Linear Model (BGLM) was used to pinpoint immune features characterizing LC. Results: COVID-19 patients exhibited depletion of innate immune cell subsets, including plasmacytoid and conventional dendritic cells, classical, non-classical, and intermediate monocytes, and monocyte-derived inflammatory dendritic cells. Elevated basal inflammation was observed in COVID-19 patients compared to LC patients, whose immune profiles were closer to those of healthy donors and recovered individuals. However, LC patients displayed persistent immune alterations, including reduced T cell subsets (CD4, CD8, Tregs) and switched memory B cells, similar to COVID-19 patients. Through BGLM, a unique adaptive immune signature for LC was identified, featuring memory CD8 and gd T cells with low proliferative capacity and diminished expression of activation and homing receptors. Discussion: The findings highlight a unique immunological signature associated with LC syndrome, characterized by persistent adaptive immune dysregulation. While LC patients displayed recovery in innate immune profiles comparable to healthy and Recovered individuals, deficits in T cell and memory B cell populations were evident, differentiating LC from full recovery. These findings provide insights into LC pathogenesis and may support the development of diagnostic tools and targeted therapies. [ABSTRACT FROM AUTHOR]

Few pathogens have historically been subjected to as intense scientific and clinical scrutiny as SARS-CoV-2. The genetic, immunological, and environmental factors influencing disease severity and post-infection clinical outcomes, known as correlates of immunity, remain largely undefined. Clinical outcomes of SARS-CoV-2 infection vary widely, ranging from asymptomatic cases to those with life-threatening COVID-19 symptoms. While most infected individuals return to their former health and fitness within a few weeks, some develop debilitating chronic symptoms, referred to as long-COVID. Autoimmune responses have been proposed as one of the factors influencing long-COVID and the severity of SARS-CoV-2 infection. The association between viral infections and autoimmune pathologies is not new. Viruses such as Epstein-Barr virus and cytomegalovirus, among others, have been shown to induce the production of autoantibodies and the onset of autoimmune conditions. Given the extensive literature on SARS-CoV-2, here we review current evidence on SARS-CoV-2-induced autoimmune pathologies, with a focus on autoantibodies. We closely examine mechanisms driving autoantibody production, particularly their connection with disease severity and long-COVID. [ABSTRACT FROM AUTHOR]

Background: Post-COVID-19 respiratory sequelae often involve lung damage, which is called residual lung abnormalities, and potentially lead to chronic respiratory issues. The adaptive immune response, involving T-cells and B-cells, plays a critical role in pathogen control, inflammation, and tissue repair. However, the link between immune dysregulation and the development of residual lung abnormalities remains unclear. Methods: 109 patients discharged with residual lung abnormalities after a critical COVID-19 were followed for 12 months and divided as full recovery patients (FRG, n = 88) and persistent lung abnormalities (PLAG, n = 21). Cell profiling analysis was done using flow cytometry at 24 h of not antigen-specific in vitro stimulation. Plasma or supernatant levels of IFN-g, IL-4, IL-10, IgM, and IgG were assessed, and 10 patients (5 FRG, 5 PLAG) were randomly selected for detailed immune cell phenotyping and functional analysis of peripheral blood mononuclear cells using flow cytometry. Results: Compared to the FRG group, PLAG exhibited an increase of unswitched (p = 0.0159) and decreased double-negative activated B-cells (p = 0.0317), systemic IL-10 levels were lower, displayed reduced frequency of total B-cells, and impaired spontaneous IgM (p = 0.0357) and IgG (p = 0.0079) release in culture. Regarding T-cells, PLAG patients showed a reduction in effector memory CD4 + cells (p = 0.0159) and an increase in CD4 + TEMRA cells (p = 0.0079) following in vitro stimulation. Notably, the PLAG group also exhibited higher frequencies of central memory CD4 + Th2 (GATA3+) T-cells in response to activation than the FRG group (p = 0.0079). Conclusions: Patients with residual lung abnormalities 12 months post-critical COVID-19 exhibit impaired B-cell function, increased unswitched B-cells, and higher frequencies of CD4 + TEMRA T-cells following in vitro activation. These immune imbalances may contribute to ongoing lung dysfunction and warrant further investigation as a potential mechanism in residual lung abnormalities. Larger studies are necessary to confirm these findings. [ABSTRACT FROM AUTHOR]

Background: Clinical and epidemiological analyses have found an association between coronavirus disease 2019 (COVID-19) and knee osteoarthritis (KOA). Infection with COVID-19 may increase the risk of developing KOA. Objectives: This study aimed to investigate the potential causal relationship between COVID-19 and KOA using Mendelian randomization (MR) and to explore the underlying mechanisms through a systematic bioinformatics approach. Methods: Our investigation focused on exploring the potential causal relationship between COVID-19, acute upper respiratory tract infection (URTI) and KOA utilizing a bidirectional MR approach. Additionally, we conducted differential gene expression analysis using public datasets related to these three conditions. Subsequent analyses, including transcriptional regulation analysis, immune cell infiltration analysis, single-cell analysis, and druggability evaluation, were performed to explore potential mechanisms and prioritize therapeutic targets. Results: The results indicate that COVID-19 has a one-way impact on KOA, while URTI does not play a causal role in this association. Ribosomal dysfunction may serve as an intermediate factor connecting COVID-19 with KOA. Specifically, COVID-19 has the potential to influence the metabolic processes of the extracellular matrix, potentially impacting the joint homeostasis. A specific group of genes (COL10A1, BGN, COL3A1, COMP, ACAN, THBS2, COL5A1, COL16A1, COL5A2) has been identified as a shared transcriptomic signature in response to KOA with COVID-19. Imatinib, Adiponectin, Myricetin, Tranexamic acid, and Chenodeoxycholic acid are potential drugs for the treatment of KOA patients with COVID-19. Conclusions: This study uniquely combines Mendelian randomization and bioinformatics tools to explore the possibility of a causal relationship and genetic association between COVID-19 and KOA. These findings are expected to provide novel perspectives on the underlying biological mechanisms that link COVID-19 and KOA. [ABSTRACT FROM AUTHOR]

Impaired airway epithelial barrier and decreased expression of E-cadherin are key features of severe asthma. As a gatekeeper of the mucosa, E-cadherin can be cleaved from the cell surface and released into the apical lumen in soluble form. The aim of this study was to investigate the role of soluble E-cadherin (sE-cadherin) in severe asthma. Induced sputum was obtained from healthy subjects and patients with asthma. Two murine models of severe asthma were established using either toluene diisocyanate or ovalbumin/complete Freund's adjuvant. The role of sE-cadherin in severe asthma was evaluated by intraperitoneal injection of DECMA-1, a neutralizing antibody against sE-cadherin. Mice or THP-1–derived macrophages were treated with recombinant sE-cadherin to explore the proinflammatory mechanism of sE-cadherin. Patients with severe asthma had significantly higher sputum sE-cadherin concentrations than healthy subjects and those with mild to moderate asthma, which were positively correlated with sputum HMGB1 concentration and the glucocorticoid dose required for daily control. Allergen exposure markedly increased sE-cadherin concentration in the BAL fluid in mice. Treatment with DECMA-1 significantly attenuated allergen-induced airway inflammation and hyperresponsiveness in both models of severe asthma. In contrast, exposure to recombinant sE-cadherin dramatically upregulated VEGF expression in THP-1–derived macrophages and increased neutrophil and eosinophil infiltration into the airway, as well as the release of VEGF and IL-6 in mice, both of which can be suppressed by pharmacological inhibition of ERK signaling. Taken together, our data indicate that sE-cadherin contributes to airway inflammation in severe asthma in an ERK-dependent pathway. [ABSTRACT FROM AUTHOR]

Introduction: Upon infection, T cell-driven B cell responses in GC reactions induce memory B cells and antibody-secreting cells that secrete protective antibodies. How formation of specifically long-lived plasma cells is regulated via the interplay between specific B and CD4+ T cells is not well understood. Generally, antibody levels decline over time after clearance of the primary infection. Method: In this study, convalescent individuals with stable RBD antibody levels (n=14, "sustainers") were compared with donors (n=13) with the greatest antibody decline from a cohort of 132. To investigate the role of the cellular immune compartment in the maintenance of antibody levels, SARS-CoV-2-specific responses at 4 to 6 weeks post-mild COVID-19 infection were characterized using deep immune profiling. Results: Both groups had similar frequencies of total SARS-CoV-2-specific B and CD4+ T cells. Sustainers had fewer Spike-specific IgG+ memory B cells early after infection and increased neutralizing capacity of RBD antibodies over time, unlike the declining group. However, declining IgG titers correlated with lower frequency of Spike-specific CD4+ T cells. Conclusion: These data suggest that "sustainers" have unique dynamics of GC reactions, yield different outputs of terminally differentiating cells, and improve the quality of protective antibodies over time. This study helps identify factors controlling formation of long-lived PC and sustained antibody responses. [ABSTRACT FROM AUTHOR]

Background: Vaccine protection against severe acute respiratory syndrome coronavirus 2 infection reduces gradually over time, requiring administration of updated boosters. However, long-term immune response following up to the sixth dose of the messenger RNA vaccine has not been well studied. Case presentation: We longitudinally determined anti-spike protein immunoglobulin G antibody levels in a 69-year-old Japanese man 76 times (first to sixth dose) to investigate their dynamics. Regarding the messenger RNA BNT162b2 vaccine, first to fourth doses were identical monovalent vaccines, and fifth and sixth doses were identical bivalent vaccines. T-cell responses after fourth and fifth doses were studied using T-SPOT. Immunoglobulin G levels peaked at 1–2 weeks after second to sixth dose, declining exponentially after each dose. The decline was approximated using the formula f (t) = Ae−t/τ + C. Time constant τ increased with each booster vaccination, indicating a decreasing rate of antibody titer decay with increasing number of doses. Baseline and peak immunoglobulin G levels were similar in the second and third dose. Conversely, baseline immunoglobulin G levels after the fourth dose increased over fivefold over the second and third dose; however, peak immunoglobulin G levels after fourth dose decreased to 60% of those after the third dose. Baseline immunoglobulin G levels after the sixth dose increased 1.4-fold over the fifth dose; however, peak immunoglobulin G levels after the sixth dose decreased to 56% of those after the fifth dose. Dynamics of T-cell responses differed from those of immunoglobulin G antibodies. T cell responses increased gradually; however, their peak level was difficult to determine. Conclusions: Ceiling effect or downregulation of peak immunoglobulin G levels was clearly observed after messenger RNA booster vaccination. After peaking, the IgG level declined exponentially, and the rate of decay decreased with each subsequent booster. Although this was a single-case study, this data may provide a generalized mathematical decay model for humoral immunity in healthy older adults. Moreover, our study provides insights into the immunogenicity after booster vaccination with messenger RNA vaccines. [ABSTRACT FROM AUTHOR]

Background and objective: Chronic prostatitis (CP) is a condition markered by persistent prostate inflammation, yet the specific cytokines driving its progression remain largely undefined. This study aims to identify key cytokines involved in CP and investigate their role in driving inflammatory responses through mechanistic and therapeutic exploration. Methods: A 48-cytokine panel test was conducted to compare the plasma cytokine profiles between participants with CP-like symptoms (CP-LS) and healthy controls. Experimental autoimmune prostatitis (EAP) models were used for functional validation, with further mechanistic studies performed through in vivo and in vitro assays. Pharmacological inhibition was applied using maraviroc, and pathway inhibitors to assess therapeutic potential. Results: Our analysis identified CCL5 as one of the most prominently elevated cytokines in CP-LS patients. Further validation in the EAP model mice confirmed elevated CCL5 levels, highlighting its role in driving prostatic inflammation. Mechanistic studies revealed that CCL5 interacts with the CCR5 receptor, promoting M1 macrophage polarization and activating key inflammatory signaling pathways, including Stat1 and NF-κB, as indicated by increased phosphorylation of Stat1 and p65. In vitro, CCL5 combined with LPS stimulation amplified these effects, further promoting M1 polarization. CCL5 also sustained Stat1 activation by inhibiting its dephosphorylation through reduced interaction with SHP2, leading to prolonged inflammatory signaling. Single-cell transcriptomics confirmed high CCR5 expression in macrophages, correlating with inflammatory pathways. Pharmacological inhibition of CCR5, or its downstream signaling, significantly reduced macrophage-driven inflammation both in vivo and in vitro. Conclusion: These findings establish the CCL5/CCR5 axis as a critical driver of persistant prostatic inflammation and present it as a potential therapeutic target for CP. The graphic abstract illustrates the central role of the CCL5/CCR5 axis in promoting chronic prostatitis progression. CCL5 binds to the CCR5 receptor on macrophages, enhancing M1 polarization and activating key inflammatory pathways, including Stat1 and NF-κB, as shown by the increased phosphorylation of Stat1 and p65. The interaction also inhibits SHP2-mediated Stat1 dephosphorylation, sustaining prolonged inflammatory signaling. Pharmacological inhibition of CCR5 or its downstream pathways attenuates macrophage-driven inflammation, highlighting this axis as a critical driver and potential therapeutic target for chronic prostatitis. Highlights: ⦁ Elevated levels of CCL5 were detected in both CP-LS patients and EAP model mice through systematic screening, and its expression was strongest correlated with disease progression. Our data indicate that CCL5 promotes prostate inflammation through interaction with CCR5. ⦁ This study demonstrated that CCL5, via CCR5, promotes the M1 macrophage phenotype, further driving proinflammatory responses. This leads to increased immune cell infiltration and macrophage activation in the prostate. ⦁ The CCL5/CCR5 axis activates both the Stat1 and NF-κB pathways, which are critical for sustaining M1 macrophage polarization. We found that Stat1 phosphorylation is prolonged by inhibiting its dephosphorylation through SHP2, maintaining the inflammatory response. ⦁ Inhibiting CCR5 with maraviroc, blocking Stat1 signaling with fludarabine, or blocking the NF-κB pathway with JSH-23 reduced prostatic inflammation and M1 macrophage activation, suggesting a potential therapeutic strategy for managing CP. [ABSTRACT FROM AUTHOR]

Background: Specific biomarkers, such as eosinophilia in peripheral blood or fractional exhaled nitric oxide (FeNO), can guide us in the choice of biologic therapy, allowing a more personalized approach. Although there are multiple evidences in the literature about the role of FeNO as a predictor of response to different biologic treatments, there are no data on the relationship between FeNO changes and clinical response to the four biologic drugs currently in use. Objective: To evaluate and to compare the expression of multiple-flows FeNO parameters in a cohort of patients with severe asthma (SA) before and during the treatment with biologics to evaluate the performance of these biomarkers in predicting the achievement of clinical remission. Methods: We prospectively enrolled 50 patients with severe asthma eligible for biologic therapy. Patients underwent clinical and functional monitoring at baseline (T0) and after 1, 6, and 12 months of treatment (T1, T6, T12), including multiple flows FeNO assessment. Results: A statistically significant reduction of FeNO50 values and J'awNO was observed only in benralizumab and dupilumab subgroups. Among biomarkers, the reduction of FeNO 50 values at T1 was associated with a higher probability of achieving clinical remission at T12 (p = 0.003), which was also confirmed by ROC curve analysis (AUC 0.758, p = 0.002; sensitivity 60% and specificity 74% for a reduction of 16 ppb). Conclusion: These data confirm the potential of this biomarker in predicting clinical response to biologic treatment in patients with severe asthma in order to guide clinical decisions and evaluate a shift to other biologic therapy. [ABSTRACT FROM AUTHOR]

The total and SARS-CoV-2-specific antibody content in convalescent plasma (CP) samples from Bulgarian donors and their therapeutic potential for COVID-19 patients was subjected to characterization. CPs (n = 90) were obtained after informed consent at National Centre of Transfusion Hematology in Sofia, Bulgaria, in the period 01 June 2021 and were tested for RBD-IgG, RBD-IgA and anti-nuclear antibodies (ANA) by semi-quantitative ELISA. Concentrations of total IgG, IgG isotypes, IgA, and IgM, as well as of 25 Th1, Th2, Th17 and regulatory cytokines were determined for all samples; concentrations of Neutralizing antibodies against six SARS-CoV-2 variants were determined in Receptor-Binding Domain (RBD-positive) samples (Luminex xMAP technology). Concordant production of RBD-specific IgG and IgA was detected in 45 (50%); 12 (13.3%) were RBD-IgG single-positive, 8 (8.8%) RBD-IgA single-positive, and 25 (27.7%) – double negative. Absence of neutralizing activity was documented for 8/65 (12.3%) of RBD-positive samples. No correlation existed between the levels of RBD-IgG and RBD-IgA and the total neutralizing activity of CPs (p > 0.05). Total IgG, IgA, IgM and IgG Isotype concentrations did not differ from reference values. Increased concentrations of IL-18, IL-27, IL-1Ra, IL-21 and IL-22 were detected in most tested samples (80% respectively). The comparison between 45 RBD-double positive and 25 RBD-double negative CPs showed significant differences for the concentrations of IL-22 (2.4 vs 40, p < 0.05) and IL-10 (1 vs 15, p < 0.001). All CPs were ANA negative. Detailed characterization for SARS-CoV-2 specific antibody content and cytokine concentrations might improve the results of CPs application for in early stage treatment in resource-limited settings. [ABSTRACT FROM AUTHOR]

Objectives: CD209L and its homologous protein CD209 act as alternative entry receptors for the SARS‐CoV‐2 virus and are highly expressed in the virally targeted tissues. We tested for the presence and clinical features of autoantibodies targeting these receptors and compared these with autoantibodies known to be associated with COVID‐19. Methods: Using banked samples (n = 118) from Johns Hopkins patients hospitalised with COVID‐19, we defined autoantibodies against CD209 and CD209L by enzyme‐linked immunosorbent assay (ELISA). Clinical associations of these antibodies were compared with those of patients with anti‐interferon (IFN) and anti‐angiotensin‐converting enzyme‐2 (ACE2) autoantibodies. Results: Amongst patients hospitalised with COVID‐19, 19.5% (23/118) had IgM autoantibodies against CD209L and were more likely to have coronary artery disease (44% vs 19%, P = 0.03). Antibodies against CD209 were present in 5.9% (7/118); interestingly, all 7 were male (P = 0.02). In our study, the presence of either antibody was positively associated with disease severity [OR 95% confidence interval (95% CI): 1.80 (0.69–5.03)], but the association did not reach statistical significance. In contrast, 10/118 (8.5%) had IgG autoantibodies against IFNα, and 21 (17.8%) had IgM antibodies against ACE2. These patients had significantly worse prognosis (intubation or death) and prolonged hospital stays. However, when adjusting for patient characteristics on admission, only the presence of anti‐ACE2 IgM remained significant [pooled common OR (95% CI), 4.14 (1.37, 12.54)]. Conclusion: We describe IgM autoantibodies against CD209 and CD209L amongst patients hospitalised with COVID‐19. These were not associated with disease severity. Conversely, patients with either anti‐ACE2 IgM or anti‐IFNα IgG antibodies had worse outcomes. Due to the small size of the study cohort, conclusions drawn should be considered cautiously. [ABSTRACT FROM AUTHOR]

Purpose of Review: To highlight the current evidence that supports the view that eosinophils may not drive disease in chronic rhinosinusitis with nasal polyps (CRSwNP) and the emerging evidence for B cells as an important player in this disease., Recent Findings: Eosinophil depletion studies in CRSwNP do not fully support a critical role for eosinophils in CRSwNP. Almost complete eosinophil depletion with dexpramipexole had no impact on polyp size reduction or clinical improvement. Anti-interleukin (IL)-5 and IL-5Rα inhibition were more effective though with less clinical impact when compared to anti-immunoglobulin E (IgE) or IL-4Rα inhibition strategies. As IL-5Rα is also expressed on CRSwNP derived IgE+ and IgG4+ plasma cells to the same extent as eosinophils, improvements in CRSwNP with IL-5 inhibition may suggest a role for B cells over eosinophils in CRSwNP. We review both eosinophils and B cells in the context of CRSwNP and highlight the current evidence that supports an emerging role for B cells., Summary: Despite many aspects of immunopathology in CRSwNP explainable by B cell dysfunction, B cells have so far been ignored in CRSwNP. Further work is needed, as targeting B cells may offer an exciting new therapeutic option in the future., (Copyright © 2023 Wolters Kluwer Health, Inc. All rights reserved.)

Plasmodium falciparum infections elicit strong humoral immune responses to two main groups of antigens expressed by blood-stage parasites: merozoite antigens that are involved in the erythrocyte invasion process and variant surface antigens that mediate endothelial sequestration of infected erythrocytes. Long-lived B cells against both antigen classes can be detected in the circulation for years after exposure, but have not been directly compared. Here, we studied the phenotype of long-lived memory and atypical B cells to merozoite antigens (MSP1 and AMA1) and variant surface antigens (the CIDRα1 domain of PfEMP1) in ten Ugandan adults before and after local reduction of P. falciparum transmission. After a median of 1.7 years without P. falciparum infections, the percentage of antigen-specific activated B cells declined, but long-lived antigen-specific B cells were still detectable in all individuals. The majority of MSP1/AMA1-specific B cells were CD95+CD11c+ memory B cells, which are primed for rapid differentiation into antibody-secreting cells, and FcRL5-T-bet- atypical B cells. On the other hand, most CIDRα1-specific B cells were CD95-CD11c- memory B cells. CIDRα1-specific B cells were also enriched among a subset of atypical B cells that seem poised for antigen presentation. These results point to differences in how these antigens are recognized or processed by the immune system and how P. falciparum-specific B cells will respond upon re-infection. Author summary: Immunity to malaria depends in part on memory B cells that rapidly start producing antibodies upon the next infection with the malaria-causing parasite Plasmodium falciparum. Studying memory B cells, in particular long-lived memory B cells, in people living in malaria-endemic regions is difficult, because every P. falciparum infection leads to the activation of existing memory B cells and the formation of new memory B cells. To overcome this problem, we used samples collected from the same people at two time points: (1) during high P. falciparum transmission and (2) following effective mosquito control that resulted in a two-year period without P. falciparum infection. Analyzing antigen-specific B cells from these two time points allowed us to evaluate which P. falciparum-specific B cell subsets remained present in the absence of new infections and could thus be considered long-lived. We found that long-lived memory B cells against erythrocyte invasion antigens expressed the surface markers CD95 and CD11c, while B cells recognizing parasite antigens involved in vascular adhesion and immune evasion did not. These results suggest that the immune response 'sees' and responds to these antigens differently. [ABSTRACT FROM AUTHOR]

Objective: To analyze the risk of systemic lupus erythematosus (SLE) flare after admission for COVID-19. Methods: We performed a matched cohort study using the Assistance Publique—Hôpitaux de Paris Clinical Data Warehouse which collects structured medical, biological and administrative information from 11 million patients in Paris area, France. Each SLE patient hospitalized with a COVID-19 diagnosis code between March 2020 and December 2021 was matched to one SLE control patient with an exact matching procedure using age ±3 years, gender, chronic kidney disease, end-stage renal disease, and serological activity. The main outcome was a lupus flare during the 6 months follow-up. A flare was considered if a) documented by the treating physician in the patient's EHR and b) justifying a change in SLE treatment. The electronic health records (EHRs) were individually checked for data accuracy. Results: Among 4,533 SLE patients retrieved from the database, 81 (2.8%) have been admitted for COVID-19 between March 2020 and December 31, 2021, and 79 (n = 79/81,97.5%) were matched to a unique unexposed SLE. During follow-up, a flare occurred in 14 (17.7%) patients from the COVID-19 group as compared to 5 (6.3%) in the unexposed control group, including 4 lupus nephritis in the exposed group and 1 in the control group. After adjusting for HCQ use at index date and history of lupus nephritis, the risk of flare was higher in exposed SLE patients (hazard ratio [95% confidence interval] of 3.79 [1.49–9.65]). Conclusions: COVID-19 hospitalization is associated with an increased risk of flare in SLE. [ABSTRACT FROM AUTHOR]

The coronavirus disease 2019 (COVID-19) pandemic underscores the critical need to integrate immunomics within the One Health framework to effectively address zoonotic diseases across humans, animals, and environments. Employing advanced high-throughput technologies, this interdisciplinary approach reveals the complex immunological interactions among these systems, enhancing our understanding of immune responses and yielding vital insights into the mechanisms that influence viral spread and host susceptibility. Significant advancements in immunomics have accelerated vaccine development, improved viral mutation tracking, and broadened our comprehension of immune pathways in zoonotic transmissions. This review highlights the role of animals, not merely as carriers or reservoirs, but as essential elements of ecological networks that profoundly influence viral epidemiology. Furthermore, we explore how environmental factors shape immune response patterns across species, influencing viral persistence and spillover risks. Moreover, case studies demonstrating the integration of immunogenomic data within the One Health framework for COVID-19 are discussed, outlining its implications for future research. However, linking humans, animals, and the environment through immunogenomics remains challenging, including the complex management of vast amounts of data and issues of scalability. Despite challenges, integrating immunomics data within the One Health framework significantly enhances our strategies and responses to zoonotic diseases and pandemic threats, marking a crucial direction for future public health breakthroughs. [ABSTRACT FROM AUTHOR]

The leucine-rich repeat-based variable lymphocyte receptor B (VLRB) antibody system of jawless vertebrates is capable of generating an antibody repertoire equal to or exceeding the diversity of antibody repertoires of jawed vertebrates. Unlike immunoglobulin-based immune repertoires, the VLRB repertoire diversity is characterized by variable lengths of VLRB encoding transcripts, rendering conventional immunoreceptor repertoire sequencing approaches unsuitable for VLRB repertoire sequencing. Here we demonstrate that long-read single-molecule real-time (SMRT) sequencing (PacBio) approaches permit the efficient large-scale assessment of the VLRB repertoire. We present a computational pipeline for sequence data processing and provide the first repertoire-based analysis of VLRB protein characteristics including properties of its subunits and regions of diversity within each structural leucine-rich repeat subunit. Our study provides a template to explore changes in the VLRB repertoire during immune responses and to establish large scale VLRB repertoire databases for computational approaches aimed at isolating monoclonal VLRB reagents for biomedical research and clinical applications. [ABSTRACT FROM AUTHOR]

The aim of this retrospective multicentre study is to describe the clinical characteristics of patients diagnosed with severe eosinophilic asthma receiving anti-IL-5/anti-IL-5Rα therapies and to compare their effectiveness. We collected and analysed results separately for anti-IL-5 and anti-IL-5Rα therapies from January 2016 until December 2021 in multidisciplinary severe asthma units. We collected demographic and clinical data, treatment with previous anti-IgE and/or anti-IL-5 agents, and comorbidities. We compared the number of exacerbations and admissions to the hospital, daily oral corticosteroid intake, pulmonary function tests, and Asthma Control Test scores before and after 12 months of therapy. 261 patients were included: 176 patients in the anti-IL-5 group and 85 in the anti-IL-5Rα group. Both groups led to statistically significant reductions in asthma exacerbations, hospital admissions, and visits to the Emergency Room. Although both groups showed a significant reduction in blood eosinophiliccount, we found a difference, although not significant, in the magnitude of reduction as benralizumab was able to decrease eosinophil counts to zero. Patients in the anti-IL-5 group achieved higher ACT scores after treatment, although this improvement was seen in both treatment groups. The anti-IL-5 and anti-IL-5Rα biologics have shown similar effectiveness despite having different mechanisms of action. The anti-IL-5 group appeared to be better than benralizumab at improving ACT scores and FEV1/FVC and at reducing the number of inhalers. Although these differences were not statistically significant, it is not clear whether they may have clinical relevance and they might highlight the need for further head-to-head studies comparing these treatments. [ABSTRACT FROM AUTHOR]

Long COVID, now unmistakably identified as a syndromic entity encompassing a complex spectrum of symptoms, demands immediate resolution of its elusive pathogenic underpinnings. The intricate interplay of diverse factors presents a complex puzzle, difficult to resolve, and thus poses a substantial challenge. As instances of long COVID manifest by repeated infections of SARS-CoV-2 and genetic predisposition, a detailed understanding in this regard is needed. This endeavor is a comprehensive exploration and analysis of the cascading pathogenetic events driven by viral persistence and replication. Beyond its morbidity, long COVID, more disabling than fatal, exacts one of the most substantial tolls on public health in contemporary times, with the potential to cripple national economies. The paper introduces a unified theory of long COVID, detailing a novel pathophysiological framework that interlinks persistent SARS-CoV-2 infection, autoimmunity, and systemic vascular pathology. We posit a model where viral reservoirs, immune dysregulation, and genetic predispositions converge to perpetuate disease. It challenges prevailing hypotheses with new evidence, suggesting innovative diagnostic and therapeutic approaches. The paper aims to shift the paradigm in long COVID research by providing an integrative perspective that encapsulates the multifaceted nature of the condition. We explain the immunological mechanisms, hypercoagulability states, and viral reservoirs in the skull that feed NeuroCOVID in patients with long COVID. Also, this study hints toward a patient approach and how to prioritize treatment sequences in long COVID patients in hospitals and clinics. [ABSTRACT FROM AUTHOR]

Pulmonary manifestations in patients with allergic bronchopulmonary aspergillosis (ABPA) and nontuberculous mycobacterial‐pulmonary disease (NTM‐PD) include bronchiectasis and mucus plugging. A 68‐year‐old woman, treated with antibiotics and inhaled corticosteroids for NTM‐PD and asthma, presented with fever and wheezing. ABPA was diagnosed based on laboratory findings (elevated peripheral blood eosinophil counts and serum total IgE levels and positive Aspergillus‐specific IgE and IgG) and imaging observation of a high‐attenuation mucus plug. Systemic prednisolone was avoided to prevent NTM‐PD progression. Dupilumab, a monoclonal antibody that blocks IL‐4/13, was introduced to improve the clinical findings. Herein, we discuss the pathophysiological mechanisms underlying this rare comorbidity. [ABSTRACT FROM AUTHOR]

Circulating follicular helper T cells (cTfh) can show phenotypic alterations in disease settings, including in the context of tissue-damaging autoimmune or anti-viral responses. Using severe COVID-19 as a paradigm of immune dysregulation, we have explored how cTfh phenotype relates to the titre and quality of antibody responses. Severe disease was associated with higher titres of neutralising S1 IgG and evidence of increased T cell activation. ICOS, CD38 and HLA-DR expressing cTfh correlated with serum S1 IgG titres and neutralising strength, and interestingly expression of TIGIT by cTfh showed a negative correlation. TIGIT+cTfh expressed increased IFNg and decreased IL-17 compared to their TIGIT-cTfh counterparts, and showed reduced capacity to help B cells in vitro. Additionally, TIGIT+cTfh expressed lower levels of CD40L than TIGIT-cTfh, providing a potential explanation for their poor B-helper function. These data identify phenotypic changes in polyclonal cTfh that correlate with specific antibody responses and reveal TIGIT as a marker of cTfh with altered function. [ABSTRACT FROM AUTHOR]

Rationale: The comparative effectiveness of biologic agents used as add-on therapy in the management of difficult-to-control asthma is unclear. Objective: To compare the effectiveness of dupilumab, mepolizumab, and benralizumab among patients with difficult-to-control asthma. Methods: Retrospective multicenter cohort study of adult patients with difficult-to-control asthma starting treatment with dupilumab, mepolizumab, or benralizumab as documented in a multicenter electronic health record and claims-based database between October 19, 2018, and September 30, 2022. Propensity-score matching was used to minimize bias from nonrandomized treatment assignment; a prespecified α-level was set at 0.017 to account for three primary comparisons. The exposure of interest was the new initiation of dupilumab, benralizumab, or mepolizumab treatment. The primary outcome was the rate of asthma exacerbations in the 1 year after initiation of biologic therapy modeled using a negative binomial approach. Results: Among 893,668 patients with asthma who were prescribed an inhaled corticosteroid and were ⩾12 years old (65% female; mean age, 49 yr), 3,943 started dupilumab, 1,902 started benralizumab, and 2,012 started mepolizumab, all without an alternative indication for biologic therapy. After matching, there were 1,805 patients in each group for comparisons between dupilumab and benralizumab, 1,865 for comparisons between dupilumab and mepolizumab, and 1,721 for comparisons between mepolizumab and benralizumab. For all pairwise comparisons, covariates were well balanced after matching (all standardized mean differences <0.1). Patients who initiated dupilumab had a significantly lower rate of asthma exacerbations (1.07 per year) compared with benralizumab (1.47 per year), with a rate ratio (RR) of 0.73 (95% confidence interval, 0.63–0.85), and also had a significantly lower rate of asthma exacerbations compared with mepolizumab (1.04 per year vs. 1.45 per year), with an RR of 0.72 (0.62–0.84). There was no statistically significant difference in the rate of asthma exacerbations between mepolizumab (1.40 per year) and benralizumab (1.41 per year), with an RR of 1.00 (0.85–1.17). Conclusions: In patients with difficult-to-control asthma who had newly initiated biologic therapy, dupilumab was associated with a decreased rate of asthma exacerbations in the 1 year after initiation compared with mepolizumab or benralizumab. [ABSTRACT FROM AUTHOR]

Clinical trials and real world studies demonstrated benefit of mepolizumab treatment in severe asthma but data on its effectiveness beyond 2 years remain limited. Herein, we provide mepolizumab treatment evaluation up to 4 years. we studied all patients initiated on mepolizumab in our center from June 2017 to August 2018. Clinical outcomes data were retrieved from the local dendrite systems registry. Comparison analyses and logistic regression were conducted to explore longevity and predictors of response to mepolizumab treatment. a total of 66 patients initiated on mepolizumab with a median follow-up of 45.8 (42.4,48.1) months were included in the study [mean age 50.3 years (range 18-79), females 50 (73%) ]. At 20.7 months of treatment, 42 patients (63.6%) had positive response, 13 (19.7%) negative response, and 11 (16.7%) discontinued due to other factors. At 45.8 months, 35 (53%) patients were still on mepolizumab, 21 (31.8%) switched to a different biologic, and 10 (15.2%) discontinued biologics. Two deaths were recorded during the study period. The median blood eosinophil was reduced from 0.43x109/L (0.27, 0.75) to 0.04 (0.0, 0.1) (p < 0.00001)]. The median annual exacerbations were reduced from 6.0 (4,8) to 1.0 (0.0,3.0) (p < 0.00001), and mOCS use was reduced from59% to 29%, p = 0.001. The mean asthma control questionnaire-6 (ACQ6) improved from 3.1 ± 1.7 to 2.1 ± 1.3 (p < 0.00001). mepolizumab clinical benefit was sustained over 4 years. However, approximately half of the cohort discontinued the treatment prompting the need for further research into the treatment response longevity. [ABSTRACT FROM AUTHOR]

Background: Routine use of immunosuppressive agents in systemic lupus erythematosus (SLE) patients infected with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) potentially increases the risk of adverse outcomes. belimumab, a monoclonal antibody for the treatment of SLE, remains untested for its specific impact on coronavirus disease 2019 (COVID-19) symptoms in these patients. Here, this research investigated the effect of belimumab on COVID-19 symptoms in SLE patients infected with SARS-CoV-2. Methods: This study enrolled SLE patients who underwent treatment with belimumab. After thorough screening based on the inclusion and exclusion criteria, data pertaining to COVID-19 for both the participants and their cohabitants were obtained through telephone follow-up. The potential impact of belimumab on COVID-19 was evaluated by comparing COVID-19 symptoms and medication use across various groups to investigate the association between belimumab treatment and COVID-19 in SLE. Results: This study involved 123 SLE patients, of whom 89.4% tested positive for SARS-CoV-2. Among cohabitants of SLE patients, the SARS-CoV-2 positive rate was 87.2% (p = 0.543). Patients treated with belimumab exhibited a lower incidence of multiple COVID-19 symptoms than their cohabitating counterparts (p < 0.001). This protective effect was found to be partially related to the time of last belimumab administration. Among those with COVID-19, 30 patients opted to discontinue their anti-SLE drugs, and among them, 53% chose to discontinue belimumab. Discontinuing drugs did not increase the risk of hospitalization due to SARS-CoV-2 infection. Conclusion: This study concluded that treatment with belimumab did not increase susceptibility to COVID-19 and beneficially alleviated the symptoms of COVID-19. [ABSTRACT FROM AUTHOR]

Immunosenescence is a weakening of the immune system due to aging, characterized by changes in immune cells and dysregulated immune function. Age-related immune cells are increasing with aging. They are associated with chronic prolonged inflammation, causing tissue dysfunction and age-related diseases. Here, we discuss increased pro-inflammatory activity of aged macrophages, accumulation of lymphocytes with an age-associated phenotype, and specific alterations in both functions and characteristics of these immune cells. These cellular changes are associated with development of age-related diseases. Additionally, we reviewed various therapeutic strategies targeting age-related immunosenescence, providing pathways to mitigate effects of age-related diseases., Competing Interests: Declarations. Conflict of interest: The authors declare that there are no conflict of interests., (© 2024. The Pharmaceutical Society of Korea.)

Purpose: This systematic review aims to collect and examine recent research findings regarding hypophysitis in COVID-19 patients., Method: We conducted a comprehensive literature review in English on the topic "Hypophysitis in COVID-19," using the MEDLINE (PubMed) database in July 2024. The selected articles were systematically tabulated and we have assessed in this review patient demographics, symptom presentation, imaging results, diagnosis, clinical management, and outcomes., Results: Seven reported cases of post-COVID-19 hypophysitis were identified, comprising 4 (57%) females and 3 (43%) males, with a median age of 37 years. The interval between COVID-19 infection symptoms and the onset of hypophysitis ranged from 2 to 3 weeks. Initial symptoms included frontal headache in 4 (57%) cases and polyuria and polydipsia in 3 (43%) cases. Anterior or posterior hypopituitarism was observed in 6 (85%) patients. Radiological findings varied: 2 (28.5%) cases showed panhypophysitis, 3 (43%) cases exhibited gland enlargement with homogeneous contrast enhancement on magnetic resonance imaging (MRI), 1 case involved the loss of the posterior pituitary bright spot, and 1 case involved pituitary apoplexy/enlargement of the gland and infundibulum. No pituitary biopsies were performed. Four (57%) patients received glucocorticoid (GC) treatment. Long-term follow-up was documented in only one case, a 16-year-old female followed for 2 years reporting complete clinical and radiological resolution., Conclusion: Although rare, hypophysitis related to COVID-19 is documented in the literature exhibiting distinct characteristics such as a homogeneous gender prevalence, an average age of onset around 35 years, and primary symptoms of headache, polyuria, and polydipsia which are indicative of angiotensin-vasopressin deficiency. This is in contrast with primary autoimmune hypophysitis characterized by a female prevalence and typical symptoms with headache and visual impairment. Longer-term follow-up of these patients is needed to better understand the potential lasting impact on pituitary function and radiological improvement. Future research should also explore the presence of anti-pituitary antibodies and the other possible pathophysiological mechanisms potentially involved in these cases., Competing Interests: Declarations. Ethics approval: An ethics statement was not required for this study type since no human or animal subjects or materials were used. Competing interests: The authors declare no competing interests., (© 2024. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

Introduction: B cells play a pivotal role in adaptive immunity which has been extensively characterised primarily via flow cytometry-based gating strategies. This study addresses the discrepancies between flow cytometry-defined B cell subsets and their high-confidence molecular signatures using single-cell multiomics approaches. Methods: By analysing multi-omics single-cell data from healthy individuals and patients across diseases, we characterised the level and nature of cellular contamination within standard flow cytometric-based gating, resolved some of the ambiguities in the literature surrounding unconventional B cell subsets, and demonstrated the variable effects of flow cytometric-based gating cellular heterogeneity across diseases. Results: We showed that flow cytometric-defined B cell populations are heterogenous, and the composition varies significantly between disease states thus affecting the implications of functional studies performed on these populations. Importantly, this paper draws caution on findings about B cell selection and function of flow cytometric-sorted populations, and their roles in disease. As a solution, we developed a simple tool to identify additional markers that can be used to increase the purity of flow-cytometric gated immune cell populations based on multi-omics data (AlliGateR). Here, we demonstrate that additional non-linear CD20, CD21 and CD24 gating can increase the purity of both naïve and memory populations. Discussion: These findings underscore the need to reconsider B cell subset definitions within the literature and propose leveraging single-cell multi-omics data for refined characterisation. We show that single-cell multi-omics technologies represent a powerful tool to bridge the gap between surface marker-based annotations and the intricate molecular characteristics of B cell subsets. [ABSTRACT FROM AUTHOR]

Background: The gut is an important site for human immunodeficiency virus (HIV) infection and immune responses. The role of gut mucosal immune cells in immune restoration in patients infected with HIV undergoing antiretroviral therapy remains unclear. Methods: Ileocytes, including 54 475 immune cells, were obtained from colonoscopic biopsies of five HIV‐negative controls, nine immunological responders (IRs), and three immunological non‐responders (INRs) and were analyzed using single‐cell RNA sequencing. Immunohistochemical assays were performed for validation. The 16S rRNA gene was amplified using PCR in faecal samples to analyze faecal microbiota. Flow cytometry was used to analyze CD4+ T‐cell counts and the activation of T cells. Results: This study presents a global transcriptomic profile of the gut mucosal immune cells in patients infected with HIV. Compared with the IRs, the INRs exhibited a lower proportion of gut plasma cells, especially the IGKC+IgA+ plasma cell subpopulation. IGKC+IgA+ plasma cells were negatively associated with enriched f. Prevotellaceae the INRs and negatively correlated with the overactivation of T cells, but they were positively correlated with CD4+ T‐cell counts. The INRs exhibited a higher proportion of B cells than the IRs. Follicular and memory B cells were significantly higher in the INRs. Reduced potential was observed in the differentiation of follicular or memory B cells into gut plasma cells in INRs. In addition, the receptor‐ligand pairs CD74_MIF and CD74_COPA of memory B/ follicular helper T cells were significantly reduced in the INRs, which may hinder the differentiation of memory and follicular B cells into plasma cells. Conclusions: Our study shows that plasma cells are dysregulated in INRs and provides an extensive resource for deciphering the immune pathogenesis of HIV in INRs. Key points: An investigation was carried out at the single‐cell‐level to analyze gut mucosal immune cells alterations in PLWH after ART.B cells were significantly increased and plasma cells were significantly decreased in the INRs compared to the IRs and NCs.There are gaps in the transition from gut follicular or memory B cellsinto plasma cells in INRs. [ABSTRACT FROM AUTHOR]

Introduction: COVID-19 patients can develop autoantibodies against a variety of secreted and membrane proteins, including some expressed on lymphocytes. However, it is unclear what proportion of patients might develop antilymphocyte antibodies (ALAb) and what functional relevance they might have. Methods: We evaluated the presence and lytic function of ALAb in the sera of a cohort of 85 COVID-19 patients (68 unvaccinated and 17 vaccinated) assigned to mild (N=63), or moderate/severe disease (N=22) groups. Thirty-seven patients were followed-up after recovery. We also analyzed in vivo complement deposition on COVID-19 patients' lymphocytes and examined its correlation with lymphocyte numbers during acute disease. Results: Compared with healthy donors (HD), patients had an increased prevalence of IgM ALAb, which was significantly higher in moderate/severe disease patients and persisted after recovery. Sera from IgM ALAb+ patients exhibited complement-dependent cytotoxicity (CDC) against HD lymphocytes. Complement protein C3b deposition on patients' CD4 T cells was inversely correlated with CD4 T cell numbers. This correlation was stronger in moderate/severe disease patients. Discussion: IgM ALAb and complement activation against lymphocytes may contribute to the acute lymphopenia observed in COVID-19 patients. [ABSTRACT FROM AUTHOR]