The Journal of Immunology

Antigen (ag)-specific T cell analysis is an important step for investigation of cellular immunity in many settings, such as infectious diseases, cancer and vaccines. Multiparameter flow cytometry has advantages in studying both the rarity and heterogeneity of these cells. In the cellular immunologists toolbox, the expression of activation-induced markers (AIM) following antigen exposure has made possible the study and sorting of ag-specific T cells without using human leukocyte antigen (HLA)-mul...

Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), the causative agent of the pandemic human respiratory illness COVID-19, is a global health emergency. While severe acute disease has been linked to an expansion of antibody-secreting plasmablasts, we sought to identify B cell responses that correlated with positive clinical outcomes in convalescent patients. We characterized the peripheral blood B cell immunophenotype and plasma antibody responses in 40 recovered non-hospitalized COVI...

BackgroundRepeated mRNA vaccination against SARS-CoV-2 has been shown to induce class switching to IgG4, a non-inflammatory human antibody subclass linked to tolerance. Although poorly understood, prolonged antigenic stimulation and IL-4 signalling may be instrumental in IgG4 switching. We and others have previously shown that widely used immunosuppressive drugs such as methotrexate (MTX) and TNF inhibitors (TNFi) have a minor inhibitory impact on humoral SARS-CoV-2 mRNA vaccination responses. H...

Chimeric antigen receptor (CAR) T cells have demonstrable efficacy in treating B-cell malignancies. Factors such as product composition, lymphodepletion and immune reconstitution are known to influence functional persistence of CAR+ T cells. However, little is known about the determinants of differentiation and phenotypic plasticity of CAR+ T and immune cells early post-infusion. We report single cell multi-omics analysis of molecular, clonal, and phenotypic profiles of CAR+ T and other immune c...

Since the first report of V (D) J " allelic exclusion/inclusion"and" dual BCR "in 1961, despite continuous new discoveries, the proportion and source mechanism of dual BCR under physiological conditions have been puzzling immuologists.This study takes advantage of the single cell V (D) J sequencing technology, which can perfectly match the heavy and light chains of BCR at the level of a single B cell, and obtain the full length mRNA sequence of the CDR3 region. By analyzing the pairing of functi...

As research in the field of food allergy is gaining momentum with new and emerging therapies there is need for both researchers and clinicians to have a better understanding on how to put all this new information into context in clinical care. We are continuously learning from other fields, such as oncology, that a one-shoe-fits all type approaches are becoming the practice of the past and there is need to incorporate markers of disease activity as well as drug selection into clinical care. In t...

Chronic lymphocytic leukemia (CLL) patients have lower seroconversion rates and antibody titers following SARS-CoV-2 vaccination, but the reasons for this diminished response are poorly understood. Here, we studied humoral and cellular responses in 95 CLL patients and 30 healthy controls after two BNT162b2 or mRNA-2173 mRNA immunizations. We found that 42% of CLL vaccinees developed SARS-CoV-2-specific binding and neutralizing antibodies (NAbs), while 32% had no response. Interestingly, 26% were...

A correct identification of seropositive individuals for the Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2) infection is of paramount relevance to assess the degree of protection of a human population to present and future outbreaks of the COVID-19 pandemic. We describe here a sensitive and quantitative flow cytometry method using the cytometer-friendly non-adherent Jurkat T cell line that stably expresses the full-length native spike "S" protein of SARS-CoV-2 and a truncated form ...

In this investigation we examined the magnitude, breadth, and durability of SARS-CoV-2 specific antibodies in two distinct B-cell compartments: long-lived plasma cell-derived antibodies in the plasma, and peripheral memory B-cells along with their associated antibody profiles elicited after in vitro stimulation. We found that magnitude varied amongst individuals, but was the highest in hospitalized subjects. Variants of concern (VoC) -RBD-reactive antibodies were found in the plasma of 72% of sa...

Detecting antigen-specific lymphocytes is crucial for immune monitoring in the setting of vaccination, infectious disease, cancer, and autoimmunity. However, their low frequency and dispersed distribution across lymphoid organs, peripheral tissues, and blood pose challenges for reliable detection. To address this issue, we developed a strategy exploiting the functions of tissue-resident memory T cells (TO_SCPLOWRMC_SCPLOWs) to concentrate target circulating immune cells in the skin and then samp...

Vertebrates differ greatly in responses to pro-inflammatory agonists such as bacterial lipopolysaccharide (LPS), complicating use of animal models to study human sepsis or inflammatory disorders. We compared transcriptomes of resting and LPS-exposed blood from six LPS-sensitive species (rabbit, pig, sheep, cow, chimpanzee, human) and four LPS-resilient species (mice, rats, baboon, rhesus), as well as plasma proteomes and lipidomes. Unexpectedly, at baseline, sensitive species already had enhance...

To address the need for a safe, efficacious vaccine against SARS-CoV-2 infection with the critical properties of enabling both blocking viral entry into cells and clearing virus from cells already infected, we have developed a bivalent, human adenovirus serotype 5 (hAd5) SARS-CoV- 2 S-Fusion + N-ETSD vaccine that is currently in clinical testing. This vaccine uses the next- generation hAd5 [E1-, E2b-, E3-] platform previously used successfully in cancer patients with pre-existing adenovirus immu...

The emergence of Omicron and Delta variants of SARS-CoV-2 has begun a number of discussions regarding breakthrough infection, waning immunity, need and timing for vaccine boosters and whether existing mRNA vaccines for the wildtype strain are adequate. Our work leverages a biosensor-based technique to evaluate the binding efficacy of SARS-CoV-2 S1 specific salivary antibodies to the Omicron and Delta variants using a cohort of mRNA vaccinated (n=109) and convalescent (n=19) subjects. We discover...

Coronavirus disease 2019 (COVID-19) displays high clinical variability but the parameters that determine disease severity are still unclear. Pre-existing T cell memory has been hypothesized as a protective mechanism but conclusive evidence is lacking. Here we demonstrate that all unexposed individuals harbor SARS-CoV-2-specific memory T cells with marginal cross-reactivity to common cold corona and other unrelated viruses. They display low functional avidity and broad protein target specificitie...

Abstract/IntroductionA wide clinical spectrum has become a hallmark of the SARS-CoV-2 (COVID-19) pandemic, although its immunologic underpinnings remain to be defined. We have performed deep characterization of B cell responses through high-dimensional flow cytometry to reveal substantial heterogeneity in both effector and immature populations. More notably, critically ill patients displayed hallmarks of extrafollicular B cell activation as previously described in autoimmune settings. Extrafolli...

BackgroundCytokine storm syndromes (CSS), including hemophagocytic lymphohistiocytosis (HLH), are increasingly recognized as hyper-inflammatory states leading to multi-organ failure and death. Familial HLH (FHL) in infancy results from homozygous genetic defects in perforin-mediated cytolysis by CD8 T-lymphocytes and natural killer (NK) cells. Later onset CSS are frequently associated with heterozygous defects in FHL genes, but genetic etiologies for most are unknown. We identified rare DOCK8 va...

Graves disease (GD) is the leading cause of hyperthyroidism and is often treated with antithyroid drugs (ATDs). Although ATD therapy is effective, it might cause a rare but serious adverse effect called ATD-induced agranulocytosis (TiA), which can lead to severe neutropenia and life-threatening infections. Previous studies have shown that certain human leukocyte antigen (HLA) alleles, including HLA-B*38:02 and HLA-DRB1*08:03 in Asian populations, have been associated with TiA susceptibility. How...

The SARS-CoV-2 infection is associated with increased levels of autoantibodies targeting immunological proteins such as cytokines and chemokines. Reports further indicate that COVID-19 patients may develop a wide spectrum of autoimmune diseases due to reasons not fully understood. Even so, the landscape of autoantibodies induced by SARS-CoV-2 infection remains uncharted territory. To gain more insight, we carried out a comprehensive assessment of autoantibodies known to be linked to diverse auto...

SARS-Cov-2 (severe acute respiratory disease coronavirus 2), which causes Coronavirus Disease 2019 (COVID19) was first detected in China in late 2019 and has since then caused a global pandemic. While molecular assays to directly detect the viral genetic material are available for the diagnosis of acute infection, we currently lack serological assays suitable to specifically detect SARS-CoV-2 antibodies. Here we describe serological enzyme-linked immunosorbent assays (ELISA) that we developed us...

A dysregulated immune response against coronavirus-2 (SARS-CoV-2) plays a critical role in the outcome of patients with coronavirus disease 2019 (COVID-19). A significant increase in circulating plasmablasts is characteristic of COVID-19 though the underlying mechanisms and its prognostic implications are not known. Here, we demonstrate that in the acute phase of COVID-19, activated PD-1highCXCR5-CD4+ T cells, peripheral helper T cells, (Tph) are significantly increased and promote inflammatory ...