Science Immunology

Feedback inhibition of humoral immunity by antibodies was initially documented in guinea pigs by Theobald Smith in 1909, who showed that passive administration of excess anti-Diphtheria toxin inhibited immune responses1. Subsequent work documented that antibodies can enhance or inhibit immune responses depending on antibody isotype, affinity, the physical nature of the antigen, and engagement of immunoglobulin (Fc) and complement (C) receptors2, 3. However, little is known about how pre-existing...

In patients with common variable immune deficiencies, primary vaccination followed by two booster doses is recommended for protection against COVID-19. Seroconversion has been shown in 60% of patients. We have no information on whether serum antibodies reflect the generation of durable immune memory. In a longitudinal study on 47 common variable immune deficiencies patients who received the third and fourth vaccine dose, we show that the measurement of specific antibodies is not sufficient to p...

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...

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...

The goal of any vaccine is to induce long-lived plasma cells (LLPC) to provide life-long protection. Natural infection by influenza, measles, or mumps viruses generates bone marrow (BM) LLPC similar to tetanus vaccination which affords safeguards for decades. Although the SARS-CoV-2 mRNA vaccines protect from severe disease, the serologic half-life is short-lived even though SARS-CoV-2-specific plasma cells can be found in the BM. To better understand this paradox, we enrolled 19 healthy adults ...

Intestinal inflammation continues in a subset of celiac disease (CD) patients despite a gluten-free diet. Here, by applying multiomic single cell analysis to duodenal biopsies, we find low-grade malignancies with lymphoma driver mutations in refractory CD type 2 (RCD2) patients comprise surface CD3 negative (sCD3-) lymphocytes stalled at an innate lymphoid cell (ILC) - progenitor T cell stage undergoing extensive TCR recombination. In people with refractory CD type 1 (RCD1), who currently lack e...

T cells play key protective but also pathogenic roles in COVID-19. We studied expression of long non-coding RNAs (lncRNAs) in COVID-19 T cell transcriptomes by integrating previously published single-cell RNA sequencing datasets. The long intergenic non-coding RNA MALAT1 was the most highly transcribed lncRNA in T cells, with Th1 cells demonstrating the lowest and CD8+ resident memory cells the highest MALAT1 expression, amongst CD4+ and CD8+ T cells populations, respectively. We then identified...

The SARS-CoV-2 pandemic underscored the need for innovative approaches to study humoral immunity and isolate monoclonal antibodies (mAbs) with diagnostic and therapeutic potential. Current methods for repertoire analysis at the clonal level require large-scale recombinant mAb production, limiting accessibility and delaying functional insight. We developed a single-cell culture (SCC) platform that enables profiling of human memory B cells (MBCs) and direct recovery of functional mAbs. Using sampl...

In previously unvaccinated and uninfected individuals, non-RBD SARS-CoV-2 spike-specific B cells were prominent in two distinct, durable, resting, cross-reactive, "pre-existing" switched memory B cell compartments. While pre-existing RBD-specific B cells were extremely rare in uninfected and unvaccinated individuals, these two pre-existing switched memory B cell compartments were molded by vaccination and infection to become the primary source of RBD-specific B cells that are triggered by vaccin...

The IKAROS family transcription factors regulate lymphocyte development. Loss-of-function variants in IKZF1 cause primary immunodeficiency, but IKAROS family members IKZF2 and IKZF3 have not yet been associated with immunodeficiency yet. Here, we describe a pedigree with a heterozygous truncating variant in IKZF2, encoding the translational activator and repressor HELIOS which is highly expressed in regulatory T cells and effector T cells, particularly of the CD8+ T cell lineage. Protein-protein...

Clinical manifestations of COVID-19 caused by the novel coronavirus SARS-CoV-2 are associated with age. While children are largely spared from severe respiratory disease, they can present with a SARS-CoV-2-associated multisystem inflammatory syndrome (MIS-C) similar to Kawasakis disease. Here, we show distinct antibody (Ab) responses in children with MIS-C compared to adults with severe COVID-19 causing acute respiratory distress syndrome (ARDS), and those who recovered from mild disease. There ...

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...

ADCC (antibody-dependent cell-mediated cytotoxicity) is dependent on the varying capacity of NK cells to kill, the affinities of FCGR3A-encoded CD16A receptors for antibody, and the presence of antigen-specific antibodies. In vivo ADCC depends on the number of CD16A receptor-positive NK cells in blood. We hypothesized that low ADCC cell function or low effector cell numbers could be biomarkers or risk factors for myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS). We measured NK cell AD...

BackgroundThe role of cellular immunity in pathogenesis of COVID-19 is unclear and conflicting data points to insufficient or pathogenic immunity as drivers of COVID-19 progression. Here we aimed to delineate the phenotype and function of the immune system in patients with moderate, severe, and critical COVID-19. MethodsIn this prospective study, we included 53 patients with moderate (n=21), severe (n=18), and critical (n=14) COVID-19 manifestations. Using multiparametric flow cytometry we comp...

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...

Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is a debilitating but poorly-understood disease. ME/CFS symptoms can range from mild to severe, and include immune system effects alongside incapacitating fatigue and post-exertional disease exacerbation. In this study, we examined immunological profiles of people living with ME/CFS by flow cytometry, focusing on cytotoxic cells, to determine whether people with mild/moderate (n= 43) or severe ME/CFS (n=53) expressed different immunolog...

Autoimmunity is a key clinical feature in both post-infectious Myalgic encephalomyelitis / chronic fatigue syndrome (ME/CFS) and Post-Acute Sequelae of COVID (PASC). Passive transfer of immunoglobulins from patients sera into mice induces some clinical features of PASC. IgG-induced transfer of disease phenotypes has long been appreciated, yet the exact mechanism of disease development remains largely elusive. Here, we demonstrate that IgG isolated from post-infectious ME/CFS patients selectively...

BackgroundParenteral COVID-19 vaccines induce strong systemic immunity, but they do not typically trigger pronounced respiratory immunity. In this context, mucosally applied vaccines might help to induce local immune responses for early viral clearance and reduced viral transmission. MethodsIn this investigator-initiated, open-label single-dose phase I trial, we analyzed the immunogenicity and safety of the vaccine candidate MVA-SARS-2-ST administered as an inhalation boost in COVID-19-immunize...

BackgroundGastroenteric tract requires robust tolerogenic mechanisms to tolerize foreign antigens like foods and microbiota. This is critical to establish the immune homeostasis, which upon disruption, might contribute to a plethora of atopic disorders, including food allergy and eosinophilic esophagitis (EOE). Recently, there was a new subset of tolerizing dendritic cells (tolDCs), PRDM16 tolDC, discovered in the gut of mice and humans, which confers protection against food allergy. Whether an ...

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...