SARS-CoV-2 messenger RNA vaccination in healthy individuals generates immune protection against COVID-19. However, little is known about SARS-CoV-2 mRNA vaccine-induced responses in immunosuppressed ...patients. We investigated induction of antigen-specific antibody, B cell and T cell responses longitudinally in patients with multiple sclerosis (MS) on anti-CD20 antibody monotherapy (n = 20) compared with healthy controls (n = 10) after BNT162b2 or mRNA-1273 mRNA vaccination. Treatment with anti-CD20 monoclonal antibody (aCD20) significantly reduced spike-specific and receptor-binding domain (RBD)-specific antibody and memory B cell responses in most patients, an effect ameliorated with longer duration from last aCD20 treatment and extent of B cell reconstitution. By contrast, all patients with MS treated with aCD20 generated antigen-specific CD4 and CD8 T cell responses after vaccination. Treatment with aCD20 skewed responses, compromising circulating follicular helper T (T
) cell responses and augmenting CD8 T cell induction, while preserving type 1 helper T (T
1) cell priming. Patients with MS treated with aCD20 lacking anti-RBD IgG had the most severe defect in circulating T
responses and more robust CD8 T cell responses. These data define the nature of the SARS-CoV-2 vaccine-induced immune landscape in aCD20-treated patients and provide insights into coordinated mRNA vaccine-induced immune responses in humans. Our findings have implications for clinical decision-making and public health policy for immunosuppressed patients including those treated with aCD20.
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GEOZS, IJS, IMTLJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBMB, UL, UM, UPUK, ZAGLJ
SARS-CoV-2 mRNA vaccines have shown remarkable clinical efficacy, but questions remain about the nature and kinetics of T cell priming. We performed longitudinal antigen-specific T cell analyses on ...healthy SARS-CoV-2-naive and recovered individuals prior to and following mRNA prime and boost vaccination. Vaccination induced rapid antigen-specific CD4+ T cell responses in naive subjects after the first dose, whereas CD8+ T cell responses developed gradually and were variable in magnitude. Vaccine-induced Th1 and Tfh cell responses following the first dose correlated with post-boost CD8+ T cells and neutralizing antibodies, respectively. Integrated analysis revealed coordinated immune responses with distinct trajectories in SARS-CoV-2-naive and recovered individuals. Last, whereas booster vaccination improved T cell responses in SARS-CoV-2-naive subjects, the second dose had little effect in SARS-CoV-2-recovered individuals. These findings highlight the role of rapidly primed CD4+ T cells in coordinating responses to the second vaccine dose in SARS-CoV-2-naive individuals.
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•mRNA vaccines generate antigen-specific T cells in a coordinated immune response•Vaccine-induced T cells resemble the durable memory cells primed by infection•Th1 and cTfh cell responses to the first dose correlate with second-dose responses•SARS-CoV-2-recovered individuals benefit from the first but not the second dose
SARS-CoV-2 mRNA vaccines have demonstrated remarkable efficacy, but T cell responses to vaccination have not been well studied. In a longitudinal cohort, Painter et al. show that mRNA vaccines activate SARS-CoV-2-specific T cells that could contribute to durable immunity. The findings highlight the central role of T cells in the two-dose vaccine regimen for individuals not previously infected with SARS-CoV-2.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
We examined antibody and memory B cell responses longitudinally for ∼9–10 months after primary 2-dose SARS-CoV-2 mRNA vaccination and 3 months after a 3rd dose. Antibody decay stabilized between 6 ...and 9 months, and antibody quality continued to improve for at least 9 months after 2-dose vaccination. Spike- and RBD-specific memory B cells remained durable over time, and 40%–50% of RBD-specific memory B cells simultaneously bound the Alpha, Beta, Delta, and Omicron variants. Omicron-binding memory B cells were efficiently reactivated by a 3rd dose of wild-type vaccine and correlated with the corresponding increase in neutralizing antibody titers. In contrast, pre-3rd dose antibody titers inversely correlated with the fold-change of antibody boosting, suggesting that high levels of circulating antibodies may limit the added protection afforded by repeat short interval boosting. These data provide insight into the quantity and quality of mRNA-vaccine-induced immunity over time through 3 or more antigen exposures.
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•Neutralizing antibody titers stabilize ∼6 months after primary vaccination•Memory B cells are stable for >9 months postvaccination and >50% cross-bind Omicron•Omicron-reactive memory B cells are reactivated by a 3rd dose of wild-type vaccine•Low preboost antibody levels correlate with a greater fold increase after boosting
Immunization with 2 doses of mRNA vaccine encoding the ancestral SARS-CoV-2 spike protein induces a population of durable memory B cells with broad reactivity to viral variants including Omicron. Boosting with a 3rd dose of ancestral vaccine increases variant-neutralizing antibody levels, highlighting the significance of vaccine-induced B cell memory.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Vaccine-mediated immunity often relies on the generation of protective antibodies and memory B cells, which commonly stem from germinal center (GC) reactions. An in-depth comparison of the GC ...responses elicited by SARS-CoV-2 mRNA vaccines in healthy and immunocompromised individuals has not yet been performed due to the challenge of directly probing human lymph nodes. Herein, through a fine-needle aspiration-based approach, we profiled the immune responses to SARS-CoV-2 mRNA vaccines in lymph nodes of healthy individuals and kidney transplant recipients (KTXs). We found that, unlike healthy subjects, KTXs presented deeply blunted SARS-CoV-2-specific GC B cell responses coupled with severely hindered T follicular helper cell, SARS-CoV-2 receptor binding domain-specific memory B cell, and neutralizing antibody responses. KTXs also displayed reduced SARS-CoV-2-specific CD4 and CD8 T cell frequencies. Broadly, these data indicate impaired GC-derived immunity in immunocompromised individuals and suggest a GC origin for certain humoral and memory B cell responses following mRNA vaccination.
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•Human GC responses to SARS-CoV-2 vaccines are restricted to draining lymph nodes•Vaccine-induced GC responses are associated with SARS-CoV-2 neutralizing antibodies•Kidney transplant recipients lack GC responses to SARS-CoV-2 vaccines•Vaccines expand S+RBD− memory B cells in healthy donors and transplant recipients
Fine-needle aspiration of lymph nodes in humans reveals that SARS-CoV-2 vaccination induces neutralizing antibody-producing germinal centers, enhanced by repeated vaccination. Conversely, in patients receiving immunosuppressant medication, this process is disrupted, resulting in stunted protective immune responses, highlighting issues about vaccine and booster efficacy in patients with compromised immune systems.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Combinations of drugs that affect distinct mechanisms of HIV latency aim to induce robust latency reversal leading to cytopathicity and elimination of the persistent HIV reservoir. Thus far, attempts ...have focused on combinations of protein kinase C (PKC) agonists and pan-histone deacetylase inhibitors (HDIs) despite the knowledge that HIV gene expression is regulated by class 1 histone deacetylases. We hypothesized that class 1-selective HDIs would promote more robust HIV latency reversal in combination with a PKC agonist than pan-HDIs because they preserve the activity of proviral factors regulated by non-class 1 histone deacetylases. Here, we show that class 1-selective agents used alone or with the PKC agonist bryostatin-1 induced more HIV protein expression per infected cell. In addition, the combination of entinostat and bryostatin-1 induced viral outgrowth, whereas bryostatin-1 combinations with pan-HDIs did not. When class 1-selective HDIs were used in combination with pan-HDIs, the amount of viral protein expression and virus outgrowth resembled that of pan-HDIs alone, suggesting that pan-HDIs inhibit robust gene expression induced by class 1-selective HDIs. Consistent with this, pan-HDI-containing combinations reduced the activity of NF-κB and Hsp90, two cellular factors necessary for potent HIV protein expression, but did not significantly reduce overall cell viability. An assessment of viral clearance from
cultures indicated that maximal protein expression induced by class 1-selective HDI treatment was crucial for reservoir clearance. These findings elucidate the limitations of current approaches and provide a path toward more effective strategies to eliminate the HIV reservoir.
Despite effective antiretroviral therapy, HIV evades eradication in a latent form that is not affected by currently available drug regimens. Pharmacologic latency reversal that leads to death of cellular reservoirs has been proposed as a strategy for reservoir elimination. Because histone deacetylases (HDACs) promote HIV latency, HDAC inhibitors have been a focus of HIV cure research. However, many of these inhibitors broadly affect multiple classes of HDACs, including those that promote HIV gene expression (class 1 HDACs). Here, we demonstrate that targeted treatment with class 1-selective HDAC inhibitors induced more potent HIV latency reversal than broadly acting agents. Additionally, we provide evidence that broadly acting HDIs are limited by inhibitory effects on non-class 1 HDACs that support the activity of proviral factors. Thus, our work demonstrates that the use of targeted approaches to induce maximum latency reversal affords the greatest likelihood of reservoir elimination.
Naïve CD8
T cells can differentiate into effector (T
), memory (T
) or exhausted (T
) T cells. These developmental pathways are associated with distinct transcriptional and epigenetic changes that ...endow cells with different functional capacities and therefore therapeutic potential. The molecular circuitry underlying these developmental trajectories and the extent of heterogeneity within T
, T
and T
populations remain poorly understood. Here, we used the lymphocytic choriomeningitis virus model of acute-resolving and chronic infection to address these gaps by applying longitudinal single-cell RNA-sequencing (scRNA-seq) and single-cell assay for transposase-accessible chromatin sequencing (scATAC-seq) analyses. These analyses uncovered new subsets, including a subpopulation of T
cells expressing natural killer cell-associated genes that is dependent on the transcription factor Zeb2, as well as multiple distinct TCF-1
stem/progenitor-like subsets in acute and chronic infection. These data also revealed insights into the reshaping of T
subsets following programmed death 1 (PD-1) pathway blockade and identified a key role for the cell stress regulator, Btg1, in establishing the T
population. Finally, these results highlighted how the same biological circuits such as cytotoxicity or stem/progenitor pathways can be used by CD8
T cell subsets with highly divergent underlying chromatin landscapes generated during different infections.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
Human immunodeficiency virus type 1 (HIV-1) establishes transcriptionally silent latent infections in resting memory T cells and hematopoietic stem and progenitor cells (HSPCs), which allows the ...virus to persist in infected individuals despite antiretroviral therapy. Developing
models of HIV-1 latency that recapitulate the characteristics of latently infected cells
is crucial to identifying and developing effective latency-reversing therapies. HSPCs exist in a quiescent state
, and quiescence is correlated with latent infections in T cells. However, current models for culturing HSPCs and for infecting T cells
require that the cells be maintained in an actively proliferating state. Here we describe a novel culture system in which primary human HSPCs cultured under hypothermic conditions are maintained in a quiescent state. We show that these quiescent HSPCs are susceptible to predominantly latent infection with HIV-1, while actively proliferating and differentiating HSPCs obtain predominantly active infections. Furthermore, we demonstrate that the most primitive quiescent HSPCs are more resistant to spontaneous reactivation from latency than more differentiated HSPCs and that quiescent HSPCs are resistant to reactivation by histone deacetylase inhibitors or P-TEFb activation but are susceptible to reactivation by protein kinase C (PKC) agonists. We also demonstrate that inhibition of HSP90, a known regulator of HIV transcription, recapitulates the quiescence and latency phenotypes of hypothermia, suggesting that hypothermia and HSP90 inhibition may regulate these processes by similar mechanisms. In summary, these studies describe a novel model for studying HIV-1 latency in human primary cells maintained in a quiescent state.
Human immunodeficiency virus type 1 (HIV-1) establishes a persistent infection for which there remains no feasible cure. Current approaches are unable to clear the virus despite decades of therapy due to the existence of latent reservoirs of integrated HIV-1, which can reactivate and contribute to viral rebound following treatment interruption. Previous clinical attempts to reactivate the latent reservoirs in an individual so that they can be eliminated by the immune response or viral cytopathic effect have failed, indicating the need for a better understanding of the processes regulating HIV-1 latency. Here we characterize a novel
model of HIV-1 latency in primary hematopoietic stem and progenitor cells isolated from human cord blood that may better recapitulate the behavior of latently infected cells
This model can be used to study mechanisms regulating latency and potential therapeutic approaches to reactivate latent infections in quiescent cells.
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