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Zhou, J. Q.

Publications and source records attributed to Zhou, J. Q..

6 recordsLinked to original sources

mRNA-based influenza vaccine expands breadth of B cell response in humans

Summary paragraphEliciting broad and durable antibody responses against rapidly evolving pathogens like influenza viruses remains a formidable challenge1,2. The germinal center (GC) reaction enables the immune system to generate broad, high-affinity, and durable antibody responses to vaccination3-5. mRNA-based severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccines induce persistent GC B cell responses in humans6-9. Whether an mRNA-based influenza vaccine could induce a superior GC response in humans compared to the conventional inactivated influenza virus vaccine remains unclear. We assessed B cell responses in peripheral blood and draining lymph nodes in cohorts receiving the inactivated or mRNA-based quadrivalent seasonal influenza vaccine. Participants receiving the mRNA-based vaccine produced more robust plasmablast responses and higher antibody titers to H1N1 and H3N2 influenza A viruses and comparable antibody titers against influenza B virus strains. Importantly, mRNA-based vaccination stimulated robust recall B cell responses characterized by sustained GC reactions that lasted at least 26 weeks post-vaccination in three of six participants analyzed. In addition to promoting the maturation of responding B cell clones, these sustained GC reactions resulted in enhanced engagement of low-frequency pre-existing memory B cells, expanding the landscape of vaccine-elicited B cell clones. This translated to expansion of the serological repertoire and increased breadth of serum antibody responses. These findings reveal an important role for the induction of persistent GC responses to influenza vaccination in humans to broaden the repertoire of vaccine-induced antibodies.

immunology↗

Spatiotemporal development of the human T follicular helper cell response to Influenza vaccination

We profiled blood and draining lymph node (LN) samples from human volunteers after influenza vaccination over two years to define evolution in the T follicular helper cell (TFH) response. We show LN TFH cells expanded in a clonal-manner during the first two weeks after vaccination and persisted within the LN for up to six months. LN and circulating TFH (cTFH) clonotypes overlapped but had distinct kinetics. LN TFH cell phenotypes were heterogeneous and mutable, first differentiating into pre-TFH during the month after vaccination before maturing into GC and IL-10+ TFH cells. TFH expansion, upregulation of glucose metabolism, and redifferentiation into GC TFH cells occurred with faster kinetics after re-vaccination in the second year. We identified several influenza-specific TFH clonal lineages, including multiple responses targeting internal influenza proteins, and show each TFH state is attainable within a lineage. This study demonstrates that human TFH cells form a durable and dynamic multi-tissue network.

immunology↗

SARS-CoV-2 Omicron boosting induces de novo B cell response in humans

The primary two-dose SARS-CoV-2 mRNA vaccine series are strongly immunogenic in humans, but the emergence of highly infectious variants necessitated additional doses of these vaccines and the development of new variant-derived ones1-4. SARS-CoV-2 booster immunizations in humans primarily recruit pre-existing memory B cells (MBCs)5-9. It remains unclear, however, whether the additional doses induce germinal centre (GC) reactions where reengaged B cells can further mature and whether variant-derived vaccines can elicit responses to novel epitopes specific to such variants. Here, we show that boosting with the original SARS- CoV-2 spike vaccine (mRNA-1273) or a B.1.351/B.1.617.2 (Beta/Delta) bivalent vaccine (mRNA-1273.213) induces robust spike-specific GC B cell responses in humans. The GC response persisted for at least eight weeks, leading to significantly more mutated antigen-specific MBC and bone marrow plasma cell compartments. Interrogation of MBC-derived spike-binding monoclonal antibodies (mAbs) isolated from individuals boosted with either mRNA-1273, mRNA-1273.213, or a monovalent Omicron BA.1-based vaccine (mRNA-1273.529) revealed a striking imprinting effect by the primary vaccination series, with all mAbs (n=769) recognizing the original SARS-CoV-2 spike protein. Nonetheless, using a more targeted approach, we isolated mAbs that recognized the spike protein of the SARS-CoV-2 Omicron (BA.1) but not the original SARS-CoV-2 spike from the mRNA-1273.529 boosted individuals. The latter mAbs were less mutated and recognized novel epitopes within the spike protein, suggesting a naive B cell origin. Thus, SARS-CoV-2 boosting in humans induce robust GC B cell responses, and immunization with an antigenically distant spike can overcome the antigenic imprinting by the primary vaccination series.

immunology↗

Germinal centre-driven maturation of B cell response to SARS-CoV-2 vaccination

Germinal centres (GC) are lymphoid structures where vaccine-responding B cells acquire affinity-enhancing somatic hypermutations (SHM), with surviving clones differentiating into memory B cells (MBCs) and long-lived bone marrow plasma cells (BMPCs)1-4. Induction of the latter is a hallmark of durable immunity after vaccination5. SARS-CoV-2 mRNA vaccination induces a robust GC response in humans6-8, but the maturation dynamics of GC B cells and propagation of their progeny throughout the B cell diaspora have not been elucidated. Here we show that anti-SARS-CoV-2 spike (S)-binding GC B cells were detectable in draining lymph nodes for at least six months in 10 out of 15 individuals who had received two doses of BNT162b2, a SARS-CoV-2 mRNA vaccine. Six months after vaccination, circulating S-binding MBCs were detected in all participants (n=42) and S-specific IgG-secreting BMPCs were detected in 9 out of 11 participants. Using a combined approach of single-cell RNA sequencing of responding blood and lymph node B cells from eight participants and expression of the corresponding monoclonal antibodies, we tracked the evolution of 1540 S-specific B cell clones. SHM accumulated along the B cell differentiation trajectory, with early blood plasmablasts showing the lowest frequencies, followed by MBCs and lymph node plasma cells whose SHM largely overlapped with GC B cells. By three months after vaccination, the frequency of SHM within GC B cells had doubled. Strikingly, S+ BMPCs detected six months after vaccination accumulated the highest level of SHM, corresponding with significantly enhanced anti-S polyclonal antibody avidity in blood at that time point. This study documents the induction of affinity-matured BMPCs after two doses of SARS-CoV-2 mRNA vaccination in humans, providing a foundation for the sustained high efficacy observed with these vaccines.

immunology↗

Immunoglobulin heavy chains are sufficient to determine most B cell clonal relationships

B cell clonal expansion is vital for adaptive immunity. High-throughput B cell receptor (BCR) sequencing enables investigating this process, but requires computational inference to identify clonal relationships. This inference usually relies on only the BCR heavy chain, as most current protocols do not preserve heavy:light chain pairing. The extent to which paired light chains aids inference is unknown. Using human single-cell paired BCR datasets, we assessed the ability of heavy chain-based clonal clustering to identify clones. Of the expanded clones identified, <20% grouped cells expressing inconsistent light chains. Heavy chains from these misclustered clones contained more distant junction sequences and shared fewer V segment mutations than the accurate clones. This suggests that additional heavy chain information could be leveraged to refine clonal relationships. Conversely, light chains were insufficient to refine heavy chain-based clonal clusters. Overall, the BCR heavy chain alone is sufficient to identify clonal relationships with confidence.

immunology↗

Repertoire-wide phylogenetic models of B cell molecular evolution reveal evolutionary signatures of aging and vaccination

In order to produce effective antibodies, B cells undergo rapid somatic hypermutation (SHM) and selection for binding affinity to antigen via a process called affinity maturation. The similarities between this process and evolution by natural selection have led many groups to use evolutionary and phylogenetic methods to characterize the development of immunological memory, vaccination, and other processes that depend on affinity maturation. However, these applications are limited by several features of affinity maturation that violate assumptions in standard phylogenetic models. Further, most phylogenetic models are designed to be applied to individual lineages comprising genetically diverse sequences, while B cell repertoires often consist of hundreds to thousands of separate low-diversity lineages. Here, we introduce a hierarchical phylogenetic framework that incorporates the unique features of SHM, and integrates information from all lineages in a repertoire to more precisely estimate model parameters. We demonstrate the power of this approach by characterizing previously un-described phenomena in affinity maturation. First, we find evidence consistent with age related changes in SHM hot-and cold-spot motifs. Second, we identify a consistent relationship between increased tree length and signs of increased negative selection, apparent in the repertoires of both healthy subjects and those undergoing active immune responses. This suggests that B cell lineages shift towards negative selection over time as a general feature of affinity maturation. Our study provides a framework for undertaking repertoire-wide phylogenetic testing of SHM hypotheses, and provides a new means of charactering the process of mutation and selection during affinity maturation.

immunology↗