Biology subjects

Linterman, M. A.

Publications and source records attributed to Linterman, M. A..

9 recordsLinked to original sources

bioRxiv2026

Expression and role of the RNA-binding protein, ZFP36L1, in mouse T follicular helper cell differentiation and function

T follicular helper (Tfh) cells are critical for germinal centers (GC), the specialised microenvironment where long-lived humoral immunity is generated in response to vaccination or infection. Within the GC, B cells engage with Tfh cells and elicit their help in the form of cytokines and cell-surface co-stimulator molecules. Tfh helper activity must be rapidly available in response to B cell engagement, yet the mechanisms controlling this helper activity remain poorly characterized. Post-transcriptional regulation of mRNA decay and translation offer one way to rapidly and temporally tune Tfh cell activity. ZFP36L1, a member of the ZFP family of RNA-binding proteins, is a candidate modulator of Tfh cell helper activity as it controls cytokine production and responses in other T cell lineages, modulating their differentiation and function. We sought to determine if ZFP36L1 is also important for Tfh cell biology. In this study, we show expression of ZFP36L1 by Tfh cells. We selectively delete ZFP36L1 from Tfh cells and analyze the effect this has on the GCs. Surprisingly, we find the GC response and affinity maturation is resilient to deletion of ZFP36L1 from Tfh cells.

immunology↗

bioRxiv2026

Antigen accumulation in the B cell follicle is impaired in aged mice

Vaccine responses are impaired in aged mice and older people. An essential early step in mounting successful responses to vaccines is the delivery of antigens from the site of injection to the draining lymph node. This study tested the hypothesis that particle drainage to the lymph node is impaired in older mice after intramuscular injection. We observed fewer 20nm nanoparticles in the B cell follicle of the draining lymph node in aged mice after intramuscular injection. However, there was no significant difference in the abundance of larger 1000nm particles in the lymph nodes of aged mice, which are typically transported to the lymph node by antigen presenting cells. This data suggests that access of smaller antigens to the B cell follicle is impaired in ageing and may have implications for the initiation of T and B cell responses after vaccination.

immunology↗

bioRxiv2025

Mucosal B cell memory selection integrates tissue-specific microbial cues via the IgA BCR

B cells engender plasma cells (PCs) and memory B cells (MBCs) to combat recurrent pathogens. While B cell receptor (BCR) affinity dictates fate decisions in clonally-restricted set-ups, the driving factors in more complex systems remain unknown. Here, we show that memory selection during mucosal infection is imprinted by inherent cues from barrier tissues: lungs skew selection towards MBCs while the gut favors PC entry, even in response to the same pathogen. This divergence is linked to differential BCR isotype usage across barrier tissues rather than to affinity. In the gut, the commensal-induced TGF-{beta}-rich milieu promotes B cell class-switching to IgA. Consequently, the IgA BCR bias selection towards PCs, a process that is counteracted by its cytosolic tail domain. Overall, mucosal B cell selection integrates tissue-specific cues by strongly relying on BCR isotype usage rather than affinity, with implications for nasal and oral vaccine development. One sentence summaryDivergent B cell memory strategies evolved in lung and gut mucosa to counteract recurrent pathogens.

immunology↗

bioRxiv2024

RNA-binding proteins control the G2-M checkpoint of the germinal centre B cell

How germinal centre (GC) B cells undergo rapid cell division while maintaining genome stability is poorly understood. Here, we show that the RNA-binding proteins ZFP36L1 and ZFP36L2 act downstream of antigen-sensing and protect GC B cells from replication stress by controlling a cell cycle-related RNA post-transcriptional regulon. ZFP36L1 and ZFP36L2 safeguard faithful completion of mitosis by restraining the expression of CDK1 and cyclin B1, whilst controlling their activity through regulation of a p21-mediated negative feedback loop. In the absence of ZFP36L1 and ZFP36L2, GC B cells arrest in G2-M and die by apoptosis, resulting in curtailed GC responses. This is associated with stalling of the DNA replication fork at active replication initiation zones, which causes replication stress and increased activity of the ATR/CHK1 DNA damage response. Our findings reveal that gene regulation by RNA-binding proteins is essential for a functional G2-M checkpoint to operate in GC B cells.

immunology↗

bioRxiv2023

B cells from aged mice do not have intrinsic defects in affinity maturation

Affinity maturation, the progressive increase in serum antibody affinity after vaccination, is an essential process that contributes to an effective humoral response against vaccines and infections. Germinal centres (GCs) are key for affinity maturation, as they are where B cells undergo somatic hypermutation of their immunoglobulin genes in the dark zone, before going through positive selection in the light zone via interactions with T follicular helper cells and follicular dendritic cells. In aged mice, affinity maturation has been shown to be impaired, but whether B cell-intrinsic factors contribute to this defect remains unclear. In this study, we show that B cells from aged B cell receptor transgenic mice are able to become GC B cells, which are capable of receiving positive selection signals to a similar extent as B cells from young adult mice. Consistent with this, ageing also does not impact the ability of B cells to undergo somatic hypermutation and acquire affinity-enhancing mutations. Together, this shows that there are no B cell-intrinsic defects in affinity maturation with age when the B cell receptor repertoire is constant.

immunology↗

bioRxiv2022

Plasma cell maintenance and antibody secretion are under the control of Sec22b-mediated regulation of organelle dynamics

Despite the essential role of plasma cells in health and disease, the cellular mechanisms controlling their survival and secretory capacity are still poorly understood. Here, we identified the SNARE Sec22b as a unique and critical regulator of plasma cell maintenance and function. In absence of Sec22b, plasma cells were barely detectable and serum antibody titres were dramatically reduced. Accordingly, Sec22b deficient mice fail to mount a protective immune response. At the mechanistic level, we demonstrated that Sec22b is indispensable for efficient antibody secretion but also for plasma cell fitness through the regulation of the morphology of the endoplasmic reticulum and mitochondria. Altogether, our results unveil a critical role for Sec22b-mediated regulation of plasma cell biology through the control of organelle dynamics.

immunology↗

bioRxiv2021

The memory B cell response to influenza vaccination is impaired in older persons

Influenza imparts an age-related increase in mortality and morbidity. The most effective countermeasure is vaccination; however, vaccines offer modest protection in older adults. To investigate how ageing impacts the memory B cell response we tracked haemagglutinin specific B cells by indexed flow sorting and single cell RNA sequencing in twenty healthy adults administered the trivalent influenza vaccine. We found age-related skewing in the memory B cell compartment six weeks after vaccination, with younger adults developing haemagglutinin specific memory B cells with an FCRL5+ "atypical" phenotype, showing evidence of somatic hypermutation and positive selection, which happened to a lesser extent in older persons. We confirmed the germinal center ancestry of these FCRL5+ "atypical" memory B cells using scRNASeq from fine needle aspirates of influenza responding human lymph nodes and paired blood samples. Together, this study shows that the aged human germinal center reaction and memory B cell response following vaccination is defective. SummaryImmune responses to vaccination wane with age. Using single cell RNA sequencing of influenza vaccine specific B cells, this study delineates changes in B cell memory generation, antibody mutation and their subsequent selection in older persons.

immunology↗

bioRxiv2020

A booster dose enhances immunogenicity of the COVID-19 vaccine candidate ChAdOx1 nCoV-19 in aged mice

The spread of SARS-CoV-2 has caused a global pandemic that has affected almost every aspect of human life. The development of an effective COVID-19 vaccine could limit the morbidity and mortality caused by infection, and may enable the relaxation of social distancing measures. Age is one of the most significant risk factors for poor health outcomes after SARS-CoV-2 infection, therefore it is desirable that any new vaccine candidates should elicit a robust immune response in older adults. Here, we test the immunogenicity of the adenoviral vectored vaccine ChAdOx1 nCoV-19 (AZD-1222) in aged mice. We find that a single dose of this vaccine induces cellular and humoral immunity in aged mice, but at a reduced magnitude than in younger adult mice. Furthermore, we report that a second dose enhances the immune response to this vaccine in aged mice, indicating that a primeboost strategy may be a rational approach to enhance immunogenicity in older persons.

immunology↗

bioRxiv2020

Intrinsic defects in lymph node stromal cells underpin poor germinal center responses during aging

The failure to generate enduring humoral immunity after vaccination is a hallmark of advancing age. This can be attributed to a reduction in the germinal center response, which generates long-lived antibody-secreting cells that provide protection against (re)infection. Despite intensive investigation into the effect of age on the lymphoid compartment, the primary cellular defect that causes impaired germinal centers in aging has not been identified. Herein we demonstrate that aging reduces the capacity of germinal center-associated stromal cells to respond to vaccination. Heterochronic parabiosis and mathematical modeling demonstrate that a poor stromal cell response limits the size of the germinal center. This study reveals that age-associated defects in stromal cells are a significant barrier to efficacious vaccine responses in older individuals.

immunology↗