Biology subjects

Garside, P.

Publications and source records attributed to Garside, P..

7 recordsLinked to original sources

bioRxiv2024

IL-6 and IL-27 negatively regulate CRTAM-expressing CD4+ T-cells associated with lymphoid-driven synovitis.

ABSTRACT-Joint pathology in rheumatoid arthritis is heterogeneous, with histology providing evidence of fibroblast-driven, myeloid-driven, and lymphoid-driven synovitis. However, the immuno-modulatory pathways underlying their development remain unclear. Profiling synovial tissues from rheumatoid arthritis patients and mice with antigen-induced arthritis, we identified a subset of synovial infiltrating CD4+ T-cells expressing CRTAM (class-I MHC-restricted T-cell-associated molecule). In human synovial biopsies, CRTAM correlated with the expression of effector cytokines (IL21, IFNG), chemokine receptors (CXCR3, CXCR4, CCR5), granzymes (GZMA, GZMB, GZMK), and regulatory factors (TIGIT, EOMES, BATF) linked with T-cell-mediated immunity. Studies of antigen-induced arthritis showed that CRTAM+CD4+ T-cells accumulate in the inflamed synovium following disease onset. CRTAM+CD4+ T-cells were particularly abundant in synovial tissue from Il27ra-/- mice displaying ectopic lymphoid-like structures. CADM1 (cell adhesion molecule-1), the endogenous ligand for CRTAM, was also expressed in human synovitis and synovial tissues from wild-type, Il6ra-/-, and Il27ra-/- mice with antigen-induced arthritis. Cells expressing human CADM1 included synovial fibroblasts and subsets of monocytic and CD19+ cells. Considering the ex vivo regulation of CRTAM, we identified that activation of naive CD4+ T-cell increased CRTAM expression. This induction was blocked by IL-6 and IL-27, with further studies identifying a role for STAT3 in controlling the CRTAM transcriptional repressor, ZEB1. These results provide insights into the cytokine control of CRTAM on CD4+ T-cells and support the involvement of CRTAM+CD4+ T-cells in lymphoid-driven synovitis.

immunology↗

bioRxiv2022

A discovery pipeline for identification and in vivo validation of drugs that alter T cell/ dendritic cell interaction

The interaction between T cells and dendritic cells (DC) is central to determining whether or not an adaptive immune response develops. Autoimmune diseases like rheumatoid arthritis result from inappropriate activation of self-antigen specific T cells, therefore targeting the interaction between T cells and DCs is of considerable therapeutic interest. Here, we describe the development and validation of a drug development platform that includes a high-throughput image-based screening assay and a complementary in vivo model. The in vitro assay directly measures the ability of compounds to influence the interaction of T cells with DC, both negatively and positively. While the in vivo model allows the validation of hit molecules directly in the lymph nodes of intact animals. Using this pipeline, we identify a new function for the protein kinase inhibitor AS703569 by inhibiting T cell/ DC interactions in vitro and in vivo.

immunology↗

bioRxiv2022

Orally administered antigen can reduce or exacerbate pathology in an animal model of inflammatory arthritis dependent upon the timing of administration

Currently, treatments for rheumatoid arthritis (RA) are focussed on treatment of disease symptoms rather than addressing the cause of disease, which could lead to remission and cure. Central to disease development is the induction of autoimmunity through a breach of self-tolerance. There is considerable research in RA focussed on antigens and approaches to re-establish antigen specific tolerance. A crucial step in this research is to employ appropriate animal models to test prospective antigen specific immunotherapies, preferably in the context of joint inflammation. In this short communication, we use our previously developed model of antigen specific inflammatory arthritis in which OVA-specific TcR tg T cells drive breach of tolerance to endogenous antigens to determine the impact that the timing of therapy administration has upon disease progression. Using antigen feeding to induce tolerance we demonstrate that administration prior to articular challenge results in a reduced disease score as evidenced by pathology and serum antibody responses. By contrast, feeding antigen after articular challenge had the opposite effect and resulted in the exacerbation of pathology. Although preliminary, these data suggest that the timing of antigen administration may be key to the success of tolerogenic immunotherapies. This has important implications for the timing of potential tolerogenic therapies in patients.

immunology↗

bioRxiv2020

TCRβ Sequencing Reveals Spatial and Temporal Evolution of Clonal CD4 T cell Responses in a Breach of Tolerance Model of Inflammatory Arthritis

Effective tolerogenic intervention in Rheumatoid Arthritis (RA) will rely upon understanding the evolution of articular antigen specific CD4 T cell responses. TCR clonality of endogenous CD4 T cell infiltrates in early inflammatory arthritis was assessed to monitor evolution of the TCR repertoire in the inflamed joint and associated lymph node (LN). Mouse models of antigen-induced breach of self-tolerance and chronic polyarthritis were used to recapitulate early and late phases of RA. The infiltrating endogenous, antigen experienced CD4 T cells in inflamed joints and LNs were analysed using flow cytometry and TCR{beta} sequencing. TCR repertoires from inflamed late phase LNs displayed increased clonality and diversity compared to early phase LNs, while inflamed joints remained similar with time. Repertoires from late phase LNs accumulated clones with a diverse range of TRBV genes, while inflamed joints at both phases contained clones expressing similar TRBV genes. Repertoires from LNs and joints at the late phase displayed reduced CDR3{beta} sequence overlap compared to the early disease phase, however the most abundant clones in LNs accumulate in the joint at the later phase. The results indicate CD4 T cell repertoire clonality and diversity broadens with progression of inflammatory arthritis and is first reflected in LNs before mirroring in the joint. These observations imply that antigen specific tolerogenic therapies could be more effective if targeted at earlier phases of disease when CD4 T cell clonality is least diverse.

immunology↗

bioRxiv2020

Tolerance induction in memory CD4 T cells is partial and reversible

Memory T cells respond rapidly in part because they are less reliant on heightened levels of costimulatory molecules. This presents challenges to silencing memory T cells in tolerance strategies for autoimmunity or allergy. We find that memory CD4 T cells generated by infection or immunisation survive secondary activation with antigen delivered without adjuvant, regardless of their location in secondary lymphoid organs or peripheral tissues. These cells were, however, functionally altered following a tertiary immunisation with antigen and adjuvant, proliferating poorly but maintaining their ability to produce inflammatory cytokines. Transcriptional and cell cycle analysis of these memory CD4 T cells suggest they are unable to commit fully to cell division potentially because of low expression of DNA repair enzymes. In contrast, these memory CD4 T cells could proliferate following tertiary reactivation by viral re-infection. These data suggest that tolerance induction in memory CD4 T cells is partial and can be reversed.

immunology↗

bioRxiv2019

Developing a xenograft model of human vasculature in the mouse ear pinna

Humanised xenograft models allow for the analysis of human tissue within a physiological environment in vivo. However, current models often rely on the angiogenesis and ingrowth of recipient vasculature to perfuse tissues, preventing analysis of biological processes and diseases involving human blood vessels. This limits the effectiveness of xenografts in replicating human physiology and may lead to issues with translating findings into human research. We have designed a xenograft model of human vasculature to address this issue. Human subcutaneous fat was cultured in vitro to promote blood vessel outgrowth prior to implantation into immunocompromised mice. We demonstrate that implants survived, retained human vasculature and anastomosed with the circulatory system of the recipient mouse. Significantly, by performing transplants into the ear pinna, this system enabled intravital observation of xenografts by multiphoton microscopy, allowing us to visualise the steps leading to vascular cytoadherence of erythrocytes infected with the human parasite Plasmodium falciparum. This model represents a useful tool for imaging the interactions that occur within human tissues in vivo and permits visualization of blood flow and cellular recruitment in a system which is amenable to intervention for various studies in basic biology together with drug evaluation and mechanism of action studies.

pathology↗

bioRxiv2017

T cell activation and the HLA locus associate with latent infections of human African trypanosomiasis

Infections by many pathogens can result in a wide range of phenotypes, from severe to mild, or even asymptomatic. Understanding the genetic basis of these phenotypes can lead to better tools to treat patients or detect reservoirs. To identify human genetic factors that contribute to symptoms diversity, we examined the range of disease severities caused by the parasite T. b. gambiense, the primary cause of human African trypanosomiasis (HAT). We analyzed the transcriptomes of immune cells from both symptomatic HAT cases and individuals with latent infections. Our analysis identified several genes and pathways that associated with the latent phenotype, primarily suggesting increased T and B cell activation in HAT patients relative to latent infections. We also used these transcriptome data to conduct an exome-wide single nucleotide polymorphism (SNP) association study. This suggested that SNPs in the human major histocompatibility locus (HLA) associate with severity, supporting the transcription data and suggesting that T cell activation is a determining factor in outcome. Finally, to establish if T cell activation controls disease severity, we blocked co-stimulatory dependent T cell activation in an animal model for HAT. This showed that reducing T cell activation during trypanosome infection improves symptoms and reduces parasitemia. Our data has used a combination of transcriptome-wide analysis and an in vivo model to reveal that T cell activation and the HLA locus associate with the development of symptoms during HAT. This may open new avenues for the development of new therapeutics and prognostics.

genetics↗