Biology subjects

Marsden, B. D.

Publications and source records attributed to Marsden, B. D..

3 recordsLinked to original sources

bioRxiv2025

Cell type specific analysis of ALS associated proteins reveals immune-regulated targets

A substantial fraction of amyotrophic lateral sclerosis (ALS)-associated proteins remain poorly characterized, in part because of the limited availability of validated research antibodies. We established knockout (KO)-based antibody characterization workflows and demonstrated that widely used antibodies against the major ALS-associated protein C9orf72 lacked specificity (Laflamme et al., 2019). We subsequently scaled this framework to systematically benchmark research antibodies, revealing that up to 61% fail to perform as recommended by manufacturers (Ayoubi et al., 2023). Here, we extend this approach by establishing the ALS-Reproducible Antibody Platform (ALS-RAP), a comprehensive effort to generate a publicly available dataset of KO-validated antibodies targeting proteins encoded by ALS risk genes. In total, we characterized 303 antibodies against 33 ALS-associated proteins to identify high-quality reagents for use in western blot, immunoprecipitation, and immunofluorescence. Using these antibodies, we profiled protein levels across human induced pluripotent stem cell (iPSC)-derived and primary neurological cell types. These analyses revealed diverse cellular distributions and higher levels of several ALS-associated proteins in glial populations, consistent with emerging evidence for immune contributions to ALS. Together, ALS-RAP provides a validated antibody toolbox and protein expression resource to support the study of ALS-associated proteins.

neuroscience↗

bioRxiv2024

Early regional lymph node activation drives influenza vaccine responses in an ancestrally diverse cohort

Early in vivo dynamics of human immune-cell activation across regionally activated lymphoid tissue sites upon immunisation are poorly characterised in ancestrally diverse individuals. Here, we profiled draining and non-draining axillary lymph nodes (dLNs and ndLNs) by ultrasound-guided fine-needle aspiration (FNA) in 13 Black and Asian ancestry individuals, before and 3-7 days after vaccination with adjuvanted influenza vaccine. Draining but not ndLNs rapidly increased in size post-vaccination, by day 3, with distinct cellular dynamics determined through single cell multiomics. Dissecting LN cellular diversity into 42 lymphoid and non-lymphoid cell states, post-vaccination cell abundance changes were observed across all LNs, but dLNs were specifically characterised by CD4+ T follicular helper (CD4+ Tfh) cell expansion. Gene expression analysis revealed a dLN post-vaccination hub of multicellular activity defined by CD4+ Tfh signalling, cross-compartmental activation, translation, and enhanced antigen-presentation capacity. Thus, robust responses to intramuscular immunisation transcending ancestral inter-individual variation are elicited through temporal, anatomical and cellular lymphatic co-ordination with implications for vaccine design in ancestrally diverse populations. SummaryIn this study of ancestrally diverse young adults, the temporarily co-ordinated response to an adjuvanted influenza vaccine at lymph nodes local to (draining) and distal from (non-draining) the injection site, reveals early regulation of cellular kinetics and anatomical hierarchy of the innate and adaptive immune responses.

immunology↗

bioRxiv2024

CD4+ tissue resident memory Th17 cells drive IL-17A-mediated joint pathology in Spondyloarthritis

ObjectivesInterleukin (IL)-17A is a key driver of Spondyloarthritis (SpA) joint pathology. We aimed to identify its cellular source in synovial tissue from patients with two forms of SpA namely Axial SpA (AxSpA) and Psoriatic arthritis (PsA). MethodsSynovial tissue from patients with SpA was profiled using single-cell RNA sequencing (scRNA-seq: AxSpA, n=5 and PsA, n=6) or spatial RNA profiling (PsA, n=4). CellPhoneDB was used to infer cell-cell communication. Tissue resident memory Th17 (TRM17)-like cells were generated in vitro using blood memory CD4+ T cells from SpA patients. An epigenetic inhibitor library, siRNA and clustered regularly interspaced short palindromic repeats (CRISPR) were used to identify epigenetic regulator(s) for TRM17. ResultsscRNA-seq showed that CD4+CXCR6+ TRM17 cells are the predominant spontaneous IL17A producers in SpA synovium. Cell-cell communication and single-cell spatial analysis support the interaction between TRM17 and CLEC10A+ dendritic cells, which were activated in SpA. Both sublining and lining fibroblasts in SpA synovium showed evidence of IL-17A activation. In vitro-generated CD4+ TRM17-like cells phenocopied joint tissue TRM17, producing IL-17A/F upon T cell receptor (TCR) stimulation, which was further enhanced by cytokines. Perturbation of BRD1 inhibited the generation of TRM17-like cells. ConclusionsCD4+ TRM17 cells are the predominant source of IL-17A in SpA synovial tissue. TCR stimulation is essential for the secretion of IL-17A by CD4+TRM17-like cells. The epigenetic regulator BRD1 contributes to the generation of CD4+TRM17. Depleting CD4+TRM17 cells in SpA is thus a therapeutic strategy with potential to induce long-term remission. Key messagesO_ST_ABSWhat is already known on this topicC_ST_ABSInterleukin (IL)-17A plays a key role in the immunopathogenesis of Spondyloarthritis (SpA), but its cellular source in joint tissue has not been determined previously. The induction and accumulation of CD4+ tissue resident memory Th17 (TRM17) cells following the clearance of pathogens has been described in skin, lung and kidney. Whether CD4+ TRM17 cells also accumulate in the joint and contribute to the pathology of SpA is not clear. What this study addsO_LICD4+ TRM17 cells are present in SpA synovial tissue and are the predominant source of IL17A C_LIO_LICD4+ TRM17 cells in SpA joints express IL17A without any in vitro exogenous stimulation C_LIO_LIT cell receptor (TCR) rather than cytokine stimulation is essential for IL-17A production by CD4+ TRM17-like cells C_LIO_LIThe epigenetic regulator BRD1 contributes to the generation of CD4+ TRM17-like cells. C_LI How this study might affect research, practice or policyOur findings identify CD4+ TRM17 cells as the primary source of IL-17A in SpA synovium, a previously unrecognized role for these cells. Key questions remain: How do CD4+ TRM17 cells relate to IL-17A producers in synovial fluid? What mechanisms induce and maintain them in the joint? How do they interact with other cells to promote arthritis? These questions warrant further investigation. In addition, our data suggest that targeting CD4+ TRM17 cells, the "factory" of IL-17A in SpA synovial tissue, has the potential to induce long-term remission, encouraging future efforts to develop new therapies to deplete CD4+ TRM17 cells in SpA.

immunology↗