Biology subjects

Ellis, R.

Publications and source records attributed to Ellis, R..

3 recordsLinked to original sources

bioRxiv2021

Two subsets of human marginal zone B cells resolved by global analysis of lymphoid tissues and blood

B cells generate antibodies that are essential for immune protection. Major events driving B cell responses occur in lymphoid tissues, which guide antigen acquisition and support cellular interactions, yet complexities of B cell subsets in human lymphoid tissues are poorly understood. Here we perform undirected, global profiling of B cells in matched human lymphoid tissues from deceased transplant organ donors and tracked dissemination of B cell clones. In addition to identifying unanticipated features of tissue-based B cell differentiation, we resolve two clonally independent subsets of marginal zone B cells that differ in cell surface and transcriptomic profiles, tendency to disseminate, distribution bias within splenic marginal zone microenvironment and immunoglobulin repertoire diversity and hypermutation frequency. Each subset is represented in spleen, gut-associated lymphoid tissue, mesenteric lymph node, and also blood. Thus, we provide clarity and diffuse controversy surrounding human MZB - the elephant in the room of human B cell biology.

immunology↗

bioRxiv2020

Human marginal zone B cell development from early T2 progenitors

B cells emerge from the bone marrow as transitional (TS) B cells that differentiate through T1, T2 and T3 stages to become naive B cells. We have identified a bifurcation of human B cell maturation from the T1 stage forming IgMhi and IgMlo developmental trajectories. IgMhi T2 cells have higher expression of 4{beta}7 integrin and lower expression of IL4 receptor (IL4R) compared to the IgMlo branch and are selectively recruited into gut-associated lymphoid tissue. IgMhi T2 cells also share transcriptomic features with marginal zone B cells (MZB). Lineage progression from T1 cells to MZB via an IgMhi trajectory is identified by pseudotime analysis of scRNA-sequencing data. Reduced frequency of IgMhi gut homing T2 cells is observed in severe SLE and is associated with reduction of MZB and their putative IgMhi precursors. The collapse of the gut-associated MZB maturational axis in severe SLE affirms its existence and importance for maintaining health.

cell biology↗

bioRxiv2020

Regional transmission and reassortment of 2.3.4.4b highly pathogenic avian influenza (HPAI) viruses in Bulgarian poultry 2017/18

Between 2017 and 2018, several farms across Bulgaria reported outbreaks of H5 HPAI viruses. In this study we use genomic and traditional epidemiological analyses to trace the origin and subsequent spread of these outbreaks within Bulgaria. Both methods indicate two separate incursions, one restricted to the North-Eastern region of Dobrich, and another largely restricted to Central and Eastern Bulgaria including places such as Plovdiv, Sliven and Stara Zagora, as well as one virus from the Western region of Vidin. Both outbreaks likely originate from different European 2.3.4.4b virus ancestors circulating in 2017. The viruses were likely introduced by wild birds or poultry trade links in 2017 and have continued to circulate, but due to lack of contemporaneous sampling and sequences from wild bird viruses in Bulgaria, the precise route and timing of introduction cannot be determined. Analysis of whole genomes indicates complete lack of reassortment in all segments but the MP, which presents as multiple smaller clusters associated with different European 2.3.4.4b viruses. Ancestral reconstruction of host states of the HA gene of viruses involved in the outbreaks suggests that transmission is driven by domestic ducks into galliform poultry. Thus, according to present evidence we suggest that surveillance of domestic ducks as epidemiologically relevant species for subclinical infection. Monitoring spread due to movement between farms within regions and links to poultry production systems in European countries can help to predict and prevent future outbreaks.

microbiology↗