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Mousa, H.

Publications and source records attributed to Mousa, H..

2 recordsLinked to original sources

Cross-tissue immune cell analysis reveals tissue-specific adaptations and clonal architecture across the human body

Despite their crucial role in health and disease, our knowledge of immune cells within human tissues remains limited. Here, we surveyed the immune compartment of 15 tissues of six deceased adult donors by single-cell RNA sequencing and paired VDJ sequencing. To systematically resolve immune cell heterogeneity across tissues, we developed CellTypist, a machine learning tool for rapid and precise cell type annotation. Using this approach, combined with detailed curation, we determined the tissue distribution of 45 finely phenotyped immune cell types and states, revealing hitherto unappreciated tissue-specific features and clonal architecture of T and B cells. In summary, our multi-tissue approach lays the foundation for identifying highly resolved immune cell types by leveraging a common reference dataset, tissue-integrated expression analysis and antigen receptor sequencing. One Sentence SummaryWe provide an immune cell atlas, including antigen receptor repertoire profiling, across lymphoid and non-lymphoid human tissues.

immunology

The MS remyelinating drug bexarotene (an RXR agonist) promotes induction of human Tregs and suppresses Th17 differentiation in vitro

The retinoid X receptor (RXR) agonist bexarotene has recently been shown to promote remyelination in individuals with multiple sclerosis. Murine studies demonstrated that RXR agonists can have anti-inflammatory effects by enhancing the ability of all-trans-retinoic acid (tRA), the primary active metabolite of vitamin A, to promote T regulatory cell (Treg) induction and reduce Th17 differentiation in vitro, following stimulation of naive CD4 cells in the presence of TGF-{beta}. Stimulating naive human CD4 T cells for 7 days, in the presence of either Treg or Th17 skewing cytokines {+/-} bexarotene (1 M), {+/-} other RXR agonists (9CisRA and NRX 194204), or {+/-} tRA (100 nM) shows that RXR agonists, including bexarotene, are capable of tipping the human Treg/Th17 axis in favour of Treg induction. Furthermore, this occurs independently of tRA and retinoic acid receptor (RAR) signalling. Tregs induced in the presence of bexarotene express many of the canonical markers of T cell regulation and are functionally suppressive in vitro. These findings support a potential immunomodulatory role for bexarotene and highlight the possible therapeutic application of RXR agonists in autoimmune disease, with bexarotenes pro-remyelinating effects making multiple sclerosis a particularly attractive disease target. Significance StatementThe pan-retinoid X receptor (RXR) agonist bexarotene has recently been shown to promote remyelination in patients with multiple sclerosis. Here we demonstrate that bexarotene, and other RXR agonists have immunomodulating effects, tipping the Th17/T regulatory cell (Treg) differentiation axis in favour of Treg development. These findings lend support to the idea of developing RXR agonists as treatments of autoimmune diseases, in particular multiple sclerosis.

immunology