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Biology subjects

Vila de Mucha, M.

Publications and source records attributed to Vila de Mucha, M..

2 recordsLinked to original sources

A post-transcriptional regulatory checkpoint controls the response of tumor-infiltrating cytotoxic CD4+ T cells to immunotherapy

Acquisition of cytotoxic activity in CD4+ T cells (TCTX) can promote potent anti-tumor activity thus holding promise as a therapeutic approach. However, how this activity is regulated remains poorly understood. Here, we demonstrate that tumor-infiltrating CD4+ TCTX activity is restrained by a post-transcriptional regulatory checkpoint. In untreated tumors, CD4+ TCTX exist in a poised state, characterized by abundant Gzmb mRNA but limited Granzyme B (GzmB) protein. Differentiation into poised TCTX is regulated by the Blimp-1-Bcl6 axis and requires type-I interferon signaling. Treatment with anti-CTLA-4 or anti-LAG-3 plus anti-PD-1 removed the block to GzmB protein production by repressing expression of the post-transcriptional regulator Zfp36l1. Constitutive Zfp36l1 expression abrogated the effects of anti-CTLA-4 while deletion of Zfp36l1 and its paralog Zfp36 triggered GzmB protein production and promoted tumor control. These data identify ZFP36/ZFP36L1 as a key post-transcriptional regulatory checkpoint of CD4+ TCTX activity and a potential immunotherapy target in cancer.

immunology↗

A population of CD4+ T cells with a naive phenotype stably polarized to the TH1 lineage

T-bet is the lineage-specifying transcription factor for CD4+ T helper type 1 (TH1) cells. T-bet has also been found in other CD4+ T cell subsets, including TH17 cells and TREG, where it modulates their functional characteristics. However, we lack information on when and where T-bet is expressed during T cell differentiation and how this impacts T cell function. To address this, we traced the ontogeny of T-bet-expressing cells using a fluorescent fate-mapping mouse line. We demonstrate that T-bet is expressed in a subset of CD4+ T cells with naive cell surface markers and that this novel cell population is phenotypically and functionally distinct from conventional naive CD4+ T cells. These cells are also distinct from previously described populations of memory phenotype and stem cell-like T cells. Naive-like T-bet-experienced cells are polarised to the TH1 lineage, predisposed to produce IFN{gamma} upon cell activation, and resist repolarisation to other lineages in vitro and in vivo. These results demonstrate that lineage-specifying factors can function to polarise T cells in the absence of canonical markers of T cell activation and that this has an impact on the subsequent T helper response.

immunology↗