UNASSIGNED: @entity1961 (+) @entity3744 (+) regulatory T cells (Treg) are necessary for the maintenance of self-tolerance and T cell homeostasis. This population is kept in stable frequencies in secondary lymphoid organs for the majority of lifetime, despite permanent thymic emigration or in face of thymic involution. A continuous competition is expected to occur between recently thymus-emigrated and resident Treg cells (either natural or post-thymically-induced). In the present work, we analyzed the renewal dynamics of Treg cells compared to @entity1961 (+) @entity3744 (-) conventional T cells (Tconv), using protocols of single or successive T cell transfers into syngeneic euthymic or lymphopenic (nu/nu or @entity6233 (-/-) ) @entity19 , respectively. Our results show a higher turnover for Treg cells in the peripheral compartment, compared to Tconv, when B cell-sufficient euthymic or nude hosts are studied. This increased renewal within the Treg pool, evidenced by the greater replacement of resident Treg cells by donor counterparts, correlates with augmented rates of proliferation and is not modified following temporary environmental perturbations induced by inflammatory state or microbiota alterations. Notably, the preferential substitution of Treg lymphocytes was not observed in @entity6233 (-/-) hosts. We showed that limited B cell replenishment in the @entity6233 (-/-) hosts decisively contributes for the altered peripheral T cell homeostasis. Accordingly, weekly transfers of B cells to @entity6233 (-/-) hosts rescued the preferential substitution of Treg lymphocytes. Our study discloses a new aspect of T cell homeostasis that depends on the presence of B lymphocytes to regulate the relative incorporation of recently-arrived Treg and Tconv cells in the peripheral compartment. This article is protected by copyright. All rights reserved.

Enhanced renewal of regulatory t cells in relation to XXXX (+) conventional t lymphocytes in the peripheral compartment.

@entity19 :: ('10090', 'Species') :: ['mice'] @entity3744 :: ('20371(Tax:10090)', 'Gene') :: ['Foxp3'] @entity1961 :: ('12504(Tax:10090)', 'Gene') :: ['CD4'] @entity6233 :: ('19374(Tax:10090)', 'Gene') :: ['RAG2']
@entity1961 :: (12504(Tax:10090),Gene) :: ['cd4']
