The Poly(C)-binding protein Pcbp2 is essential for CD4+ T cell development and proliferation.

ABSTRACT: Defining the molecular mechanisms that impact T cell maturation and function is important because abnormalities in these processes can lead to immunodeficient states or autoimmunity. RNA-binding proteins (RBPs) have emerged as critical factors in thymopoiesis, immune cell lineage commitment and maintenance, and as modulators of immune responses. The RBP paralogs Pcbp1 and Pcbp2 are widely expressed in the innate and adaptive immune systems and are each essential for mouse development. Pcbp1 has been shown to prevent conversion of CD4+ effector T cells into Foxp3+ regulatory T cells (Treg), with loss of Pcbp1 resulting in increased Treg differentiation. To determine whether Pcbp2 also is required for CD4+ T cell development and function, we derived mice with conditional Pcbp2 deletion in CD4+ T cells and assessed their overall phenotype and proliferative responses to activating stimuli. We found that Pcbp2 is essential for CD4+ T conventional cell (Tconv) proliferation, working through regulation of CD4 receptor co-stimulatory signaling. In addition, our data demonstrate a clear association between Pcbp2 control of Runx1 exon 6 splicing in CD4+ T cells and a specific role for Pcbp2 in the maintenance of peripheral CD4+ lymphocyte population size. Pcbp2 deficiency in the CD4+ lineage did not impact Treg abundance in vivo or function in vitro. Last, we show that Pcbp2 function is required for optimal in vivo Tconv cell activation in a T cell adoptive transfer colitis model system. These data lead us to conclude that Pcbp2 is a critical regulator of T cell signaling and function in the CD4+ lineage. 

ORGANISM(S): Mus musculus

PROVIDER: GSE197059 | GEO | 2022/12/29

REPOSITORIES: GEO