Yassir Hassen

University of Chicago, Chicago, Illinois, United States

Are you Yassir Hassen?

Claim your profile

Publications (1)3.99 Total impact

  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Program death-1 (PD-1) has been documented to negatively regulate immune responses. However, the cellular and molecular mechanisms for PD-1-mediated immune suppression have not been fully elucidated. In this study, we show that loss of PD-1 does not lead to defective induction of CD4(+) T cell anergy in vitro and in vivo. Rather, the absence of PD-1 inhibits the development of inducible CD4(+)Foxp3(+) regulatory T cells (iTregs) induced by TGF-β in vitro. In support of this finding, PD-1 deficiency impairs the generation of iTregs in vivo and leads to development of severe T cell-transfer-induced colitis. Mechanistically, defective iTreg generation in the absence of PD-1 was attributed to the heightened phosphorylation of Akt. Therefore, we first demonstrate that PD-1 controls peripheral T cell tolerance via an anergy-independent but iTreg-dependent mechanism.
    Clinical Immunology 03/2012; 143(2):128-33. DOI:10.1016/j.clim.2012.02.006 · 3.99 Impact Factor