ICOS regulates the generation and function of human CD4+ Treg in a CTLA-4 dependent manner.

Autor: Jian Zheng, Ping-Lung Chan, Yinping Liu, Gang Qin, Zheng Xiang, Kwok-Tai Lam, David B Lewis, Yu-Lung Lau, Wenwei Tu
Jazyk: angličtina
Rok vydání: 2013
Předmět:
Zdroj: PLoS ONE, Vol 8, Iss 12, p e82203 (2013)
Druh dokumentu: article
ISSN: 1932-6203
DOI: 10.1371/journal.pone.0082203
Popis: Inducible co-stimulator (ICOS) is a member of CD28/Cytotoxic T-lymphocyte Antigen-4 (CTLA-4) family and broadly expressed in activated CD4(+) T cells and induced regulatory CD4(+) T cells (CD4(+) iTreg). ICOS-related signal pathway could be activated by the interaction between ICOS and its ligand (ICOSL). In our previous work, we established a cost-effective system to generate a novel human allo-antigen specific CD4(hi) Treg by co-culturing their naïve precursors with allogeneic CD40-activated B cells in vitro. Here we investigate the role of ICOS in the generation and function of CD4(hi) Treg by interrupting ICOS-ICOSL interaction with ICOS-Ig. It is found that blockade of ICOS-ICOSL interaction impairs the induction and expansion of CD4(hi) Treg induced by allogeneic CD40-activated B cells. More importantly, CD4(hi) Treg induced with the addition of ICOS-Ig exhibits decreased suppressive capacity on alloantigen-specific responses. Dysfunction of CD4(hi) Treg induced with ICOS-Ig is accompanied with its decreased exocytosis and surface CTLA-4 expression. Through inhibiting endocytosis with E64 and pepstatin A, surface CTLA-4 expression and suppressive functions of induced CD4(hi) Treg could be partly reversed. Conclusively, our results demonstrate the beneficial role of ICOS-ICOSL signal pathway in the generation and function of CD4(hi) Treg and uncover a novel relationship between ICOS and CTLA-4.
Databáze: Directory of Open Access Journals