Binding of HLA-G to ITIM-bearing Ig-like transcript 2 receptor suppresses B cell responses.
Article Details
- CitationCopy to clipboard
Naji A, Menier C, Morandi F, Agaugue S, Maki G, Ferretti E, Bruel S, Pistoia V, Carosella ED, Rouas-Freiss N
Binding of HLA-G to ITIM-bearing Ig-like transcript 2 receptor suppresses B cell responses.
J Immunol. 2014 Feb 15;192(4):1536-46. doi: 10.4049/jimmunol.1300438. Epub 2014 Jan 22.
- PubMed ID
- 24453251 [ View in PubMed]
- Abstract
Inhibition of B cells constitutes a rational approach for treating B cell-mediated disorders. We demonstrate in this article that the engagement of the surface Ig-like transcript 2 (ILT2) inhibitory receptor with its preferential ligand HLA-G is critical to inhibit B cell functions. Indeed, ILT2-HLA-G interaction impedes both naive and memory B cell functions in vitro and in vivo. Particularly, HLA-G inhibits B cell proliferation, differentiation, and Ig secretion in both T cell-dependent and -independent models of B cell activation. HLA-G mediates phenotypic and functional downregulation of CXCR4 and CXCR5 chemokine receptors on germinal center B cells. In-depth analysis of the molecular mechanisms mediated by ILT2-HLA-G interaction showed a G0/G1 cell cycle arrest through dephosphorylation of AKT, GSK-3beta, c-Raf, and Foxo proteins. Crucially, we provide in vivo evidence that HLA-G acts as a negative B cell regulator in modulating B cell Ab secretion in a xenograft mouse model. This B cell regulatory mechanism involving ILT2-HLA-G interaction brings important insight to design future B cell-targeted therapies aimed at reducing inappropriate immune reaction in allotransplantation and autoimmune diseases.