LLT1 and CD161 Expression in Human Germinal Centers Promotes B Cell Activation and CXCR4 Downregulation

作者：Llibre Alba; Lopez Macias Constantino; Marafioti Teresa; Mehta Hema; Partridge Amy; Kanzig Carina; Rivellese Felice; Galson Jacob D; Walker Lucy J; Milne Paul; Phillips Rodney E; Kelly Dominic F; Freeman Gordon J; El Shikh Mohey Eldin; Klenerman Paul; Willberg Christian B

来源：The Journal of Immunology, 2016, 196(5): 2085-2094.

DOI：10.4049/jimmunol.1502462

Germinal centers (GCs) are microanatomical structures critical for the development of high-affinity Abs and B cell memory. They are organized into two zones, light and dark, with coordinated roles, controlled by local signaling. The innate lectin-like transcript 1 (LLT1) is known to be expressed on B cells, but its functional role in the GC reaction has not been explored. In this study, we report high expression of LLT1 on GC-associated B cells, early plasmablasts, and GC-derived lymphomas. LLT1 expression was readily induced via BCR, CD40, and CpG stimulation on B cells. Unexpectedly, we found high expression of the LLT1 ligand, CD161, on follicular dendritic cells. Triggering of LLT1 supported B cell activation, CD83 upregulation, and CXCR4 downregulation. Overall, these data suggest that LLT1-CD161 interactions play a novel and important role in B cell maturation within the GC in humans.

• 出版日期2016-3-1