Hi all,
Tomorrow I will present a Nature Immunology article from Mark Shlomchik's group that describes the role of PD-1 signaling in plasma cell formation (attached). We've heard a lot about PD-1 as an inhibitory signal for T cells, especially CD8s, that maintains them in an "exhausted" state. Here, they investigate the role of PD-1 signaling in the humoral immune response. Unexpectedly, they found that PD-1 signaling is necessary for optimal generation of antibody forming cells and, to a lesser extent, memory B cells. They provide preliminary evidence that follicular helper T cells expressing PD-1 respond to PD-1 ligands expressed by germinal center B cells. The absence of this signal increases numbers of Tfh, but decreases their ability to produce cytokines necessary to help antibody production.
http://pig.wikidot.com/local--files/forum:new-thread/PD-1%20and%20GC.pdf
