Signaling pathways in T follicular helper cells.
Th cell functional subsets have unique transcriptional programs that form the molecular basis for T cell differentiation and functions. T follicular helper (TFH) cells have emerged as the main providers of T cell help to B cells during the germinal center (GC) reaction, where B cells undergo selection events through competition for Ag and for access to GC T cell-mediated prosurvival and differentiation signals. Because T cell help is one limiting factor for GC B cells, the molecular mechanisms controlling TFH cell abundance and functionality are central to the GC reaction and generation of long-term humoral immunity. Two signaling pathways are absolutely critical for TFH cells: phosphoinositide-3 kinase pathway and the signaling lymphocyte activation molecule-associated protein. In this review, the molecular mechanisms constituting the signaling network in TFH cells will be explored.
Rolf
Julia
J
Laboratory of Lymphocyte Signalling and Development, Babraham Institute, Cambridge, United Kingdom.
Fairfax
Kirsten
K
Turner
Martin
M
D000818:Animals; D018858:Germinal Center / Q000276:immunology*; D006801:Humans; D008213:Lymphocyte Activation / Q000276:immunology; D015398:Signal Transduction / Q000276:immunology*; D016176:T-Lymphocyte Subsets / Q000276:immunology*; D006377:T-Lymphocytes, Helper-Inducer / Q000276:immunology*