Changes in follicular dendritic cell and CD8+ cell function in macaque lymph nodes following infection with SIV251.

Abstract

By virtue of their extensive meshlike network of dendritic processes expressing C3b, C3d and Fc receptors, follicular dendritic cells (FDC) found in lymphoid follicles are able to trap and retain unprocessed antigen in the form of Ag/Ab complexes (1-4). As such these cells provide the microenvironment for germinal centre reactions in which antigen specific B cells proliferate, differentiate into memory cells and antibody forming cell precursors and undergo class switching and affinity maturation. To date FDCs appear to serve two major functions. Firstly to present immunogen in the form of iccosomes to B cells and secondly as a source of of a costimulatory signal(s) required for B cell proliferation (Tew et. al. and Burton et.al., this volume). Although T cells are also required for germinal centre formation in vivo and for cluster formation and proliferation in vitro, little is known about FDC/T cells interactions. An understanding of these roles is achieved by dissecting the cellular and molecular interactions leading to the spontaneous cluster formation and proliferation observed in in vitro cultures of FDC-enriched lymphoid cells 5,6).KeywordsSimian Immunodeficiency VirusFollicular Dendritic CellCostimulatory SignalSimian Immunodeficiency Virus InfectionGerminal Centre Formation