The influence of immune complex-bearing follicular dendritic cells on the IgM response, Ig class switching, and production of high affinity IgG.

摘要: It is believed that Ag in immune complexes (ICs) on follicular dendritic cells (FDCs) selects high affinity B and promotes maturation. However, selection has been documented the absence of readily detectable ICs FDCs, suggesting FDC-ICs may not be important. These results prompted experiments to test hypothesis IC-bearing murine FDCs can promote IgG responses by selecting after stimulating naive IgM+ mature class switch. Coculturing λ+ cells, (4-hydroxy-3-nitrophenyl)acetyl-chicken γ-globulin (CGG) + anti-CGG ICs, CGG-primed T resulted FDC-lymphocyte clusters production anti-4-hydroxy-5-iodo-3-nitrophenyl acetyl. Class switching was indicated a shift from IgM IgG, maturation change mostly low first week virtually all acetyl second week. were easily presence bearing appropriate but FDCs. Free plus only apparent when bore ICs. activation-induced cytidine deaminase (AID) dependent, blocking FDC-CD21 ligand-B cell CD21 interactions inhibited FDC-IC-mediated enhancement AID response. In short, these data support concept production, switching, further suggest help select produce IgG.