In vitro stimulation of human tonsillar subepithelial B cells: requirement for interaction with activated T cells.
Human tonsillar subepithelial B cells, which are a marginal zone-equivalent B cell subset, respond readily to T-independent type 2 antigens, but not to polyclonal B cell activators in vitro. In this study, subepithelial (SE) B cells were induced to proliferate and mature into plasma cells when co-cultured with activated T cells. The response of SE B cells was not observed when co-cultures were carried out in transwell chambers or in the presence of blocking anti-LFA-1 antibodies, demonstrating the need for a close T-B cell interaction. The presence of soluble CD40 also prevented the B cell response in vitro suggesting a pivotal role of CD40-CD40 ligand interactions. The data are discussed in terms of the T cell dependence of marginal zone (MZ) B cell response and the possible existence of various MZ B cell subsets.
Dono
M
M
Servizio di Immunologia Clinica, Istituto Nazionale per la Ricerca sul Cancro, IST, Genova, Italy. mdono@hp380.ist.unige.it
Zupo
S
S
Massara
R
R
Ferrini
S
S
Melagrana
A
A
Chiorazzi
N
N
Ferrarini
M
M
D001402:B-Lymphocytes / Q000276:immunology*; D019013:CD40 Antigens / Q000276:immunology; D002478:Cells, Cultured; D004848:Epithelium / Q000276:immunology; D006801:Humans; D007136:Immunoglobulins / Q000096:biosynthesis; D008213:Lymphocyte Activation; D008211:Lymphocyte Cooperation; D016169:Lymphocyte Function-Associated Antigen-1 / Q000276:immunology; D014066:Palatine Tonsil / Q000276:immunology*; D013601:T-Lymphocytes / Q000276:immunology*
D019013:CD40 Antigens; D007136:Immunoglobulins; D016169:Lymphocyte Function-Associated Antigen-1