HLA class II-mediated aggregation is associated with the proliferation of B lymphocytes.
We have studied the role of LFA-1 antigens in human B lymphocyte aggregation, proliferation, and Ig production induced by a short stimulation via class II antigens. Cell stimulation with either bacterial superantigens or anti-DR mAbs rapidly induced homotypic cell aggregation. In response to IL-4, an increase in cell proliferation and Ig production was observed only when aggregation preceded addition of IL-4. The involvement of LFA-1 molecules in class II-induced aggregation was supported as LFA-1-deficient cells or B cells incubated with anti-LFA-1/ICAM-1 mAbs failed to aggregate after stimulation. The association between aggregation and subsequent Ig production and proliferation was further supported as, after IL-4 stimulation, in both LFA-1-deficient cells and B cells incubated with anti-LFA-1 mAbs, class II-mediated signals failed to increase Ig production or cell proliferation. These data suggest that in class II-stimulated cells, LFA-1-dependent aggregation has a major role in IL-4-dependent Ig production and proliferation of B cells.
Ramirez
R
R
Unidad de Investigación, Hospital Universitario Reina Sofia, Cordoba, Spain.
Carracedo
J
J
Mooney
N
N
Charron
D
D
D001402:B-Lymphocytes / Q000276:immunology*; D015815:Cell Adhesion Molecules / Q000502:physiology; D002449:Cell Aggregation / Q000276:immunology*; D002460:Cell Line; D006681:HLA-D Antigens / Q000502:physiology*; D006801:Humans; D007074:Immunoglobulin G / Q000096:biosynthesis; D007075:Immunoglobulin M / Q000096:biosynthesis; D018799:Intercellular Adhesion Molecule-1; D015847:Interleukin-4 / Q000502:physiology; D008213:Lymphocyte Activation / Q000276:immunology*; D016169:Lymphocyte Function-Associated Antigen-1 / Q000502:physiology*
D015815:Cell Adhesion Molecules; D006681:HLA-D Antigens; D007074:Immunoglobulin G; D007075:Immunoglobulin M; D016169:Lymphocyte Function-Associated Antigen-1; D018799:Intercellular Adhesion Molecule-1; D015847:Interleukin-4