title: Human antigen-specific IgA responses in blood and secondary lymphoid tissue: an analysis of help and suppression.
abstract: Antigen-specific IgA responses to influenza virus were obtained from lymphocytes derived from human secondary lymphoid tissue but not from the circulating pool (blood). T helper cells for IgA were present in both the circulating pool and secondary lymphoid tissue, were of the Leu-3A+ subset, and were relatively radioresistant. In addition, T alpha cells were shown to be important, but not crucial, for IgA helper responses. T cell-dependent suppression of IgA responses was demonstrated with T cells from both mucosal and systemic lymphoid tissue and was mediated by a radiosensitive Leu-2a+ cell. In contrast to T cells, functional B cell precursors for antigen-specific IgA responses were found only in secondary lymphoid tissue and not in the circulating pool.
mesh_terms: D000914:Antibodies, Viral / Q000096:biosynthesis; D000921:Antibody-Producing Cells / Q000276:immunology; D001402:B-Lymphocytes / Q000276:immunology; D000939:Epitopes; D006801:Humans; D007070:Immunoglobulin A / Q000032:analysis / Q000096:biosynthesis*; D007156:Immunologic Memory; D009980:Influenza A virus / Q000276:immunology; D008221:Lymphoid Tissue / Q000276:immunology* / Q000502:physiology; D006377:T-Lymphocytes, Helper-Inducer / Q000276:immunology*; D050378:T-Lymphocytes, Regulatory / Q000276:immunology*
chemical_list: D000914:Antibodies, Viral; D000939:Epitopes; D007070:Immunoglobulin A