[Alpha 1-antitrypsin: production and binding of in vitro stimulated peripheral blood lymphocytes].

Three day cultures of human peripheral blood lymphocytes (PBL) contain significant numbers of lymphoblasts binding 125I-alpha 1-AT as well as those with membrane-associated alpha 1-AT detectable by immunofluorescence. Co-cultivation of PBL with T cell mitogens leads to the appearance of lymphoblasts with membrane-associated alpha 1-AT while B cell mitogens induce lymphoblasts with a binding capacity for 125I-alpha 1-AT. It could be shown that unstimulated lymphocytes neither have membrane-associated alpha 1-AT nor possess a binding capacity for it. The highest number of lymphoblasts with membrane-associated alpha 1-AT was found in Con A stimulated cultures as revealed by indirect immunofluorescence. By contrast, PHA or PPD stimulated cultures contained much less such cells of lower fluorescence intensity. Co-cultivation of PBL with the B cell mitogens LPS and rabbit-anti-human gammaglobulin-IgG-F(ab')2 induced lymphoblasts with a clear binding capacity for 125I-alpha 1-AT, while dextran-sulphate had no effect. A possible regulative role of alpha 1-AT in the immune response is discussed.