title: Alpha-1-antichymotrypsin (ACT) as an immune regulatory agent.
abstract: This study was carried out to elucidate the interaction of alpha-1-antichymotrypsin (ACT) with the immune reaction induced by interleukin-2 (IL-2). ACT, isolated from human sera and determined to be a single glycoprotein, was added to human peripheral T-cell cultured with IL-2. It was found that ACT effectively suppressed T-cell activation induced by IL-2, but the suppressive effect of ACT was inversely proportional to the concentration of IL-2. A similar effect was found when T-cells were stimulated with PHA. ACT had a suppressive effect when suboptimal concentrations of PHA were used, however this suppressive effect could not be found at the optimal PHA concentration. These findings suggest that ACT may be a regulatory agent in immune reactivity where low concentrations of IL-2 are present. Even under normal conditions, an individual is surrounded and invaded by numerous foreign elements and it may be that small amounts of IL-2 are constantly produced, which would indefinitely trigger chained immune reactions if there were no regulatory agent like ACT.
authors.affiliation: Department of Biochemistry, School of Medicine, Tokai University, Kanagawa, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Kurahashi
authors.forename: M
authors.initials: M
authors.lastname: Yamamura
authors.forename: K
authors.initials: K
authors.lastname: Nakamura
authors.forename: K
authors.initials: K
authors.lastname: Kato
authors.forename: T
authors.initials: T
authors.lastname: Katsunuma
mesh_terms: D000276:Adjuvants, Immunologic; D002478:Cells, Cultured; D006801:Humans; D007376:Interleukin-2 / Q000494:pharmacology; D008213:Lymphocyte Activation / Q000187:drug effects; D010835:Phytohemagglutinins / Q000494:pharmacology; D013601:T-Lymphocytes / Q000187:drug effects / Q000276:immunology; D000514:alpha 1-Antichymotrypsin / Q000276:immunology* / Q000494:pharmacology
chemical_list: D000276:Adjuvants, Immunologic; D007376:Interleukin-2; D010835:Phytohemagglutinins; D000514:alpha 1-Antichymotrypsin