title: The production of a soluble human T-lymphocyte derived factor which substitutes for helper T lymphocytes in the in vitro production of immunoglobulin.
abstract: A soluble factor(s), human T-lymphocyte derived help factor (HHF), generated following pokeweed mitogen (PWM) activation of irradiated human peripheral blood T lymphocytes was shown to substitute partially for T-lymphocyte helper activity in the T-lymphocyte dependent PWM-stimulated synthesis of immunoglobulin by B cells. The degree of help provided was proportional to the number of cultured irradiated T-lymphocytes producing factor as well as the amount of factor added to the B-cell culture. The helper effect was equally provided by HHF syngeneic and allogeneic to the B lymphocyte. Although there was little stimulation of total protein synthesis, the synthesis and secretion of IgG, IgM and IgA were all stimulated three- to ten-fold by this factor. The B cells required a minimum of 40--55 h exposure to the factor from the initiation of the culture for an increase in Ig synthesis on day 5 to be observed. Addition of HHF to B cells pre-incubated with PWM for different time intervals showed that a maximum helper effect was exerted when the factor was added on day 0. Addition on day 1 provided less than 20% of maximum help. The factor did not promote significant increases in either B-cell or T-cell cell division.
mesh_terms: D001402:B-Lymphocytes / Q000276:immunology; D004247:DNA / Q000096:biosynthesis; D004591:Electrophoresis, Polyacrylamide Gel; D006801:Humans; D007136:Immunoglobulins / Q000096:biosynthesis*; D066298:In Vitro Techniques; D008213:Lymphocyte Activation; D008938:Mitosis; D011043:Pokeweed Mitogens / Q000494:pharmacology; D013601:T-Lymphocytes / Q000276:immunology*; D013997:Time Factors
chemical_list: D007136:Immunoglobulins; D011043:Pokeweed Mitogens; D004247:DNA