[The effect of gammaglobulin preparations on in vitro immunoglobulin production induced by pokeweed mitogen].

It has been recognized in the experiments of animals, that high dose of administration of IgG suppresses the immunoglobulin production in vitro, because of masking of antigen determinants. The study evaluated the effect of several gammaglobulin preparations on in vitro immunoglobulin production induced by pokeweed mitogen. And the effect of these preparations was estimated by following system. Mononuclear cells (5 X 10(5)/ml) were incubated (37 degrees C, 5% CO2) in the presence of gammaglobulin preparations (0.01 mg/ml-1.0 mg/ml). On the sixth day of culture, the cells were spun down, washed three times, resuspended in MEM without L-4,5 [3H]-leucine. After 24 hours, supernatants were harvested, and the concentration of immunoglobulin produced by mononuclear cells was analyzed by solid-phase RIA. And the results which have been obtained as follows. PWM induced immunoglobulin production (IgG) was analyzed in the presence of immunoglobulin preparations. Among these preparations, the suppressive effect of ISG was most significant, and the effect was dose dependent. S-sulfonated and PEG-treated preparations also suppressed the IgG production, but not so strong as ISG. In the suppressive effect between S-sulfonation and PEG treatment, no significant difference was found. Pepsin treated preparation had no suppressive effect. Not only IgG production, but also IgA, IgM production were suppressed by the co-culture of ISG, S-sulfonated, and PEG treated IgG. ISG inhibits directly the differentiation of B cells, and also induces the activation of suppressor T cells. ISG was considered to suppress immunoglobulin production in vitro by these both pathways. The suppressor T cells, which are induced by ISG, are radiation resistant, hydrocortisone resistant and same population with OKT 8 positive cells.