The effects of alpha 2-antiplasmin complex and alpha 2-antiplasmin on the secretion of IgG and IgM by cultured human mononuclear cells.

We tested alpha 2-antiplasmin (AP) and its complex with plasmin (PL) for their capacity to modulate spontaneous secretion of immunoglobulins (Ig) G and M by mononuclear cells (MNC). MNC were obtained from peripheral blood of 10 donors (5 males and 5 females) and cultured for 7 days in the presence of various concentrations of AP and AP-PL complex. The 18 hr incubation of MNC with AP-PL complex resulted in a dose-dependent increase in IgG and IgM secretion but the stimulatory effect was less significant than under conditions of incubation of MNC with the complex during a 7 day culture period. The AP-PL complex-induced stimulation occurred only in the cultures in which the dose of the complex was either close to or higher than the mean value of the complex levels in plasma of healthy donors. Elevation of IgG secretion in AP-PL complex-treated cultures from females was slightly higher than in those from males. No significant change in IgG and IgM secretion was observed in the presence of native AP.