[Effect of human colostrum and its fraction on functional activity of B-lymphocytes]

The human colostrum stimulated by suboptimal doses (50 ng/ml) of lipopolysaccharide (LPS) has induced proliferation of mouse splenocytes. Addition of the human colostrum has elicited a rise in splenocyte culture supernatants. Effect of human colostrum on Ig synthesis was dose-dependent and was expressed at 0.5% concentrations in the medium. In contrast to the human colostrum, the bovine colostrum exerted a suppressive effect on proliferation of mouse splenocytes and Ig synthesis induced by suboptimal doses of LPS. Bovine casein did not significantly affect the Ig synthesis by mouse splenocytes. Suppression of the Ig synthesis was associated with bovine colostral globulins. Using the ELISPOT method we have found that a rise in the Ig level in the culture after treatment with the human colostrum was due to an increase of the number of IgG2a-secreting cells. B-cell promoting fraction was found after HPLC gel-filtration. The molecular weight of this fraction was 70-75 kD.