Influence of the thymic extract (TP2) on some humoral and cell mediated immunity reactions in normal or irradiated animals.

The authors have studied the action of a thymic extract (TP2) containing thymic polypeptides with a molecular weight under 10,000 daltons, on humoral and cell-mediated immunity reactions in normal animals or in animals immunologically depressed by X-ray irradiation. The following were investigated: serum antibodies, such as antiflagelar agglutinins of TH Salmonella and anti-influenza antibodies in the rat, the plaque-forming hemolytic cells in the mouse spleen, delayed hypersensitivity reaction in guinea-pigs innoculated with BCG, the lymphocyte rosetting reaction in the mouse spleen, and the inhibition of macrophages migration in the rats innoculated with TH Salmonella typhi vaccine. The results showed that TP2 stimulates both the humoral and the cell-mediated immunity reactions and has a radioprotecting effect.