Action of thymic polypeptides of low molecular weight on some immune reactions at tissular and humoral level in guinea-pigs and mice.

Administration of the TP2 extract containing thymic polypeptides of low molecular weight (under 10,000 daltons) was found to stimulate the delayed hypersensitivity reaction in guinea-pigs injected with BCG. It was also found to reduce the hemagglutination titre in mice injected with the APR 8 influenza virus and to raise the antiflagellar agglutinins titre in rats injected with TH Salmonella vaccine. The cellular type of immune reactions was stronger than the humoral one.