In vivo effect of prothymosin-alpha 1 on humoral and cell-mediated immune responses in the young rat

Abstract

There is a large body of evidence for the role of thymosin peptides in immunogenesis and immunity. In this paper we report on the influence of prothymosin alpha 1 (ProT-α), a hormone-like peptide derived from the calf thymus, on humoral and cellular immune reactions in the rat. Young adult rats received intraperitoneal injections of ProT-α 1 in the periods before and after immunization with cellular and soluble antigens. ProT-α-treatment produced a dose-dependent increase of both humoral and cell-mediated immune responses. The thymus weight increased but not that of spleen. Treatment of nonimmunized rats with this polypeptide significantly elevated the number of CD4+ and decreased the number of CD8+ cells in the peripheral blood. The results suggest a potent immunostimulatory activity of ProT-α 1 and imply direct action of this polypeptide on T lymphocytes.

Key Words:

• prothymosin-alpha 1
• humoral immune response
• cell-mediated immune response
• immunomodulation
• thymosin