Modulation of polymorphonucleate-mediated cytotoxicity against Candida albicans by thymosin alpha 1

In the present work we analyze the effects of thymosin alpha 1 treatment on the number and the candidacidal activity of murine polymorphonuclear leukocytes. The data we obtained showed that the treatment with thymosin alpha 1 (100 micrograms/Kg s.c.) 10, 8, 6, 4 and 2 days before the assay may result in a significant numerical augmentation of circulating polymorphonucleates in the peripheral blood, as well as of their candidacidal activity when measured in vitro in both a 4-h cytotoxicity assay and a CFU inhibition assay against Candida albicans microorganisms. On the other hand, a single dose of thymosin alpha 1 (500 micrograms/Kg s.c.) 3 days before the assay resulted in a significant decrease of the candidacidal activity of mouse polymorphonucleates. The data are discussed with regard to the immunomodulating capacity of thymosin alpha 1 and to our previously reported observations concerning the ability of the drug to modulate the resistance against systemic Candida albicans infection.