PROTHYMOSIN ALPHA-1 EFFECTS IN-VITRO ON CHEMOTAXIS, CYTOTOXICITY AND OXIDATIVE RESPONSE OF NEUTROPHILS FROM MELANOMA, COLORECTAL AND BREAST-TUMOR PATIENTS

Immunoregulatory effects of thymic peptides on functions of polymorpho nuclear leukocytes (PMNs) are poorly investigated. We studied the effe cts of prothymosin alpha 1 (Pro alpha 1) on PMNs from patients with co lorectal tumors, breast tumors and melanoma (total n = 37) in comparis on with healthy donors (n = 18), with respect to chemotaxis, cytotoxic ity against HCT-116 colon tumor cells, oxidative response (chemilumine scence reaction) as well as expression of surface marker molecules. We found that Pro ctl was equally effective in stimulating the chemotact ic activity of PMNs from tumor patients and healthy donors (43% increa se). PMNs from tumor patients, especially with breast tumor, showed a significant enhancement of cytotoxicity against the tumor target cells in comparison with healthy donors. With respect to the PMNs cytotoxic ity, only about 50% of the colorectal tumor patients and healthy donor s responded to Pro al and FMLP. As to the oxidative response of PMNs, elevated levels were found only among colorectal tumor patients. Pro a lpha 1 significantly increased the oxidative response in breast and co lorectal tumor patients by 55% and 25%, respectively. Pro alpha 1 decr eased the expression of CD16 on PMNs of healthy donors, but not that o f CD11a, CD11b, CD11c, CD13, CD14, CD15 and CD32. Therefore, we sugges t, that Pro alpha 1 may improve some PMN functions of tumor patients, associated with the proposed role in host-tumor interaction. (C) 1998 International Society for Immunopharmacology.