In vitro induction of monocyte chemotactic protein-1 and interleukin-8 in human whole blood by low molecular thymic peptides

Thymic peptides show immunoreconstitutive und tumor suppressive effects. They are used in oncology to improve the immunological status of patients. Chemokines are able to activate immune cells and inhibit tumor growth. In this study it was proved whether low molecular thymic peptides are able to increase the secretion of the chemokines monocyte chemotactic protein-1 (MCP-1), interleukin-8 (IL-8), makrophage inflammatory protein-1 alpha (MIP-1 alpha) and makrophage inflammatory protein-1 beta (MIP-1 beta) as well as the cytokin tumor necrosis factor-alpha (TNF-alpha) which is not related to chemokines using cell cultures of human whole blood. The thymic peptides induced a significant (p < 0.05) elevated secretion of MCP-1 and IL-8 whereas for MIP-1 alpha, MIP-1 beta and TNF-alpha no significant chances were seen. MCP-1 and IL-8 showed divergent dose-dependent effects and a different time kinetic of their secretion. The MCP-1 concentration correlated positively with the count of monocytes in whole blood of the volunteers while the IL-8 concentration in dependence with the incubation time correlated positively with the count of granulocytes or monocytes of the volunteers. The results indicate an activation of monocytes and/or granulocytes by low molecular thymic peptides followed by selectiv elevated secretion of MCP-1 and IL-8.