Preclinical screening and analysis of the immunotoxic and immunomodulatory activity using a multiple immunoassay (MIA) in mice.

Screening and analysis of immunotoxic and immunomodulatory activity has become an integral component in preclinical studies of pharmaceuticals and xenobiotics. In an attempt to replace laborious and expensive batteries of assays used at present we developed a multiple immunoassay (MIA) enabling the determination, in a single mouse, of: the weight of the thymus, spleen and a group of lymph nodes; delayed type hypersensitivity and antibody response to SRBC; phagocytic activity of peritoneal macrophages and the responsiveness of spleen lymphocytes to "T" (PHA, ConA) and "B" (LPS) mitogens in vitro. The MIA responsiveness to two prototype immunostimulators (Thymostimulin and Listeria factor Ei) was tested at two time periods after antigenic stimulation, not only in normal mice, but also in animals with selectively depressed T-systems (anti-Thy1.2 monoclonal antibody) and B-systems (cyclophosphamide); in both dexamethasone-treated and irradiated animals. The findings indicate, that this MIA is capable of reflecting both immunosuppressive and immunostimulatory activities of the tested agents and permits partial insight into the mechanisms underlying these activities.