[Effect of pretreatment with immunomodulating agents on the outcome of lymphocytic choriomeningitis virus infection in athymic (nude) and euthymic mice].

Balb/c (euthymic) and nu/nu (athymic) mice were treated intraperitoneally with TP-4 (a synthetic tetrapeptide, thymopoietin sequence analog, Pharmaceutical Product's Factory Gedeon Richter, Budapest, Hungary) or with Mannozym (0.1% zymosan suspension, Institute for Serobacterological Production and Research, HUMAN, Budapest, Hungary), and were infected intracerebrally with LCM virus. Both of the agents contributed to the development of fatal choriomeningitis, consequently they stimulated the cellular immune response in euthymic mice, but the athymic mice, either treated or not, survived the infection, consequently the agents had no effect on the course of LCM virus infection. The results showed that the cellular immune response stimulating effect by both agents was thymus-dependent. Using these agents immunostimulatory effect can be realized only in the presence of the thymus or the T-dependent lymphoid system, respectively.