Modulation of early immune responses and suppression of Trypanosoma bruceibrucei infections by surgical denervation of the spleen

Objective: To examine critical interactions between the nervous system and the immune system during experimental African trypanosomiasis. Methods and Results: Inoculation of Trypanosoma brucei brucei resulted in early interfe ron (IFN)-gamma production, elevated corticosterone and prostaglandin E-2 ( PGE(2)) levels and increased splenocyte proliferation, as measured by enzym e-linked immunospot assay, radioimmunoassay and thymidine incorporation ass ay, respectively. Splenic denervation suppressed IFN-gamma, corticosterone and PGE(2) production, enhanced splenocyte proliferation, and significantly reduced parasitemia and prolonged rat survival. Conclusions: Our data show substantial effects of the nervous system on early immune responses that m ay influence the outcome of this disease. These effects were not dependent on cytokine inhibitory mediators such as prostaglandins or stress hormones. More investigations are required to understand the evident neural control over the immune system during infectious challenges, which may assist in no vel therapeutic approaches. Copyright (C) 2000 S. Karger AG. Basel.