Splenic Denervation Suppresses mRNA Gene Expression and Protein Production of IL-1β and IL-6 by Peritoneal Macrophages in both <i>Trypanosoma brucei brucei</i>-Infected and Non-Infected Rats

Abstract

Objective: To test the hypothesis that the nervous system participates in modulating the immune response during experimental African trypanosomiasis caused by Trypanosoma brucei brucei. Methods and Results: Using in situ hybridization and immunochemistry, we studied the effects of splenic sympathectomy on mRNA gene expression and protein production of IL-1β and IL-6 in splenic and peritoneal macrophages (PMΦ) of Sprague-Dawley rats infected with T. brucei brucei and non-infected rats. The enhancements of mRNA gene expression and production of IL-1β and IL-6 by peritoneal macrophages were significantly suppressed by the splenic sympathectomy in both infected and non-infected rats. Conclusions: Our data indicate a probably stimulatory role of the sympathetic nervous system during the host immune response in both normal and T. brucei brucei-infected rats.

A novel nervous system‐induced factor inducing immune responses in the spleen

“…Substantial effects of the nervous system on immune responses that influence the outcome of EAMG were shown, as surgical denervation of the spleen significantly reduced the clinical severity of the disease, suppressed the numbers of immunoglobin G and interferon (IFN)‐γ‐secreting cells, downregulated the mRNA expression for cytokines and reduced corticosterone and PGE2 production 14 . Also, immune responses to the parasite infection in the early stages of experimental African trypanosomiasis (EAT) were found to be modulated through autonomic innervation of the spleen 15 , 16 . African trypanosomiasis, a disease of tropical Africa affecting mainly the central nervous system and characterized by profound induction of cytokines such as IFN‐γ early during infections 17 , 18 , 19 and late immunosuppression, 20 , 21 was used in this study as a model to identify factors involved during nervous‐immune communications in innate immunity.…”

“…14 Also, immune responses to the parasite infection in the early stages of experimental African trypanosomiasis (EAT) were found to be modulated through autonomic innervation of the spleen. 15,16 African trypanosomiasis, a disease of tropical Africa affecting mainly the central nervous system and characterized by profound induction of cytokines such as IFN-g early during infections [17][18][19] and late immunosuppression, 20,21 was used in this study as a model to identify factors involved during nervous-immune communications in innate immunity. Within few seconds after parasitic challenge in EAT, a dramatic expression of a novel gene in the spleen together with uppregualtion of its encoding protein (immune system-released activating agent; ISRAA) was depicted.…”