Relationship between viral infections and subsequent predisposition to bacterial infections: role of splanchnic nerves

• Grant number: 22/13206-5
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: November 01, 2022
• End date: September 30, 2023
• Field of knowledge: Biological Sciences - Immunology - Cellular Immunology
• Principal Investigator: Alexandre Alarcon Steiner
• Grantee: Rayssa Navarro de Souza
• Host Institution: Instituto de Ciências Biomédicas (ICB). Universidade de São Paulo (USP). São Paulo , SP, Brazil
• Associated research grant: 18/03418-0 - Hypothermia in Sepsis: causes and consequences, AP.TEM

Abstract

There is a two-way communication between the nervous and immune systems.Recent evidence has revealed that the splanchnic nerve, through its sympathetic fibers,suppresses by up to 80% the inflammatory response to a bacterial component, thelipopolysaccharide (LPS). Considering the intimate relationship between inflammation and immunity, this reflex is likely to have implications for infectious diseases. In this project,we propose that splanchnic nerve activation against a viral mimetic (poly I:C) limits theseverity of inflammation induced by it, but, a few days later, increases the risk of a secondary bacterial infection. Male Wistar rats submitted or not tobilateral splanchnic nerve denervation will receive poly I:C or saline 1, 3or 5 days before E. coli challenge. The following outcomes will be evaluated: bacterial burden at the primary site ofinfection; bacterial burden at secondary infection sites; migration of neutrophils,monocytes and lymphocytes; and production of cytokines and chemokines.