44. Cohabitation with a sick-cage mate exacerbates allergic lung inflammatory response in mice

Abstract

The objective of this study was analyze the effects of cohabitation with sick partner on allergic lung inflammatory response in ovalbumin (OVA) sensitized and challenged mice. Pairs of mice were divided into control and experimental groups. Within each group, one mouse from each pairs was immunized with a solution containing (OVA). The remaining mouse from the experimental group was injected with Ehrlich tumor cells being designated as “companion of sick partner” (CSP); the remaining mouse of the control group was injected with PBS being designated as “companion of healthy partner” (CHP). CSP mice presented in relation to CHP mice: increased number of eosinophils and neutrophils in the BAL; increased IL-4 and IL-5 levels and decreased IL-10 and INF-γ in the BAL supernatant; increased IgG1-OVA and decrease IgG2a-OVA levels on peripheral blood; increased expression of L-selectin in the BAL granulocytes; decreased in vitro tracheal reactivity to metacholine; no changes on plasma corticosterone levels and increased levels of plasmatic noradrenaline. The results suggest that the exacerbation of the allergic lung inflammatory response in CSP mice is a consequence of the psychological stress induced by forced long-term cohabitation with sick the partner, a fact that might ultimately depend on the changes induced by catecholamines on Th1/Th2 balance, toward a Th2 cytokine profile and finally the recruitment and activation of eosinophils in the airways. FAPESP: 2012/03372-3; 2009/51886-3.