title: Cohabitation with a sick partner increases allergic lung inflammatory response in mice.
abstract: The bidirectional relationship between the nervous system and the immune system is relevant for homeostatic organism maintenance. Studies from our laboratory showed that 14days of cohabitation with a sick partner (injected with Ehrlich tumor cells-TAE) produced behavioral, neurochemical, endocrinological and immunological changes. This study analyzes the effects of cohabitation with an Ehrlich tumor-bearing animal on ovalbumin (OVA)-induced lung inflammatory response in mice. Pairs of male mice were divided into three groups: naïve, control and experimental. Animals of the naïve group were kept undisturbed being used for the assessment of basal parameters. One animal of each experimental and control pair of mice was immunized with OVA. On ED(0), these OVA-immunized animals received an OVA booster. At this day (D(0)) the experimental mice that were kept undisturbed were inoculated with 5×10(6) Ehrlich tumor cells; their immunized cage-mates were then referred as to CSP ("companion of sick partner"). The undisturbed mice of each control pair were i.p. treated on D(0) with 0.9% NaCl; their sensitized cage-mates were subsequently referred as CHP ("companion of health partner"). The OVA challenge was performed on CSP and CHP mice on ED(12) and ED(13); blood and tissue collection were performed on ED(14). Fourteen days after cohabitation, in comparison to the CHP mice, the CSP mice displayed the following: (1) an increased number of eosinophils and neutrophils in the BAL, (2) a decreased bone marrow cell count, (3) increased levels of IL-4 and IL-5 and decreased levels of IL-10 and IFN-γ in the BAL supernatant, (5) increased levels of IgG1-OVA, decreased levels of IgG2a-OVA and no changes in OVA-specific IgE in the peripheral blood, (6) increased expression of L-selectin in the BAL granulocytes, (7) decreased tracheal reactivity to methacholine measured in vitro, (8) no changes in plasma corticosterone levels and (9) increased levels of plasmatic noradrenaline. These results suggest that allergic lung inflammatory response exacerbation in CSP mice is a consequence of the psychological stress induced by forced cohabitation with the sick partner. Strong involvement of the sympathetic nervous system (SNS) through adrenaline and noradrenaline release and a shift of the Th1/Th2 cytokine profile toward a Th2 response were considered to be the mechanisms underlying the cell recruitment to the animal's airways.
authors.affiliation: Neuroimmunomodulation Research Group, Department of Pathology, School of Veterinary Medicine, University of São Paulo, São Paulo, SP, Brazil.
authors.forename: Eduardo Kenji
authors.initials: EK
authors.lastname: Hamasato
authors.affiliation: Neuroimmunomodulation Research Group, Department of Pathology, School of Veterinary Medicine, University of São Paulo, São Paulo, SP, Brazil.
authors.forename: Ana Paula Nascimento
authors.initials: AP
authors.lastname: de Lima
authors.affiliation: Post Graduate Program in Biophotonics Applied to Health Sciences, Nove de Julho University, UNINOVE, São Paulo, Brazil.
authors.forename: Ana Paula Ligeiro
authors.initials: AP
authors.lastname: de Oliveira
authors.affiliation: Department of Clinical and Toxicological Analyses, Faculty of Pharmaceutical Sciences, University of São Paulo, São Paulo, Brazil.
authors.forename: Adriana Lino
authors.initials: AL
authors.lastname: dos Santos Franco
authors.affiliation: Department of Pharmacology, University of São Paulo, São Paulo, Brazil.
authors.forename: Wothan Tavares
authors.initials: WT
authors.lastname: de Lima
authors.affiliation: Neuroimmunomodulation Research Group, Department of Pathology, School of Veterinary Medicine, University of São Paulo, São Paulo, SP, Brazil. Electronic address: jpalermo@usp.br.
authors.forename: João
authors.initials: J
authors.lastname: Palermo-Neto
mesh_terms: D000485:Allergens / Q000276:immunology*; D000818:Animals; D001249:Asthma / Q000276:immunology*; D001522:Behavior, Animal / Q000502:physiology; D001992:Bronchoalveolar Lavage Fluid / Q000737:chemistry; D002286:Carcinoma, Ehrlich Tumor / Q000276:immunology; D016207:Cytokines / Q000032:analysis; D004195:Disease Models, Animal; D006799:Housing, Animal; D007107:Immune System / Q000276:immunology*; D008168:Lung / Q000276:immunology*; D008297:Male; D051379:Mice; D009368:Neoplasm Transplantation; D009504:Neutrophils / Q000276:immunology; D013315:Stress, Psychological / Q000276:immunology
chemical_list: D000485:Allergens; D016207:Cytokines
keywords: Adhesion molecules; Airways reactivity; Allergic lung inflammation; Asthma; Catecholamine; Cytokines; Ehrlich tumor; Inflammatory mediators