Chronic exposure to environmental stressors enhances production of natural and specific antibodies in rats

CUERVO P; BELDOMENICO PM; SANCHEZ A; PEITROBON E; VALDEZ SR; RACCA AL

JOURNAL OF EXPERIMENTAL ZOOLOGY PART A-ECOLOGICAL GENETICS AND PHYSIOLOGY

WILEY-LISS, DIV JOHN WILEY & SONS INC

Lugar: New York; Año: 2018

1932-5223

Although the immunosuppressive effect of chronic stress has been established, a stress response that down-regulates the whole immune system does not make biological sense, especially if an animal has to endure difficult times in which there is also increased infection risk. At high animal densities, animals are faced simultaneously with food restriction, social conflict, and greater parasite/pathogen exposure. We hypothesised that the stress response to chronic stressors that co-vary with infection risk is not entirely immunosuppressive. Our prediction was that a chronically stressed animal would respond by enhancing innate defences, while reducing investment in acquired immunity. In a laboratory setting, rats were exposed to prolonged food limitation and/or social conflict, and natural and specific antibody levels were repeatedly measured. Our prediction was fulfilled only partly, as food restriction and social conflict interacted to enhance natural antibodies, but rats exposed to either or both stressors also showed significantly higher levels of specific antibodies. These results suggest that, in the rat, chronic stress results in a prioritization of both innate and acquired humoural defences, which makes biological sense provided the stressors examined usually signal an increased infection risk.