Differences in the age-related immuno-endocrine response during T. cruzi infection or LPS challenge

MANARIN R, PEREZ AR, BOTTASSO O, REVELLI S.

Rosario, Argentina

Otro; Galeria de Producción Científica Facultad Ciencias Medicas; 2009

Facultad de Ciencias Médicas, UNR

Differences in the age-related immuno-endocrine response in rats after T. cruzi infection or LPS challenge. Manarin R, Pérez AR, Bottasso O, Revelli S. We previously demonstrated that T. cruzi-infected weaning rats (21-day old) were more susceptible to infection than their adult counterparts (aged 70-days). To gain a further insight on this age-related susceptibility, we evaluated some features of the inflammatory response elicited either by T. cruzi infection or LPS (mimetic to T. cruzi-GPI anchors) challenge in weaning and adult rats. LPS inoculation in weaning rats led to a 50% mortality and an increased IL-10 production respect adult-challenged rats (overall p<0.02). Opposite cytokine profiles were seen during T. cruzi infection, with TNF-a levels being higher in weaning rats (90 h p.i.; p=0.016), and IL-10 showing increased values in adult animals (24 h p.i.; p=0.029). Accompanying these findings, corticosterone and TGF-b levels detectable in both infected groups were more elevated in weaning animals (p<0.05). Noticeably, younger rats had a decreased ability to control parasitemia compared with adult animals. In vitro studies evidenced that weaning rat-derived peritoneal macrophages exposed to LPS produced higher TNF-a levels in comparison to whose derived from adult counterparts (p=0.05). The greater susceptibility of weaning rats T. cruzi infection seems to be related to a different profile of the inflammatory reaction, also involving the adrenal endocrine response.