immunology of infectious and parasitic diseases - XXXVII Congress ...

RHIZOPUS SP INFECTION TRIGGERS H2O2 PRODUCTION BY
PERITONEAL PHAGOCYTIC CELLS ONLY IN HYPOINSULINEMIC-
HYPERGLICEMIC MICE
DÉBORA DE FÁTIMA ALMEIDA (IC)(1); GABRIELA PICCARO ERAZO(IC)(1);
AMANDA RIBEIRO DOS SANTOS(IC)(1); CAMILA MARTINS
MARCHETTI(PG)(2); JAMES VENTURINI (PG)(2); MARIA SUELI PARREIRA
DE ARRUDA(1).
(1) Faculdade de Ciências, UNESP - Univ Estadual Paulista, Bauru,
Departamento de Ciências Biológicas, Laboratório de Imunopatolgia
Experimental (LIPE);(2) Faculdade de Medicina, UNESP - Univ Estadual
Paulista, Botucatu, Programa de Pós-graduação em Doenças Tropicais.
Introduction: Mucormycosis is the third most common invasive fungal infection
among immunocompromised patients and Rhizopus sp are the most prevalent
etiological agents. It is a progressive disease which is almost always fatal.
Furthermore, the Diabetes Mellitus is the main underlying disease associated
with this fungal infection, especially during diabetic ketoacidosis episodes.
Although macrophages are one of the first cells to recognize and trigger the
immune response against the pathogens, there are few studies evaluating the
macrophage activity in a murine experimental model of diabetes during
mucormycosis. In the present study we evaluate the in vitro production of
hydrogen peroxide (H2O2) and nitric oxide (NO) by peritoneal phagocytic cells
from hypoinsulinemic-hyperglicemic (HH) mice infected with Rhizopus sp.
Methods and Results: Female Swiss mice were divided into the following
groups: Group HH: composed by HH-induced mice by alloxan (60 mg/kg);
Group Rhi: composed by Rhizopus-infected mice which were intravenously
inoculated with 3x104 spores of Rhizopus sp; Group Rhi-HH: HH-induced and
Rhizopus-infected mice; Group CTL, composed by naïve mice inoculated with
sterile saline solution. After 24 hours, the mice were killed and sample of
spleens, brains, livers, lungs and kidneys were collected and submitted to
microbiological evalation fungal load determination. Also we performed an in
vitro assay to determine the H2O2 and NO by peritoneal phagocytic cells. The
results showed no differences in the fungal load in the infected groups as well
as in the NO production by peritoneal phagocytic cells culture. Moreover, we
only observed high production of H2O2 in the Rhi-HH mice.
Conclusion: The Rhizopus sp infection triggered H2O2 production by peritoneal
phagocytic cells only when both infectious and HH condition were associated.