Role of neutrophils in experimental murine leptospirosis

GABRIELA PRETRE; NOELIA OLIVERA; MAIA CEDOLA; ALBERDI L; RICARDO MARTÍN GÓMEZ

Merida

Encuentro; 7 International Leptospirosis Society Meeting; 2011

UNAM

The role played by the innate immune response in the pathogenesis of leptospirosis is still unclear. Depletion of specific immune cells has been successfully used to understand their roles in the immune response. The lack of animals "knockout" in neutrophils has demanded the use of antibodies for depletion of neutrophils in order to investigate the role of these cells in animal models of disease. In this study, three-week-old male C3H/HeJ mice were treated or not with RB6-8C5 antibody or an antibody against CXCR2 for neutrophils depletion or inhibition of its chemotactic responses to chemokines, respectively. Animals were then infected with the virulent strain L1-130 of Leptospira interrogans serovar Copenhageni. At 14 days post-infection (pi), several parameters, including survival, bacterial burden in kidneys determined by q-PCR, degree of tissue injury by histopathological analysis; and serological levels of IgM and IgG anti-leptospiral antibodies measured by ELISA, were studies. Results showed that mice depleted of neutrophils by treatment with RB6-8C5 antibody have lower mortality, increased bacterial burden in kidneys, aggravated tubulointerstitial nephritis, and higher humoral response. This results show that neutrophils play an important role in leptospirosis.