Neutrofilos e macrófagos cooperam na resistência contra Leishmania braziliensis

Com a correria de final de ano, não divulgamos no site o trabalho de Fernanda Novais, publicado no J. Immunology, em 15 de dezembro, sobre a cooperação entre neutrófilos e macrofagos na resistência contra L. braziliensis.

A depleção in vivo de neutrófilos leva ao aumento da carga parasitária, por outro lado a inoculação com parasitas e neutrófilos resulta em proteção. Veja o resumo:

1. “Neutrophils play an active role in the control of infections caused by intracellular pathogens such as Leishmania. In the present study, we investigated the effect of neutrophil depletion at the time of Leishmania braziliensis infection of BALB/c miceand how neutrophils interact with the infected macrophage to promote parasite elimination. The in vivo depletion of neutrophils led to a significant increase in parasite load and enhanced the Th1-Th2 immune response in this experimental model of infection. BALB/c mice coinoculated with both parasites and live neutrophils displayed lower parasite burdens at the site of infection and in the draining lymph nodes. In vitro, we observed that live neutrophils significantly reduced the parasite load in L. braziliensis-infected murine macrophages, an effect not observed with Leishmania major. L. braziliensis elimination was dependent on the interaction between neutrophils and macrophages and was associated with TNF-

   

   as well as superoxide production. Furthermore, cooperation between neutrophils and macrophages toward parasite elimination was also observed in experiments performed with L. braziliensis-infectedhuman cells and, importantly, with two other New World Leishmania species. These results indicate that neutrophils play an important and previously unappreciated role in L. braziliensis infection, favoring the induction of a protective immune response.”
   Novais, F., Santiago, R., Bafica, A., Khouri, R., Afonso, L., Borges, V., Brodskyn, C., Barral-Netto, M., Barral, A., & de Oliveira, C. (2009). Neutrophils and Macrophages Cooperate in Host Resistance against Leishmania braziliensis Infection The Journal of Immunology, 183 (12), 8088-8098 DOI:10.4049/jimmunol.0803720