Neutrophils have a protective role during early stages of Leishmania amazonensis infection in BALB/c mice

作者：Sousa L M A; Carneiro M B H; Resende M E; Martins L S; Dos Santos L M; Vaz L G; Mello P S; Mosser D M; Oliveira M A P; Vieira L Q^*

来源：Parasite Immunology, 2014, 36(1): 13-31.

DOI：10.1111/pim.12078

• IL-10
• immune response
• Leishmania amazonensis
• neutrophils

Neutrophils are involved in the early stages of immune responses to pathogens. Here, we investigated the role of neutrophils during the establishment of Leishmania amazonensis infection in BALB/c and C57BL/6 mice. First, we showed an accumulation of neutrophils between 6 and 24h post-infection, followed by a reduction in neutrophil numbers after 72h. Next, we depleted neutrophils prior to infection using RB6-8C5 or 1A8 mAb. Neutrophil depletion led to faster lesion development, increased parasite numbers and higher arginase activity during the first week of infection in BALB/c mice, but not in C57BL/6 mice. Increased susceptibility was accompanied by augmented levels of anti-L.amazonensis IgG and increased production of IL-10 and IL-17. Because IL-10 is a mediator of susceptibility to Leishmania infection, we blocked IL-10 signalling in neutrophil-depleted mice using anti-IL-10R. Interestingly, inhibition of IL-10 signalling abrogated the increase in parasite loads observed in neutrophil-depleted mice, suggesting that parasite proliferation is at least partially mediated by IL-10. Additionally, we tested the effect of IL-17 in inflammatory macrophages and observed that IL-17 increased arginase activity and favoured parasite growth. Taken together, our data indicate that neutrophils control parasite numbers and limit lesion development during the first week of infection in BALB/c mice.

• 出版日期2014-1