In order to investigate a possible correlation of resistance to leptospirosis and leukocytes’ phagocytosis we evaluated the capacity of spleen cells isolated from C3H/HeJ (toll-like receptor 4 deficient), C3H/HePas and BALB/c mouse strains and the RAW 264.7 macrophages to phagocyte L. interrogans serovar Copenhageni, and possible effects of CCL2/MCP-1 treatment. Here, TLR4 is linked to leptospirosis.