Since it has already been documented that human monocytes-derived macrophages have an innate capacity to kill L. braziliensis through increased production of reactive oxygen species, we assessed the infection rate and the average number of amastigotes per cell in these cultures and demonstrated that, regardless of the inflammatory modulation conditions, macrophages showed a reduction in these metrics from 4 to 48 hours, confirming their innate microbicidal capacity, independent of low levels of IL-1β (46, 47). This evidence concerns the gene IL1B and infection.