Figure 3.

Toll-like receptor 2 (TLR2) plays an active role in Leishmania amazonensis internalization by human neutrophils. Neutrophils were cultured alone (unstimulated [unst]) or treated with neutralizing antibodies against TLR2 and TLR4 (100 µg/mL) for 15 minutes prior to infection with L. amazonensis–GFP (1 neutrophil to 10 L. amazonensis). The kinetics of TLR2 (A) and TLR4 (B) expression were compared by flow cytometry for unstimulated and GFP⁺ cells after 30 minutes and 3 hours of infection. The percentage of infected cells (C) and the number of internalized parasites (D) were quantified by optical microscopy after 3 hours of infection. *P ≤ .05; **P ≤ .01; ***P ≤ .001.