Figure 5.

Interleukin (IL)-18 is detectable on fixed, but non-permeabilized monocytes after exposure to Leishmania. Purified CD14⁺ monocytes attached to an adhesion slide were incubated with or without Leishmania major promastigotes (multiplicity of infection 10) for 20 h. Thereafter, monocytes were either fixed with paraformaldehyde (Pfa) or fixed with Pfa and permeabilized with methanol, before being stained for IL-18 (white) and with DAPI (blue). As controls, the mouse-anti-IL-18 antibody (Ab) was pre-absorbed with rhuL-18, or the cells were incubated with the secondary Ab alone. Representative images of one of three independent experiments are shown.