Effect of macrophage blockade on the resistance to a primary Brugia pahangi infection of female BALB/c mice.

Role of macrophages in the higher resistance of female BALB/c mice than males to a primary Brugia pahangi infection was investigated. Macrophage blockade by carbon injection on the day of infection or by carrageenan injection one day before infection was effective to reduce the higher resistance of females to the level of males. The timing of macrophage blockade seems to be critical because carbon treatment on day 0 or 5 post-infection (PI) was much more effective than the same treatment on day 10 PI. These results suggest that macrophages play an important role in the expression of the higher resistance of female BALB/c mice than males to a primary B. pahangi infection.