FIG 7.

Depletion of macrophages does not abolish primary low-dose i.d. resistance and susceptibility to rechallenge infection. Groups of BALB/c mice (n = 4) were treated with liposomal chlodronate (Chlod.) to deplete macrophages or with control liposome (Lip). After 24 h, all mice were infected i.d. with 10² T. congolense parasites and monitored for parasitemia (A). Three weeks after primary infection (pri. inf.) (without parasitemia), all mice were rechallenged (chall. inf.) with 10³ T. congolense parasites, and parasitemia (A) and survival (B) were monitored. The results presented are representative of 2 different experiments with similar results. Error bars show means ± SEM.