Fig. 5.

CRIg is essential for intravascular clearance of parasites by KCs, enhancing the survival of infected mice. (A) The parasitemia of WT, CR3^−/−, and CRIg^−/− mice (n = 4–5 per group) i.p. infected with 1 × 10³ T. congolense. (B) Representative IVM images showing the parasites in the liver sinusoids of WT, CR3^−/−, and CRIg^−/− mice 7 d post i.p. infection with 1 × 10³ T. congolense. The parasites (arrows) in the sinusoids were labeled by i.v. administration of rhodamine 6G 10 min prior to imaging. (Scale bars, 20 µm.) (C) Representative images of immunohistological staining showing parasite TC13 antigens (red) in liver KCs (blue, labeled by anti-F4/80 mAb) of WT, CR3^−/−, and CRIg^−/− mice 7 d post i.p. infection with 1 × 10³ T. congolense. (Scale bars, 50 µm.) (D) The survival of WT, CR3^−/−, and CRIg^−/− mice (n = 10 per group) i.p. infected with 1 × 10³ T. congolense. Data are expressed as mean ± SEM of 2 independent experiments. *P < 0.05, **P < 0.01, ***P < 0.001 by Student’s t test or log-rank test.