Figure 3 From: Heterologous expression of the filarial nematode alt gene products reveals their potential to inhibit immune function In vitro infection of macrophages with transfected amastigotes. (A, B). Bone marrow derived macrophages from CBA mice were infected for (A) 24 hours or (B) 7 days with wild-type or transfected amastigotes at a ratio of 10 parasites per macrophage. Parasites were detected and counted by immunofluorescence. Between 100 and 200 macrophages were counted for each time-point. The χ2 test showed significant differences in the numbers of infected vs uninfected macrophages between wild-type and either alt-1 or alt-2 transfectants at both time points (p < 0.001). (C, D). In vitro infection of macrophages with L. mexicana expressing the cysteine protease inhibitor-2 (CPI-2) gene of B. malayi (C) after 24 hours and (D) after 7 days. (E, F) Infection of C57BL/6 mice with transfected L. mexicana. (E) Time-course of lesion development in mice. Groups of 8 female C57BL/6 mice were injected subcutaneously in the footpad with 3 × 106 stationary-phase wild-type L. mexicana, alt-1 transfectants or alt-2 transfectants. Lesion size was measured weekly during the course of infection with a dial micrometer and expressed as the difference in size between the infected footpad and the contralateral uninfected footpad. One of two replicate experiments with similar results is shown; because data are not normally distributed (see for example recovery of wild-type parasites in panel F), standard error values cannot be applied. (F) Recovery of parasites from footpads at 15 weeks post-infection. The number of parasites in the footpad was estimated by limiting dilution assay. Results are expressed as log10 of the highest dilution containing parasites.Back to article page