Figure 8. Neutrophil depletion abrogates the LdCen^−/− induced host protective immunity; albeit neutrophil repletion before challenge partially restore protection.

Mice were either treated with neutrophil depleting 1A8 antibody or GL113, 1 day prior to immunization with LdCen^−/− as described in Materials and Methods. (A) Schematic diagram showing the treatment regimen. (B) Leishmania Ag-specific cytokines were measured from splenocytes of GL113 or 1A8 treated LdCen^−/− immunized mice at the time of challenge (3WI, 3 wk post immunization) and after challenge (3WI + 8WPC: 8 wk post challenge) by sandwich ELISA. The ratio of IFNγ :IL-10 is shown. The data represent the mean values ± SEM of results from 2 independent experiments. Mean and SEM of 6 mice in each group are shown. ** P < 0.005; *** P <0. 0005. (C) Splenic parasite burden was measured at 8 wk post challenge in different groups of immunized challenged and naïve challenged mice. The data represent the mean values ± SEM of results from 2 independent experiments. Mean and SEM of 10 mice in each group are shown *** P < 0.0005.

In a separate experiment mouse were either treated with 1A8 antibody or GL113, 1 day prior to immunization with LdCen^−/− but the neutrophil level was allowed to return to normal as described in Materials and Methods. (D) Schematic diagram showing the treatment regimen. (E) Splenic parasite burden was measured at 8 wk post challenge in different groups of immunized challenged and naïve challenged mice. The data represent the mean values ± SEM of results from 2 independent experiments. Mean and SEM of 10 mice in each group are shown ** P < 0.005.