Figure 2. Effect of in vivo treatment with SLA-CpG-DCs on the parasite load in liver and spleen of Leishmania donovani–infected BALB/c mice.

Mice were either vaccinated with SLA-pulsed, SLA+ CpG-ODN pulsed, SLA+ control-CpG-ODN pulsed, only CpG-ODN-pulsed DCs or either phosphate buffered saline (PBS; control) followed by intravenous infection with 1×10⁷ stationary phase Leishmania donovani promastigotes after 7 days. Mice were sacrificed on days 1, 7, 14, 28, and 56 after infection. Levels of parasite burden in liver (A) and spleen (B) samples were determined by stamp-smear method and expressed in Leishman Donovan Units (LDU). Results are from 3 independent experiments and represent the mean values ± standard errors of the means for 5 animals per group per time point. **P<.001 and *P<.005, compared to infected mice. (C) Cured mice after 5 weeks of vaccination (4 weeks of infection) along with age-matched controls were re-infected with similar dose of Leishmania donovani and at 12 weeks of primary infection, were sacrificed and liver and spleen parasitic loads were determined by stamp-smear method and expressed as Leishman Donovan Units (LDU). Results are from 3 independent experiments and represent the mean values ± standard errors of the means for 5 animals per group per time point. **P<.001, compared to infected mice.