Figure 8. Highly effective sequential therapy with Sm and Sb^v enhances CD4⁺ T cell cytokine responses and splenic NO production.

(A) Groups of L. donovani–infected mice were treated from 21 to 28 dpi with Sm (black) or vehicle (gray) and then given a single i.p. injection of Sb^v at the doses indicated. Percent inhibition in spleen parasite burden (determined as LDU) was calculated relative to that of untreated infected mice (108 ± 15 LDU). Data are mean ± SEM (n = 6 per group). (B and C) Splenic CD3⁺CD4⁺ from Sm- and vehicle control–treated mice with or without additional Sb^v therapy were restimulated with L. donovani–infected BMDCs and analyzed by multicolor flow cytometry for intracellular IFN-γ and TNF (B) as well as IL-10 and IL-17a (C). Dot plots show representative mice from data pooled in D–F. (D–F) Frequency of CD3⁺CD4⁺ T cells from the indicated treatment groups that produced IFN-γ alone (D), IFN-γ and TNF (E), and TNF alone (F). (G) NO production by adherent splenocytes from infected mice treated as indicated. Data (mean ± SEM) are from 1 experiment (n = 6 per group). *P < 0.05, **P < 0.01, ***P < 0.001.