Fig. 1.

Recognition of truncated cysteine protease B protein (ΔCPB) by L. donovani-affected individuals. In a, serum antibodies against ΔCPB were measured by ELISA in samples from VL patients (VL; n = 23) and non-endemic control individuals (NEC; n = 24). Each point represents the response of each individual sample with black bars indicating the mean OD for each group. In b, peripheral blood mononuclear cells from subjects living in either a highly endemic (n = 20) or non-endemic (n = 10) region were incubated with L. donovani SLA or ΔCPB prior to analyses by flow cytometry to identify CD4 T cells producing IFN-γ, TNF or IL-2, respectively. Each point represents the response of each individual sample with black bars indicating the mean for each group. Positive responses were determined as having optical densities (OD) or cell populations greater than the mean plus 3 s.e.m of that observed with NEC. Statistical significance was calculated by Kolmogorov–Smirnov test, *p < 0.05, ***p < 0.001, and ****p < 0.0001