<p>NO levels (μM) were determined in supernatants from PBMCs cultures maintained upon vaccine-soluble antigen (VSA) or soluble <i>Leishmania chagasi</i> antigen (SLcA) stimuli <i>in vitro</i>. Data were analyzed early (90 days—T<sub>90</sub>) and late (885 days—T<sub>885</sub>) after experimental <i>L</i>. <i>chagasi</i>-challenge. The groups are represented as follows: C (“Control”; white bars); “Sal” (<i>Lutzomyia longipalpis</i> salivary glands; <i>light gray bars</i>); “LbSal” (antigen of <i>L</i>. <i>braziliensis</i> plus <i>Lutzomyia longipalpis</i> salivary glands; <i>dark gray bars</i>); and “LbSapSal” (<i>L</i>. <i>braziliensis</i> antigen plus saponin and <i>Lutzomyia longipalpis</i> salivary glands; black bars). Top panels: The x-axis displays the different experimental groups (“Control”, “Sal”, “LbSal” and “LbSapSal”) according to the <i>in vitro</i> stimuli (control culture [CC], VSA or SLcA). The y-axis represents the nitrite levels [μM]. Data are presented as mean values ± standard deviations. The connecting lines represent significant difference (<i>P <0</i>.<i>05</i>) between the CC, VSA or SLcA-stimulated cultures. The symbols C, Sal and LbSal indicate significant differences in comparison to the “Control”, “Sal” or “LbSal” groups, respectively. Bottom panels: Correlation between NO levels and spleen parasite load (# amastigotes/20ng of total DNA) at T<sub>885</sub> considering CC (bottom left panel) or the presence of a stimulus (VSA: bottom middle panel; or SLcA: bottom right panel) in all groups. The groups are distinguishable by colors as follows: as follows: “C” (white circles); “Sal” (ligh gray circles); “LbSal” (dark gray circles) and “LbSapSal” (black circles). The quadrants represented in the bottom panels delimit the low and high NO producers (y-axis) and the low and high spleen parasite load (x axis).</p
