Fig. 1

Co-culture system using L. infantum infected macrophages (MØ) and CD4⁺ T-cells, 24 months after experimental challenge with L. infantum. Control group (n = 6 dogs) and Leishmune® (n = 5 dogs) received three doses of PBS or vaccine, respectively, at 21 day intervals; LdCen^−/− group (n = 6 dogs) received 10⁷ LdCen^−/− stationary phase promastigotes in single-dose. a Infection rate (%) of macrophages after 3 h of in vitro infection with L. infantum (5 × 10⁶ promastigotes; ratio ten parasites: 1 MØ). b Number of amastigote forms by macrophages after 3 h of in vitro infection with L. infantum. c Number of amastigote forms by macrophages after 72 h of in vitro infection with L. infantum. The cytokine profile (pg/mL) was analyzed in supernatant from L. infantum infected macrophages (MØ) co-cultured with CD4⁺ T-cells for IFN-γ (d), TNF-α (e), IL-12 (f), IL-4 (g), IL-10 (h) and IFN-γ/IL-10 ratio (i). The x-axis represents the control group (C), Leishmune® and LdCen^−/− vaccines. The connecting lines between the bars indicate significant differences (P < 0.05)