Fig 1.
Malnutrition disrupts anti-parasitic immunity during visceral leishmaniasis.
(A and B) Body weight of naive or L. infantum-infected control diet or polynutrient deficient diet (PND diet) over time. (C) Final tail lengths at 6 weeks of diet and 4 weeks post-infection (wpi). (D) Spleen and (E) liver weight. Parasite number in the (F) spleen and (G) liver of control diet and PND diet-fed mice at 4 weeks post-infection. Absolute number of (H) CD3+ cells, (I) CD4+ T cells, (J) CD4+ T cells expressing T-bet, and (K) CD4+ T cells expressing IFNγ in the spleen of control and PND diet-fed mice. Cells were gated based on their characteristic size (FSC) and granularity (SSC), singlet cells, live+, and CD45+ cells. (L) IL-10 levels in the supernatants from splenocytes restimulated with L. infantum crude antigen or medium for 72 h at 4 wpi. (M) IL-10 levels in the liver homogenate supernatant at 4 wpi. The data are expressed as mean ± SEM and represent two experiments (n = 4 mice/group). The statistical significance was calculated by one-way ANOVA or Student’s t-test (*p < 0.05, **p < 0.01, ***p < 0.001 and ****p < 0.0001).
Fig 2.
IL-10R blockade restores anti-parasitic immunity.
L. infantum-infected mice fed with control diet or PND diet were treated with anti-IgG control or anti-IL-10R antibody and euthanized at 4 wpi. Treatment was initiated at the time of infection and continued weekly until the termination of the experiment. (A and B) Body weight of infected mice treated with (A) α-IgG control or (B) α-IL-10R antibody. (C) Tail lengths at 6 weeks of diet and 4 weeks post-infection (wpi). (D) Spleen and (E) liver weight. Parasite number in the (F) spleen and (G) liver. Absolute number of (H) CD4+ T cells, (I) percentage and (J) number of CD4+ T cells expressing CD44, (K) number of CD4+ T cells expressing IFNγ at the spleen of control and PND diet-fed mice treated with anti-IgG control or anti-IL-10R antibody. (L-M) Percentage and number of CD11b+ cells expressing iNOS at the spleen of infected control and PND diet-fed mice treated with α-IgG control or α-IL-10R antibody. Cells were gated based on their characteristic size (FSC) and granularity (SSC), singlet cells, live+, and CD45+ cells. T cells were gated on CD3+, CD4+, and myeloid cells on CD11b+, CD11b+ iNOS+ cells. (N-O) Representative pictures of H&E-stained liver sections (20x magnification) and bar graph of the number of granulomas per field (counted in 10x magnification). The data are expressed as mean ± SEM and represent two experiments (n = 3–5 mice/group). The statistical significance was calculated by one-way ANOVA (*p < 0.05, **p < 0.01, ***p < 0.001 and ****p < 0.0001).