α-DEC-ESAT treatment increases IFN-γ⁺ T cells in the lung during the acute phase of experimental tuberculosis.

<p>The production of IFN-γ by CD4⁺ and CD8⁺ T cells was assessed in different tissues at two time-points during the experimental Mtb infection. α-DEC-ESAT treatment increased the percentages of IFN-γ⁺ CD4⁺ (A) and CD8⁺ (B) T cells in the lungs, during the acute (day 14) but not during the chronic (day 60) phase of the disease. In the lymphoid organs analyzed such as mediastinal lymph nodes (MedLN; C-D), inguinal lymph nodes (IngLN; E-F), and spleen (G-H), we observed very low levels of IFN-γ production either by CD4⁺ (left side panels) or CD8⁺ (right side panels) T cells. Individual mice were analyzed and 3–5 mice were used per group. Data are presented as mean plus standard error. (*) indicates P < 0.05. All bars represent groups of infected mice with different treatments. Black bars: untreated mice (Inf/No-Tx); white bars: α-DEC-ESAT-treated mice (Inf/DE6-Tx); stripped bars: mice treated with isotype control antibody conjugated with ESAT-6 (Inf/IsoE6-Tx). Cell suspensions were cultured either with medium alone (M) or medium with ESAT-6 pool 1 of peptides (p1) as detailed in Materials and Methods. MedLN = Mediastinal lymph nodes, IngLN = Inguinal lymph nodes.