Splenocytes from <i>T. cruzi</i> infected mice treated with Tc mucin produce low levels of IFN-γ.

<p>BALB/c mice were infected <i>i.p.</i> with 2×10⁵ chemically induced metacyclic forms of <i>Trypanosoma cruzi</i> Dm28c clone. The mice received <i>i.p.</i> injections of Tc Muc (20 µg/mouse) or PBS on alternate days starting at day of infection. Non-infected mice were used as control group. Twenty four days after infection, purified splenocytes were stimulated with PMA and ionomycin, as described in the Methods section, and supernatants were harvested at 24 h for determination of (<b>A</b>) IFN-γ and (<b>B</b>) TNFα by ELISA. The <i>y</i>-axis represents the levels of cytokines, detected by a specific ELISA assay, expressed in ng/ml. Asterisks represent statistical significance (p<0.05) as determined by the Student t test. To access the T cell activation profile CD69 expression on both CD4⁺ (<b>D</b>) and CD8⁺ (<b>E</b>) T cells were analysed by FACS analysis; the frequency of IFN-γ producing T cells from splenocytes polyclonally stimulated with PMA/ionomycin, and the percentages of both IFN-γ producing CD4⁺ T cells (<b>F</b>) and CD8⁺ T cells (<b>G</b>)<b>,</b> were determined by intracellular cytokine FACS-staining. #Infected group are statistically different from non-infected control mice (<i>P</i>≤0.05). Asterisks represent statistical differences between Tc mucin treated <i>versus</i> non-treated mice from infected groups as determined by the Student t test (<i>P</i>≤0.05). All experiments were repeated at least 3 times.