Pre-patent schistosome infection impairs the ability of CD11b⁺ cells to stimulate CD4⁺ cells.

<p>A, CD11c⁺ dendritic cells isolated from the spleen of 4 week <i>S. mansoni</i>-infected or non-infected wild type mice and CD4⁺ T cells isolated from non-infected OT-II/RAG-1^−/− mice were co-cultured for 72 hours without antigen, with OVA peptide or with anti-CD3 antibody. The concentration of IFN-γ in the cell culture supernatants was measured by ELISA. B, CD11b⁺ cells were isolated from the spleens of 4 week <i>S. mansoni</i>-infected or non-infected OT-II/RAG-1^−/− mice; CD4⁺ T cells were isolated from non-infected OT-II/RAG-1^−/− mice, and stained with CFSE. Cells were then co-cultured for 72 hours without antigen, with OVA peptide or with anti-CD3 antibody. The concentration of IFN-γ in the cell culture supernatants was measured by ELISA. Data shown are mean +/− SEM. C, CD4⁺ T cell proliferation in the co-cultures stimulated with OVA peptide or anti-CD3 antibody described in (B) was analyzed by flow cytometry and proliferation index calculated. Horizontal bars represent mean of 5 independent mice. No Ag, no antigen; OVA, OVA peptide; αCD3, anti-CD3.