Effect of Schistosoma mansoni infection on innate and HIV-1 specific T cell immune responses in HIV-1 infected Ugandan fisher folk
In Uganda, fisher folk have HIV prevalence rates about 4 times higher than the national average and are often co-infected with S. mansoni. We hypothesized that innate immune responses and HIV specific Th1 immune responses might be downmodulated in HIV/S. mansoni co-infected individuals compared to HIV+ /S. mansoni negative individuals. We stimulated whole blood with innate receptor agonists and analysed supernatant cytokines by Luminex. We evaluated HIV-specific responses by intracellular cytokine staining for IFN-γ, IL-2 and TNF-α. We found that the plasma viral load and CD4 count was similar between the HIV+SM+ and HIV+SM- individuals. In addition, the TNF-α response to the imidazolequinoline compound CL097 and β-1, 3-glucan curdlan, was significantly higher in HIV/S. mansoni co-infected individuals compared to HIV only infected individuals. The frequency of HIV specific IFN-γ+IL-2-TNF-α- CD8 T cells and IFN-γ+IL-2-TNF-α+ CD4 T-cells was significantly higher in HIV/S. mansoni co-infected individuals compared to HIV only infected individuals. These findings do not support the hypothesis that S. mansoni down-modulates innate or HIV specific Th1 responses in HIV/S. mansoni co-infected individuals.