Cytokine production profile of CD4+ T cells and iNKT-cell (invariant natural killer T cell) subsets in the blood and gut mucosal compartments in persons with and without HIV-1 infection. The concentrations of cells producing (a–c) interferon (IFN)-γ, (d–f) interleukin (IL)-4 and (g) IL-17 are indicated for total CD4+ T cells (a, d, g), CD4+ iNKT cells (b, e) and CD4 − iNKT cells (c, f) in the blood and gut mucosal compartments of persons with (gray boxes) and without (white boxes) HIV-1 infection.