IL10 and HIV infectious disease: This may explain the low incidence of hyperinfection in HIV-infected adults, and attests to differences in the nature of the immune deficit between advanced HIV infection and other immunosuppressive states: corticosteroid-induced immunosuppression is associated with prominent expression of regulatory cytokines, such as IL-10 (91), and HTLV-1 infection with depletion of type 2 cytokines (92), but in HIV infection, regulatory T cells may be preferentially destroyed (31) and type 2 cytokine responses may be relatively preserved (93).