Immunosuppression during Leishmania donovani infection: a potential target for the development of therapy.

Dysfunction of T-helper 1 mediated immune responses is a hallmark of the progression of visceral leishmaniosis (VL). Several factors such as altered antigen presentation, and abnormalities in MHC/HLA, antigen processing, and T cell receptor recognition regulate the onset of immunosuppression. Recent investigations on VL patients suggest that susceptibility to visceral leishmaniosis is genetically determined and varies between populations in different geographical locations.