Immunopathology of
leishmaniasis: an update.Int
J Immunopathol Pharmacol. 2007 Jul-Sep;20(3):435-45.
Leishmaniasis
represents a severe, increasing, public health problem. The
perspective of its control is highly dependent on research progress,
on therapeutic manipulations of the immune system, and on vaccine
development. There is a correlation between the clinical outcome of
Leishmania infection and the cytokine response profile. While a
protective immune response against Leishmania has been clearly
identified to be related to the influence of a type-1 response and IFN-gamma
production, the precise role of T helper (TH) 2 cytokines in
non-healing infections requires further exploration. IL-4 and IL-13
(TH2 cytokines) can promote disease progression in cutaneous
leishmaniasis, whereas IL-4 would appear to enhance protective type-1
responses in visceral leishmaniasis.
Thus, the TH1/TH2
paradigm of resistance/susceptibility to intracellular parasites is
probably an oversimplification of a more complicated network of
regulatory/counter regulatory interactions. Moreover, the presence of
antigen specific regulatory T cell subsets may provide an environment
that contributes to the balance between TH1 and TH2 cells. Finally,
the involvement of CD8 positive T cells has been described, but the
modality of their function in this kind of infection has not been so
far elucidated. |
