GM-CSF produced by recombinant vaccinia virus or in GM-CSF transgenic mice has no effect in vivo on murine cutaneous leishmaniasis.

The hemopoietic growth and differentiation regulators, granulocyte-macrophage colony-stimulating factor (GM-CSF) and the multipotential stimulating factor (multi-CSF) have been shown to have major effects on the effector function of mature macrophages. In this study we have examined the effect of recombinant GM-CSF and multi-CSF expressed transiently from recombinant vaccinia virus, or constitutively in GM-CSF transgenic mice on the development of cutaneous leishmaniasis, caused by Leishmania major in genetically susceptible or resistant mice. We observed no effect on the development of lesions when GM-CSF or multi-CSF were administered before infection, nor on the healing of lesions when they were administered after appearance of lesions. Although only some of the GM-CSF transgenic mice or their normal littermates developed lesions after infection with L. major, there was no difference between the groups in the rate of lesion development or in the size of lesions.