Increase in Colony Stimulating Factor(CSF) in serum and augmentation of CSF responsiveness of lymphoid mononuclear cells by acute Trypanosoma cruzi infection in mice.

Abstract

Acute infection of Trypanosoma (T.) cruzi to C3H/HeN mice caused the induction of a higher level of serum colony stimulating factor (CSF) activity to support the proliferation of mouse bone marrow cells. The CSF activity reached a maximum 2 days after the infection and declined thereafter. Spleen cells of the T. cruzi-infected mice showed higher levels of responsiveness to CSF in L929-conditioned medium, mouse recombinant GM-CSF and infected mouse sera as compared with normal mouse spleen cells. The induction of CSF-responding cells became plateau 4 days after the infection and it decreased thereafter. In concomitant with the production of CSF activity in the infected mouse sera, large granular cells bearing high intensity of Mac-2 antigen increased in the infected mouse spleen. These cells were nylon nonadherent and displayed inhibitory effect on T cell response to Con A. These findings indicate that T. cruzi infection induces augmentation of in vivo CSF production, leading to the abnormal proliferation of CSF-responding cells and that augmented production of, and responsiveness to, CSF might be one of important mechanisms responsible for the induction of immune abnormalities in T. cruzi-infected mice.