Polyclonal B‐Cell Stimulative and Immunosuppressive Activities at Different Developmental Stages of <i>Trypanosoma gambiense</i>

Abstract

Bloodstream trypomastigote and cultured procyclic (insect midgut) forms of a monomophic strain of Trypanosoma gambiense were tested for their abilities to induce polyclonal B-cell activation (PBA) and immunosuppression (IS) in mice. Injection of a cell homogenate of bloodstream trypomastigotes induced both PBA and IS, while neither PBA nor IS was observed in mice injected with a cell homogenate of cultured procyclics. The results indicate that the substance(s) inducing PBA or IS is related to the developmental stage of the parasites.