Cortisone-induced immunotolerance to nematode infection in CBA/Ca mice. II. A model for human chronic trichuriasis.

Treatment of CBA/Ca mice with cortisone acetate for a short period after infection with Trichuris muris induces a state of immunotolerance which allows the development and survival of a chronic infection. Mice harbouring such infections were found to be less capable of responding to a primary infection with Trichinella spiralis or of producing humoral responses to lipopolysaccharide and sheep red blood cells. Mesenteric lymph node T cells, however, were as responsive to the polyclonal activator phytohaemagglutinin as those from normal mice. Homing to the intestinal tract of activated mesenteric lymph node cells from helminth-infected donors was not impaired in the animals harbouring chronic infections. The results are discussed in terms of antigenic competition and with respect to their relevance to chronic human trichuriasis.