A CRITICAL ROLE FOR STEM-CELL FACTOR AND C-KIT IN HOST PROTECTIVE IMMUNITY TO AN INTESTINAL HELMINTH

In common with many intestinal nematode infections, Trichinella spiral is infections in mice are associated with a pronounced intestinal mast cell hyperplasia, The expulsion of the parasite from the gut is tempo rally associated with intestinal mastocytosis and mast cell function r eflected by the secretion of mast cell protease into tissue and serum, In vivo, mucosal mast cell production is highly dependent upon T cell -derived cytokines including IL-3 and IL-4, We present data here to sh ow that intestinal mast cell hyperplasia induced by helminth infection is also dependent upon the production of stem cell factor (SCF), Neut ralization of SCF by anti-SCF or anti-SCF receptor mAb completely abro gated the mast cell hyperplasia generated by T. spiralis infection, Mo reover, worm expulsion was dramatically delayed in treated mice and a reduced intestinal eosinophilia was observed, These effects did not ap pear to be mediated through alteration of Th cell responses and the pa rasite-specific serum antibody response was not affected, The reductio n in the mast cell response and worm expulsion observed after SCF neut ralization were reversible following cessation of monoclonal treatment , The data presented here clearly demonstrate a major role for SCF in the generation of intestinal mastocytosis and the host protective immu ne response following parasitic infection.