“…Simultaneously, infection with H. polygyrus suppresses immune responses to a variety of heterologous antigens such as ovine erythrocytes (Shrimp, Crandall & Crandall 1975) and other nematode parasites (Behnke, Wakelin & Wilson 1978) normally expelled by what we now know to be Th2 mediated immune mechanisms. Suppressive activity is also demonstrable in vivo (Pritchard & Behnke 1985, Pritchard, Lawrence, Appleby, Gibb & Glover 1994, and in vitro using parasite extracts or excretory secretory (ES) products (Pritchard, Ali & Behnke 1984, Crawford, Behnke & Pritchard 1989. It is possible that such suppressive activity, which potentially has the ability to counteract mammalian Th2 driven immune responses (DeKruyff, Fang & Umetsu 1992), could be exploited for the development of novel therapeutics for Th2 mediated disease states e.g.…”