IMMUNITY TO A CHALLENGE INFECTION OF STRONGLOIDES-STERCORALIS 3RD-STAGE LARVAE IN THE JIRD

Jirds support the entire life-cycle of Strongyloides stercoralis. We t herefore used this host as a model to define the mechanism of the immu ne response to a challenge infection, as well as the parasite stage ef fected by the response. Jirds given a primary infection of S. stercora lis are resistant to re-infection. The use of implanted diffusion cham bers containing larvae showed that the immune response killed the thir d-stage larvae, and this was confirmed by subcutaneous infections. The larvae of a challenge infection are killed within 48 h, a time period too short to allow for the development of L4 and adult worms. The imm une response is dependent on both a serum factor and cells, suggestive of an ADCC type response.