You are here:
ENCYSTATION AND EXPRESSION OF CYST ANTIGENS BY 'GIARDIA LAMBLIA' IN VITRO
Citation:
Gillin, F., D. Reiner, M. Gault, H. Douglas, AND S. Das. ENCYSTATION AND EXPRESSION OF CYST ANTIGENS BY 'GIARDIA LAMBLIA' IN VITRO. U.S. Environmental Protection Agency, Washington, D.C., EPA/600/J-87/021 (NTIS PB87196150), 1987.
Description:
The cyst form of Giardia lamblia is responsible for transmission of giardiasis, a major waterborne intestinal disease. These studies demonstrate for the first time expression of cyst antigens and encystation of G. lamblia in vitro by both morphologic and immunologic criteria. The researchers first showed that the jejunum is a major site of encystation in the suckling mouse model and therefore tested small intestinal factors as stimuli of encystation. As a sensitive probe for differentiation in vitro, researchers raised antisera which react with cysts and precysts, but not with cultured trophozoites. Exposure of cultured trophozoites to glycodeoxycholate, a bile salt, increased the number of oval, refractile cells which react strongly with anticyst antibodies from <0.1% to 8.9%. Encystation expression under anaerobic conditions reached 51.2%. In vitro expression of a major cyst antigen of approximately 26,000 daltons (26K) was demonstrated on immunoblots. These studies are an important step in understanding the differentiation of a major protozoan pathogen. (Copyright (c) 1987, Science.)