Identification of developmental regulated <em>Giardia lamblia</em> cyst antigens using GCSA-1, a cyst-specific monoclonal antibody.

Ward, H. D.; Kane, A. V.; Ortega-Barria, E.; Keusch, G. T.; Pereíra, M. E. A.

GCSA-1, a monoclonal antibody raised against cysts generated in vitro was shown to be Giardia cyst-specific by immunoblot analysts and immunofluorescence. GCSA-1 recognized four polypeptides ranging from 29-45 kD present in the cyst wall. These antigens appeared within eight hours of exposure of trophozoites to encystation medium and were shown to be synthesized by encysting parasites by means of metabolic labelling with [35S]-cysteine. Trophozoites were not stained by the antibody. GCSA-1 also reacted with in vivo cysts obtained from faeces of infected humans, gerbils and mice. These data demonstrate that the determinants recognized by GCSA-1 are early cyst antigens which are developmentally regulated and conserved components of the cyst wall. The actual role of the antigens detected by GCSA-1 in encystation are unknown, but they represent a potential target for strategies directed at inhibiting this process.

MONOCLONAL antibodies; CYSTS (Pathology); GIARDIA; IMMUNOFLUORESCENCE; ANTIGENS

Molecular Microbiology, 1990, Vol 4, Issue 12, p2095

0950-382X

Academic Journal

10.1111/j.1365-2958.1990.tb00570.x