The Journal of Immunology, Vol 144, Issue 11 4362-4369, Copyright © 1990 by American Association of Immunologists

ARTICLES

Antigenic variation of Giardia lamblia in experimental human infections

TE Nash, DA Herrington, MM Levine, JT Conrad and JW Merritt Jr
Laboratory of Parasitic Disease, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892.

To determine if Giardia surface Ag vary in human infections volunteers were inoculated enterally with trophozoites of uncloned GS/M-85 and in later experiments with two clones derived from GS/M. The surface Ag of trophozoites reisolated from 6/6 volunteers differed from the inoculum. To determine if the surface Ag of trophozoites derived from clones would also change, volunteers were inoculated with two clones, B6 or H7. B6 possesses a 200-kDa surface Ag recognized by mAb 3F6 and H7 has a 72-kDa surface Ag recognized by mAb G10/4. One of thirteen B6 and four of four H7-inoculated volunteers became infected. Analysis of Giardia obtained on day 22 from the intestines of the four H7-infected volunteers and cultures derived from these trophozoites revealed loss of the initial major surface Ag as determined by surface IFA using mAb, surface radiolabeling and loss of cytotoxicity to mAb, and Western blots. Loss of the 72-kDa Ag began after day 14 and was practically complete by day 22. The 200-kDa surface Ag was almost totally absent from the surface of Giardia isolated from the single B6-infected volunteer. Serum surface-reactive antibodies, as measured by IFA and cytotoxicity to H7 and the day 22 isolates, showed high levels of antibodies to H7, primarily to the 72-kDa surface Ag, but negligible or low levels of late-appearing antibodies to the day 22 isolates. These studies document antigenic variation of Giardia in human infections and show that humoral responses are in part isolate-specific.

This article has been cited by other articles:

				M. C. Touz, A. S. Ropolo, M. R. Rivero, C. V. Vranych, J. T. Conrad, S. G. Svard, and T. E. Nash Arginine deiminase has multiple regulatory roles in the biology of Giardia lamblia J. Cell Sci., September 1, 2008; 121(17): 2930 - 2938. [Abstract] [Full Text] [PDF]

				M. Marti, Y. Li, P. Kohler, and A. B. Hehl Conformationally Correct Expression of Membrane-Anchored Toxoplasma gondii SAG1 in the Primitive Protozoan Giardia duodenalis Infect. Immun., February 1, 2002; 70(2): 1014 - 1016. [Abstract] [Full Text] [PDF]

				M. Bienz, M. Siles-Lucas, P. Wittwer, and N. Muller vsp Gene Expression by Giardia lamblia Clone GS/M-83-H7 during Antigenic Variation In Vivo and In Vitro Infect. Immun., September 1, 2001; 69(9): 5278 - 5285. [Abstract] [Full Text] [PDF]

				A. G. McArthur, L. A. Knodler, J. D. Silberman, B. J. Davids, F. D. Gillin, and M. L. Sogin The Evolutionary Origins of Eukaryotic Protein Disulfide Isomerase Domains: New Evidence from the Amitochondriate Protist Giardia lamblia Mol. Biol. Evol., August 1, 2001; 18(8): 1455 - 1463. [Abstract] [Full Text] [PDF]

				R. D. Adam Biology of Giardia lamblia Clin. Microbiol. Rev., July 1, 2001; 14(3): 447 - 475. [Abstract] [Full Text] [PDF]

				S. Stager, B. Gottstein, H. Sager, T. W. Jungi, and N. Muller Influence of Antibodies in Mother's Milk on Antigenic Variation of Giardia lamblia in the Murine Mother-Offspring Model of Infection Infect. Immun., April 1, 1998; 66(4): 1287 - 1292. [Abstract] [Full Text] [PDF]

				D. M. Rosales-Borjas, J. Diaz-Rivadeneyra, A. Dona-Leyva, S. A. Zambrano-Villa, C. Mascaro, A. Osuna, and L. Ortiz-Ortiz Secretory Immune Response to Membrane Antigens during Giardia lamblia Infection in Humans Infect. Immun., February 1, 1998; 66(2): 756 - 759. [Abstract] [Full Text] [PDF]

				H. D. Luján, M. R. Mowatt, J.-j. Wu, Y. Lu, A. Lees, M. R. Chance, and T. E. Nash Purification of a Variant-specific Surface Protein of Giardia lamblia and Characterization of its Metal-binding Properties J. Biol. Chem., June 9, 1995; 270(23): 13807 - 13813. [Abstract] [Full Text] [PDF]