Orally administered Giardia duodenalis extracts enhance an antigen-specific antibody response.
We have identified novel adjuvant activity in specific cytosol fractions from trophozoites of Giardia isolate BRIS/95/HEPU/2041 (J. A. Upcroft, P. A. McDonnell, and P. Upcroft, Parasitol. Today, 14:281-284, 1998). Adjuvant activity was demonstrated in the systemic and mucosal compartments when Giardia extract was coadministered orally with antigen to mice. Enhanced antigen-specific serum antibody responses were demonstrated by enzyme-linked immunosorbent assay to be comparable to those generated by the "gold standard," mucosal adjuvant cholera toxin. A source of adjuvant activity was localized to the cytosolic component of the parasite. Fractionation of the cytosol produced fraction pools, some of which, when coadministered with antigen, stimulated an enhanced antigen-specific serum response. The toxic component of conventional mucosal adjuvants is associated with adjuvant activity; therefore, in a similar way, the toxin-like attributes of BRIS/95/HEPU/2041 may be responsible for its adjuvanticity. Complete characterization of the adjuvant is under way.
Dunn
L A
LA
Queensland Institute of Medical Research and the Tropical Health Program, Australian Centre for International and Tropical Health and Nutrition, The University of Queensland, The Bancroft Centre, Brisbane, Queensland 4029, Australia. lindaD@qimr.edu.au
Upcroft
J A
JA
Fowler
E V
EV
Matthews
B S
BS
Upcroft
P
P
D000276:Adjuvants, Immunologic; D000284:Administration, Oral; D000818:Animals; D000906:Antibodies / Q000276:immunology; D000914:Antibodies, Viral / Q000096:biosynthesis / Q000276:immunology; D000917:Antibody Formation; D000941:Antigens / Q000276:immunology*; D002458:Cell Fractionation; D003600:Cytosol / Q000276:immunology; D005872:Giardia / Q000276:immunology*; D006241:Haptens / Q000276:immunology*; D006433:Hemocyanins / Q000276:immunology*; D051379:Mice; D008810:Mice, Inbred C57BL; D008808:Mice, Inbred CBA; D009975:Orthomyxoviridae / Q000276:immunology*
D000276:Adjuvants, Immunologic; D000906:Antibodies; D000914:Antibodies, Viral; D000941:Antigens; D006241:Haptens; D006433:Hemocyanins; C032808:keyhole-limpet hemocyanin