Antibodies to the ventral disc protein delta-giardin prevent in vitro binding of Giardia lamblia trophozoites.
A cDNA coding for detlaq-giardin was cloned from Giardia lamblia trophozoites to localize the protein and to study its function in mediating surface attachment. Recombinant delta-giardin antigen was expressed in Escherichia coli as a poly-histidine fusion protein and was purified by affinity chromatography for production of antisera to delta-giardin. By immunoblotting analysis, antisera to recombinant delta-giardin antigen recognized a 31-kDa protein on G. lamblia trophozoites. Anti-recombinant delta-giardin was used to localize the native protein to the trophozoite ventral disk in both immunofluorescence and immunoelectron microscopy assays. Pre-treatment of G. lamblia trophozoites with anti-delta-giardin sera caused morphological changes in the parasite and inhibited trophozoite binding to the surface of cell culture slides. Binding of antibodies to delta-giardin may provide a means of inhibiting attachment of G. lamblia trophozoites to the intestinal epithelium and thereby prevent clinical giardiasis.
Jenkins
Mark C
MC
Animal Parasitic Diseases Laboratory, Agricultural Research Service, USDA, Beltsville, Maryland 20705, USA. mark.jenkins@ars.usda.gov
O'Brien
Celia N
CN
Murphy
Charles
C
Schwarz
Ryan
R
Miska
Katarzyna
K
Rosenthal
Benjamin
B
Trout
James M
JM
D000818:Animals; D000913:Antibodies, Protozoan / Q000096:biosynthesis / Q000276:immunology*; D003001:Cloning, Molecular; D003598:Cytoskeletal Proteins / Q000032:analysis / Q000235:genetics / Q000276:immunology*; D005455:Fluorescent Antibody Technique; D015870:Gene Expression; D016829:Giardia lamblia / Q000737:chemistry / Q000235:genetics / Q000276:immunology*; D006801:Humans; D007106:Immune Sera / Q000096:biosynthesis / Q000276:immunology*; D016253:Microscopy, Immunoelectron; D015800:Protozoan Proteins / Q000032:analysis / Q000235:genetics / Q000276:immunology*; D012333:RNA, Messenger / Q000032:analysis; D011994:Recombinant Proteins / Q000096:biosynthesis / Q000235:genetics / Q000276:immunology*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D053058:Trophozoites / Q000737:chemistry / Q000276:immunology
D000913:Antibodies, Protozoan; D003598:Cytoskeletal Proteins; D007106:Immune Sera; D015800:Protozoan Proteins; D012333:RNA, Messenger; D011994:Recombinant Proteins; C038207:giardin protein, Giardia lamblia