Enzyme-linked immunosorbent assay using a recombinant baculovirus-expressed Bacillus anthracis protective antigen (PA): measurement of human anti-PA antibodies.
We developed an antigen capture enzyme-linked immunosorbent assay (ELISA) which does not require purified protective antigen (PA) for detection of human antibodies to Bacillus anthracis PA. Lysates of Spodoptera frugiperda (Sf-9) cells infected with recombinant baculovirus containing the PA gene were used as the source of PA to develop the ELISA. Recombinant PA from crude Sf-9 cell lysates or PA purified from B. anthracis Sterne strain was captured by an anti-PA monoclonal antibody coated onto microtiter plates. We demonstrated that human serum antibody titers to PA were identical in the ELISA whether we used crude Sf-9 cell lysates containing recombinant baculovirus-expressed PA or purified Sterne PA. Finally, false-positive results observed in a direct ELISA were eliminated with this antigen capture ELISA. Thus, the antigen capture ELISA with crude preparations of baculovirus-expressed PA is reliable, safe, and inexpensive for determining anti-PA antibody levels in human sera.
D000818:Animals; D000907:Antibodies, Bacterial / Q000097:blood*; D000942:Antigens, Bacterial / Q000276:immunology*; D001408:Bacillus anthracis / Q000276:immunology*; D001428:Bacterial Vaccines / Q000276:immunology; D016367:Baculoviridae / Q000235:genetics; D004797:Enzyme-Linked Immunosorbent Assay; D005822:Genetic Vectors; D006801:Humans; D011994:Recombinant Proteins / Q000276:immunology; D018411:Spodoptera; D014614:Vaccines, Synthetic / Q000276:immunology
D000907:Antibodies, Bacterial; D000942:Antigens, Bacterial; D001428:Bacterial Vaccines; D011994:Recombinant Proteins; D014614:Vaccines, Synthetic