Immunization of cattle with a 36-kilodalton surface protein induces protection against homologous and heterologous Anaplasma marginale challenge.
Immunization of cattle with a purified Anaplasma marginale major surface protein, AmF36, induced protection against homologous challenge with the Florida isolate. Similarly, immunized cattle were protected from challenge with the antigenically and structurally distinct Washington-O isolate of A. marginale. The degree of protection in AmF36-immunized cattle varied from complete prevention of rickettsemia to significant delay in the onset of rickettsemia compared with control immunized cattle. A single AmF36 vaccinate was not protected against homologous challenge despite development of a strong antibody response. Immunoprecipitation of A. marginale proteins with a monoclonal antibody to AmF36 identified minor molecular size heterogeneity in this protein from different isolates, including the Florida and Washington-O isolates. The apparent molecular size of this surface protein in the Florida isolate was 36 kilodaltons, whereas the analogous proteins in Washington-O and four other isolates of A. marginale from the United States had molecular masses of 33 to 34 kilodaltons. Significantly, the surface-exposed peptides of these proteins appear to be conserved among the different isolates. These results demonstrate the potential of AmF36 as a subunit immunogen for bovine anaplasmosis and indicate a structural basis for its cross-protective ability.
Palmer
G H
GH
Department of Comparative and Experimental Pathology, University of Florida, Gainesville 32610.
Oberle
S M
SM
Barbet
A F
AF
Goff
W L
WL
Davis
W C
WC
McGuire
T C
TC
D000709:Anaplasma / Q000276:immunology*; D000712:Anaplasmosis / Q000276:immunology* / Q000517:prevention & control; D000818:Animals; D000907:Antibodies, Bacterial / Q000096:biosynthesis / Q000302:isolation & purification; D000942:Antigens, Bacterial / Q000008:administration & dosage* / Q000276:immunology / Q000302:isolation & purification; D002417:Cattle; D002418:Cattle Diseases / Q000276:immunology* / Q000517:prevention & control; D008565:Membrane Proteins / Q000276:immunology* / Q000302:isolation & purification; D008970:Molecular Weight
D000907:Antibodies, Bacterial; D000942:Antigens, Bacterial; D008565:Membrane Proteins