Sodium Dodecyl Sulfate- and Salt-Extracted Antigens from Various Brucella Species Induce Proliferation of Bovine Lymphocytes

One- and two-dimensional gel electrophoresis and cellular immunoblotting were used to compare the protein profiles and immunogenic capabilities of salt- and sodium dodecyl sulfate-extracted components isolated from different BruceUla species. Cellular immunoblotting demonstrated that freshly isolated bovine peripheral blood mononuclear cells proliferated to similar molecular mass components from the various Brucella extractions. One- and two-dimensional gel electrophoresis showed similarities in protein profiles among the different BruceUla species that correlated with lymphocyte reactivity. The results presented in this study provide preliminary evidence that common proteins that induce lymphocyte proliferation are present among different Brucella species, suggesting that a genuswide subunit vaccine may be feasible. Brucella organisms are small gram-negative facultative intracellular pathogens that cause zoonoses of importance throughout the world (22). There are six recognized species of Brucella, each differing in its host specificity. The factors that account for host preferences have not been identified. At the DNA level, comparison of the restriction endonucle-ase digestion patterns of Brucella abortus 19 and 230