Submitted to: American College of Veterinary Pathologists Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: 12/5/1996
Publication Date: N/A
Technical Abstract: Brucella abortus induces placentitis and abortion in cattle. A new brucellosis vaccine for cattle, B. abortus strain RB51, prevents abortions, although it can also occasionally induce placentitis. The purpose of this study was to identify the receptor that mediates adhesion of strain RB51 to bovine trophoblastic cells. Adhesion of strain RB51 to trophoblastic cell cultures was not inhibited by collagen and laminin. However, fibronectin inhibited adhesion by 53%. The alpha 5/beta 1 integrin is a high affinity receptor for fibronectin. Antibody to alpha 5 or beta 1 inhibited adhesion of strain RB51 by 42% or 63%, respectively. Both antibodies combined resulted in a 98% inhibition of adhesion. The inhibition was confirmed by double fluorescent labeling of strain RB51 which differentiated intracellular from extracellular bacteria. These results indicate that adherence of B. abortus strain RB51 to bovine trophoblasts is mediated by the alpha 5/beta 1 integrin.