Modulation of lymphocyte proliferative responses by a canine Lyme disease vaccine of recombinant outer surface protein A (OspA)

The modulation of human lymphocyte proliferative responses was demonstrated with a recombinant outer surface protein A (OspA) vaccine preparation for the prevention of Borrelia burgdorferi infection. After exposure to either the unaltered vaccine preparation or OspA prepared in saline. normal lympho cyte responses to the mitogens concanavalin A, phytohemagglutinin-M or poke weed mitogen, or the antigen BCG were consistently reduced. Whole cell extr acts of B. burgdorferi also modulated immune responses but required a much greater quantity of protein than needed for the OspA preparation. The magni tude of modulation was directly dependent on the quantity of OspA. OspA int erferes with the response of lymphocytes to proliferative stimuli including a blocking of cell cycle phase progression. Future studies designed to del ete the particular region or component of the OspA molecule responsible for this effect may lead to improved vaccine preparations. (C) 2000 Federation of European Microbiological Societies. Published by Elsevier Science B.V. All rights reserved.