Immunoregulatory effects of Borrelia burgdorferi on T-B cell interactions

Late stages of Lyme borreliosis are characterized by a disproportionate inflammatory response presumably elicited by only minute amounts of persisting antigen. To explore the possibility that amplification mechanisms of the immune response shape disease manifestations, we studied immunoregulatory properties of Borrelia burgdorferi antigens and analyzed whether they influence B cell-T cell cooperation. B. burgdorferi was found to induce peripheral resting B cells to function as effective antigen presenting cells for B. burgdorferi sonicate (Bb) and unrelated third party antigens. Morphologically and phenotypically, pulsed B cells represented small resting B cells and did not acquire activation markers. These data suggest that distinct antigen-presenting cells are involved in B. burgdorferi induced immune responses. B lymphocytes may play a crucial role in amplifying T cell responses, especially by recruiting antigen specific and nonspecific T cells to regions where minute amounts of spirochetal antigens are present.