TEMPERATURE-RELATED DIFFERENTIAL EXPRESSION OF ANTIGENS IN THE LYME-DISEASE SPIROCHETE, BORRELIA-BURGDORFERI

Previous studies have demonstrated that Borrelia burgdorferi in the mi dguts of infected ticks shows increased expression of the antigenic ou ter surface protein OspC after the ticks have ingested a blood meal. T his differential expression is at least partly due to a change in temp erature, as an increase in OspC levels is also observed when cultures are shifted from 23 to 35 degrees C. Immunoblotting of bacterial lysat es with sera from infected mice indicated that the levels of several a dditional antigens were also increased in bacterial cultures shifted t o 35 degrees C; we have identified one antigen as OspE. We have also o bserved differential expression of OspF, which has been proposed to be coexpressed in an operon with the gene encoding OspE.