PURIFICATION OF IMMUNOSUPPRESSIVE FACTOR FROM CAPNOCYTOPHAGA-OCHRACEA

Capnocytophaga, one of the genera of oral bacteria, has been implicate d in the pathogenesis of several diseases, including endocarditis, sep ticaemia and disorders of the oral cavity such as abscesses and period ontal disease. This study examined sonic extracts (SE) of Capnocytopha ga strains for their ability to alter lymphocyte function. The SE of t ested Capnocytophaga caused dose-dependent suppression of spleen cells in response to mitogen. This suppressive effect was heat-labile and s ensitive to the proteolytic enzyme pronase E. The suppressive factor ( SF) was purified from SE of C. ochrasea by a combination of ultrogel-A cA34, high-pressure liquid DEAE ion-exchange chromatography and hydrox yapatite columns, which revealed a single band of 14 kDa by SDS-PAGE. Rabbit anti-serum against the purified SF inhibited the immunosuppress ion induced by SE of C. ochracea with the recovery of lymphocyte proli feration.