Actinobacillus actinomycetemcomitans possesses an antigen binding to anti-human IL-10 antibody

It is well known that the cell components of periodontopathic bacteria are able to induce several cytokines and possibly to affect the cytokine networ k. In order to determine the presence of the periodontopathic Actinobacillu s actinomycetemcomitans components recognized by antibodies against cytokin e molecules, ELISA reactivities of sonic extracts from the bacterial cells were determined by use of ELISA kits specific for human interleukin (IL)-1 beta, IL-4, IL-5, IL-6, IL-10, tumor necrosis factor-alpha, and interferon- gamma. The ELISA analysis demonstrated that the sonic extracts from eight s trains of A. actinomycetemcomitans bound with anti-human IL-10 monoclonal a ntibody. Western blotting analysis revealed that the molecular mass of the antigen was approximately 65 kDa. IL-10 is produced by type 2 helper T cell s and mainly down-regulates the type 1 helper T cell response. The present study suggests that the 65-kDa antigen of A. actinomycetemcomitans may affe ct the host defense function through binding to IL-10 receptor as an agonis t or an antagonist for IL-10. (C) 2001 Federation of European Microbiologic al Societies. Published by Elsevier Science BN. All rights reserved.