POLYCLONAL B-CELL ACTIVATORS AND IN-VITRO INDUCTION OF AUTOANTIBODY REACTIVE WITH COLLAGEN

Cells producing autoantibodies are known to be present in chronically inflamed periodontal tissues. In sites of chronic inflammation, polycl onal B cell activators (PBA) are known to exhibit adjuvant activity wh en combined with foreign antigens. These results prompted an examinati on of PBA in eliciting an antibody response to an autoantigen (i.e. co llagen type I). Rat lymphocytes were stimulated with rat collagen (typ e I), microbial PBA (LPS) or the combination of LPS plus rat collagen in vitro. Anti-collagen antibody-forming cells (AFC) were enumerated u sing an ELISPOT assay. Collagen or LPS alone elicited few anti-collage n AFC but the addition of LPS to collagen resulted in a substantial ad juvant effect and yielded maximal responses to collagen. Comparisons o f anti-collagen AFC from short-term immunized (2-6 wk after booster), non-immunized and long-term immunized (3-4 months after booster) anima ls were performed. It revealed that cells from recently immunized rats were significantly easier to activate than the other 2 groups. The ad juvant effect of microbial PBA may be important in anti-collagen antib ody production and thus the localization of PBA in periodontal pockets may explain why anti-collagen AFC are restricted to the chronically i nflamed periodontal tissues.