IL6 and infection: Previous reports have shown that systemic infection with periodontitis-associated bacteria potentiates the induction of RA through the spread of inflammatory cytokines, such as IL-1β and IL-6.33,34 To examine how infection with A. actinomycetemcomitans can trigger arthritis systemically, we used a CAIA model in BALB/c mice infected with A. actinomycetemcomitans ATCC29522 isolated from mandibular abscess.