Immunomodulating Activities of Sodium-dodecyl-sulphate-extracted Antigens from

Actinobacillus actinomycetemcomitans (serotype b) whole lysates, LPS-free cell wall polymers (CWP) and CWP fractions obtained by immunoblot were assayed for immunomodulating activity. Whole cell lysates and purified CWP stimulated mouse splenocytes to proliferate in vitro. Five CWP fractions, ranging from 15 to 209 kDa, suppressed in vitro splenocyte proliferation. Fraction-induced inhibition of proliferation was not due to cytotoxicity. Purified A. actinomycetemcomitans CWP stimulated murine splenocyte interleukin- 1 release during 72 h of in vitro culture. Two CWP fractions preferentially stimulated splenocyte interleukin-4 release during in vitro culture. This mixed response of CWP-induced splenocyte stimulation and suppression, and IL-1IIL-4 release, is dependent on fragment size. Therefore, A. aclinomycetemcomitans CWP may play a role in the inflammatory process of periodontal disease as large bacterial fragments stimulate inflammation and smaller, degraded fragments promote anti-inflammatory activities. KEY WORDS-Actinobacih actinom~cetemcomitans; Cell wall polymers; Periodontal disease; Cytokines. INTRODUCTION injection of streptococcal cell wall polymers Periodontal disease is a chronic, erosive inflamma-tion of the gingiva, periodontal ligament, alveolar bone and cementum. The gram-negative, cocco