Cytolethal distending toxin (CDT): analysis of humoral immunity response in sera of patients with different periodontal conditions and the effect on macrophage activity.

Aggregatibacter actinomycetemcomitans está associado à periodontite agressiva e produz CDT. Visando contribuir no entendimento do papel da CDT na regulação da resposta imune, foi determinada sua atividade sobre macrófagos e a resposta humoral contra a toxina. CDT inibiu a proliferação de células epiteliais OBA-9 e macrófagos Raw 264.7 e também a produção de NO por células Raw 264.7 e macrófagos peritoneais de camundongos C3H/HePas e C3H/HeJ, mas estimulou a produção de IL-12. Na imunidade humoral, 75% dos soros de indivíduos com PAgL e 81,8% dos PAgG foram reativos para A. actinomycetemcomitans. Não houve diferença na resposta contra CDTA e CDTB entre o soro de pacientes com diferentes condições periodontais. Todos os pacientes PAgG foram soropositivos para a CDTC, porém apenas 8,3% dos indivíduos com PAgL, nenhum dos PC e 25% dos saudáveis foram positivos. CDT tem atividade imunomodulatória e a resposta humoral difere entre indivíduos infectados pela bactéria.Aggregatibacter actinomycetemcomitans is associated with aggressive periodontitis and produces CDT. Aiming to contribute in the understanding the CDT activity in the immune response regulation, its action on macrophages was determined and the response against the toxin analyzed. CDT inhibited the proliferation of OBA-9 epithelial cells and Raw 264.7 macrophages and also inhibited the NO production by Raw 264.7 cells and peritoneal macrophages of C3H/HePas and C3H/HeJ mice, however, stimulated the IL-12 production. In the humoral immunity, 75% of sera from LAgP subjects and 81.8% were reactive to A. actinomycetemcomitans. There was not difference in the response against CDTA and CDTB among sera of patients with different periodontal conditions. All GAgP subjects were sera-reactivity to CDTC, however only 8.3% LAgP subjects, none in CP and 25% of healthy subjects were positive. CDT has immunomodulatory activity and the humoral response differ among bacteria infected subjects