Immune response in lymphocyte cultures stimulated by oral bacteria preparations

Lymphocyte cultures were used as an in vitro experimental model to get a de eper insight into immune response to oral bacteria in periapical granulomas . Lymphocytes isolated from leucocyte concentrate were in lymphocyte cultur es stimulated by antigen preparations of oral bacteria. Lymphocyte subsets that have developed in lymphocyte cultures after a week of stimulation were analysed by flow cytometry. A significant increase in expression of INF-ga mma molecules in CD3+ cells stimulated by antigen preparations of oral stre ptococci was found, compared with negative control. On the other hand we ob served a significant increase in expression of IL-4 in CD3+ cells stimulate d by antigens of anaerobic bacteria, compared with negative control. Our re sults show that antigens of oral streptococci in in vitro lymphocyte cultur es induce the differentiation of T helper cells into Th2 cells and that ant igen preparations of anaerobic bacteria induce the differentiation of T hel per cells into Th1 cells. Furthermore, an increased expression of HLA-DR mo lecules on CD8+ T cells stimulated by antigens of oral streptococci was Fou nd, compared with negative control.