The role of gingival lymphocytes on the establishment of IgG dominant B cell lesion in periodontitis.

人类牙周炎已被证实是一种富含免疫球蛋白的细胞病变。我们在牙周病变中检测到&lt；T4^+&gt；和&lt；T8^+&gt；细胞以及免疫球蛋白，特别是免疫球蛋白，产生细胞。在&lt；T4^+&gt；和&lt；T8^+&gt；细胞群体中，人类白细胞抗原-DR(Ia)的发生率也大致相同。这些结果提示，B细胞的辅助和抑制功能可能参与了牙周病变的形成。另一方面，由于多种牙周菌群具有多克隆B细胞激活能力，B细胞在牙周病变中可能被多克隆性激活。我们证明了免疫球蛋白抗体形成细胞是由表面免疫球蛋白阳性的B细胞分化而来，而不是从表面免疫球蛋白阴性的B细胞分化而来。结果提示，经抗原激活的记忆B细胞可能迁移到牙周病变中，并被多克隆激活并发育为产生免疫球蛋白的细胞，因此，牙周病变可能是由T细胞和巨噬细胞与PBA的免疫调节机制协同作用所致。事实上，T细胞，特别是辅助性/诱导性T(Th/I)细胞，可促进T非依赖性B细胞激活剂(TI-PBAs)如脂多糖和粘性放线菌制剂激活的B细胞的免疫球蛋白G合成。识别B细胞上表达的Ia可激活TH/I细胞。TI-PBAS刺激的B细胞的IA增加。活化的Th/I细胞产生的可溶性因子可促进TI-PBAS激活的B细胞的免疫球蛋白G合成。提示T细胞参与了牙周病变的发生发展。

Human periodontitis has been confirmed to be IgG producing cell rich lesion. We detected <T4^+> and <T8^+> cells as well as immunoglobulins, particularly IgG, producing cells in periodontal lesions. The incidence of HLA-DR(Ia) was also approximately equal in both <T4^+> and <T8^+> cell population. These results suggested that helper and suppressor functions could participate in the establishment of periodontal lesions.On the other hand, B cells might be activated polyclonally in periodontal lesion, because a variety of periodontal flora possessed polyclonal B cell activating capacities. We demonstrated that IgG antibody forming cells differentiated from surface IgG positive B cells but not from surface IgG negative B cells. The results suggested that the memory B cells primed with antigens might migrate into periodontal lesions, then they might be activated polyclonally and developed into IgG producing cells.Periodontal lesion could be, therefore, induced by the collaboration of the immunoregulatory mechanisms by T cells and macrophages with PBA. In fact, T cells, particularly helper/inducer T (Th/i) cells, enhanced IgG synthesis of B cells activated with T-independent B cell activators (TI-PBAs) such as LPS and Actinomyces viscosus preparation. Th/i cells were activated by recognition of Ia expressed on B cells. Ia increased on B cells stimulated with TI-PBAs. Activated Th/i cells produced soluble factors which enhanced IgG synthesis of B cells activated with TI-PBAs. T cells were strongly suggested to participate in the development of periodontal lesions.