正常年轻恒牙发育过程中牙髓免疫活性细胞的动态研究

The change of immunocompetent cells in normal human dental pulp during development of immature permanent teeth

目的 研究人完全萌出但尚未发育完成的前磨牙牙髓组织中牙髓树突状细胞 (pulpaldendriticcells ,PDCs) ,T、B淋巴细胞 ,血管内皮细胞的变化特点 ,以探明年轻恒牙发育过程中牙髓局部免疫防御状态的改变。方法 按根尖孔的闭合状态分为大喇叭组、小喇叭组和闭合组。应用SP免疫组化法分别标记上述细胞 ,并对前两种细胞进行双标免疫组化染色。结果 ①大喇叭组HLA DR+细胞数多于小喇叭组及闭合组 ;② 3组HLA DR+血管表达率相比较差异无显著性 (P >0 0 5 ) ;③ 3组CD4 5RO+T细胞比较差异无显著性 (P >0 0 5 ) ;④双标免疫组化染色显示 ,HLA DR+PDCs和CD4 5RO+T细胞几乎很少接触。两者的相关性分析结果尚不能认为两者间有直线相关关系。结论 PDCs在人正常发育性牙髓组织中随年龄增加而逐渐减少 ,其他免疫活性细胞与此进程无明显相关。

Objective To study changes of several immunocompete nt cells (ICCs), namely, pulpal dendritic cells (PDCs), T lymphocytes, B lymphoc ytes, and endothelial cells, in normal human dental pulp according to different develo pment stage of completely erupted but not fully developed premolar in order to p rovide evidence for local immune defense mechanisms during development of immatu re permanent teeth. Methods Based on the dental development st atus, the pulp tissue was classified into the following groups: big trumped-sha ped group, small trumped-shaped group and closed group. The above mentioned ce lls were immunohistochemically examined by use of HLA-DR, CD45RO, CD20 mouse an ti-human monoclonal antibodies. Double-staining was also done by use of the f ormer tw o antibodies. The number of positively stained cells or blood vessels was counted and statistically anal yzed. Results ① Normal dental tissue of three groups all expr essed HLA-DR^+PDCs . Among three groups, the number of HLA-DR^+cells in big trumped-shaped gro up was more than that of small trumped-shaped group and closed group. ② There was n o si gnificant difference of positive blood vessel rate of HLA-DR expressing endothe l ial cells among three groups. ③ There was no significant difference of CD45RO ^+T cells among three groups. ④ By use of double-labeling immunohistochemistry, H LA-DR^+ PDCs and CD45RO^+ T cells were found to be rarely in cont act with each other. Correlation analysis between two kinds of cells did not in dicate the linear relationship. Conclusions The number of PDCs tends to decrease with increasing age in the developing dental pulp of human normal tooth, other ICCs are not related with dental development.