接触性过敏反应中附着素在抗原呈递细胞中的超微结构定位

UL TRASTKUCTURAL LOCALIZATION OF HAPTEN IN ANTIGEN PRESENTING CELLS INVOLVED INONTACT SENSITIZATION

异硫氰酸荧光素（ＦＩＴＣ）使Ｃ３Ｈ小鼠致敏后，其淋巴结中树突状细胞（ＤＣ）明显增加，而且均发荧光，电镜下证实为郎格罕氏细胞（ＬＣ）样。利用免疫电镜进行ＤＣ内ＦＩＴＣ超微结构定位，可见大部分免疫金标记分布在细胞核周区和呈丛样定位于溶酶体。金标Ｔｈｙ－１．２抗体只显示在淋巴细胞上。结果证实多数附着素ＦＩＴＣ位于抗原呈递细胞内，并与细胞器有关，由此建议附着素的呈递涉及到细胞内化和内处理作用，而不是与细胞表面蛋白的结合。

xposure of C3 H mice to the contact sensitizer,(Fluorescein isothrocyanate.FITC),was chara-cterized by an increase in dcndritic cells(DC)in the draining lymph node(DLN),Many of these DCwere fluorescent and were identified by electron microscopy as Langerhans cells.The purpose of this investigation was to identify the fluorescent DC by immunoelectron microscopy to determine the ultra-stucture localization of FITC. The majority of the antiFITC label was inside the cells in the perinucleararea.Gold particles were present in clusters in lysosomes. Serial sections immunostained with polycIonalanti-thyl.2 antibody showed gold label only in lymphocytes.These results demon strate that most hapten is internalized and associated with cytoplasmic organelles in antigen-presenting cells,suggesting thatpresentaion of hapten involves action processing and internalization,rather than binding of hapten tosurface proteins.