Gershon H E, Kuang Y D, Scala G, Oppenheim J J
J Leukoc Biol. 1985 Aug;38(2):279-91. doi: 10.1002/jlb.38.2.279.
Two reproducible and sensitive assays have been developed for the detection of cell-free HLA-DR antigen, an antibody-mediated complement-dependent cytotoxicity inhibition assay (CIA) and a competition enzyme-linked immunosorbent assay (CELISA). One unit of cell-free HLA-DR antigen has been quantitated to be the equivalent of 27.5 ng pure DR antigen/ml. Human peripheral blood adherent mononuclear cells (PBAMC), as well as DR+ monocytes and B lymphoblastoid cell lines but not T lymphocytes, were observed to shed DR-bearing vesicles in vitro. Human recombinant IFN-gamma induces the expression of Ia/DR antigen by PBAMC by increasing both the number of cells expressing DR antigen and the density per cell. After incubation with IFN-gamma, PBAMC also shed significantly more DR antigen. The degree of DR expression and shedding is dependent on the dose of IFN-gamma. The shedding of DR antigen occurred concomitantly with the inductive phase of cell membrane antigen expression, and very little DR antigen appeared in culture supernatants subsequent to the removal of IFN-gamma. The possible physiologic significance of shed DR antigen is discussed.
已开发出两种可重复且灵敏的检测方法用于检测游离的HLA - DR抗原，一种是抗体介导的补体依赖性细胞毒性抑制试验（CIA），另一种是竞争酶联免疫吸附试验（CELISA）。已将一个单位的游离HLA - DR抗原定量为相当于27.5 ng纯DR抗原/毫升。观察到人类外周血贴壁单核细胞（PBAMC）以及DR +单核细胞和B淋巴母细胞系而非T淋巴细胞在体外会脱落携带DR的囊泡。人重组干扰素 - γ通过增加表达DR抗原的细胞数量和每个细胞的密度来诱导PBAMC表达Ia/DR抗原。与干扰素 - γ孵育后，PBAMC也会显著释放更多的DR抗原。DR表达和释放的程度取决于干扰素 - γ的剂量。DR抗原的释放与细胞膜抗原表达的诱导期同时发生，在去除干扰素 - γ后，培养上清液中出现的DR抗原极少。文中讨论了脱落的DR抗原可能的生理意义。
