Characterization of antigen-presenting cells that present exogenous antigens in association with class I MHC molecules.
Characterization of antigen-presenting cells that present exogenous antigens in association with class I MHC molecules.
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DOI：
10.4049/jimmunol.150.2.438
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发表时间：
1993-01
影响因子：
4.4
通讯作者：
K. L. Rock;L. Rothstein;S. Gamble;C. Fleischacker
中科院分区：
文献类型：
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作者：
K. L. Rock;L. Rothstein;S. Gamble;C. Fleischacker
在大多数细胞中，细胞外液中的外源性Ag不能进入I类Ag呈递途径。然而，脾脏中存在一种APC，它可以处理和呈递与I类分子相关的外源性Ag。我们描述了这种细胞的表型。该APC具有低浮力密度，粘附于琼脂糖凝胶和玻璃，并表达II类分子和FcR。该表型将该APC鉴定为巨噬细胞。居民，蛋白胨和巯基乙酸诱导的腹腔巨噬细胞也显示这种Ag呈递活性。与CTL克隆分析表明，这种Ag呈递途径可能是活跃的，只有在一个子集的巨噬细胞。类似的Ag呈递活性也存在于脾树突状细胞富集群体中，尽管我们不能排除污染巨噬细胞的可能参与。相反，驻留在脾和LPS母细胞中的B和T细胞不能呈递与I类分子相关的外源性Ag。外源性OVA与I类分子的呈递不受巯基蛋白酶、亮抑酶肽和抗痛剂的抑制剂的抑制。白树毒素，一种核糖体失活蛋白，在细胞外液中的存在抑制了这些APC呈递外源性OVA的能力。在相同条件下，白树毒素不抑制Con A刺激的T细胞增殖，或LPS刺激的B细胞增殖和Ag呈递。这些结果进行了讨论的潜在途径，通过该途径，在细胞外液中的Ag与MHC I类分子。
Exogenous Ag in the extracellular fluids do not gain access to the class I Ag-presenting pathway in most cells. However, there is an APC resident in spleen that can process and present exogenous Ag in association with class I molecules. We characterize the phenotype of this cell. This APC is of low buoyant density, is adherent to Sepharose and glass, and expresses both class II molecules and FcR. This phenotype identifies this APC as a macrophage. Resident, peptone- and thioglycolate-induced peritoneal macrophages also display this Ag-presenting activity. Analysis with CTL clones suggest that this Ag-presenting pathway may be active in only a subset of macrophages. A similar Ag-presenting activity is also present in dendritic cell-enriched populations from spleen although we cannot rule out the possible involvement of contaminating macrophages. In contrast, B and T cells that are resident in spleen and LPS blasts are unable to present exogenous Ag in association with class I molecules. The presentation of exogenous OVA with class I molecules is not inhibited by the inhibitors of thiol proteases, leupeptin, and antipain. The presence of gelonin, a ribosomal inactivating protein, in the extracellular fluids inhibits the ability of these APC to present exogenous OVA. Under identical conditions, gelonin does not inhibit Con A-stimulated T cell proliferation, or LPS-stimulated B cell proliferation and Ag presentation. These results are discussed in relation to the potential pathways through which an Ag in the extracellular fluids is presented with MHC class I molecules.