Schön E, Ansorge S
Medizinische Akademie Magdeburg, Forschungsabteilung Experimentelle Immunologie.
Biol Chem Hoppe Seyler. 1990 Aug;371(8):699-705. doi: 10.1515/bchm3.1990.371.2.699.
Dipeptidyl peptidase IV (DP IV) is a membrane peptidase with essential functional significance in thymus derived lymphocytes. This conclusion is drawn from 1) the induction of this enzyme after stimulation of T lymphocytes in vitro and 2) the impairment of T cell functions in presence of active site-specific inhibitors of the enzyme. The first item will be addressed in this paper, whereas the second one will be treated in a forthcoming article. Using flow cytofluorometry we investigated the expression of dipeptidyl peptidase IV on activated lymphocytes and the phenotype of lymphocytes expressing this enzyme. After stimulation by mitogenic lectins the number of epitopes on the cell surface binding polyclonal antibodies against DP IV increases 4 to 6 times. By means of double fluorescence staining the enzyme has been shown to be restricted nearly exclusively to T lymphocytes even after mitogenic stimulation. The highest density of DP IV epitopes has been found in cells coexpressing activation markers like receptors for interleukin 2 or transferrin in a high density.
二肽基肽酶IV（DP IV）是一种在胸腺来源的淋巴细胞中具有重要功能意义的膜肽酶。这一结论基于以下两点：1）体外刺激T淋巴细胞后该酶的诱导产生；2）在该酶的活性位点特异性抑制剂存在的情况下T细胞功能受损。本文将探讨第一项内容，而第二项内容将在后续文章中论述。我们使用流式细胞荧光术研究了活化淋巴细胞上二肽基肽酶IV的表达以及表达该酶的淋巴细胞的表型。经促有丝分裂凝集素刺激后，细胞表面结合抗DP IV多克隆抗体的表位数量增加4至6倍。通过双荧光染色显示，即使在促有丝分裂刺激后，该酶几乎仅局限于T淋巴细胞。在共表达诸如白细胞介素2受体或转铁蛋白受体等高密度活化标志物的细胞中发现了最高密度的DP IV表位。
