Thomson L F, Ruedi J M, Glass A, Moldenhauer G, Moller P, Low M G, Klemens M R, Massaia M, Lucas A H
Department of Immunology, Scripps Clinic and Research Foundation, La Jolla, CA.
Tissue Antigens. 1990 Jan;35(1):9-19. doi: 10.1111/j.1399-0039.1990.tb01750.x.
A panel of monoclonal antibodies to the 69 kDa glycosyl phosphatidylinositol anchored lymphocyte differentiation antigen ecto-5'-nucleotidase (ecto-5'-NT, CD73) was produced using highly purified human placental 5'-NT as immunogen. Antibodies 1E9.28.1 and 7G2.2.11 inhibit soluble placental 5'-NT activity and recognize lymphocyte CD73 in indirect immunofluorescence and immunoprecipitation assays. In addition, 1E9.28.1 induces vigorous T cell proliferation in the presence of submitogenic doses of phorbol myristate and F(ab')2 goat anti-mouse Ig. Both antibodies can be used to purify the three major forms of placental 5'-NT by affinity chromatography. By two-color immunofluorescence, CD73 was found to be expressed on 19 +/- 5% of CD3+, 11 +/- 4% of CD4+, 51 +/- 14% of CD8+, 25 +/- 8% of CD28+, 15 +/- 5% of CD29+, 27 +/- 7% of CD45RA+, and 70 +/- 6% of CD19+ lymphocytes. Within T cells, CD73 expression is restricted to the CD28+ subset. Thus, CD73 is found on subsets of both T and B lymphocytes, with the highest expression on B cells and CD8+ T cells. In sections of hyperplastic tonsil, CD73 expression is restricted to the small lymphocytes of the follicular mantle zone, a small subset of extrafollicular lymphocytes situated within the epithelium of the tonsillar crypt, and to follicular dendritic cells within the lower part of the "light-zone." CD73 is also detected on subsets of endothelial cells of capillaries and venules and the basal layer of non-keratinizing squamous epithelium and transitional cell type mucosa of many tissues. Given the tissue distribution of CD73, along with its glycosyl phosphatidylinositol membrane anchoring and the observation that some CD73 antibodies are mitogenic, we propose that this interesting antigen may play a role in cell activation, lymphocyte homing, and/or cell adhesion.
以高度纯化的人胎盘5'-核苷酸酶（ecto-5'-NT，CD73）作为免疫原，制备了一组针对69 kDa糖基磷脂酰肌醇锚定淋巴细胞分化抗原ecto-5'-核苷酸酶的单克隆抗体。抗体1E9.28.1和7G2.2.11可抑制可溶性胎盘5'-NT活性，并在间接免疫荧光和免疫沉淀试验中识别淋巴细胞CD73。此外，在亚致有丝分裂剂量的佛波醇肉豆蔻酸酯和F(ab')2山羊抗小鼠Ig存在的情况下，1E9.28.1可诱导强烈的T细胞增殖。两种抗体均可用于通过亲和层析纯化胎盘5'-NT的三种主要形式。通过双色免疫荧光法发现，CD73在19±5%的CD3+、11±4%的CD4+、51±14%的CD8+、25±8%的CD28+、15±5%的CD29+、27±7%的CD45RA+和70±6%的CD19+淋巴细胞上表达。在T细胞内，CD73表达仅限于CD28+亚群。因此，在T和B淋巴细胞亚群上均发现有CD73，在B细胞和CD8+T细胞上表达最高。在增生性扁桃体切片中，CD73表达仅限于滤泡套区的小淋巴细胞、位于扁桃体隐窝上皮内的滤泡外淋巴细胞的一小部分亚群以及“亮区”下部的滤泡树突状细胞。在许多组织的毛细血管和小静脉内皮细胞亚群以及非角化鳞状上皮和移行细胞型黏膜的基底层也检测到CD73。鉴于CD73的组织分布，以及其糖基磷脂酰肌醇膜锚定特性，再加上观察到一些CD73抗体具有促有丝分裂作用，我们提出这种有趣的抗原可能在细胞活化、淋巴细胞归巢和/或细胞黏附中发挥作用。
