PD-L1 Antibodies to Its Cytoplasmic Domain Most Clearly Delineate Cell Membranes in Immunohistochemical Staining of Tumor Cells.
PD-L1 Antibodies to Its Cytoplasmic Domain Most Clearly Delineate Cell Membranes in Immunohistochemical Staining of Tumor Cells.
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DOI：
10.1158/2326-6066.cir-15-0116
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发表时间：
2015-12
影响因子：
10.1
通讯作者：
Freeman GJ
中科院分区：
文献类型：
--
作者：
Mahoney KM;Sun H;Liao X;Hua P;Callea M;Greenfield EA;Hodi FS;Sharpe AH;Signoretti S;Rodig SJ;Freeman GJ
阻断PD-1途径在转移性癌症中具有临床益处，并已导致单抗(MAbs)Pembrolizumab和nivolumab被批准用于治疗黑色素瘤，nivolumab用于非小细胞肺癌。在多项研究中，肿瘤细胞或浸润性免疫细胞表面PD-L1的表达与PD-1阻断的反应可能性较高有关。大多数针对PD-L1的单抗针对其胞外区，并对肿瘤组织进行免疫组织化学染色，胞浆和膜染色的混合。胞浆染色模糊了对肿瘤细胞膜上阳性反应的解释，从而影响了PD-L1评分系统的准确性。我们研制了一种针对PD-L1胞外区的单抗405.9A11(9A11)，与以往针对PD-L1胞外区的单抗相比，它对膜性PD-L1具有更高的选择性，在免疫组织化学和Western blotting中也更敏感。在这里，我们使用五种PD-L1单抗：9A11、7G11和三种商用单抗，比较了五种类型肿瘤中PD-L1表达的免疫组织化学染色模式。我们证明，9A11以及另外两个细胞质结构域特异性单抗E1L3N和SP142可以清楚地描绘福尔马林固定的石蜡包埋组织中PD-L1阳性细胞的膜，并有助于解释染色结果。
Blocking the PD-1 pathway has clinical benefit in metastatic cancer and has led to the approval of the monoclonal antibodies (mAbs) pembrolizumab and nivolumab to treat melanoma and nivolumab for non-small cell lung cancer. Expression of PD-L1 on the cell surface of either tumor cells or infiltrating immune cells is associated with a higher likelihood of response to PD-1 blockade in multiple studies. Most mAbs to PD-L1 in use are directed to its extracellular domain and immunohistochemically stain tumor tissue with a mixture of cytoplasmic and membrane staining. Cytoplasmic staining obscures the interpretation of a positive reaction on the tumor cell membrane, and thus affects the accuracy of PD-L1 scoring systems. We developed a mAb to the cytoplasmic domain of PD-L1, 405.9A11 (9A11), which is both more selective for membranous PD-L1 and more sensitive in immunohistochemistry and western blotting, compared to previous mAbs specific for the PD-L1 extracellular domain. Here we compare immunohistochemical staining patterns of PD-L1 expression in five types of tumors, using five PD-L1 mAbs: 9A11, 7G11 and three commercially available mAbs. We demonstrate that 9A11, as well as two other cytoplasmic domain-specific mAbs, E1L3N and SP142, can clearly delineate the membrane of PD-L1 positive cells in formalin-fixed paraffin-embedded tissue and facilitates interpretation of staining results.