Inmunología, Facultad de Medicina, Universidad Complutense de Madrid, Madrid, Spain.
Servicio de Cirugía General y Aparato Digestivo, Hospital Universitario Príncipe de Asturias, Alcalá de Henares, Madrid, Spain.
J Immunol Res. 2020 Nov 28;2020:1039458. doi: 10.1155/2020/1039458. eCollection 2020.
Reduced TCR chain surface has been reported in T cells from patients with different inflammatory conditions and cancer. However, the causes of this diminished expression in cancer remain elusive.
T cell-enriched populations of blood or tissue (tumoral and nontumoral) origin from 44 patients with gastric adenocarcinoma and 33 healthy subjects were obtained. Samples were subjected to cytofluorimetry, Western blot analysis, TCR cDNA sequencing experiments, measurement of TCR mRNA levels, and caspase-3 activity assays.
Cytofluorimetry revealed a decreased TCR expression in T cells of patients, assessed either as percentage of cells expressing this chain (blood: control subjects 99.8 ± 0.1%, patients 98.8 ± 1.1% < 0.001; tissue: control subjects 96.7 ± 0.9%, patients tumoral tissue 67.9 ± 27.0%, patients nontumoral tissue 82.8 ± 12.6%, = 0.019) or mean fluorescence intensity (MFI) value (blood: control subjects 102.2 ± 26.0; patients 58.0 ± 12.3, = 0.001; tissue: control subjects 99.4 ± 21.4; patients tumoral tissue 41.6 ± 21.4; patients nontumoral tissue 62.3 ± 16.6, = 0.001). Other chains pertaining to the TCR-CD3 complex (CD3) showed no significant differences (MFI values). Subsequent TCR cDNA sequencing experiments or measurements of TCR mRNA levels disclosed no differences between patients and control subjects. Evaluation of caspase-3 activity showed higher levels in T cell extracts of patients, and this activity could be decreased by 70% with the use of the inhibitor Ac-DEVD-FMK, although CD3 expression levels did not recover.
These results further place the defect responsible for the low TCR expression in cancer at the posttranscriptional level and suggests contrary to what has been proposed in other pathologies that elevated caspase-3 activity is not the causative agent.
在患有不同炎症性疾病和癌症的患者的 T 细胞中，已经报道了 TCR 链表面减少。然而，癌症中这种表达减少的原因仍不清楚。
从 44 例胃腺癌患者和 33 例健康受试者的血液或组织（肿瘤和非肿瘤）来源中获得 T 细胞富集群体。对样品进行细胞荧光分析、Western blot 分析、TCR cDNA 测序实验、TCR mRNA 水平测量和 caspase-3 活性测定。
细胞荧光分析显示，患者的 T 细胞中 TCR 表达减少，无论是作为表达该链的细胞百分比（血液：对照受试者 99.8 ± 0.1%，患者 98.8 ± 1.1% < 0.001；组织：对照受试者 96.7 ± 0.9%，患者肿瘤组织 67.9 ± 27.0%，患者非肿瘤组织 82.8 ± 12.6%， = 0.019）还是平均荧光强度（MFI）值（血液：对照受试者 102.2 ± 26.0；患者 58.0 ± 12.3， = 0.001；组织：对照受试者 99.4 ± 21.4；患者肿瘤组织 41.6 ± 21.4；患者非肿瘤组织 62.3 ± 16.6， = 0.001）。TCR-CD3 复合物的其他链（CD3）没有显示出显著差异（MFI 值）。随后的 TCR cDNA 测序实验或 TCR mRNA 水平的测量未显示患者与对照受试者之间存在差异。评估 caspase-3 活性显示患者 T 细胞提取物中的水平较高，并且使用抑制剂 Ac-DEVD-FMK 可将其活性降低 70%，尽管 CD3 表达水平未恢复。
这些结果进一步将负责癌症中低 TCR 表达的缺陷置于转录后水平，并表明与在其他病理学中提出的相反，升高的 caspase-3 活性不是致病因素。
