[An experimental study of CD4 targeted chimeric antigen receptor modified T cell with anti-lymphoma activity]

目的

探讨针对CD4膜蛋白的CAR-T细胞对CD4⁺T细胞淋巴瘤细胞的靶向特异性杀伤作用。

方法

采用重组DNA技术构建含4-1BB共刺激分子的第二代针对CD4的CAR慢病毒载体，应用293T细胞包装慢病毒，采用流式细胞术检测T细胞的转染效率及T细胞亚群动态变化，采用流式细胞术微球法检测培养上清中IFN-γ浓度。

结果

①构建的慢病毒载体转染激活的T细胞后CAR膜蛋白阳性率达到50.0%~70.0%。T细胞激活后部分CD8⁺T细胞弱表达（dim）CD4膜蛋白。T细胞转染针对CD4的CAR慢病毒后CD4⁺ T细胞、CD8⁺ CD4^dim T细胞逐渐被清除。②CAR-T细胞、对照组T细胞（空载体转染的T细胞）以8∶1效靶比分别与CD4⁺人T细胞淋巴瘤细胞株KARPAS 299细胞共培养24 h，杀伤效率分别为（96.9±2.1）%和（11.2±3.1）%，前者明显高于后者（t=7.137，P=0.028）。③CAR-T细胞单独培养，与转染慢病毒载体表达人CD4的K562细胞（K562-CD4细胞）、K562细胞共培养后上清中IFN-γ浓度分别为（1 785±268）、（15 648±2 168）、（1 978±354）pg/ml，CAR-T细胞与K562-CD4细胞共培养上清IFN-γ浓度明显高于其他两组，差异有统计学意义（P<0.01）。

结论

CD4特异性CAR-T细胞效应细胞免疫表型为CD8⁺ CD4⁺ T细胞，在体外具有杀伤正常CD4⁺ T细胞和CD4⁺ T细胞淋巴瘤细胞的活性，对于CD4^dim T细胞也有较好的清除活性。

Diagnostic Utility of a Clonality Test for Lymphoproliferative Diseases in Koreans Using the BIOMED-2 PCR Assay

Background

A clonality test for immunoglobulin (IG) and T cell receptor (TCR) is a useful adjunctive method for the diagnosis of lymphoproliferative diseases (LPDs). Recently, the BIOMED-2 multiplex polymerase chain reaction (PCR) assay has been established as a standard method for assessing the clonality of LPDs. We tested clonality in LPDs in Koreans using the BIOMED-2 multiplex PCR and compared the results with those obtained in European, Taiwanese, and Thai participants. We also evaluated the usefulness of the test as an ancillary method for diagnosing LPDs.

Methods

Two hundred and nineteen specimens embedded in paraffin, including 78 B cell lymphomas, 80 T cell lymphomas and 61 cases of reactive lymphadenitis, were used for the clonality test.

Results

Mature B cell malignancies showed 95.7% clonality for IG, 2.9% co-existing clonality, and 4.3% polyclonality. Mature T cell malignancies exhibited 83.8% clonality for TCR, 8.1% co-existing clonality, and 16.2% polyclonality. Reactive lymphadenitis showed 93.4% polyclonality for IG and TCR. The majority of our results were similar to those obtained in Europeans. However, the clonality for IGK of B cell malignancies and TCRG of T cell malignancies was lower in Koreans than Europeans.

Conclusions

The BIOMED-2 multiplex PCR assay was a useful adjunctive method for diagnosing LPDs.