Freitas Monteiro Marta, Papaserafeim Maria, Andreani Matteo, Réal Aline, Kouklas Athanasios, Reis Galvão Daniela, Seebach Jörg D, Puga Yung Gisella L
Laboratory of Translational Immunology, Department of Medicine, Division of Immunology and Allergology, University Hospitals Geneva, Medical Faculty, CH-1211 Geneva, Switzerland.
Antibodies (Basel). 2024 Jul 12;13(3):55. doi: 10.3390/antib13030055.
Natural killer (NK) cells play an important role in the surveillance of viral infections and cancer. NK cell antibody-dependent cellular cytotoxicity (ADCC) and direct cytotoxicity are mediated by the recognition of antibody-coated target cells through the Fc gamma receptor IIIA (FcγRIIIa/CD16) and by ligands of activating/inhibitory NK receptors, respectively. Allelic variants of the gene include the high-affinity single-nucleotide polymorphism (SNP) rs396991 (V176F), which is associated with the efficacy of monoclonal antibody (mAb) therapies, and the SNP rs10127939 (L66H/R). The contribution of SNPs to NK cell effector functions remains controversial; therefore, we generated a panel of eight NK-92 cell lines expressing specific combinations of these SNPs and tested their cytotoxicities. NK-92 cells were stably transfected with plasmids containing different combinations of SNPs. Messenger RNA and FcγRIIIa/CD16 cell surface expressions were detected using new generation sequencing (NGS) and flow cytometry, respectively. All FcγRIIIa/CD16-transfected NK-92 cell lines exhibited robust ADCC against three different target cell lines with minor differences. In addition, enhanced direct NK cytotoxicity against K562 target cells was observed, suggesting a mechanistic role of FcγRIIIa/CD16 in direct NK cytotoxicity. In conclusion, we generated eight FcγRIIIa/CD16-transfected NK-92 cell lines carrying different combinations of two of the most studied SNPs, representing the major genotypes described in the European population. The functional characterization of these cell lines revealed differences in ADCC and direct NK cytotoxicity that may have implications for the design of adoptive cancer immunotherapies using NK cells and tumor antigen-directed mAbs.
自然杀伤（NK）细胞在监测病毒感染和癌症方面发挥着重要作用。NK细胞抗体依赖性细胞毒性（ADCC）和直接细胞毒性分别通过Fcγ受体IIIA（FcγRIIIa/CD16）识别抗体包被的靶细胞以及通过激活/抑制性NK受体的配体介导。该基因的等位基因变体包括与单克隆抗体（mAb）治疗疗效相关的高亲和力单核苷酸多态性（SNP）rs396991（V176F）以及SNP rs10127939（L66H/R）。这些SNP对NK细胞效应功能的贡献仍存在争议；因此，我们构建了一组八个表达这些SNP特定组合的NK-92细胞系，并测试了它们的细胞毒性。用含有不同SNP组合的质粒稳定转染NK-92细胞。分别使用新一代测序（NGS）和流式细胞术检测信使RNA和FcγRIIIa/CD16细胞表面表达。所有转染FcγRIIIa/CD16的NK-92细胞系对三种不同靶细胞系均表现出强大的ADCC，差异较小。此外，观察到对K562靶细胞的直接NK细胞毒性增强，表明FcγRIIIa/CD16在直接NK细胞毒性中起机制性作用。总之，我们构建了八个转染FcγRIIIa/CD16的NK-92细胞系，它们携带两个研究最多的该基因SNP的不同组合，代表了欧洲人群中描述的主要基因型。这些细胞系的功能特性揭示了ADCC和直接NK细胞毒性的差异，这可能对使用NK细胞和肿瘤抗原导向mAb的过继性癌症免疫疗法的设计有影响。
