Uhl Christopher, Nyirenda Themba, Siegel David S, Lee Woo Y, Zilberberg Jenny
Center for Discovery and Innovation, 111 Ideation Way, Building 102, Nutley, NJ 07110, USA.
John Theurer Cancer Center, 92 2nd St Ste 301 Hackensack, NJ 07601, USA.
Heliyon. 2022 Mar 24;8(3):e09167. doi: 10.1016/j.heliyon.2022.e09167. eCollection 2022 Mar.
Natural killer (NK) cells are part of the innate arm of the immune system; as such NK cells can be activated rapidly to target virus-infected cells and tumor cells without prior sensitization. The human NK-92MI cell line is among the most widely used NK cell in preclinical research studies and has also been approved for clinical applications. Previous studies have shown that osteoblasts (OSB) confer drug resistance in multiple myeloma (MM) and other cancers that metastasize to the bone marrow.
We evaluated here how OSB, which are bone forming cells and a key cellular component of the bone marrow microenvironment, modulate the cytotoxic activity of NK-92MI cells against the MM.1S multiple myeloma cell line.
The osteoblastic niche was recapitulated with either the osteoblastic cell line hFOB 1.19 (hFOB) or primary osteoblasts (P-OSB) derived from surgical resections. Time-lapse imaging was utilized to quantify changes in MM.1S cell viability under different conditions, including: (1) Co-culture of MM.1S with NK92MI cells, (2) triple-culture of hFOB or P-OSB with MM.1S and NK-92MI, and (3) MM.1S or NK-92MI cells primed with OSB-derived supernatant. Cytokine analysis was conducted to quantify potential secreted factors associated with the protective effects of OSB.
The physical presence of OSB hindered the activity of NK-92MI cells, resulting in the increased viability of MM.1S compared to co-cultures which lacked OSB. This observation was accompanied by reduced perforin and granzyme A secretion from NK-92MI cells. Contact of OSB and NK-92MI cells also induced interleukin 6 (IL-6) and interleukin 10 (IL-10) production; two cytokines which are known to impair the NK cell immunity against MM and other cancers. OSB supernatant also conferred cytoprotection to MM.1S, suggesting a dual mechanism by which OSB may modulate both NK and MM cells.
We demonstrated here that OSB can negatively impact the activity of NK cells against MM. As NK cells and their chimeric antigen receptor-modified versions become more widely used in the clinic, our results suggest that understanding the role of OSB as potential immunoregulators of the NK cell-mediated cytotoxic response in the bone marrow tumor microenvironment may provide new opportunities for enhancing the effectiveness of this potent immunotherapeutic approach.
自然杀伤（NK）细胞是免疫系统固有部分；因此，NK细胞无需预先致敏就能迅速被激活，以靶向病毒感染细胞和肿瘤细胞。人NK-92MI细胞系是临床前研究中使用最广泛的NK细胞之一，也已获批用于临床应用。先前研究表明，成骨细胞（OSB）在多发性骨髓瘤（MM）和其他转移至骨髓的癌症中赋予耐药性。
我们在此评估作为骨形成细胞和骨髓微环境关键细胞成分的OSB如何调节NK-92MI细胞对MM.1S多发性骨髓瘤细胞系的细胞毒活性。
用成骨细胞系hFOB 1.19（hFOB）或手术切除获得的原代成骨细胞（P-OSB）重建成骨细胞生态位。利用延时成像技术量化MM.1S细胞在不同条件下的活力变化，包括：（1）MM.1S与NK92MI细胞共培养；（2）hFOB或P-OSB与MM.1S和NK-92MI三培养；（3）用OSB来源的上清液预处理MM.1S或NK-92MI细胞。进行细胞因子分析以量化与OSB保护作用相关的潜在分泌因子。
OSB的实际存在阻碍了NK-92MI细胞的活性，导致与缺乏OSB的共培养相比，MM.1S的活力增加。这一观察结果伴随着NK-92MI细胞穿孔素和颗粒酶A分泌减少。OSB与NK-92MI细胞的接触还诱导了白细胞介素6（IL-6）和白细胞介素10（IL-10）的产生；已知这两种细胞因子会损害NK细胞对MM和其他癌症的免疫。OSB上清液也赋予MM.1S细胞保护作用，提示OSB可能通过双重机制调节NK细胞和MM细胞。
我们在此证明OSB可对NK细胞针对MM的活性产生负面影响。随着NK细胞及其嵌合抗原受体修饰版本在临床上越来越广泛地应用，我们的结果表明，了解OSB作为骨髓肿瘤微环境中NK细胞介导的细胞毒反应潜在免疫调节因子的作用，可能为提高这种有效免疫治疗方法的有效性提供新机会。
