Engineering lymph node homing of ex vivo–expanded human natural killer cells via trogocytosis of the chemokine receptor CCR7

Abstract

Until recently, the main limiting factor to the clinical application and efficacy of NK cells was the difficulty in obtaining sufficient cell numbers for adoptive transfer. Development of novel methods of expanding primary human NK cells ex vivo has renewed interest in NK cells for immunotherapy for cancer. [2][3][4][5][6] Expanded NK cells have enhanced expression of activating receptors, 4,7,8 that in turn improves their antitumor cytotoxicity. Where activating receptors did not sufficiently elicit an antitumor response, researchers augmented the antitumor effect of NK cells by expression of chimeric Ag receptors. 9-11 Ultimately, the success of NK cell adoptive immunotherapy for cancer depends not only on target recognition but also on homing of NK cells to the tumor target in vivo. Thus, the effector cells must express the appropriate chemokine receptors.Cancer cells express a wide array of chemokines and chemokine receptors that are instrumental in tumor survival 12 and metastatic spread. 13 Lymph nodes, particularly the tumor-draining nodes, are the foci of metastatic spread of tumors for a vast number of cancer types. 13,14 The expression of CCR7, a member of the G protein-coupled receptor family, on lymphocytes directs their homing to lymph node, coordinates primary immune responses, and induces peripheral immune tolerance. 15 CCR7 expression on tumor cells has been reported and shown to play a pivotal role in lymph node metastasis of various cancers such as breast, 16 pancreatic, 17 thyroid, 18 and colorectal 19 cancers; oral squamous cell carcinoma 20 ; melanoma 21 ; and lymphoma. 22 Lymph node involvement in these cancers is generally associated with poor prognosis.Peripheral NK cells express a variety of chemokine receptors such as CXCR1, CXCR3, and CXCR4 with subsets expressing CCR1, CCR4, CCR5, CCR6, CCR7, CCR9, CXCR5, and CXCR6. Expression of CCR7 on NK cells can facilitate homing to lymph nodes, which, in the context of adoptive immunotherapy for various cancers, would offer a main advantage in targeting lymph node metastases. However, CD56 bright CD16 Ϫ NK cells, which primarily secrete cytokines, express CCR7, but CD56 dim CD16 ϩ NK cells, which are primarily responsible for cytotoxicity, do not. 23 In a previous study, we reported that expanded NK cells are predominantly of CD56 ϩ CD16 bright phenotype and did not express CCR7. 7 In this study, we sought to express CCR7 on expanded NK cells ex vivo to facilitate lymph node homing on adoptive transfer. Although investigators have used viral vectors to gene modify NK cell lines 10,24 and primary NK cells, 9,25 because of safety concerns over integrating viral vectors there has been a recent shift in emphasis toward nonviral methods of gene transfer, particularly nonintegrating, mRNA-based electroporation approaches. 11 However, electroporation of NK cells has been difficult in that the transfection efficiency and viability of NK cells are low, and high-throughput electroporation methods for gene modifying clinically relevant NK cell numbers are ...

Bringing natural killer cells to the clinic: ex vivo manipulation

“…K562 cells expressing mbIL-21 and CCR7 (clone9.CCR7) rapidly transferred CCR7 to expanded NK after a brief 1-hour culture, with up to 80% of NK cells acquiring CCR7 surface expression ( Figure 5). 69 Although surface expression was transient, declining to baseline by 72 hours, NK cells that became positive for CCR7 had improved NK cell migration toward the CCR7 ligands CCL19 and CCL21 in transwell experiments and had increased homing into the lymph nodes of athymic mice. The relative ease of this approach to modify NK cells potentially makes it a viable strategy for scale-up under GMP conditions to explore its ability to improve ex vivo-expanded NK cell homing in humans.…”

Umbilical cord blood graft engineering: challenges and opportunities

“…129 Modification of K562 feeder cells to transfer CCR7 to NK cells via trogocytosis transiently increases NK cell CCR7 expression and improves homing to LNs of athymic mice. 130 Culture with irradiated EBV LCL reduces CD62L-mediated homing to marrow and secondary lymphoid tissues, which can be improved by adding nicotinamide to the culture. 113 5.…”

Microfluidic‐based, live‐cell analysis allows assessment of NK‐cell migration in response to crosstalk with dendritic cells

“…They Correspondence: Dr. Sam K. P. Kung e-mail: Sam.Kung2@med.umanitoba.ca acquire specific chemokine surface receptors during development and maturation [2,[10][11][12][13][14][15]. Chemokine receptors such as CCR7, CCR5, and CXCR3 are involved in the preferential migrations and localization of NK cells into the LNs [8,[16][17][18][19], whereas NK cells reside in blood, liver, and spleen exhibit higher CXCR1 and CX 3 CR1 expression [8,9,[20][21][22][23][24][25]. Nonchemokine family proteins such as chemerin and SIP 5 are also involved in the regulation of NK-cell trafficking [26,27].…”