Genetic engineering of human NK cells to express CXCR2 improves migration to renal cell carcinoma

Abstract

BackgroundAdoptive natural killer (NK) cell transfer is being increasingly used as cancer treatment. However, clinical responses have so far been limited to patients with hematological malignancies. A potential limiting factor in patients with solid tumors is defective homing of the infused NK cells to the tumor site. Chemokines regulate the migration of leukocytes expressing corresponding chemokine receptors. Various solid tumors, including renal cell carcinoma (RCC), readily secrete ligands for the chemokine receptor CXCR2. We hypothesize that infusion of NK cells expressing high levels of the CXCR2 chemokine receptor will result in increased influx of the transferred NK cells into tumors, and improved clinical outcome in patients with cancer.MethodsBlood and tumor biopsies from 14 primary RCC patients were assessed by flow cytometry and chemokine analysis. Primary NK cells were transduced with human CXCR2 using a retroviral system. CXCR2 receptor functionality was determined by Calcium flux and NK cell migration was evaluated in transwell assays.ResultsWe detected higher concentrations of CXCR2 ligands in tumors compared with plasma of RCC patients. In addition, CXCL5 levels correlated with the intratumoral infiltration of CXCR2-positive NK cells. However, tumor-infiltrating NK cells from RCC patients expressed lower CXCR2 compared with peripheral blood NK cells. Moreover, healthy donor NK cells rapidly lost their CXCR2 expression upon in vitro culture and expansion. Genetic modification of human primary NK cells to re-express CXCR2 improved their ability to specifically migrate along a chemokine gradient of recombinant CXCR2 ligands or RCC tumor supernatants compared with controls. The enhanced trafficking resulted in increased killing of target cells. In addition, while their functionality remained unchanged compared with control NK cells, CXCR2-transduced NK cells obtained increased adhesion properties and formed more conjugates with target cells.ConclusionsTo increase the success of NK cell-based therapies of solid tumors, it is of great importance to promote their homing to the tumor site. In this study, we show that stable engineering of human primary NK cells to express a chemokine receptor thereby enhancing their migration is a promising strategy to improve anti-tumor responses following adoptive transfer of NK cells.Electronic supplementary materialThe online version of this article (doi:10.1186/s40425-017-0275-9) contains supplementary material, which is available to authorized users.

CCL5-armed oncolytic virus augments CCR5-engineered NK cell infiltration and antitumor efficiency

“…Previous studies have shown that the enhanced expression of either chemokines or chemokine receptors can promote the tumor-specific migration of human cytotoxic cells. 19 31 46 47 For NK cells, the enforced expression of specific chemokine receptors can improve their accumulation with tumors. 19 Consistent with this, we showed that CCR5 overexpression enhances the directional movement of NK cells (figures 1 and 2).…”

“…Lentiviruses are a powerful tool for gene modification in NK cells, 19 using which we can construct CCR5-overexpressing NK Open access cells. Additionally, oncolytic viruses (OVs) represent an attractive tool for local adaption of the tumor microenvironment as they can selectively replicate and produce exogenous proteins within tumor cells.…”

Genetic reprogramming for NK cell cancer immunotherapy with CRISPR/Cas9

“…[47][48][49][50][51] The importance of migration and homing of NK cells to disease sites is critical to its success for cell-based immunotherapy upon adoptive infusion. 52 This indicates that CXCR2 represents a potential chemokine receptor that can be overexpressed on NK cells for improving infiltration into tumours. Intra-tumoural infiltration of one NK cell subpopulation in tumours of renal cell carcinoma patients correlates with high concentrations of CXCR2 ligands.…”

“…Intra-tumoural infiltration of one NK cell subpopulation in tumours of renal cell carcinoma patients correlates with high concentrations of CXCR2 ligands. 52 Genetic engineering of human NK cells to express CXCR2 has been shown to improve their ability to specifically migrate along a chemokine gradient of recombinant CXCR2 ligands in vitro, as well as migration to renal cell carcinoma in the mouse model. 52 This indicates that CXCR2 represents a potential chemokine receptor that can be overexpressed on NK cells for improving infiltration into tumours.…”

“…52 Genetic engineering of human NK cells to express CXCR2 has been shown to improve their ability to specifically migrate along a chemokine gradient of recombinant CXCR2 ligands in vitro, as well as migration to renal cell carcinoma in the mouse model. 52 This indicates that CXCR2 represents a potential chemokine receptor that can be overexpressed on NK cells for improving infiltration into tumours. On the other hand, the CCL-19-CCR7 axis has also been shown to promote immune cell infiltration.…”