scholarly journals Natural Killer Cells Activated By Oncolytic Reovirus Enhance Cetuximab Mediated Antibody Dependent Cellular Cytotoxicity in an in Vitro and In Vivo Model of Colorectal Cancer

Blood ◽  
2015 ◽  
Vol 126 (23) ◽  
pp. 3439-3439
Author(s):  
Xing Zhao ◽  
Narendiran Rajasekaran ◽  
Cariad Chester ◽  
Atsushi Yonezawa ◽  
Suparna Dutt ◽  
...  

Abstract The naturally occurring oncolytic virus, reovirus, exhibits cytotoxic effects on cancer cells. Reovirus is currently being tested in multiple clinical trials for the treatment of different cancers. In addition, they also activate the innate and adaptive immune responses targeting immune cells like dendritic cells and macrophages. In this study we investigated the direct effect of reovirus on Natural Killer cells (NK cells) and its effect on NK cell mediated antibody dependent cellular cytotoxicity (ADCC) against the EGFR (Epidermal Growth Factor) positive colorectal cancer cell line: DLD-1 (KRAS mutant). NK cells isolated from human PBMCs were cultured with 1pfu of reovirus for 12 hrs and subsequently co-cultured with DLD-1 cells coated with increasing concentrations anti-EGFR antibody cetuximab. ADCC was measured after 4 hrs using a lactate dehydrogenase (LDH) based cytotoxicity assay. We observed that the reovirus treated NK cells (Reo-NK cells) exhibited a ~16-fold increase in cytotoxicity against DLD-1 (16.3% ±1.5, n=3) compared to untreated NK cells (NK), even in the absence of any cetuximab. In the presence of cetuximab, NK cells showed a dose dependent increase in ADCC, with maximum ADCC, observed at 0.1 µg/ml of cetuximab (DLD-1+NK: 33.4%± 7.1, n=3). Interestingly, Reo-NK cells showed maximum ADCC even at 0.01 µg /ml of cetuximab (DLD-1+Reo-NK: 39.1±7.4, DLD-1+NK: 26.7±2.4%, n=3). Reo-NK cells also exhibited an increased expression of activation marker CD69 (Reo-NK: 70.4%, NK: 35.2%) and degranulation maker CD107a (Reo-NK: 14.6%; NK: 4.45%) compared to the untreated NK cells. We further characterized the Reo-NK cells by using the HIMChip microarray platform; a custom Agilent SurePrint HD 8x15k format array containing over 7,000 unique probes for over 4,274 human immune-related genes. In ingenuity pathway analysis, we observed that the Interferon pathway (2.13E-20) and pathway controlling activation of IRF by cytosolic pattern recognition receptors (1.27E-11) were the predominant pathways observed in the Reo-NK cells. These results suggest an interferon-mediated response could be contributing to the increased cytoxicity of the NK cells. In an in vivo study, DLD-1 cells were grown subcutaneously in athymic nude mice and injected intravenously with reovirus (5x 108 pfu), followed by intraperitoneal injection of Cetuximab (200 ug/mice) every week. We observed a significant regression of tumors in the Reovirus+Cetuximab combination group compared to the Reovirus treated (Reovirus+Cet: 349.9 mm3, Reovirus: 623.8 mm3; n=9; P=0.0028) or Cetuximab treated (Reovirus+Cet: 349.9 mm3, Cet: 730.5 mm3;n=9; P= 0.030) groups on day 28 post treatment. Thus, in this study our results demonstrated that human NK cells when treated with reovirus show increases in activation, degranulation and cytotoxicity when compared to untreated NK cells. Further, in the in vivo model we observed increased tumor regression in mice treated with reovirus in combination with cetuximab. We propose that reovirus activated NK cells are a potential candidate for cell based immunotherapy in combination with FDA approved tumor targeting antibodies to treat malignancies, including lymphomas. Further studies are ongoing to investigate the underlying mechanisms that contribute to the increase in cytotoxicity by NK cells treated with reovirus. Disclosures No relevant conflicts of interest to declare.

2003 ◽  
Vol 197 (8) ◽  
pp. 967-976 ◽  
Author(s):  
Martin Prlic ◽  
Bruce R. Blazar ◽  
Michael A. Farrar ◽  
Stephen C. Jameson

While the specificity and development of natural killer (NK) cells have been intensely studied, little is known about homeostasis of the mature NK population. Here we show that mouse NK cells undergo homeostatic proliferation when transferred into NK-deficient Rag−/− γC−/− hosts. Normal NK functional activity is maintained during this process, although there are some changes in NK phenotype. Using cell sorting, we demonstrate that mature (Mac-1hi) NK cells undergo homeostatic proliferation in an NK-deficient environment, yet immature (Mac-1lo) NK cells also proliferate in such hosts. We find that mature NK cells survive but do not proliferate in hosts which possess an endogenous NK pool. However, we go on to show that mature NK survival is critically dependent on interleukin (IL)-15. Surprisingly, NK survival is also compromised after transfer of cells into IL-15Rα−/− mice, implying that IL-15 responsiveness by bystander cells is critical for NK maintenance. These data imply that, similar to T cells, homeostasis of the NK pool is much more dynamic than previously appreciated and this may be relevant to manipulation of NK cells for therapeutic purposes.


Head & Neck ◽  
2015 ◽  
Vol 38 (3) ◽  
pp. 410-416 ◽  
Author(s):  
Takumi Kumai ◽  
Kensuke Oikawa ◽  
Naoko Aoki ◽  
Shoji Kimura ◽  
Yasuaki Harabuchi ◽  
...  

Blood ◽  
2011 ◽  
Vol 118 (21) ◽  
pp. 2918-2918
Author(s):  
Tarun K. Garg ◽  
Junaid Khan ◽  
Susann Szmania ◽  
Amy D Greenway ◽  
Joshuah D Lingo ◽  
...  

Abstract Abstract 2918 Natural killer cells (NK) have the unique ability to kill target cells without priming. While their therapeutic potential against various malignancies is becoming more apparent, it has been restricted to the allogeneic setting; NK cells are inhibited by autologous targets by engaging killer immunoglobulin-like receptors with their ligands. Another major challenge to the clinical utility of NK cells is obtaining a sufficient number of NK cells for infusion. Co-culture of blood mononuclear cells (PBMNC) with the leukemic cell line K562, genetically modified to express membrane-bound IL15 and the co-stimulatory molecule 41BBL (K562mbIL15-41BBL) in the presence of IL2 results in robust expansion and activation of NK cells. To determine if NK cells derived from myeloma (MM) patients can be used therapeutically in the autologous setting, we explored the expansion of NK cells from MM patients, their gene expression profiles (GEP), and their ability to kill autologous and allogeneic MM cells from high-risk patients in vitro and in vivo, and compared these to NK cells from healthy donors (HD). PBMNC from MM patients (N=30) co-cultured with irradiated K562mbIL15-41BBL cells expanded a median of 351 fold (range20–10, 430), comparable to the expansion of HD-derived NK cells (N=15, median 803, range 127–1, 727; p=0.5). GEP of MM non-exp-NK differed from HD non-exp-NK in the expression of only one gene (PRKCi), underexpessed in MM (false discovery rate (FDR) <0.05, p-value <3×10−10). GEP of exp-NK cells from both MM patients and HD was very different from non-exp-NK cells (8 pairs each, 10, 639 differentially overexpressed and 26, 057 underexpressed probe sets, FDR <0.05). Genes associated with proliferation, cytolytic activity, activation, adhesion, migration and cell cycle regulation were highly up-regulated in exp-NK cells. Standard chromium release assays demonstrated that MM exp-NK cells killed both allogeneic and autologous primary MM cells more efficiently compared to non-exp-NK cells, via a perforin mediated mechanism. Blocking studies revealed that the natural cytotoxicity receptors, activating receptors, and DNAX accessory molecule (DNAM-1) played a central role in target cell lysis. The killing ability of MM patient and HD derived exp-NK cells was very similar against allogeneic targets, while primary MM targets were more resistant to killing by autologous exp-NK. The anti-MM activity of allogeneic and autologous exp-NK cells was further examined in vivo. NOD/SCID/IL2R γ-null mice were implanted subcutaneously with a human fetal bone, and primary MM cells or luciferase-transfected OPM2 MM cell line were engrafted into the bone. The tumor burden was determined by ELISA for human Ig and/or bio-imaging. The mice were randomized to control and exp-NK treatment groups. A total of 160 ×106 exp-NK cells, in 4 doses 48 hrs apart, were injected in the exp-NK treatment group via tail vein injection. The mice were administered 1000U of IL2 subcu daily to support the NK cells. The mice were bled on days 7, 14, 21 & 28 for the assessment of human Ig by ELISA and enumerating circulating NK cells by flow cytometry. Exp-NK treated mice had a significantly reduced MM burden by ELISA (p<0.04) on day 21, and exp-NK could be detected in the murine blood up to day 28 post-administration in both primary MM and OPM2 tumor bearing mice. The mice were sacrificed and the tumors were harvested after 4 weeks. A noticeable reduction in tumor burden in the exp-NK cell treated mice was confirmed by histology. NK cells were detected by immunohistochemistry (CD57 or CD16) in the hu-bone implants harvested 28 days after infusion. In conclusion, MM patient-derived NK cells have a similar expansion potential, and MM exp-NK cells have cytolytic activity against allogeneic targets similar to those of HD exp-NK cells, and somewhat reduced activity against autologous targets. These exp-NK cells have significant activity against the aggressive cell line OPM2 and high-risk autologous primary MM cells in vivo. Exp-NK cells trafficked to MM tumors and persisted in the myelomatous hu bone microenvironment for 4 weeks. The anti-MM activity of autologous exp-NK cells is exciting and avails a new therapeutic avenue for patients with GEP-defined high-risk disease. A phase II clinical trial of allogeneic and autologous exp-NK cell therapy for relapsed/refractory high-risk MM is in progress at our institution. Disclosures: No relevant conflicts of interest to declare.


2016 ◽  
Vol 213 (11) ◽  
pp. 2249-2257 ◽  
Author(s):  
Luhua H. Zhang ◽  
June Ho Shin ◽  
Mikel D. Haggadone ◽  
John B. Sunwoo

A tissue-resident population of natural killer cells (NK cells) in the liver has recently been described to have the unique capacity to confer immunological memory in the form of hapten-specific contact hypersensitivity independent of T and B cells. Factors regulating the development and maintenance of these liver-resident NK cells are poorly understood. The aryl hydrocarbon receptor (AhR) is a transcription factor modulated by exogenous and endogenous ligands that is important in the homeostasis of immune cells at barrier sites, such as the skin and gut. In this study, we show that liver-resident NK (NK1.1+CD3−) cells, defined as CD49a+TRAIL+CXCR6+DX5− cells in the mouse liver, constitutively express AhR. In AhR−/− mice, there is a significant reduction in the proportion and absolute number of these cells, which results from a cell-intrinsic dependence on AhR. This deficiency in liver-resident NK cells appears to be the result of higher turnover and increased susceptibility to cytokine-induced cell death. Finally, we show that this deficiency has functional implications in vivo. Upon hapten exposure, AhR−/− mice are not able to mount an NK cell memory response to hapten rechallenge. Together, these data demonstrate the requirement of AhR for the maintenance of CD49a+TRAIL+CXCR6+DX5− liver-resident NK cells and their hapten memory function.


PLoS ONE ◽  
2012 ◽  
Vol 7 (6) ◽  
pp. e38580 ◽  
Author(s):  
Leia Wren ◽  
Matthew S. Parsons ◽  
Gamze Isitman ◽  
Robert J. Center ◽  
Anthony D. Kelleher ◽  
...  

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