Jiqing Zhang

Preventing Postoperative Metastatic Disease by Inhibiting Surgery-Induced Dysfunction in Natural Killer Cells

Natural killer (NK) cell clearance of tumor cell emboli following surgery is thought to be vital in preventing postoperative metastases. Using a mouse model of surgical stress, we transferred surgically stressed NK cells into NK-deficient mice and observed enhanced lung metastases in tumor-bearing mice as compared with mice that received untreated NK cells. These results establish that NK cells play a crucial role in mediating tumor clearance following surgery. Surgery markedly reduced NK cell total numbers in the spleen and affected NK cell migration. Ex vivo and in vivo tumor cell killing by NK cells were significantly reduced in surgically stressed mice. Furthermore, secreted tissue signals and myeloid-derived suppressor cell populations were altered in surgically stressed mice. Significantly, perioperative administration of oncolytic parapoxvirus ovis (ORFV) and vaccinia virus can reverse NK cell suppression, which correlates with a reduction in the postoperative formation of metastases. In human studies, postoperative cancer surgery patients had reduced NK cell cytotoxicity, and we show for the first time that oncolytic vaccinia virus markedly increases NK cell activity in patients with cancer. These data provide direct in vivo evidence that surgical stress impairs global NK cell function. Perioperative therapies aimed at enhancing NK cell function will reduce metastatic recurrence and improve survival in surgical cancer patients.

Maraba MG1 Virus Enhances Natural Killer Cell Function via Conventional Dendritic Cells to Reduce Postoperative Metastatic Disease

This study characterizes the ability of novel oncolytic rhabdoviruses (Maraba MG1) to boost natural killer (NK) cell activity. Our results demonstrate that MG1 activates NK cells via direct infection and maturation of conventional dendritic cells. Using NK depletion and conventional dendritic cells ablation studies in vivo, we established that both are required for MG1 efficacy. We further explored the efficacy of attenuated MG1 (nonreplicating MG1-UV(2min) and single-cycle replicating MG1-Gless) and demonstrated that these viruses activate conventional dendritic cells, although to a lesser extent than live MG1. This translates to equivalent abilities to remove tumor metastases only at the highest viral doses of attenuated MG1. In tandem, we characterized the antitumor ability of NK cells following preoperative administration of live and attenuated MG1. Our results demonstrates that a similar level of NK activation and reduction in postoperative tumor metastases was achieved with equivalent high viral doses concluding that viral replication is important, but not necessary for NK activation. Biochemical characterization of a panel of UV-inactivated MG1 (2-120 minutes) revealed that intact viral particle and target cell recognition are essential for NK cell-mediated antitumor responses. These findings provide mechanistic insight and preclinical rationale for safe perioperative virotherapy to effectively reduce metastatic disease following cancer surgery.

Perioperative Influenza Vaccination Reduces Postoperative Metastatic Disease by Reversing Surgery-Induced Dysfunction in Natural Killer Cells

Purpose: Surgical removal of solid primary tumors is an essential component of cancer treatment. Surgery-induced dysfunction in natural killer (NK) cells has been linked to the development of metastases in animal models and patients with cancer. We investigated the activation of NK cells using influenza vaccine in the perioperative period to eradicate micrometastatic disease. Experimental Design: Both the B16lacZ and 4T1 tumor models in immunocompetent mice were used to assess the in vivo efficacy of perioperative influenza vaccine administration. In healthy human donors and cancer surgery patients, we assessed NK cell function pre- and post-influenza vaccination using both in vivo and ex vivo assays. Results: Using the TLR3 agonist poly(I:C), we showed as proof-of-principle that perioperative administration of a nonspecific innate immune stimulant can inhibit surgery-induced dysfunction in NK cells and attenuate metastases. Next, we assessed a panel of prophylactic vaccines for NK cell activation and determined that inactivated influenza vaccine was the best candidate for perioperative administration. Perioperative influenza vaccine significantly reduced tumor metastases and improved NK cytotoxicity in preclinical tumor models. Significantly, IFNα is the main cytokine mediator for the therapeutic effect of influenza vaccination. In human studies, influenza vaccine significantly enhanced NK cell activity in healthy human donors and cancer surgery patients. Conclusion: These results provide the preclinical rationale to pursue future clinical trials of perioperative NK cell activation, using vaccination in cancer surgery patients. Research into perioperative immune therapy is warranted to prevent immune dysfunction following surgery and eradicate metastatic disease. Clin Cancer Res; 19(18); 5104–15. ©2013 AACR.

NK-Cell Recruitment Is Necessary for Eradication of Peritoneal Carcinomatosis with an IL12-Expressing Maraba Virus Cellular Vaccine

Antitumor vaccines are still inefficient. However, when tumor cells were infected ex vivo with an IL12-expressing oncolytic virus and used as a vaccine, peritoneal carcinomatosis mouse models showed a 90% cure rate and protective immunity from rechallenge. Despite improvements in chemotherapy and radical surgical debulking, peritoneal carcinomatosis (PC) remains among the most common causes of death from abdominal cancers. Immunotherapies have been effective for selected solid malignancies, but their potential in PC has been little explored. Here, we report that intraperitoneal injection of an infected cell vaccine (ICV), consisting of autologous tumor cells infected ex vivo with an oncolytic Maraba MG1 virus expressing IL12, promotes the migration of activated natural killer (NK) cells to the peritoneal cavity in response to the secretion of IFNγ-induced protein-10 (IP-10) from dendritic cells. The recruitment of cytotoxic, IFNγ-secreting NK cells was associated with reduced tumor burden and improved survival in a colon cancer model of PC. Even in mice with bulky PC (tumors > 8 mm), a complete radiologic response was demonstrated within 8 to14 weeks, associated with 100% long-term survival. The impact of MG1-IL12-ICV upon NK-cell recruitment and function observed in the murine system was recapitulated in human lymphocytes exposed to human tumor cell lines infected with MG1-IL12. These findings suggest that an MG1-IL12-ICV is a promising therapy that could provide benefit to the thousands of patients diagnosed with PC each year. Cancer Immunol Res; 5(3); 211–21. ©2017 AACR.

A Mouse Tumor Model of Surgical Stress to Explore the Mechanisms of Postoperative Immunosuppression and Evaluate Novel Perioperative Immunotherapies

Surgical resection is an essential treatment for most cancer patients, but surgery induces dysfunction in the immune system and this has been linked to the development of metastatic disease in animal models and in cancer patients. Preclinical work from our group and others has demonstrated a profound suppression of innate immune function, specifically NK cells in the postoperative period and this plays a major role in the enhanced development of metastases following surgery. Relatively few animal studies and clinical trials have focused on characterizing and reversing the detrimental effects of cancer surgery. Using a rigorous animal model of spontaneously metastasizing tumors and surgical stress, the enhancement of cancer surgery on the development of lung metastases was demonstrated. In this model, 4T1 breast cancer cells are implanted in the mouse mammary fat pad. At day 14 post tumor implantation, a complete resection of the primary mammary tumor is performed in all animals. A subset of animals receives additional surgical stress in the form of an abdominal nephrectomy. At day 28, lung tumor nodules are quantified. When immunotherapy was given immediately preoperatively, a profound activation of immune cells which prevented the development of metastases following surgery was detected. While the 4T1 breast tumor surgery model allows for the simulation of the effects of abdominal surgical stress on tumor metastases, its applicability to other tumor types needs to be tested. The current challenge is to identify safe and promising immunotherapies in preclinical mouse models and to translate them into viable perioperative therapies to be given to cancer surgery patients to prevent the recurrence of metastatic disease.

Surgical Stress Abrogates Pre-Existing Protective T Cell Mediated Anti-Tumor Immunity Leading to Postoperative Cancer Recurrence

Anti-tumor CD8+ T cells are a key determinant for overall survival in patients following surgical resection for solid malignancies. Using a mouse model of cancer vaccination (adenovirus expressing melanoma tumor-associated antigen (TAA)—dopachrome tautomerase (AdDCT) and resection resulting in major surgical stress (abdominal nephrectomy), we demonstrate that surgical stress results in a reduction in the number of CD8+ T cell that produce cytokines (IFNγ, TNFα, Granzyme B) in response to TAA. This effect is secondary to both reduced proliferation and impaired T cell function following antigen binding. In a prophylactic model, surgical stress completely abrogates tumor protection conferred by vaccination in the immediate postoperative period. In a clinically relevant surgical resection model, vaccinated mice undergoing a positive margin resection with surgical stress had decreased survival compared to mice with positive margin resection alone. Preoperative immunotherapy with IFNα significantly extends survival in surgically stressed mice. Importantly, myeloid derived suppressor cell (MDSC) population numbers and functional impairment of TAA-specific CD8+ T cell were altered in surgically stressed mice. Our observations suggest that cancer progression may result from surgery-induced suppression of tumor-specific CD8+ T cells. Preoperative immunotherapies aimed at targeting the prometastatic effects of cancer surgery will reduce recurrence and improve survival in cancer surgery patients.

Preventing surgery-induced NK cell dysfunction and cancer metastases with influenza vaccination

Surgical resection is the mainstay of treatment for solid tumors, but the postoperative period is uniquely inclined to the formation of metastases, largely due to the suppression of natural killer (NK) cells. We found that preoperative influenza vaccination prevents postoperative NK-cell dysfunction, attenuating tumor dissemination in murine models and promoting the activation of NK cells in cancer patients.

Correction to: Sepsis increases perioperative metastases in a murine model

It has been highlighted that the original manuscript [1] contains a typesetting error in Fig. 1 and the Fig. 1c panel gas been inadvertently duplicated in panel Fig. 1d. This does not affect the results and conclusions of the article. The correct version of Fig. 1 is included with this Correction. The original article has been updated.

Abstract A135: Phosphodiesterase-5 inhibition augments postoperative natural killer cell antitumor immunity by reducing myeloid-derived suppressor cell function

Background and Objective: Cancer surgery while necessary for primary tumor removal, has been shown to induce immune suppression and promote metastases in preclinical models and human cancer surgery patients. We have previously shown that cancer surgery induces natural killer (NK) cell dysfunction and promotes postoperative metastases formation. Activating the immune system and reversing immune suppression have emerged as promising ways to treat cancer and they can be safely employed in the perioperative period. In this study, we investigated the role of Myeloid-Derived Suppressor Cells (MDSC) as the mediators of postoperative NK cell impairment and subsequent metastases and evaluated the ability to target MDSC with a phosphodiesterase-5 (PDE-5) inhibitor in the clinically relevant postoperative period. Methods: The suppression of NK cell cytotoxic activity by MDSC from control and surgically stressed mice was compared both in vitro and in vivo. Further, NK cell function and lung tumor burden was assessed following perioperative PDE-5 administration. In human cancer patients, MDSC expansion and function were assessed prior to and following surgical resection. Results: MDSC expansion was observed following surgery in mouse melanoma and breast tumor models of surgical stress and this correlates with NK cell suppression postoperatively. Co-cultures of NK cells with MDSC from control and surgical stressed mice resulted in their functional suppression with surgically stressed MDSC, but not with control MDSC. Adoptive tranfser of MDSC from surgically stressed donor mice into recipient mice resulted in impaired in vivo clearance of NK cell sensitive RMA-S tumor cells. Further, surgically stressed mice depleted of MDSC, demonstrated enhanced ability to clear RMA-S tumor cells and fewer lung tumour metastases. Using the clinically relevant PDE-5 inhibitor (sildenafil) to target MDSC suppressive pathways, we demonstrated recovery of NK cell in vitro and in vivo function, followed by reduction of lung tumor metastases. In human cancer surgery patients, MDSC expansion and suppression of NK cells in co-culture with autologous MDSC was observed in the early postoperative period. Conclusions and Significance: MDSC are increased in both number and suppressive activity of NK cells following surgery. MDSC represent a hurdle to successful treatment of postoperative metastatic disease, but this effect is reversible using PDE-5 inhibitors. A clinical trial of perioperative PDE-5 inhibitors is currently being undertaken. Citation Format: Lee-Hwa Tai, Almohanad A. Alkayyal, Christiano Tanese de Souza, Amanda Lynn Leslie, Shalini Sahi, Sean Bennett, Jiqing Zhang, John C. Bell, Rebecca A. Auer. Phosphodiesterase-5 inhibition augments postoperative natural killer cell antitumor immunity by reducing myeloid-derived suppressor cell function. [abstract]. In: Proceedings of the CRI-CIMT-EATI-AACR Inaugural International Cancer Immunotherapy Conference: Translating Science into Survival; September 16-19, 2015; New York, NY. Philadelphia (PA): AACR; Cancer Immunol Res 2016;4(1 Suppl):Abstract nr A135.

Abstract 1558: Innovative biotherapy for brain tumors: Myxoma virus accelerates NK clearance of malignant gliomas

Innovative biotherapeutic approaches for experimental malignant gliomas (MGs) and brain tumor stem cells (BTSCs) include using oncolytic viruses such as Myxoma Virus (Myxv) or immune cells such as Natural Killer (NK) cells. In this study, we combined the individual strengths of using NK cells and Myxv to treat MGs with a view of overcoming the potential limitations posed when each is used as monotherapy. All MGs (U87, U251) and BTSCs (25EF and 48EF) investigated expressed varying levels of NK ligands including inhibitory MHC-I, activating ULBP1-3, MICA/B, and co-activating nectin-2, poliovirus receptor. Infection of MGs and BTSCs with Myxv resulted in the downregulation of MHC-I expression both on the cell surface and intracellularly. No effect was observed on the expression of NK activating ligands except for the downregulation of nectin-2. The downregulation of MHC-I and nectin-2 by Myxv was specifically mediated by M153 gene of Myxv as loss of M153 restored MHC-I and nectin-2 expression. Subsequently, NK cell degranulation and killing of MGs was enhanced in Myxv-infected cells. Loss of M153 inhibited NK degranulation and lysis of MGs. In vivo, using luciferase-expressing U87 cells in a mouse intracranial model, Myxv accelerated tumor size reduction/clearance by NK cell lysis. Combined intratumoral treatment with Myxv and NK of established U87 tumor accelerated tumor clearance when compared with single treatment with Myxv or NK. Tumor in 66% of mice (4 out of 6 mice) were cleared or significantly reduced within 14 days following combination treatment with Myxv and NK. No significant effect was observed in Myxv or NK singly-treated mice within the same time frame. Clearance of tumors was only first observed in 50% (2 out of 4) of Myxv-treated mice after 25 days Myxv treatment. In NK treated mice, the tumor size rather increased. The enhanced tumor clearance in the combined Myxv and NK treated mice was possibly due to the down-regulation of MHC-I by Myxv since combined treatment with NK cells and mutant Myxv (gene M153 which is responsible for MHC-I down-regulation was deleted) did not result in clearance of tumors. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 1558. doi:1538-7445.AM2012-1558