Interleukin-2 immunotherapy action on innate immunity cells in peripheral blood and tumoral tissue of pancreatic adenocarcinoma patients

Augmentation of IFN-γ by bone marrow derived immune cells in the presence of severe suppression of IFN-γ in gingivae induced by zoledronic acid and denosumab in Hu-BLT mice model of ONJ

Introduction

The potential mechanisms governing drug induced osteonecrosis of the jaw (ONJ) is not well understood, and is one of the objectives of this study. Thus, we tested the release of IFN-γ within different immune compartments including bone marrow and gingivae upon treatment with zoledronic acid (ZOL) and denosumab which are known to induce ONJ in susceptible individuals.

Methods

We used humanized-BLT mouse model for the in-vivo studies reported in this paper. To determine the effects of zoledronic acid and denosumab on IFN-γ secretion and NK cell-mediated cytotoxicity; peripheral blood, bone marrow, spleen and gingiva were obtained after the injection of ZOL and denosumab in mice.

Results

Percentages of B cells are much higher in wild-type mice whereas the proportions of immune subsets in humans and reconstituted hu-BLT peripheral-blood are similar. Therefore, hu-BLT mice are preferable model to study human disease, in particular, immune-pathologies induced by ZOL and denosumab. Both agents resulted in a severe suppression of IFN-γ in the gingiva, whereas they heightened the release of IFN-γ and NK cell-mediated cytotoxicity by the BM-derived immune cells. ZOL increased the IFN-γ secretion by the spleen and peripheral blood immune cells, whereas denosumab decreased the release IFN-γ by these cells significantly.

Discussion

ZOL and denosumab may likely suppress IFN-γ secretion in gingiva through different mechanisms. In addition, to the suppression of IFN-γ secretion, denosumab mediated effect could in part be due to the decrease in the bone resorptive function of osteoclasts due to the induction of antibody dependent cellular cytotoxicity and lysis of osteoclasts, whereas ZOL is able to mediate cell death of osteoclasts directly. Suppression of IFN-gamma in gingiva is largely responsible for the inhibition of immune cell function, leading to dysregulated osteoblastic and osteoclastic activities. Restoration of IFN-gamma in the local microenvironment may result in establishment of homeostatic balance in the gingiva and prevention of osteonecrosis of jaw.

The antitumor activity of hPRDX5 against pancreatic cancer and the possible mechanisms

Recombinant human peroxiredoxin-5 (hPRDX5), isolated from anti-cancer bioactive peptide (ACBPs), shows a homology of 89% with goat peroxiredoxin-5 (gPRDX5) and is reported to display anti-tumor activity in vivo. Herein, we explored the effect of hPRDX5 and the responsible mechanism in treating pancreatic cancer. Tumor-bearing mice were randomly divided into normal PBS group and treatment group (n=5; 10 mg/kg hPRDX5). Flow cytometry was employed to examine lymphocytes, myeloid-derived suppressor cell subsets, and the function proteins of natural killer (NK) cells in peripheral blood, spleen, and tumor tissues of mice. Western blot was used to measure the protein expressions of the key nodes in TLR4-MAPK-NF-κB signaling pathway. The rate of tumor suppression was 57.6% at a 10 mg/kg dose in orthotopic transplanted tumor mice. Moreover, the population of CD3+CD4+T cells, NK cells, and CD3+CD8+T cells was significantly increased in the tumor tissue of the hPRDX5 group, while the proportion of granulocytic-myeloid-derived suppressor cells decreased slightly. In addition, after treatment with hPRDX5, the percentage of NK cells in blood increased more than 4-fold. Our findings indicated that hPRDX5 effectively suppressed pancreatic cancer possibly via the TLR4-MAPK-NF-κB signaling cascade; hence hPRDX5 could be a prospective immunotherapy candidate for treating pancreatic cancer.

Probiotic-Treated Super-Charged NK Cells Efficiently Clear Poorly Differentiated Pancreatic Tumors in Hu-BLT Mice

Abstract: Background and Aims: We have previously demonstrated that the stage of differentiation of tumors has profound effect on the function of NK cells, and that stem-like/poorly differentiated tumors were preferentially targeted by the NK cells. Therefore, in this study we determined the role of super-charged NK cells in immune mobilization, lysis, and differentiation of stem-like/undifferentiated tumors implanted in the pancreas of humanized-BLT (hu-BLT) mice fed with or without AJ2 probiotics. The phenotype, growth rate and metastatic potential of pancreatic tumors differentiated by the NK cells (NK-differentiated) or patient derived differentiated or stem-like/undifferentiated pancreatic tumors were investigated. Methods: Pancreatic tumor implantation was performed in NSG and hu-BLT mice. Stage of differentiation of tumors was determined using our published criteria for well-differentiated tumors exhibiting higher surface expression of MHC- class I, CD54, and PD-L1 (B7H1) and lower expression of CD44 receptors. The inverse was seen for poorly-differentiated tumors. Results: Stem-like/undifferentiated pancreatic tumors grew rapidly and formed large tumors and exhibited lower expression of above-mentioned differentiation antigens in the pancreas of NSG and hu-BLT mice. Unlike stem-like/undifferentiated tumors, NK-differentiated MP2 (MiaPaCa-2) tumors or patient-derived differentiated tumors were not able to grow or grew smaller tumors, and were unable to metastasize in NSG or hu-BLT mice, and they were susceptible to chemotherapeutic drugs. Stem-like/undifferentiated pancreatic tumors implanted in the pancreas of hu-BLT mice and injected with super-charged NK cells formed much smaller tumors, proliferated less, and exhibited differentiated phenotype. When differentiation of stem-like tumors by the NK cells was prevented by the addition of antibodies to IFN-γ and TNF-α, tumors grew rapidly and metastasized, and they remained resistant to chemotherapeutic drugs. Greater numbers of immune cells infiltrated the tumors of NK-injected and AJ2-probiotic bacteria-fed mice. Moreover, increased IFN-γ secretion in the presence of decreased IL-6 was seen in tumors resected and cultured from NK-injected and AJ2 fed mice. Tumor-induced decreases in NK cytotoxicity and IFN-γ secretion were restored/increased within PBMCs, spleen, and bone marrow when mice received NK cells and were fed with AJ2. Conclusion: NK cells prevent growth of pancreatic tumors through lysis and differentiation, thereby curtailing the growth and metastatic potential of stem-like/undifferentiated-tumors.

DKK2 Impairs Tumor Immunity Infiltration and Correlates with Poor Prognosis in Pancreatic Ductal Adenocarcinoma

Pancreatic ductal adenocarcinoma (PDAC) remains one of the most devastating cancer types despite the improvement of modern medicine. In our present study, we found that dickkopf-related protein 2 (DKK2) shares a higher expression in PDAC compared with adjacent pancreas tissue in tissue microarray. In addition, an elevated expression of DKK2 predicts poorer prognosis of patients and positively correlated with poor tumor differentiation. Multivariate Cox regression analysis was also performed and confirmed that the expression of DKK2 is an independent prognostic factor in PDAC. A high expression of DKK2 correlates with cell migration and epithelial mesenchymal transition based on gene set enrichment analysis (GSEA) while knockdown of DKK2 in PDAC cells resulted in impaired cellular migration. Furthermore, GSEA predicts negative correlation between tumor immunity invasion and DKK2 expression. We then confirmed these results and demonstrated that a higher expression of DKK2 imparts the recruitment of CD8+ T cells. Our work suggested that DKK2 imparts tumor immune evasion and is associated with poor prognosis in pancreatic ductal adenocarcinoma.

Association of preoperative total lymphocyte count with prognosis in resected left-sided pancreatic cancer

BACKGROUND

Immunologic factors such as neutrophil-lymphocyte ratio and platelet-lymphocyte ratio play an important role in predicting the oncologic outcome of patients in pancreatic ductal adenocarcinoma (PDAC). It is hypothesized that host immunity represented by total lymphocyte count at diagnostic stage would influence oncologic outcome in left-sided PDAC.

METHODS

Between January 1992 and August 2017, total of 112 patients who underwent distal pancreatectomy for left-sided PDAC were included and analysed.

RESULTS

At the time of the diagnosis, total lymphocyte count at diagnosis of left-sided PDAC was 1.8 ± 0.7 10³ /μL (mean value ± standard deviation). Among different cut-off values, 1.7 showed most powerful significant differences in long-term oncologic outcomes. The patients with preoperative lymphocyte count (≤1.7) was associated with early recurrence (median 8.4 months versus 18.1 months, P = 0.011) and shorter survival (median 18.6 months versus 35.9 months, P = 0.028). Patients with preoperative total lymphocyte count over 1.7 showed higher white blood cell count (P < 0.001), platelet count (P = 0.039), neutrophil count (P = 0.004) and monocyte count (P = 0.001). However, more interestingly, neutrophil-lymphocyte ratio (P < 0.001) and platelet-lymphocyte ratio (P < 0.001) were found to be significantly higher in those with total lymphocyte count less than 1.7. Lymphocyte to monocyte ratio was inversely related to preoperative total lymphocyte count (P < 0.001). Only age was identified to be significantly different (P = 0.007). However, other clinicopathological parameters generally known to be related to tumour aggressiveness, were not different between two groups.

CONCLUSION

In conclusion, preoperative total lymphocyte at diagnostic stage is simple, and good prognostic factor in left-sided pancreatic cancer.

Deficiencies in Natural Killer Cell Numbers, Expansion, and Function at the Pre-Neoplastic Stage of Pancreatic Cancer by KRAS Mutation in the Pancreas of Obese Mice

The combined/synergistic effect of genetic mutation of KRAS in the pancreas and obesity, a life-style factor on suppression of natural killer (NK) cells at the pre-neoplastic stage of pancreatic cancer has not been investigated and is the subject of this report. Obese mice with KRAS (KC) mutation in the pancreas fed with high-fat calorie diet (HFCD) exhibit severe deficiencies in the NK cell expansion and function at the pre-neoplastic stage of pancreatic cancer. Decreased NK cell-mediated cytotoxicity is observed in the peripheral blood, spleen, pancreas, and peri-pancreatic adipose tissue in obese KC mice, whereas in bone marrow an increased NK cell-mediated cytotoxicity is observed when compared to lean WT mice fed with control diet (CD). Obese KC mice on HFCD demonstrated the least ability to expand NK cells or induce NK cell-mediated cytotoxicity when compared to the other groups of mice. Indeed, the following profile WT/CD > WT/HFCD > KC/CD > KC/HFCD was seen for the ability to expand NK cells or mediate cytotoxicity among four groups of mice in spleen, peripheral blood, pancreas, and peri-pancreatic adipose tissue. Sorted NK cells from the splenocytes of four groups of mice also exhibited the same profiles for the cytotoxicity as the unsorted splenocytes, and a decreased IFN-γ secretion could be seen in cultures of NK cells from KC mice fed with either CD or HFCD. Cultures of NK cells with autologous monocytes from obese KC mice fed with HFCD exhibited decreased cytotoxicity and IFN-γ secretion, whereas cultures of allogeneic NK cells from WT mice fed with CD with osteoclasts of obese mice fed with HFCD demonstrated decreased cytotoxicity but augmented IFN-γ secretion. Increased IL-6 along with decreased IFN-γ and cell-mediated cytotoxicity by the NK cells, within NK-adipose tissue of KC/HFCD mice, may provide safe microenvironment for the expansion of pancreatic tumors.

Natural killer cells and their therapeutic role in pancreatic cancer: A systematic review

Pancreatic cancer is among the three deadliest cancers worldwide with the lowest 5-year survival of all cancers. Despite all efforts, therapeutic improvements have barely been made over the last decade. Even recent highly promising targeted and immunotherapeutic approaches did not live up to their expectations. Therefore, other horizons have to be explored. Natural Killer (NK) cells are gaining more and more interest as a highly attractive target for cancer immunotherapies, both as pharmaceutical target and for cell therapies. In this systematic review we summarise the pathophysiological adaptions of NK cells in pancreatic cancer and highlight possible (future) therapeutic NK cell-related targets. Furthermore, an extensive overview of recent therapeutic approaches with an effect on NK cells is given, including cytokine-based, viro- and bacteriotherapy and cell therapy. We also discuss ongoing clinical trials that might influence NK cells. In conclusion, although several issues regarding NK cells in pancreatic cancer remain unsolved and need further investigation, extensive evidence is already provided that support NK cell oriented approaches in pancreatic cancer.

Suppression of Gingival NK Cells in Precancerous and Cancerous Stages of Pancreatic Cancer in KC and BLT-Humanized Mice

The aim of our studies is to determine the dynamics of natural killer (NK) cell modulation in gingivae in precancerous and cancerous stages of pancreatic and oral cancers in P48+/Cre;LSL-KRASG12D (KC) mice carrying a pancreas-specific oncogenic Kras mutation and BLT-humanized mice. Wild type and KC mice fed with control diet (CD) or high-fat calorie diet (HFCD), and the pancreatic and oral tumor-bearing humanized BLT (hu-BLT) mice were used to determine precancerous and cancer induced changes in numbers and function of gingival NK cells. Increased numbers of PanIN lesions and the greatest score of inflammation in pancreas of KC mice fed with CD and HFCD co-related with significant decline in percentages of circulating and gingival NK cells, lack of DX5+ NK expansion and increased secretion of IFN-γ and IL-6 after culture. At the malignant stage of pancreatic cancer, hu-BLT tumor-bearing mice had the lowest secretion of IFN-γ from cells dissociated from the gingival tissues as compared to those from non-tumor-bearing mice. Injection of NK cells into tumor-bearing mice increased IFN-γ secretion, and the secretion was similar or higher than those obtained by gingival cells from non-tumor-bearing hu-BLT control mice. The highest increase in IFN-γ secretion was observed when tumor-bearing mice were fed with AJ2 probiotic bacteria and injected with the NK cells. Along with an increase in secretion of IFN-γ, injection of NK cells in the presence and absence of feeding with AJ2 in pancreatic tumor-bearing mice increased percentages of CD45+ and CD3+ T cells in oral gingival cells. Similar results were observed with oral tumors. In conclusion, these results indicated that oral cavity may mirror systemic disease and provide a rationale for why cancer patients may be prone to suffer from diverse oral pathologies.

Cancer vaccines and immunotherapeutic approaches in hepatobiliary and pancreatic cancers

Hepatobiliary and pancreatic cancers along with other gastrointestinal malignancies remain the leading cause of cancer-related deaths worldwide. Strategies developed in the recent years on immunotherapy and cancer vaccines in the setting of primary liver cancer as well as in pancreatic cancer are the scope of this review. Significance of orthotopic and autochthonous animal models which mimic and/or closely reflect human malignancies allowing for a prompt and trustworthy analysis of new therapeutics is underlined. Combinational approaches that on one hand, specifically target a defined cancer-driving pathway, and on the other hand, restore the functions of immune cells, which effector functions are often suppressed by a tumor milieu, are shown to have the strongest perspectives and future directions. Among combinational immunotherapeutic approaches a personalized- and individual cancer case-based therapy is of special importance.

Pancreatic ductal adenocarcinoma: a review of immunologic aspects

With the continued failures of both early diagnosis and treatment options for pancreatic cancer, it is now time to comprehensively evaluate the role of the immune system on the development and progression of pancreatic cancer. It is important to develop strategies that harness the molecules and cells of the immune system to treat this disease. This review will focus primarily on the role of immune cells in the development and progression of pancreatic ductal adenocarcinoma and to evaluate what is known about the interaction of immune cells with the tumor microenvironment and their role in tumor growth and metastasis. We will conclude with a brief discussion of therapy for pancreatic cancer and the potential role for immunotherapy. We hypothesize that the role of the immune system in tumor development and progression is tissue specific. Our hope is that better understanding of this process will lead to better treatments for this devastating disease.

Effect of combined treatment with recombinant interleukin-2 and allicin on pancreatic cancer

This study aimed to evaluate the efficacy of combined treatment with recombinant interleukin-2 (rIL-2) and allicin on pancreatic cancer and explore the potential immunological mechanism. A total of 60 C57/BL6 nude mice pancreatic cancer xenograft models were randomized into four groups of 15 mice per group: control group, allicin treatment group, rIL-2 treatment group, combined treatment with allicin and rIL-2 group. Mice in each group were treated with saline, rIL-2, allicin, or combination of rIL-2 and allicin by weekly i.v injection for four weeks. After four weeks of treatment, eyeballs of the mice were extracted and blood was drawn, percentages of CD4+T, CD8+T and NK cell were analyzed by FACS, IFN-γ level was detected by ELISA. One mouse in each group was sacrificed to measure the weight and volume of the tumor and prepared to the paraffin section of tumor tissue. Apoptosis of the tumor cells was analyzed by TUNEL and FACS. Other mice continued to receive treatment, survival period were compared between each group. We observed a significant suppression of xenograft growth and a significant prolonged survival time in the combined treatment with allicin and rIL-2 group (P < 0.05). The most amount of apoptotic cells were observed in the combined therapy group (P < 0.05). The percentages of CD4+T, CD8+T and NK cell and serum IFN-γ level increased significantly in the combined treatment group compared with other groups (P < 0.05). Combined treatment with allicin and rIL-2 resulted in suppression of tumor growth and prolonged survival time possibly through activation of CD4+T, CD8+T and NK cell.

Role of immune cells and immune-based therapies in pancreatitis and pancreatic ductal adenocarcinoma

Immune cells are important in the pathogenesis of acute pancreatitis and determine disease severity. Results from cytokine-based clinical trials for acute pancreatitis have been disappointing, so strategies that target and alter the behavior of infiltrating immune cells require consideration. Recurrent acute pancreatitis can progress to chronic pancreatitis, which is a well-described risk factor for pancreatic ductal adenocarcinoma (PDA). However, most patients with chronic pancreatitis do not develop PDA, and most patients with PDA do not have a history of pancreatitis. Interestingly, chronic pancreatitis and PDA tissues have similarities in their desmoplasia and inflammatory infiltrates, indicating overlapping inflammatory responses. Further studies are needed to determine the differences and similarities of these responses, improve our understanding of PDA pathogenesis, and develop specific immune-based therapies. Immune cells in PDA produce immunosuppressive signals that allow tumors to evade the immune response. Unlike single therapeutic agent studies that block immunosuppressive mechanisms, studies of combination therapies that include therapeutic vaccines have provided promising results.

Antitumoral activity of parvovirus-mediated IL-2 and MCP-3/CCL7 delivery into human pancreatic cancer: implication of leucocyte recruitment

Pancreatic ductal adenocarcinoma (PDAC) represents the fourth leading cause of cancer-related death in western countries. The patients are often diagnosed in advanced metastatic stages, and the prognosis remains extremely poor with an overall 5-year survival rate less than 5 %. Currently, novel therapeutic strategies are being pursued to combat PDAC, including oncolytic viruses, either in their natural forms or armed with immunostimulatory molecules. Natural killer cells are critical players against tumours and infected cells. Recently, we showed that IL-2-activated human NK cells displayed killing activity against PDAC cells, which could further be enhanced through the infection of PDAC cells with the rodent parvovirus H-1PV. In this study, the therapeutic efficacy of parvovirus-mediated delivery of three distinct cyto/chemokines (Il-2, MCP-3/CCL7 and IP-10/CXCL10) was evaluated in xenograft models of human PDAC. We show here that activated NK and monocytic cells were found to be recruited by PDAC tumours upon infection with parvoviruses armed with IL-2 or the chemokine MCP-3/CCL7, resulting in a strong anti-tumour response.

Targeting the cancer-stroma interaction: a potential approach for pancreatic cancer treatment

Recent studies have demonstrated that the interaction between the cancer and the stroma, play a key role in the development of pancreatic cancer. The desmoplasia, which consists of fibroblasts, pancreatic stellate cells, lymphatic and vascular endothelial cells, immune cells, pathologic increased nerves, and the extracellular matrix (ECM), creates a complex tumor microenvironment that promotes pancreatic cancer development, invasion, metastasis, and resistance to chemotherapy. Thus, the potential approach for targeting the components of this desmoplastic reaction or the pancreatic tumor microenvironment might represent a novel therapeutic approach to advanced pancreatic carcinoma. Novel therapies that target on the pancreatic tumor microenvironment should become one of the more effective treatments for pancreatic cancer.

Pancreatic ductal adenocarcinoma: a review of immunologic aspects

With the continued failures of both early diagnosis and treatment options for pancreatic cancer, it is now time to comprehensively evaluate the role of the immune system on the development and progression of pancreatic cancer. It is important to develop strategies that harness the molecules and cells of the immune system to treat this disease. This review will focus primarily on the role of immune cells in the development and progression of pancreatic ductal adenocarcinoma and to evaluate what is known about the interaction of immune cells with the tumor microenvironment and their role in tumor growth and metastasis. We will conclude with a brief discussion of therapy for pancreatic cancer and the potential role for immunotherapy. We hypothesize that the role of the immune system in tumor development and progression is tissue specific. Our hope is that better understanding of this process will lead to better treatments for this devastating disease.

A phase II trial of intraperitoneal interleukin-2 in patients with platinum-resistant or platinum-refractory ovarian cancer

Ovarian cancer patients with persistent (platinum-resistant) or progressive (platinum-refractory) disease respond poorly to second line chemotherapy and have low survival expectancy. New and improved therapeutic approaches are needed and immune biologics are one possibility. Interleukin-2 (IL-2) is a T-cell growth factor believed to be important in anti-tumor immunity. We performed a phase II clinical trial with intraperitoneal (IP) recombinant IL-2 administered in weekly infusions of 6 x 10(5) IU/m2. Thirty-one subjects were sequentially entered into the study and clinical responses were surgically confirmed in 24 patients. The primary end point of this study was clinical response with immunologic measurements as secondary end points. The IP regimen was generally well tolerated. Of the 24 patients assessed for response, there were 6 (4 complete, 2 partial) responses for an overall response rate of 25.0% [95% confidence interval (CI) of 11-45]. The median survival of the 31 patient cohort was 2.1 years (95% CI of 1.3-4.4), but for the 6 patients with responses the median survival has not been reached (range 24-120+ months). Eosinophil and lymphocyte numbers were continuously monitored during treatment. Peripheral blood eosinophils were markedly increased at the completion of treatment (p < 0.0001) and associated with increased circulating eotaxin (p = 0.03). We also found significant associations between changes in CD3 counts and survival (p = 0.05) and between IFNγ- secreting CD8 T cells at early time points and survival (p = 0.04). This study provides important evidence for IP IL-2 in platinum-resistant ovarian cancer and identifies several immune correlates of survival.

Countering tumor-induced immunosuppression during immunotherapy for pancreatic cancer

BACKGROUND

Vaccines for pancreatic cancer have been challenged by a number of factors, especially the immunosuppressive microenvironment within the tumor that allows for escape from immune surveillance.

OBJECTIVE/METHODS

We sought to identify results that define mechanisms of pancreatic-cancer-associated immunosuppression and strategies that might be useful to overcome them thereby resulting in effective immune responses to cancer vaccines capable of deleting pancreatic cancer cells.

RESULTS/CONCLUSION

Immunosuppressive tumor-associated macrophages (TAMs), myeloid-derived suppressor cells (MDSC), and regulatory T cells (Treg) reside in tumors, and their products along with tumor derived products (such as VEGF, TGFbeta and IL-10), create a microenvironment that counters immune activation and attack. Immunotherapy with cancer vaccines must include strategies to modulate these immunosuppressive cell types and tumor byproducts. Clinical trials are beginning to test these strategies.