Expansion of transplanted islets in mice by co-transplantation with adipose tissue-derived mesenchymal stem cells.

The shortage of donor islets is a significant obstacle for widespread clinical application of pancreatic islet transplantation. To investigate whether adipose tissue-derived mesenchymal stem cells (ADSCs) induce expansion of transplanted islets, we performed co-transplantation experiments in a mouse model. Streptozotosin (STZ)-induced diabetic mice transplanted with 50 syngeneic islets remained hyperglycemic. However, hyperglycemia was ameliorated gradually when 50 islets were co-transplanted with ADSCs but not separately grafted into the contralateral kidney. Insulin and proinsulin contents of 120-day grafts containing 50 islets co-transplanted with ADSCs were significantly increased compared with those of 50 isolated islets. The Ki67-positive ratios in islets of the naïve pancreas, at 30 and 120 days grafts were 0.23%, 2.12%, and 1.52%, respectively. Ki67-positive cells were predominantly Pdx1+ and insulin+ cells. These results demonstrate that co-transplantation with ADSCs induces proliferation of transplanted islets in mice, suggesting a potential solution for the low efficiency of islet transplantation.

Hepatectomy for Liver Metastases of Colorectal Cancer After Adoptive Chemoimmunotherapy Using Activated αß T-cells.

BACKGROUND/AIM: Various types of chemoimmunotherapies for malignant tumors have been reported. However, there are few reports on hepatectomy after chemoimmunotherapy. We evaluated the safety and efficacy of hepatectomy for patients with stage IV colorectal liver metastases (CLM) after chemoimmunotherapy using activated αß T-cells. PATIENTS AND METHODS: From June 2012 to December 2016, five patients who underwent hepatectomy after receiving capecitabine and oxaliplatin (XELOX) plus bevacizumab and ex vivo-expanded αß T-lymphocytes as first-line chemoimmunotherapy were included. RESULTS: The median age of the five patients (two men, three women) was 61.4 (range=56-75) years. The surgical procedure was partial hepatectomy in two, laparoscopic partial hepatectomy in two, and one case of partial hepatectomy with subsegmentectomy. There was no postoperative complication of Clavien-Dindo grade 3A or higher. One patient had multiple lung metastases. CONCLUSION: Hepatectomy after chemoimmunotherapy using activated αß T-cells for CLM can be performed safely.

Clinical Study on the Medical Value of Combination Therapy Involving Adoptive Immunotherapy and Chemotherapy for Stage IV Colorectal Cancer (COMVI Study).

BACKGROUND: Adoptive immunotherapy for cancer has evolved through development of novel technologies for generating a large number of activated killer cells, such as αß T-cells, γδ T-cells, and natural killer cells. There has been no prospective trial of combination therapy involving adoptive immunotherapy and first-line chemotherapy for stage IV colorectal cancer. The present pilot study aimed to evaluate the safety and feasibility of combination therapy involving adoptive immunotherapy and chemotherapy for stage IV colorectal cancer (COMVI study). PATIENTS AND METHODS: The COMVI study was a prospective, single-arm pilot trial. Therapy in each 21-day treatment cycle involved XELOX (130 mg/m2 of oxaliplatin on day 1 plus 1,000 mg/m2 of capecitabine twice daily on days 1-14), bevacizumab (7.5 mg/kg on day 1), and αß T-lymphocytes (over 5×109 on day 18) cultured ex vivo with an immobilized antibody to CD3 and interleukin-2. RESULTS: The study included six patients (two men and four women) between June 2013 and September 2014. The median patient age was 68 years (range=55-75 years). The overall response rate was 83.3% [complete response in two (33.3%); partial response in three (50.0%); stable disease in one (16.7%); no cases of progressive disease]. The tumor volume reduction rate was 53% (range=38.0-100%). The median progression-free and overall survival durations were 567 and 966 days, respectively. Most adverse events were mild-to-moderate in intensity, and no grade 4 adverse events occurred in the six patients. Only one patient experienced grade 3 hypertension and ileus. Immunotherapy-associated toxicity was minimal in this study. CONCLUSION: Combination therapy involving adoptive immunotherapy and chemotherapy for stage IV colorectal cancer is feasible and safe. Phase II prospective studies are needed to confirm the safety and efficacy of such chemoimmunotherapy.

Difference in Neutropenia due to Administration Schedule of TAS-102.

TAS-102 significantly improves overall survival in patients with metastatic colorectal cancer. The most common adverse event of TAS-102 is bone marrow suppression, which leads to neutropenia. The incidence of neutropenia is high, and there is no known effective prevention method. Furthermore, the administration method of TAS-102 is complicated. We reported that neutropenia could be avoided by changing to a simple administration method of TAS-102.

Targeting TNFR2 with antagonistic antibodies inhibits proliferation of ovarian cancer cells and tumor-associated Tregs.

Major barriers to cancer therapy include the lack of selective inhibitors of regulatory T cells (Tregs) and the lack of broadly applicable ways to directly target tumors through frequently expressed surface oncogenes. Tumor necrosis factor receptor 2 (TNFR2) is an attractive target protein because of its restricted abundance to highly immunosuppressive Tregs and oncogenic presence on human tumors. We characterized the effect of TNFR2 inhibition using antagonistic antibodies. In culture-based assays, we found that two TNFR2 antagonists inhibited Treg proliferation, reduced soluble TNFR2 secretion from normal cells, and enabled T effector cell expansion. The antagonistic activity occurred in the presence of added TNF, a natural TNFR2 agonist. These TNFR2 antibodies killed Tregs isolated from ovarian cancer ascites more potently than it killed Tregs from healthy donor samples, suggesting that these antibodies may have specificity for the tumor microenvironment. The TNFR2 antagonists also killed OVCAR3 ovarian cancer cells, which have abundant surface TNFR2. The antibodies stabilized antiparallel dimers in cell surface TNFR2 that rendered the receptor unable to activate the nuclear factor κB pathway and trigger cell proliferation. Our data suggest that, by targeting tumor cells and immunosuppressive tumor-associated Tregs, antagonistic TNFR2 antibodies may be an effective treatment for cancers positive for TNFR2.

Phase II study on early start of chemotherapy after excising primary colorectal cancer with distant metastases (Pearl Star 02).

Initiating chemotherapy usually requires a delay of more than 4 weeks after surgically resecting colorectal cancer. However, there is little evidence regarding the required delay interval. We have previously reported a pilot study to determine the safety and feasibility of early initiation of chemotherapy after resecting primary colorectal cancer with distant metastases. We aimed to determine the safety and efficacy of early initiation of chemotherapy after resecting colorectal cancer with distant metastases.This phase II study (trial number UMIN000006310) was a prospective, single-arm trial. A total of 20 patients (men, 15 and women, 5) were enrolled. They underwent XELOX therapy (130 mg/m2 oxaliplatin on day 1+1000 mg/m2 capecitabine twice daily on days 1-4) on postoperative day 7 and XELOX+bevacizumab (7.5 mg/kg bevacizumab on day 1) after the second chemotherapy cycle.Baseline characteristics included a median age of 64 (range, 43-72) years. Surgical procedures included right hemicolectomy in six patients, sigmoidectomy in three, anterior resection in five, and Hartmann procedure in six. All patients started chemotherapy on postoperative day 7. Median progression-free survival was 14.9 months; overall response rate was 80%. Disease control rate was 100%. Grade 3 or higher hemotoxicity and grade 3 or higher non-hematological toxicity was noted in 5.0% and 25.0% of patients, respectively. Postoperative complications were observed in two patients (superficial incisional surgical site infection and ileus).Early initiation of chemotherapy after surgery is feasible. These findings suggest future changes of the start time of chemotherapy after surgery.

Objective evaluation of oxaliplatin-induced vascular pain secondary to peripheral vein administration.

BACKGROUND: During oxaliplatin chemotherapy administration via a peripheral vein, vascular pain requires changing of the intravenous infusion route on occasion. Vascular pain induced by anticancer drugs reduces the rate of patient continuation and completion of chemotherapy. Pain is presently appraised using subjective methods, such as the visual analog scale (VAS). However, because pain evaluation can vary depending on the physical state and mood of the patient at the time of assessment, it is desirable to evaluate pain objectively. PainVision PS-2100 (PV) is a medical device that was designed to objectively and quantitatively assess patient nociception and perception. METHODS: The present study examined the correlation of subjective and objective assessment of oxaliplatin-induced vascular pain using VAS and PV, respectively. RESULTS: Vascular pain was assessed using both PV and VAS a total of 173 times for 58 colorectal cancer patients. Partial correlation analysis was performed to evaluate the relationship between PV and VAS. The mean PV and VAS scores were 44.5 (range: 0-596) and 24.8 (range: 0-100), respectively. The partial correlation coefficient was 0.408 (p < 0.0001). CONCLUSIONS: A strong correlation was not observed between the results, and a weak correlation was observed between VAS and PV scores. Objective evaluation of oxaliplatin-induced vascular pain will be required to help patients overcome vascular pain.

Pretreatment of donor islets with papain improves allograft survival without systemic immunosuppression in mice.

Although current immunosuppression protocols improve the efficacy of clinical allogenic islet transplantation, T cell-mediated allorejection remains unresolved, and major histocompatibility complexes (MHCs) play a crucial role in this process. Papain, a cysteine protease, has the unique ability to cleave the extracellular domain of the MHC class I structure. We hypothesized that pretreatment of donor islets with papain would diminish the expression of MHC class I on islets, reducing allograft immunogenicity and contributing to prolongation of islet allograft survival. BALB/c islets pretreated with papain were transplanted into C57BL/6J mice as an acute allorejection model. Treatment with 1 mg/mL papain significantly prolonged islet allograft survival. In vitro, to determine the inhibitory effect on T cell-mediated alloreactions, we performed lymphocyte proliferation assays and mixed lymphocyte reactions. Host T cell activation against allogenic islet cells was remarkably suppressed by pretreatment of donor islet cells with 10 mg/mL papain. Flow cytometric analysis was also performed to investigate the effect of papain treatment on the expression of MHC class I on islets. One or 10 mg/mL papain treatment reduced MHC class I expression on the islet cell surface. Pretreatment of donor islets with papain suppresses MHC class I-mediated allograft rejection in mice and contributes to prolongation of islet allograft survival without administration of systemic immunosuppressants. These results suggest that pretreatment of human donor islets with papain may reduce the immunogenicity of the donor islets and minimize the dosage of systemic immunosuppressants required in a clinical setting.

Adoptive Chemoimmunotherapy Using Activated αß T Cells for Stage IV Colorectal Cancer.

BACKGROUND/AIM: Adoptive immunotherapy of cancer is evolving with the development of novel technologies that generate proliferation of large numbers of αß and γδ T cells. We evaluated the safety and efficacy of the combination of adoptive immunotherapy using αß T cells with chemotherapy for stage IV colorectal cancer (CRC). PATIENTS AND METHODS: Fifteen patients with advanced or recurrent CRC received XELOX + bevacizumab + ex vivo expanded αß T lymphocytes as a first-line chemoimmunotherapy. RESULTS: Median age of the 15 patients (4 men, 11 women) was 65 years (range=49-80). Median progression-free survival was 21.3 months. Response rate was 80% (complete response (CR)=26.7%, partial response (PR)=53.3%, stable disease (SD)=20% and progressive disease (PD)=0%). Most adverse events were mild to moderate regarding their intensity and immunotherapy-associated toxicity was minimal. CONCLUSION: Combination of adoptive αß T cell immunotherapy with chemotherapy for stage IV CRC is feasible and safe.

HMGB1-Mediated Early Loss of Transplanted Islets Is Prevented by Anti-IL-6R Antibody in Mice.

OBJECTIVES: The limited success in achieving insulin independence of patients with type 1 diabetes mellitus after islet transplantation from a single donor, mainly due to early loss of transplanted islets, hampers clinical application of islet transplantation. Previously, we have shown in mice that the early loss of transplanted islets in the liver, the site of islet transplantation, is caused by innate immune rejection triggered by high-mobility group box 1 (HMGB1) protein released from transplanted islets. We herein determined whether the HMGB1-mediated early loss of transplanted mouse islets is prevented by anti-interleukin-6 receptor (IL-6R) antibody. METHODS: The effect of anti-IL-6R antibody on amelioration of hyperglycemia in streptozocin-induced diabetic mice receiving 200 islets into the liver from a single donor was evaluated in association with HMGB1-stimulated interferon-γ production of hepatic mononuclear cells. RESULTS: Hyperglycemia of diabetic mice receiving 200 syngeneic islets was ameliorated with down-regulation of interferon-γ production of hepatic natural killer T cells and neutrophils when anti-IL-6R was administered at the time of transplantation. This beneficial effect was also seen in allografts when alloimmune rejection was prevented by anti-CD4 antibody. CONCLUSIONS: These findings demonstrate that anti-IL-6R antibody prevented the early loss of intrahepatic islet grafts with inhibiting HMGB1-induced immune activation after islet transplantation.

Removal of donor human leukocyte antigen class I proteins with papain: translation for possible whole organ practices.

BACKGROUND: Papain is a protease with potential use in transplantation because of its targeted capacity to selectively remove human leukocyte antigen (HLA) class I proteins from donor human cells. However, its proteolytic activity has not been studied under conditions suitable for use in perfusing donor organs, namely, under a temperature of 4°C and dissolution in Belzer-UW solution. METHODS: We test papain's HLA class I removing activity under recognized whole organ transplant conditions of lowered temperature. The activity of papain's substrate selectivity was tested using both a test substrate (casein) and fresh peripheral blood lymphocytes (PBLs). The activity of papain was also tested at 4°C, the temperature of whole organ storage. RESULTS: We found that papain at a range of concentrations is nearly as active in cleaving the test substrate in Belzer-UW solution as in distilled water. In distilled water, papain is as active in cleaving a test substrate at a temperature of 4°C as compared to its optimal temperature of 37°C, if the incubation time is extended from 10 min to 3 hr. This finding also holds true if papain is dissolved in Belzer-UW solution. In peripheral blood lymphocytes, papain cleaved off HLA class I proteins as effectively at 4°C as at 37°C, provided the incubation time was also extended to 3 hr. CONCLUSION: These findings suggest that papain's targeted enzymatic cleavage of donor HLA class I has potential use in the whole organ transplant setting with retained activity at lower temperatures and when activated and dissolved in Belzer-UW solution.

Homogeneous expansion of human T-regulatory cells via tumor necrosis factor receptor 2.

T-regulatory cells (T(regs)) are a rare lymphocyte subtype that shows promise for treating infectious disease, allergy, graft-versus-host disease, autoimmunity, and asthma. Clinical applications of T(regs) have not been fully realized because standard methods of expansion ex vivo produce heterogeneous progeny consisting of mixed populations of CD4 + T cells. Heterogeneous progeny are risky for human clinical trials and face significant regulatory hurdles. With the goal of producing homogeneous T(regs), we developed a novel expansion protocol targeting tumor necrosis factor receptors (TNFR) on T(regs). In in vitro studies, a TNFR2 agonist was found superior to standard methods in proliferating human T(regs) into a phenotypically homogeneous population consisting of 14 cell surface markers. The TNFR2 agonist-expanded T(regs) also were functionally superior in suppressing a key T(reg) target cell, cytotoxic T-lymphocytes. Targeting the TNFR2 receptor during ex vivo expansion is a new means for producing homogeneous and potent human T(regs) for clinical opportunities.

The Hippo signaling pathway is required for salivary gland development and its dysregulation is associated with Sjogren's syndrome.

Sjogren's syndrome (SS) is a complex autoimmune disease that primarily affects salivary and lacrimal glands and is associated with high morbidity. Although the prevailing dogma is that immune system pathology drives SS, increasing evidence points to structural defects, including defective E-cadherin adhesion, to be involved in its etiology. We have shown that E-cadherin has pivotal roles in the development of the mouse salivary submandibular gland (SMG) by organizing apical-basal polarity in acinar and ductal progenitors and by signaling survival for differentiating duct cells. Recently, E-cadherin junctions have been shown to interact with effectors of the Hippo signaling pathway, a core pathway regulating the organ size, cell proliferation, and differentiation. We now show that Hippo signaling is required for SMG-branching morphogenesis and is involved in the pathophysiology of SS. During SMG development, a Hippo pathway effector, TAZ, becomes increasingly phosphorylated and associated with E-cadherin and α-catenin, consistent with the activation of Hippo signaling. Inhibition of Lats2, an upstream kinase that promotes TAZ phosphorylation, results in dysmorphogenesis of the SMG and impaired duct formation. SMGs from non-obese diabetic mice, a mouse model for SS, phenocopy the Lats2-inhibited SMGs and exhibit a reduction in E-cadherin junctional components, including TAZ. Importantly, labial specimens from human SS patients display mislocalization of TAZ from junctional regions to the nucleus, coincident with accumulation of extracellular matrix components, fibronectin and connective tissue growth factor, known downstream targets of TAZ. Our studies show that Hippo signaling has a crucial role in SMG-branching morphogenesis and provide evidence that defects in this pathway are associated with SS in humans.

Prevention of high-mobility group box 1-mediated early loss of transplanted mouse islets in the liver by antithrombin III.

BACKGROUND: The low efficiency of pancreatic islet transplantation mainly because of the early loss of transplanted islets hampers its clinical application. Previously, we have shown in mice that the early loss of transplanted islets in the liver is caused by innate immune rejection in concert with dendritic cells, natural killer T cells, and neutrophils to produce interferon (IFN)-γ, which is triggered by high-mobility group box 1 (HMGB1) released from transplanted islets. We herein determined whether the HMGB1-mediated early loss of transplanted mouse islets is prevented by antithrombin (ATIII). METHODS: The effect of ATIII on in vitro and in vivo HMGB1-stimulated IFN-γ production of hepatic mononuclear cells was examined. Then, the effect of ATIII on amelioration of hyperglycemia in streptozotocin-induced diabetic mice receiving 200 syngeneic islets from a single donor was determined. RESULTS: In vitro and in vivo IFN-γ production of mononuclear cells in the liver of mice in response to HMGB1 was suppressed by ATIII. Hyperglycemia of streptozotocin-induced diabetic mice receiving 200 syngeneic islets into the liver from a single donor was ameliorated with down-regulation of IFN-γ production of natural killer T cells and neutrophils in the liver when ATIII but not vehicle was administered once at the time of islet transplantation. The favorable effect of ATIII was similarly achieved in mice receiving islet allografts when rejection was prevented with anti-CD4 antibody treatment. CONCLUSIONS: These findings demonstrate that ATIII prevents HMGB1-mediated early loss of transplanted islets caused by innate immune rejection, suggesting a potential application of ATIII to improve efficiency of clinical islet transplantation.

High-mobility group box 1 is involved in the initial events of early loss of transplanted islets in mice.

Islet transplantation for the treatment of type 1 diabetes mellitus is limited in its clinical application mainly due to early loss of the transplanted islets, resulting in low transplantation efficiency. NKT cell-dependent IFN-gamma production by Gr-1(+)CD11b(+) cells is essential for this loss, but the upstream events in the process remain undetermined. Here, we have demonstrated that high-mobility group box 1 (HMGB1) plays a crucial role in the initial events of early loss of transplanted islets in a mouse model of diabetes. Pancreatic islets contained abundant HMGB1, which was released into the circulation soon after islet transplantation into the liver. Treatment with an HMGB1-specific antibody prevented the early islet graft loss and inhibited IFN-gamma production by NKT cells and Gr-1(+)CD11b(+) cells. Moreover, mice lacking either of the known HMGB1 receptors TLR2 or receptor for advanced glycation end products (RAGE), but not the known HMGB1 receptor TLR4, failed to exhibit early islet graft loss. Mechanistically, HMGB1 stimulated hepatic mononuclear cells (MNCs) in vivo and in vitro; in particular, it upregulated CD40 expression and enhanced IL-12 production by DCs, leading to NKT cell activation and subsequent NKT cell-dependent augmented IFN-gamma production by Gr-1(+)CD11b(+) cells. Thus, treatment with either IL-12- or CD40L-specific antibody prevented the early islet graft loss. These findings indicate that the HMGB1-mediated pathway eliciting early islet loss is a potential target for intervention to improve the efficiency of islet transplantation.

Prevention of early loss of transplanted islets in the liver of mice by adenosine.

BACKGROUND: The low efficiency of islet transplantation necessitating sequential transplantations with the use of 2 to 3 donors for a recipient has been a major obstacle facing clinical islet transplantation. We determined whether adenosine has any beneficial effects on preventing early loss of transplanted islets in the liver, thereby facilitating successful islet transplantation from one donor to one recipient in mice. METHODS: Two hundred islets, the number of islets from a single mouse pancreas, were grafted into the liver of streptozotocin-induced diabetic C57BL/6 mice. Adenosine was administered once at the time of islet transplantation. Mononuclear cells in the liver of mice receiving islets were isolated and examined by flow cytometry. RESULTS: A single injection of adenosine at the time of transplantation ameliorated hyperglycemia of diabetic mice receiving 200 syngenic islets with suppression of interferon (IFN)-gamma production of hepatic NKT cells and neutrophils, while that of control did not. The IFN-gamma production of NKT cells and neutrophils in the liver of mice treated with alpha-galactosylceramide, a synthetic ligand of NKT cells was suppressed by adenosine. The beneficial effect of adenosine was also observed for BALB/c islet allografts when alloimmune rejection was prevented by anti-CD4 antibody. CONCLUSIONS: Adenosine suppresses the NKT cell-mediated IFN-gamma production of neutrophils in the liver of mice receiving islets, thus leading to prevention of early loss of transplanted syngenic and allogenic islets. The findings indicate that adenosine may improve efficiency of clinical islet transplantation.