Hemagglutinin virus-like particles incorporated with membrane-bound cytokine adjuvants provide protection against homologous and heterologous influenza virus challenge in aged mice

BACKGROUND

Current influenza vaccines deliver satisfactory results in young people but are less effective in the elderly. Development of vaccines for an ever-increasing aging population has been an arduous challenge due to immunosenescence that impairs the immune response in the aged, both quantitatively and qualitatively.

RESULTS

To potentially enhance vaccine efficacy in the elderly, we investigated the immunogenicity and cross-protection of influenza hemagglutinin virus-like particles (HA-VLP) incorporated with glycosylphosphatidylinositol (GPI)-anchored cytokine-adjuvants (GPI-GM-CSF and GPI-IL-12) via protein transfer in aged mice. Lung viral replication against homologous and heterologous influenza viruses was significantly reduced in aged mice after vaccination with cytokine incorporated VLPs (HA-VLP-Cyt) in comparison to HA-VLP alone. Enhanced IFN-γ⁺CD4⁺ and IFN-γ⁺CD8⁺ T cell responses were also observed in aged mice immunized with HA-VLP-Cyt when compared to HA-VLP alone.

CONCLUSIONS

Cytokine-adjuvanted influenza HA-VLP vaccine induced enhanced protective response against homologous influenza A virus infection in aged mice. Influenza HA-VLP vaccine with GPI-cytokines also induced enhanced T cell responses correlating with better protection against heterologous infection in the absence of neutralizing antibodies. The results suggest that a vaccination strategy using cytokine-adjuvanted influenza HA-VLPs could be used to enhance protection against influenza A virus in the elderly.

The magic of small-molecule drugs during ex vivo expansion in adoptive cell therapy

In the past decades, advances in the use of adoptive cellular therapy to treat cancer have led to unprecedented responses in patients with relapsed/refractory or late-stage malignancies. However, cellular exhaustion and senescence limit the efficacy of FDA-approved T-cell therapies in patients with hematologic malignancies and the widespread application of this approach in treating patients with solid tumors. Investigators are addressing the current obstacles by focusing on the manufacturing process of effector T cells, including engineering approaches and ex vivo expansion strategies to regulate T-cell differentiation. Here we reviewed the current small-molecule strategies to enhance T-cell expansion, persistence, and functionality during ex vivo manufacturing. We further discussed the synergistic benefits of the dual-targeting approaches and proposed novel vasoactive intestinal peptide receptor antagonists (VIPR-ANT) peptides as emerging candidates to enhance cell-based immunotherapy.

Influenza Virus-like Particle-Based Hybrid Vaccine Containing RBD Induces Immunity against Influenza and SARS-CoV-2 Viruses

Several approaches have produced an effective vaccine against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Since millions of people are exposed to influenza virus and SARS-CoV-2, it is of great interest to develop a two-in-one vaccine that will be able to protect against infection of both viruses. We have developed a hybrid vaccine for SARS-CoV-2 and influenza viruses using influenza virus-like particles (VLP) incorporated by protein transfer with glycosylphosphatidylinositol (GPI)-anchored SARS-CoV-2 RBD fused to GM-CSF as an adjuvant. GPI-RBD-GM-CSF fusion protein was expressed in CHO-S cells, purified and incorporated onto influenza VLPs to develop the hybrid vaccine. Our results show that the hybrid vaccine induced a strong antibody response and protected mice from both influenza virus and mouse-adapted SARS-CoV-2 challenges, with vaccinated mice having significantly lower lung viral titers compared to naive mice. These results suggest that a hybrid vaccine strategy is a promising approach for developing multivalent vaccines to prevent influenza A and SARS-CoV-2 infections.

Influenza virus-like particle-based hybrid vaccine containing RBD induces immunity against influenza and SARS-CoV-2 viruses

Several approaches have produced an effective vaccine against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). However, the influence of immunity against other vaccinations on the durability and efficacy of the immune response against SARS-CoV-2 is still unknown in settings where vaccines against other viruses need to be administered simultaneously. This will be an important factor in developing multivalent vaccines against seasonal viruses. We have developed a hybrid vaccine for SARS-CoV-2 and influenza viruses using influenza virus-like particles (VLP) incorporated with glycosylphosphatidylinositol (GPI)-anchored Spike RBD of SARS-CoV-2 fused to GM-CSF as an adjuvant. GPI-anchored fusion protein of GM-CSF and the SARS-CoV-2 S1 RBD was expressed in CHO-S cells, purified by immunoaffinity chromatography and incorporated onto influenza VLPs by protein transfer to make a hybrid VLP vaccine. The efficacy of the hybrid VLP vaccine was tested against both SARS-CoV-2 and influenza A/PR8 viruses in a mouse model. Our results show that the hybrid vaccine induced a strong antibody response and protected the mice from both influenza virus and mouse-adapted SARS-CoV-2 challenges, with vaccinated mice having less body weight loss and significantly lower lung viral titers compared to control mice. These results suggest that the hybrid vaccine is a promising candidate for preventing influenza A and SARS-CoV-2 infections.

This work was supported by NIH/NIAID (SBIR Contract# 75N93019C00017 Amendment to Pack/Ramachandiran), and Intel Corporation for the Intel COVID-19 Global Technology Response Initiative grant.

Effect of Standard of Care Treatment on Tumor Membrane Vesicle Vaccine for Triple-Negative Breast Cancer

Metastatic triple-negative breast cancer (TNBC) has a poor prognosis primarily due to metastatic potential and resistance to currently available therapies. Recent studies suggest that TNBC may be a viable target for immunotherapy due to the presence of high levels of infiltrating lymphocytes. However, many TNBC patients do not respond due to high intra-tumoral and inter-patient heterogeneity. Utilizing a novel protein transfer method, we generate a personalized vaccine based on tumor membrane vesicles (TMVs) derived from whole tumor tissues modified with glycolipid-anchored forms of the immunostimulatory molecules (GPI-ISMs) B7-1 and IL-12. In prior studies we observed that simultaneous delivery of TMVs along with biological adjuvants enhanced CD8 T cell immunity. Herein, we investigated the impact of standard-of-care (SOC) chemotherapy on the resulting quality of the TMV vaccine. Mice were injected with 4T1 TNBC cells subcutaneously and treated with three rounds of SOC drugs starting at day 15. Chemotherapies affected tumor growth to varying degrees. Mice were euthanized and tumors were harvested for TMV preparation. Results show that depending on the treatment, the yield and particle size of TMVs was impacted. While SOC drugs affected some surface markers on TMVs, expression of CD24 and CD11b was unchanged. Further, there was reduced uptake of TMVs by dendritic cells prepared from cisplatin and 5-fluorouracil treated tumors. GPI-ISMs were equally incorporated by protein transfer onto TMVs despite SOC treatments. In summary, our studies in the 4T1 model show that a TMV vaccine can be successfully prepared after chemotherapy, but the impact on TMV yield and size justifies further investigation.

Supported by R01 CA202763 

Metformin reduces PD-L1 on tumor cells and enhances the anti-tumor immune response generated by vaccine immunotherapy

Background

PD-L1 is one of the major immune checkpoints which limits the effectiveness of antitumor immunity. Blockade of PD-L1/PD-1 has been a major improvement in the treatment of certain cancers, however, the response rate to checkpoint blockade remains low suggesting a need for new therapies. Metformin has emerged as a potential new drug for the treatment of cancer due to its effects on PD-L1 expression, T cell responses, and the immunosuppressive environment within tumors. While the benefits of metformin in combination with checkpoint blockade have been reported in animal models, little remains known about its effect on other types of immunotherapy.

Methods

Vaccine immunotherapy and metformin were administered to mice inoculated with tumors to investigate the effect of metformin and TMV vaccine on tumor growth, metastasis, PD-L1 expression, immune cell infiltration, and CD8 T cell phenotype. The effect of metformin on IFN-γ induced PD-L1 expression in tumor cells was assessed by flow cytometry, western blot, and RT-qPCR.

Results

We observed that tumors that respond to metformin and vaccine immunotherapy combination show a reduction in surface PD-L1 expression compared with tumor models that do not respond to metformin. In vitro assays showed that the effect of metformin on tumor cell PD-L1 expression was mediated in part by AMP-activated protein kinase signaling. Vaccination results in increased T cell infiltration in all tumor models, and this was not further enhanced by metformin. However, we observed an increased number of CD8 T cells expressing PD-1, Ki-67, Tim-3, and CD62L as well as increased effector cytokine production after treatment with metformin and tumor membrane vesicle vaccine.

Conclusions

Our data suggest that metformin can synergize with vaccine immunotherapy to augment the antitumor response through tumor-intrinsic mechanisms and also alter the phenotype and function of CD8 T cells within the tumor, which could provide insights for its use in the clinic.

Expression of tdTomato and luciferase in a murine lung cancer alters the growth and immune microenvironment of the tumor

Imaging techniques based on fluorescence and bioluminescence have been important tools in visualizing tumor progression and studying the effect of drugs and immunotherapies on tumor immune microenvironment in animal models of cancer. However, transgenic expression of foreign proteins may induce immune responses in immunocompetent syngeneic tumor transplant models and augment the efficacy of experimental drugs. In this study, we show that the growth rate of Lewis lung carcinoma (LL/2) tumors was reduced after transduction of tdTomato and luciferase (tdTomato/Luc) compared to the parental cell line. tdTomato/Luc expression by LL/2 cells altered the tumor microenvironment by increasing tumor-infiltrating lymphocytes (TILs) while inhibiting tumor-induced myeloid-derived suppressor cells (MDSCs). Interestingly, tdTomato/Luc expression did not alter the response of LL/2 tumors to anti-PD-1 and anti-CTLA-4 antibodies. These results suggest that the use of tdTomato/Luc-transduced cancer cells to conduct studies in immune competent mice may lead to cell-extrinsic tdTomato/Luc-induced alterations in tumor growth and tumor immune microenvironment that need to be taken into consideration when evaluating the efficacy of anti-cancer drugs and vaccines in immunocompetent animal models.

Humanized mice challenged with TNBC tumor develop graft versus host disease and anemia limiting vaccine immunotherapy studies

Breast cancer is the leading cause of death among female cancer patients. Our lab has developed a therapeutic cancer vaccine approach for triple negative breast cancer (TNBC). In this study, we investigated whether vaccine developed from a human TNBC cell line could effectively induce antitumor immunity, which control the growth of tumors in humanized mice implanted with the human TNBC cell line. Human CD34+ HSC implanted NSG-SGM3 from JAX labs and NOG-EXL mice from Taconic Biosciences used for the studies. Humanized NSG-SGM3 mice were vaccinated with 100 mg of the vaccine once every 2 weeks (3 doses). Control mice were injected with vehicle (PBS). One week after the last vaccination, mice were challenged with MDA-MB-231 TNBC cells subcutaneously in the hind flank. Body weight and tumor growth were monitored. All the mice in both groups have developed tumors, splenomegaly and metastatic lesions in the liver, lungs and spleen. However, all the mice also developed GvHD and need to be euthanized before completion of the study. We have also observed an allo-response (CD69+ T cells in control mice with MDA-MB-231 tumors) to the HLA-matched tumor cells but the tumors eventually developed into metastatic disease affecting multiple organs (liver, lungs and spleen) suggesting that the allo-response is not effective against the tumor. Since the tumor-bearing mice developed GvHD and becoming anemic even in a specific pathogen-free barrier facility, future studies will need to be tested in humanized mice which do not develop GvHD and live longer for carrying out vaccine immunotherapy studies. Funding: NIH/NCI R01 CA202763 (PS & CP).

Tumor membrane-based vaccine immunotherapy in combination with anti-CTLA-4 antibody confers protection against immune checkpoint resistant murine triple-negative breast cancer

Triple-negative breast cancer (TNBC) afflicts women at a younger age than other breast cancers and is associated with a worse clinical outcome. This poor clinical outcome is attributed to a lack of defined targets and patient-to-patient heterogeneity in target antigens and immune responses. To address such heterogeneity, we tested the efficacy of a personalized vaccination approach for the treatment of TNBC using the 4T1 murine TNBC model. We isolated tumor membrane vesicles (TMVs) from homogenized 4T1 tumor tissue and incorporated glycosyl phosphatidylinositol (GPI)-anchored forms of the immunostimulatory B7-1 (CD80) and IL-12 molecules onto these TMVs to make a TMV vaccine. Tumor-bearing mice were then administered with the TMV vaccine either alone or in combination with immune checkpoint inhibitors. We show that TMV-based vaccine immunotherapy in combination with anti-CTLA-4 mAb treatment upregulated immunomodulatory cytokines in the plasma, significantly improved survival, and reduced pulmonary metastasis in mice compared to either therapy alone. The depletion of CD8⁺ T cells, but not CD4⁺ T cells, resulted in the loss of efficacy. This suggests that the vaccine acts via tumor-specific CD8⁺ T cell immunity. These results suggest TMV vaccine immunotherapy as a potential enhancer of immune checkpoint inhibitor therapies for metastatic triple-negative breast cancer.

Metformin reduces PD-L1 expression in the tumor and enhances the efficacy of vaccine generated CD8 T cells in a murine model of triple negative breast cancer

Immunotherapy has emerged as a promising treatment of breast cancer, however, response rates to therapy remain far from ideal. We have developed a new platform for personalized vaccine immunotherapy that utilizes tumor tissue to generate tumor membrane vesicles (TMVs). These TMVs can be incorporated with immunostimulatory molecules such as IL-12 and B7-1 and used for immunization. In this study, we investigated the combinatorial effect of TMV-based vaccine immunotherapy, to induce an anti-tumor immune response, with the type 2 diabetes drug metformin, which has been reported to exert anti-tumor effects by promoting CD8 T cell activity in the tumor microenvironment. Our results show that TMV vaccination inhibits primary tumor growth in preclinical tumor models, while the combination with metformin resulted in greater inhibition of primary growth. TMV vaccination reduced the metastatic burden in the lungs while the combination with metformin further abrogated metastatic spread. Interestingly, TMV vaccination alone induced a significant increase in T cell infiltration to the tumor, and combination with metformin caused a decrease in the accumulation of T cells, despite having better control of tumor growth. Further, we show that metformin can reduce PD-L1 expression within the tumor microenvironment and result in more IFN-γ producing CD8 T cells within the tumor, providing a mechanistic insight for the improvement of TMV-based vaccine immunotherapy.

Tumor membrane vesicle-based vaccine immunotherapy inhibits tumor growth and metastasis of squamous cell carcinoma of head and neck in mice

Head and neck cancer is a leading cause of cancer related deaths accounting for approximately 3% of all cancer related mortalities in the US. Currently, there is no cure for the advanced squamous cell carcinoma of the head and neck (SCCHN) thus development of efficacious therapies is urgently needed. To test whether vaccine-induced immunity inhibits tumor growth, we investigated efficacy of a tumor membrane-based vaccine (TMV) immunotherapy in murine SCCHN models. The MOC1, MOC2 and SCC VII tumors grown subcutaneously in syngeneic mice were harvested to generate TMVs. TMVs were then protein transferred with glycolipid-anchored immunostimulatory molecules GPI-B7.1 and GPI-IL-12 to generate the TMV vaccine. Mice were vaccinated with TMV vaccine after tumor cell challenge (therapeutic) and tumor growth was monitored every 3 days. Survival was then assessed using a Kaplan-Meier survival curve and significance determined using a Log-rank test for comparison analysis. The TMV vaccine inhibited tumor growth and improved the survival of mice challenged with MOC1 or SCC VII tumor cells. Interestingly, combination of anti-PD1 antibody with TMV vaccine decreased MOC1 tumor growth. However, MOC2 (poorly immunogenic tumor) did not respond to anti-PD1 or anti-CTLA-4 antibody therapy but significantly inhibited by TMV vaccine. MOC2 cells metastasize to the lungs in control mice but it is significantly inhibited in mice administered with TMV vaccine. TMV vaccine increased the infiltration of CD4+ and CD8+ T cells into the tumors suggesting that TMV vaccine converts cold tumors into hot tumors. These observations suggest that TMV vaccines can be harnessed to develop an effective immunotherapy for squamous cell carcinoma of the head and neck.

Tumor Membrane Vesicle Vaccine Augments the Efficacy of Anti-PD1 Antibody in Immune Checkpoint Inhibitor-Resistant Squamous Cell Carcinoma Models of Head and Neck Cancer

Immune checkpoint inhibitor (ICI) immunotherapy improved the survival of head and neck squamous cell carcinoma (HNSCC) patients. However, more than 80% of the patients are still resistant to this therapy. To test whether the efficacy of ICI therapy can be improved by vaccine-induced immunity, we investigated the efficacy of a tumor membrane-based vaccine immunotherapy in murine models of HNSCC. The tumors, grown subcutaneously, are used to prepare tumor membrane vesicles (TMVs). TMVs are then incorporated with glycolipid-anchored immunostimulatory molecules GPI-B7-1 and GPI-IL-12 by protein transfer to generate the TMV vaccine. This TMV vaccine inhibited tumor growth and improved the survival of mice challenged with SCCVII tumor cells. The tumor-free mice survived for several months, remained tumor-free, and were protected following a secondary tumor cell challenge, suggesting that the TMV vaccine induced an anti-tumor immune memory response. However, no synergy with anti-PD1 mAb was observed in this model. In contrast, the TMV vaccine was effective in inhibiting MOC1 and MOC2 murine oral cancer models and synergized with anti-PD1 mAb in extending the survival of tumor-bearing mice. These observations suggest that tumor tissue based TMV vaccines can be harnessed to develop an effective personalized immunotherapy for HNSCC that can enhance the efficacy of immune checkpoint inhibitors.

Abstract B32: Metformin reduces PD-L1 expression in the tumor and enhances the efficacy of vaccine-generated CD8 T cells in a murine model of triple-negative breast cancer

Immunotherapy has emerged as a promising treatment of breast cancer; however, response rates to therapy remain far from ideal. We have developed a new platform for personalized vaccine immunotherapy that utilizes tumor tissue to generate tumor membrane vesicles (TMVs). These TMVs can be incorporated with immunostimulatory molecules such as IL-12 and B7-1 and used for immunization. In this study, we investigated the combinatorial effect of TMV-based vaccine immunotherapy, to induce an antitumor immune response, with the type 2 diabetes drug metformin, which has been reported to exert antitumor effects by promoting CD8 T-cell activity in the tumor microenvironment. Our results show that TMV vaccination inhibits primary tumor growth in preclinical tumor models, while the combination with metformin resulted in greater inhibition of primary growth. TMV vaccination reduced the metastatic burden in the lungs while the combination with metformin further abrogated metastatic spread. Interestingly, TMV vaccination alone induced a significant increase in T-cell infiltration to the tumor, and combination with metformin caused a decrease in the accumulation of T cells, despite having better control of tumor growth. Further, we show that metformin can reduce PD-L1 expression within the tumor microenvironment and result in more IFN-γ-producing CD8 T cells within the tumor, providing a mechanistic insight for the improvement of TMV-based vaccine immunotherapy.

Citation Format: Luis E. Munoz, Ramireddy Bommireddy, Haley L. Huang, Christopher D. Pack, Sampath Ramachandiran, Periasamy Selvaraj. Metformin reduces PD-L1 expression in the tumor and enhances the efficacy of vaccine-generated CD8 T cells in a murine model of triple-negative breast cancer [abstract]. In: Proceedings of the AACR Special Conference on Tumor Immunology and Immunotherapy; 2019 Nov 17-20; Boston, MA. Philadelphia (PA): AACR; Cancer Immunol Res 2020;8(3 Suppl):Abstract nr B32.

Clinical and Radiological Review of a Semi-Constrained Cervical Disc Replacement with a Ceramic-Ceramic Articulation with a Minimum Seven Years Follow-Up

PURPOSE OF THE STUDY Artificial cervical disc replacement (CDR) has emerged as a viable treatment alternative to fusion for the management of symptomatic compressive radiculopathy and potentially for cervical myelopathy. The aim of our study was to evaluate the clinical and radiological outcomes of patients treated with a second generation semi-constrained CDR with a ceramicceramic articulation. MATERIAL AND METHODS A prospective cohort study of all patients undergoing a cervical disc replacement for cervical disc pathology, during the period from April 2007 to April 2011 using a ceramic-ceramic disc replacement comprised the study group. 52 patients were available for final clinical and radiological follow-up. Both, clinical and radiological evaluation were performed at each clinical visit at 6 weeks, 6 months, 12 months, 2 years, 5 years and 7 years. RESULTS There were a total of 52 patients, with 44 single level cases and 8 two level cases. The NDI improved significantly (p < 0.05) from a mean preoperative score of 56 % to a score of 20% at final follow-up. The mean preoperative mobility at the index level unit was 12.2 ± 4.5°, this decreased to 7.9 ± 3.2° at six weeks, but slightly increased to 12.9 ± 2.9° at final follow-up (gain not significant). Heterotrophic ossification (HO) was noted in 13 (25%) patients. CONCLUSIONS Cervical disc replacement with a ceramic-ceramic bearing surface is a viable option in the treatment of variety of cervical pathologies. This ceramic-ceramic interface may eliminate the potential problems of metallosis and poly-wear but further longer-term results should be studied. Key words: Cervical spine; disc replacement; ceramic articulation; neck disability; heterotrophic ossification.

Abstract 4097: TMV vaccine inhibits growth of squamous cell carcinoma of head and neck in mice

Introduction: Head and neck cancer is a leading cause of cancer related deaths accounting for approximately 3% of all cancer related mortalities in the US. Currently, there is no cure for the advanced squamous cell carcinoma of the head and neck (SCCHN) thus development of efficacious therapies is urgently needed. To test whether vaccine-induced immunity inhibits tumor growth, we investigated efficacy of a tumor membrane-based vaccine immunotherapy in a murine SCCHN (SCC VII) model.

Materials and Methods: The SCC VII tumors grown subcutaneously in C3H/HeJ mice were harvested to generate tumor membrane vesicles (TMVs). TMVs were then protein transferred with glycolipid-anchored immunostimulatory molecules mouse GPI-B7.1 and mouse GPI-IL-12 to generate the TMV vaccine. Mice were vaccinated with TMV vaccine either before (prophylactic) or after SCC VII tumor cell challenge (therapeutic) and tumor growth was monitored every 3 days. Survival was then assessed using a Kaplan-Meier survival curve and significance determined using a Log-rank test for comparison analysis.

Results: SCCVII cells express MHC I, CD44, CD47 and respond to IFN-γ in vitro. The therapeutic TMV vaccine inhibited tumor growth and improved the survival of mice challenged with SCCVII tumor cells. Tumor-free mice remained protective from rechallenge with SCCVII cells.

Conclusions: These observations suggest that tumor tissue-based vaccines can be harnessed to develop an effective immunotherapy for SCCHN.

Funding: Supported by Head and Neck SPORE pilot funding from Emory Winship Cancer Institute.

Citation Format: Ramireddy Bommireddy, Luis Munoz, Chrstopher D. Pack, Sampath Ramachandiran, Shaker JC Reddy, Janet Kim, Georgia Chen, Nabil F. Saba, Dong M. Shin, Periasamy Selvaraj. TMV vaccine inhibits growth of squamous cell carcinoma of head and neck in mice [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 4097.

Abstract LB-203: Metformin enhances the efficacy of tumor membrane vesicle (TMV)-based vaccine immunotherapy in a murine model of breast

Breast cancer remains the most commonly diagnosed cancers among women, with over 250,000 new cases per year in the United States. Immunotherapy has emerged as a promising treatment of breast cancer, however response rates to therapy remain far from ideal. In this study, we investigated the combinatorial effect of tumor membrane vesicle (TMV)-based vaccine immunotherapy, to induce an anti-tumor immune response, with the type 2 diabetes drug metformin, which has been reported to exert anti-tumor effects by maintaining CD8 T cell activity in the tumor microenvironment. Our results show that TMV vaccination inhibits primary tumor growth in preclinical tumor models, while combination with metformin resulted in greater inhibition of primary growth. Importantly, TMV vaccination reduced the metastatic burden in the lungs while combination with metformin further abrogated metastatic spread. Interestingly, TMV vaccination alone induced a significant increase in T cell infiltration to the tumor, while combination with metformin caused a decrease in the accumulation of T cells, despite having better outcomes. Further, we show that metformin is capable of reducing PD-L1 expression within the tumor microenvironment in both tumor cells as well as myeloid-derived suppressor cells, providing insight for the improvement of TMV-based immunotherapy.

Citation Format: Luis E. Munoz, Ramireddy Bommireddy, Haley Huang, Janet Kim, Periasamy Selvaraj. Metformin enhances the efficacy of tumor membrane vesicle (TMV)-based vaccine immunotherapy in a murine model of breast [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr LB-203.

Personalized T cell therapy for metastatic colon cancer

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Background: Current immunotherapies fail to benefit patients with colon cancer, largely due to high molecular heterogeneity and low frequencies of tumor infiltrating lymphocytes. In this study, we are addressing this limitation via a novel technology to expand patient tumor specific T cells ex-vivo, using patient’s matched tumor and peripheral blood mononuclear cells (PBMCs). This technology utilizes tumor membrane vesicles (TMVs) made from excised tumor tissue, as a source of tumor associated antigens, and further modified to express IL-12 and B7-1 for ex-vivo expansion of tumor specific T cells. Additionally, the T cells are cultured with PI3K delta inhibitor (idelalisib) and vasoactive intestinal peptide antagonist (VIPhyb) to increase yield, polyfunctionality and in-vivo persistence. Methods: Matched tumor and blood were collected from consented colon cancer patients. TMVs were prepared from excised tumors by homogenizing and centrifuging the tumor over a sucrose gradient. TMVs were then made to express glycosyl phosphatidylinositol (GPI) linked IL-12 and B7-1 (decorated TMV) via a proprietary protein transfer technology. PBMCs isolated from matched blood were cultured in media with 10ug/ml decorated TMV with/without VIPhyb(3uM) and idelalisib (100nM) for 14 days. T cells were then phenotyped for percentage of IFN gamma secreting CD4+ and CD8+ T cells and injected into PDX mice bearing matched tumors (2 doses of 1 million and 4 million cells, 20 days apart). Results: 14 days after expansion, T cells expanded with decorated TMVs+VIPhyb+idelalisib (TMVs+drugs) resulted in significantly increased number of IFN gamma secreting CD8+ T cells (25% of T cells), when compared to T cells treated with decorated TMVs without VIPhyb and idelalisib (13% of T cells). Further, when injected to PDX mice bearing matched tumors, and followed for differences in tumor growth, we observed that on day 30 after T cell injection, while the tumor volumes increased 4.5-fold in the untreated group, the tumors in the TMVs+drugs group only increased 2.8-fold. Conclusions: In this study, we have thus developed a novel technology to expand patient tumor specific T cells ex-vivo, for adoptive T cell therapy against metastatic colon cancer.

Immunotherapy with tumor membrane vesicle-based cancer vaccine inhibits metastatic tumor growth in lung cancer model

Lung cancer is the leading cause of cancer related deaths accounting for approximately 30% of all cancer related mortalities affecting both men and women. Currently, there is no cure for the common non-small cell lung cancer (NSCLC) thus development of efficacious therapies is urgently needed. In this study, we investigate the efficacy of tumor membrane-based vaccine immunotherapy and immune checkpoint blockade antibodies lung cancer models LL/2 and CMT-167 models. LL/2 and CMT-167 tumor tissues were harvested from C57BL/6 mice and processed to generate tumor membrane vesicles (TMVs). TMVs were then modified with immunostimulatory molecules and used for immunization. Tumor growth was monitored every 3 days. Survival was assessed using a Kaplan-Meier survival curve and significance determined using a Log-rank test for comparison analysis. Metastasis of CMT-167 was assessed by clonogenic assay. TMV vaccine alone, or in combination, anti-PD-1 or anti-CTLA-4 antibodies neither decreased the tumor growth nor improved the survival of mice challenged with LL/2 tumor cells. The prophylactic vaccination of TMV vaccine prevents the CMT-167 tumor growth in mice and helps the mice develop immunological memory to the tumor cell challenge. In a therapeutic setting, the TMV vaccine inhibited tumor growth and induced primary tumor regression in 40% of mice and significantly reduced the metastatic tumor burden. Anti-tumor immunity induced by TMV vaccine requires CD4+ and NK cells albeit to a lesser extent but not CD8+ T cells for controlling the tumor growth. These models provide a valuable tool in analyzing the mechanism of interaction of immune cells with tumors that lead to either tumor regression or resistance to immunotherapies.

Improving T cell functionality for adoptive T cell therapy in metastatic colorectal cancer

Adoptive T cell therapy in solid tumors such as colorectal cancers are challenging due the low frequency of tumor infiltrating T cells and high molecular tumor heterogeneity. In this study, we are proposing to address this issue by developing a novel technology to expand patient tumor specific T cells ex-vivo, using patient’s matched tumor and PBMCs. Published data from our group shows T cells isolated from heavily treated lymphoma patients when treated with inhibitors of PI3K delta (idelalisib) and vasoactive intestinal peptide (VIPhyb) signaling results in decreased levels of senescent T cells and increased persistence in-vivo in NSG mice. Additionally, we have demonstrated that tumor membrane vesicles (TMVs) prepared from human tumor cells decorated with IL-12 and B7-1 (decorated TMVs), stimulate expansion of tumor antigen specific T cells with increased IFN gamma release. This study thus combines both strategies to obtain tumor antigen specific T cells with enhanced anti-tumor activity and in-vivo persistence.

Preliminary data was generated with PBMCs obtained from consented colon cancer patients expanded with decorated TMVs with/without VIPhyb and idelalisib. Results showed that on day 14 of T cell expansion, T cells expanded with decorated TMVs + VIPhyb + idelalisib resulted in significantly increased number of IFN gamma secreting CD8+ T cells (25% of T cells), when compared to T cells treated with decorated TMVs without VIPhyb and idelalisib (13% of T cells). On the other hand, in the absence of decorated TMVs, there were less IFN gamma secreting T cells, both in the CD4 and CD8 compartment. Further experiments are underway to test the persistence and efficacy of the expanded T cells in PDX mice with matched human colon cancer.

Kyphoplasty Augmentation in Thoracolumbar Spine - Clinical Outcomes after 2 Years

PURPOSE OF THE STUDY With the ageing of population the vertebral insufficiency fractures are increasing in number and occur ever more frequently. Symptomatic relief is often difficult to achieve by non-operative treatment. The aim of this study was to determine the level of pain relief and functional outcomes in patients who failed initial non-operative treatment and, because of persisting or growing symptoms, underwent kyphoplasty. MATERIAL AND METHODS Total number of 303 patients who underwent balloon kyphoplasty between January 2011 and December 2016 were included in our study. These 303 patients had 357 surgeries. This is a retrospective review of a prospectively updated database maintained by our spinal surgery department. In total, 575 levels were augmented. The patients were mostly females (246). The age of the patients ranged from 30 years to 98 years, with the mean age being 72.6 years. The average follow-up for our series was 17.2 months (2-63 months). Pain relief was assessed using the Visual Analogue Scale (VAS) and functional outcome using the Oswestry Disability Index (ODI). RESULTS The average pre-operative VAS was 6.34 (p = 0.00003). At 6 weeks postoperatively the average VAS decreased to 3.80 (p = 0.00000). In our series, the VAS scores showed a progressive decline progressing from the mean value of 3.18 (p = 0.15890) at 1 year to the mean value of 2.85 (p = 0.00205) at 2 years. The average pre-operative ODI was 25.65 (p = 0.03604). At 6 weeks, the value improved to 17.69 (p = 0,00120) and further improvements were seen at 1 year (ODI 14.13) and at 2 years (ODI 12.08). In our series no clinically significant complications were reported. The social drift was observed in 17 patients in our study. DISCUSSION The pain relief and the improvement of functional outcomes were maintained even at a two-year follow-up. No clinically significant complications were reported that would require further surgical intervention and that would affect the good clinical results of our study. CONCLUSIONS Balloon kyphoplasty proved to be a safe surgical technique and should be considered in patients with an ongoing pain following vertebral insufficiency fractures that do not improve with the initial non-operative treatment. Cement augmentation significantly improves pain levels and as well functional status in elderly patients. Key words:cement augmentation, osteoporotic fracture, kyphoplasty, vertebroplasty, osteoporotic spine fracture.

Tumor membrane vesicle (TMV)-based cancer vaccine induces dendritic cell maturation and downstream T cell activation

Breast cancer remains the most commonly diagnosed cancers among American women, with over 250,000 new cases expected per year. Breast cancer can be subdivided into different categories depending on the expression of receptors, most commonly into ER+, PR+, HER2+, and TNBC. Clinically, small molecule inhibitors of the hormone receptors and antibodies for HER2 have been developed to target these receptors and inhibit tumor signaling or eliminate these cells via phagocytosis and ADCC. Despite this, tumor cells that develop resistance to therapy remain a significant unmet need as they tend to be more aggressive and metastasize. We developed a novel immunotherapy approach that addresses the high degree of inter-patient and intra-tumor heterogeneity by making tumor membrane vesicle (TMV) vaccines out of individual tumor samples and modifying them with GPI-linked molecules like IL-12 and B7-1 to induce an antitumor immune response. In the present study, we investigated whether GPI-GM-CSF and GPI-IL-12 on TMVs from HER2+ murine breast cancer can target and activate antigen presenting cells. Here, we show that TMVs containing with GPI-GM-CSF and GPI-IL-12 can be phagocytosed by both macrophages and dendritic cells, induce upregulation of MHC-I, MHC-II and CD86, and inflammatory cytokine production in vitro. Further, when the DCs activated with our TMV vaccine were co-cultured with syngeneic T cells, they induced the upregulation of T cell activation markers. In summary, our results indicate that TMVs containing GPI-IL-12 and GPI-GM-CSF can enhance uptake and maturation of APCs and induce a strong T cell response downstream making it a potential therapeutic approach for HER2+ breast cancer.

Efficacy of immunotherapy approaches in metastatic and non-metastatic lung cancer models

Lung cancer is the leading cause of cancer related deaths accounting for approximately 30% of all cancer related mortalities affecting both men and women. Currently, there is no cure for the common non-small cell lung cancer (NSCLC) thus development of efficacious therapies is urgently needed. In this study, we investigate the efficacy of tumor membrane-based vaccine immunotherapy and immune checkpoint blockade antibodies in an aggressive, non-metastatic, immune checkpoint inhibitor resistant lung cancer model (LL/2) and a highly metastatic lung cancer (CMT-167) model. LL/2 and CMT-167 tumor tissues were harvested from C57BL/6 mice and processed to generate tumor membrane vesicles (TMVs). TMVs were then mixed with adjuvants and used for immunization in conjunction with immune checkpoint inhibitors. Tumor growth was monitored every 3 days. Survival was assessed using a Kaplan-Meier survival curve and significance determined using a Log-rank test for comparison analysis. Metastasis of CMT-167 was assessed by clonogenic assay. TMV alone, or in combination with adjuvants, anti-PD-1 or anti-CTLA-4 antibodies neither decreased the tumor growth nor improved the survival of mice challenged with LL/2 tumor cells. However, anti-PD-1 antibody delayed the tumor growth, improved the survival and reduced pulmonary metastasis in mice challenged with CMT-167 tumor cells. These models provide a valuable tool in analyzing the mechanism of interaction of immune cells with tumors that lead to either tumor regression or resistance to immunotherapies.

Coccydynia - could age, trauma and body mass index be independent prognostic factors for outcomes of intervention?

Introduction The aetiology of coccydynia can be multifactorial, with several associated factors such as obesity, female gender and low mood. The long-term results of operative interventions, such as manipulation under anaesthesia and coccygectomy are variable, ranging from 63-90%. Materials and methods Our aim was to identify whether age, trauma and body mass index (BMI) were independent prognostic factors in coccydynia treatment. All patients who presented to the Royal Derby Hospital with a primary diagnosis of coccydynia between January 2011 and January 2015 who had injections, manipulation under anaesthesia or coccygectomy were included. We used patient-reported satisfaction score as the primary outcome measure. We hypothesised that patients with preceding history of trauma and with high BMI (> 25) would be less satisfied. We divided patient BMI into four groups, following World Health Organization guidelines: group A (18.5-24.9), group B (25-29.9), group C (30-39.9) and group D (> 40). Results A total of 748 patients were diagnosed with coccydynia. Of these, 201 patients had 381 injections, 40 had 98 manipulations under anaesthesia and 9 had coccygectomy. Mean age was 46.4 years; 26% of patients had trauma to the coccyx. The mean time to follow-up was 7.3 months. We found a statistically significant difference (P = 0.03) between satisfaction scores in groups B and D. Patients who had trauma improved significantly (P = 0.04). The odds ratio calculation of coccygectomy and BMI revealed a higher risk of coccygectomy in Group A. Discussion This is the first study to establish BMI and trauma as independent prognostic factors for coccydynia treatment. Our hypothesis that patients with higher BMI would have lower satisfaction levels has been proven true.

Impact of the quantity of intradiscal cement leak on the progression of intervertebral disc degeneration

Introduction We aim to assess the impact of the quantity of intradiscal cement leak during kyphoplasty on the rate of progression of degenerative changes in the affected disc. Methods Of 316 kyphoplasty procedures, we identified 32 episodes of intradiscal cement leak in 26 patients. The quantity of cement leaked was graded from I to IV. Disc degenerative changes were assessed at presentation and follow-up using radiographical scoring and magnetic resonance imaging (MRI) grading systems. Data for low-grade leaks (grade I) were compared with the medium- and high-grade leaks (grades II-IV) using a chi-squared test. Results Median follow-up radiographic and MRI assessments were made at 18 and 21 months, respectively. Medium- and high-grade leaks were associated with a significantly higher radiographic disc degeneration scores compared with low-grade leaks (P = 0.04295) but no difference was found in MRI disc degeneration grades and in adjacent vertebral fracture rates. Conclusions Our findings indicate that the quantity of cement leaking into the disc space significantly influences the rate of progression of disc degeneration.

Membrane-based immunotherapy with immune checkpoint blockade antibodies confers protection against metastatic breast cancer

Objective

The 4T1 triple negative breast cancer (TNBC) model resembles many of the hallmarks of advanced TNBC in humans. In this study we investigate if combining a membrane-based immunotherapy with immune checkpoint blockade antibodies in a metastatic tumor model could effectively generate protective immunity. This personalized strategy is applicable to indications such as TNBC that exhibit a high degree of heterogeneity and do not respond to approved cancer therapies.

Methods

4T1 tumor tissue was harvested from BALB/c mice and processed to generate tumor membrane vesicles (TMVs). TMVs were then incorporated with GPI-B7-1 and GPI-IL-12 by protein transfer and used for immunization in conjunction with immune checkpoint inhibitors. Survival was assessed using a Kaplan-Meier survival curve and significance determined using a Log-rank test for comparison analysis. Metastasis was assessed by clonogenic assay. Immune response was assessed by IFN-γ ELISPOT. Cell depletion studies were performed with anti-CD4 and anti-CD8 antibodies. Significance was determined using a student’s t test to compare metastasis and immune responses.

Results

TMV-based immunotherapy in combination with anti-CTLA-4 antibody significantly improved survival, reduced pulmonary metastasis, and increased tumor-specific CD8 T cell responses. Interestingly, either treatment alone failed to have a significant impact on survival, metastasis, or immune response.

Conclusions

These results strongly suggest that a TMV-based immunotherapy in combination with anti-CTLA-4 antibody generates effective antitumor immunity. Such a combinatorial approach could potentially translate into an effective treatment for patients with metastatic TNBC.

HER-2+ breast cancer cells expressing GPI-anchored cytokines induce long lasting antitumor memory response

Breast cancer is the leading cause of death among female cancer patients. Human epidermal growth factor receptor 2 (HER-2) overexpression is associated with poor prognosis in 15–20% of breast cancer patients. Anti-HER-2 antibody (Herceptin) prolongs the survival of the HER-2+ breast cancer patients. However, resistance to Herceptin is a cause for relapse of aggressive metastatic cancer in these patients. Our earlier studies have demonstrated that PD-L1 blockade enhances the efficacy of HER-2+ breast cancer whole cell vaccine by increasing infiltration of T cells into the tumor. The goal of the present study is to determine the duration of protective anti-tumor memory response to HER-2+ breast cancer. Here, we demonstrate the beneficial effect of GPI-anchored cytokine molecules as adjuvants for generating long lasting memory response against HER-2+ as well as HER-2 negative breast cancer in syngeneic tumor models. Female BALB/c mice were challenged with D2F2/E2 (HER-2 transfected D2F2) cells or D2F2/E2 transfected with GPI-IL-12 or GPI-GM-CSF. While the wild-type challenged mice developed tumors, the mice challenged with transfected D2F2/E2 cells were protected. Protected mice were re-challenged with D2F2/E2 cells 3 months later and D2F2 cells 4 months later. All the mice challenged with D2F2 or D2F2/E2 were protected. We have observed strong antibody response against HER-2 and D2F2 cells in these mice. Our results show that long lasting protective anti-tumor memory response against D2F2 and D2F2/E2 is generated by vaccination with D2F2/E2 cells expressing GPI-anchored immunostimulatory molecules.

Imaging colon cancer development in mice: IL-6 deficiency prevents adenoma in azoxymethane-treated Smad3 knockouts

The development of colorectal cancer in the azoxymethane-induced mouse model can be observed by using a miniaturized optical coherence tomography (OCT) imaging system. This system is uniquely capable of tracking disease development over time, allowing for the monitoring of morphological changes in the distal colon due to tumor development and the presence of lymphoid aggregates. By using genetically engineered mouse models deficient in Interleukin 6 (IL-6) and Smad family member 3 (Smad3), the role of inflammation on tumor development and the immune system can be elucidated. Smad3 knockout mice develop inflammatory response, wasting, and colitis associated cancer while deficiency of proinflammatory cytokine IL-6 confers resistance to tumorigenesis. We present pilot data showing that the Smad3 knockout group had the highest tumor burden, highest spleen weight, and lowest thymus weight. The IL-6 deficiency in Smad3 knockout mice prevented tumor development, splenomegaly, and thymic atrophy. This finding suggests that agents that inhibit IL-6 (e.g. anti-IL-6 antibody, non-steroidal anti-inflammatory drugs [NSAIDs], etc.) could be used as novel therapeutic agents to prevent disease progression and increase the efficacy of anti-cancer agents. OCT can also be useful for initiating early therapy and assessing the benefit of combination therapy targeting inflammation.

Time-serial Assessment of Drug Combination Interventions in a Mouse Model of Colorectal Carcinogenesis Using Optical Coherence Tomography

Optical coherence tomography (OCT) is a high-resolution, nondestructive imaging modality that enables time-serial assessment of adenoma development in the mouse model of colorectal cancer. In this study, OCT was utilized to evaluate the effectiveness of interventions with the experimental antitumor agent α-difluoromethylornithine (DFMO) and a nonsteroidal anti-inflammatory drug sulindac during early [chemoprevention (CP)] and late stages [chemotherapy (CT)] of colon tumorigenesis. Biological endpoints for drug interventions included OCT-generated tumor number and tumor burden. Immunochistochemistry was used to evaluate biochemical endpoints [Ki-67, cleaved caspase-3, cyclooxygenase (COX)-2, β-catenin]. K-Ras codon 12 mutations were studied with polymerase chain reaction-based technique. We demonstrated that OCT imaging significantly correlated with histological analysis of both tumor number and tumor burden for all experimental groups (P < 0.0001), but allows more accurate and full characterization of tumor number and burden growth rate because of its time-serial, nondestructive nature. DFMO alone or in combination with sulindac suppressed both the tumor number and tumor burden growth rate in the CP setting because of DFMO-mediated decrease in cell proliferation (Ki-67, P < 0.001) and K-RAS mutations frequency (P = 0.04). In the CT setting, sulindac alone and DFMO/sulindac combination were effective in reducing tumor number, but not tumor burden growth rate. A decrease in COX-2 staining in DFMO/sulindac CT groups (COX-2, P < 0.01) confirmed the treatment effect. Use of nondestructive OCT enabled repeated, quantitative evaluation of tumor number and burden, allowing changes in these parameters to be measured during CP and as a result of CT. In conclusion, OCT is a robust minimally invasive method for monitoring colorectal cancer disease and effectiveness of therapies in mouse models.

Otolaryngological complications of occipitocervical injury

Occipitocervical injuries are rare, accounting for 15% of all fatal spinal trauma. In patients who survive the initial incident, early detection and appropriate management is vital to avoid significant neurological disability and mortality. We present the case of a patient with neck trauma who was initially cleared of spinal injuries in the emergency department but who later developed acute hearing loss. We describe how the investigation of the hearing loss led to the detection of this devastating injury and report its successful management. Patients with persistent neck pain following trauma, particularly in the presence of degenerative spinal disease, should have cervical spine computed tomography to exclude occipitocervical injuries and other occult injuries.

Tertiary syphilis in the cervical spine: a case report and review of the literature

As the prevalence of syphilis rises, an increase in tertiary syphilis with spinal involvement is predicted. We report what we believe to be the first case of compressive cervical spine syphilitic gummata, with central cord compression signs. We also review the relevant literature to date. The diagnosis of syphilis in the spine relies on the physician to be aware of it as part of the differential diagnosis. Treponemal laboratory tests are an important aid in establishing a diagnosis.

Cervical spondylotic myelopathy: the outcome and potential complications of surgical treatment

PURPOSE OF THE STUDY

Cervical spondylotic myelopathy is the most common cause of spinal cord dysfunction in patients over 60 years old. Symptoms often develop gradually and insidiously and are characterized by neck stiffness, arm pain, numbness and clumsiness of hands, as well as weakness of the hands and legs frequently leading to a change in mobility. Surgery is performed primarily to prevent the progression of symptoms but also with the aim of improving existing symptoms. Aim of our study was to assess the outcomes and potential complications of surgical decompression of cervical spondylotic myelopathy (CSM).

MATERIAL AND METHODS

Prospective data was collected from 71 patients who were treated surgically for CSM over a four-year period (June 2006 to June 2010). Only patients with confirmed spondylotic cervical myelopathy were included in the study; those with an inflammatory, infectious or neoplastic etiology were excluded. The Nurick scale was used as a primary outcome measure, and the improvement in upper limb function as a secondary outcome measure. Statistical significance was assessed using the paired t-test.

RESULTS

34/71 (47.9%) patients had an anterior decompression, 36/71 (50.7%) patients underwent posterior surgery and one patient (1.4%) received a combined approach: The Nurick score: The mean score improved by 0.9 from 2.4 preoperatively to 1.5 postoperatively for the whole series. Three patients were able to return to work. The preoperative Nurick score showed a positive correlation with the postoperative Nurick score at one year (Pearson Coefficient = 0.85). Upper limb symptoms: Postoperatively, 24 patients were free of any upper limb involvement compared with 6 patients preoperatively. The main improvement was in patients who prior to surgery had subjective symptoms with no objective signs of weakness or muscle wasting. 35/48 (72.9%) of this group showed improvement compared to 7/17 (41.2%) of patients who demonstrated objective weakness and/or wasting preoperatively.

COMPLICATIONS

The overall rate of complications was 18.2%. There were two mortalities as a result of pneumonia (2.8%), one patient had to be transferred to the intensive care unit for cardiac failure (1.4%), fixation failure occurred in two patients (2.8%), worsening of myelopathy occurred in two patients (2.8%), C5 temporary radiculopathy presented in two patients (2.8%), superficial wound infection developed in one patient (1.4%) and three patients (4.2%) complained of severe axial pain in the postoperative period. DISCUSSION Our results demonstrate that the greater the preoperative disability the greater the final disability is expected to be. Cord signal change, as an indicator of the pathological severity of the disease, correlates with a worse functional outcome. The degree of improvement postoperatively (i.e. the functional change) does not show a significant correlation with the initial preoperative status. It appears however, that there is a better chance of improvement in patients with no objectively detectable weakness or muscle wasting. The rate of complications encountered in this series is comparable with those in the literature, which renders them valid for quoting when considering surgical treatment for CSM.

CONCLUSION

Surgical decompression offers a real chance of improvement in the functional outcome of CSM, especially during the earlier stages of the disease. The surgical decision needs to be considered carefully due to the advanced age of the patient population and the greater burden of co-morbidities, which increase the surgical risks significantly.

Accuracy of prognostic scores in decision making and predicting outcomes in metastatic spine disease

INTRODUCTION

Management of metastatic spinal disease has changed significantly over the last few years. Different prognostic scores are used in clinical practice for predicting survival. The aim of this study was to assess the accuracy of prognostic scores and the role of delayed presentation in predicting the outcome in patients with metastatic spine disease.

METHODS

Retrospectively, four years of data were collected (2007-2010). Medical records review included type of tumour, duration of symptoms, expected survival and functional status. The Karnofsky performance score was used for functional assessment. Modified Tokuhashi and Tomita scores were used for survival prediction.

RESULTS

A total of 55 patients who underwent surgical stabilisation were reviewed. The mean age was 63 years (range: 32-87 years). The main primary sources of tumours included myeloma, breast cancer, lymphoma, lung cancer, renal cell cancer and prostate cancer. Of the cases studied, 29 patients had posterior instrumented stabilisation alone, 10 patients had an anterior procedure alone and 16 patients (with an expected survival of more than one year) had both anterior and posterior procedures performed. Twenty-three patients presented with spinal cord compression. The mean follow-up duration was 9 months (range: 1-39 months). Patients who were treated within one week of referral survived longer than anticipated. Patients were divided into three groups based on their expected survival. Actual survival was better in all three groups after surgery. Discrepancies in scores were prominent in patients with myeloma, breast and prostate cancers. Functional outcome was better in patients under 65 years of age.

CONCLUSIONS

The prognostic scoring systems are not uniformly effective in all types of primary tumours. However, they are useful in decision making for surgical intervention, taking other factors into account, in particular the age of the patient, the type and stage of the primary tumour and general health.

Characterization of a novel mouse model for human B-cell lymphomas (127.31)

The risk of developing lymphoma is markedly increased after solid organ transplantation. Up to 20% of people who receive a solid organ transplant develop a lymphoma. Calcineurin (CN) A beta knockout (Cnab-/-) mice do not reject allogeneic tumors suggesting an immunosuppressive state, is also a unique model for reverse immunosurveillance. Currently, there is no mouse model for low grade lymphomas based on immune dysregulation. Since we observed a spontaneous activation of T cells, and B-cell lymphomas in CNAβ deficient mice, we hypothesize that CN is involved in T-cell regulation, the lack of regulation causes smoldering inflammation which in turn activates B cells and results in lymphomagenesis. The lymphomas in Cnab-/- mice are positive for B cell surface marker (CD21) but negative for T cell (TCRβ) markers and they are clonal in origin and exhibit malignant (destroying the normal architecture of adjoining area) phenotype. In addition, we do see spontaneous activation of T cells in Cnab-/- mice early in life and continue to accumulate, and B cells later when they are old with mild inflammatory lesions in the gut and liver in Helicobacter-free (clean) colony. Since inflammation is considered to be one of the hallmarks of cancer and also the root cause of cancer, this is a novel mouse model for understanding a slow growing, difficult to cure form of lymphomas.

Accuracy of prognostic scores in decision making and predicting outcomes in metastatic spine disease

INTRODUCTION

Management of metastatic spinal disease has changed significantly over the last few years. Different prognostic scores are used in clinical practice for predicting survival. The aim of this study was to assess the accuracy of prognostic scores and the role of delayed presentation in predicting the outcome in patients with metastatic spine disease.

METHODS

Retrospectively, four years of data were collected (2007-2010). Medical records review included type of tumour, duration of symptoms, expected survival and functional status. The Karnofsky performance score was used for functional assessment. Modified Tokuhashi and Tomita scores were used for survival prediction.

RESULTS

A total of 55 patients who underwent surgical stabilisation were reviewed. The mean age was 63 years (range: 32-87 years). The main primary sources of tumours included myeloma, breast cancer, lymphoma, lung cancer, renal cell cancer and prostate cancer. Of the cases studied, 29 patients had posterior instrumented stabilisation alone, 10 patients had an anterior procedure alone and 16 patients (with an expected survival of more than one year) had both anterior and posterior procedures performed. Twenty-three patients presented with spinal cord compression. The mean follow-up duration was 9 months (range: 1-39 months). Patients who were treated within one week of referral survived longer than anticipated. Patients were divided into three groups based on their expected survival. Actual survival was better in all three groups after surgery. Discrepancies in scores were prominent in patients with myeloma, breast and prostate cancers. Functional outcome was better in patients under 65 years of age.

CONCLUSIONS

The prognostic scoring systems are not uniformly effective in all types of primary tumours. However, they are useful in decision making for surgical intervention, taking other factors into account, in particular the age of the patient, the type and stage of the primary tumour and general health.

Spondylodiscitis in children: a retrospective series

We retrospectively reviewed the records of 16 children treated for spondylodiscitis at our hospital between 2000 and 2007. The mean follow-up was 24 months (12 to 38). There was a mean delay in diagnosis in hospital of 25 days in the ten children aged less than 24 months. At presentation only five of the 16 children presented with localising signs and symptoms. Common presenting symptoms were a refusal to walk or sit in nine children, unexplained fever in six, irritability in five, and limping in four. Plain radiography showed changes in only seven children. The ESR was the most useful investigation when following the clinical course of the disease. Positive blood cultures were obtained in seven children with Staphylococcus aureus being isolated in five. Antibiotics were used in 14 children and spinal bracing in six. Children with spondylodiscitis often present with a confusing clinical picture leading to late diagnosis. The early use of MRI in the investigation of children with an atypical picture may avoid unnecessary delay in starting treatment and possibly prevent long-term problems. All except one of our children had made a complete clinical recovery at final follow-up. However, all six children in the > 24-month age group showed radiological evidence of degenerative changes which might cause problems in the future.

SMAD3 deficiency causes immune dysregulation, colitis and colon tumorigenesis (66.13)

Introduction: TGFβ plays important role in T cell development, differentiation, tolerance and autoimmune diseases. However, recent studies have shown an important role for TGF-β1 and β3 in pathogenic helper T-cell (Th17) differentiation in the presence of IL-1β, IL-6 and IL-23. SMAD3 is mediates TGFβ signaling in many cell types including lymphocytes. Smad3 /- mice develop inflammation-induced colon cancer upon Helicobacter hepaticus infection suggesting that TGFβ1 signaling through SMAD3 is essential to prevent inflammation and progression to colon cancer. In this study we investigated the role of SMAD3 in inflammation using mice deficient in Smad3. Methods: Splenocytes are cultured in the presence of anti-CD3/CD28 beads, TGFβ1 and IL-2 for 3 days. Cytokines are determined by ELISA, CBA and MSD methods. Cells are stained with antibodies for CD4, CD25, CD62L and intracellular FOXP3 and Helios. Results: Smad3-/- mice exhibit inflammatory response upon infection with commensal bacterium H. hepaticus. We find that while SMAD3 signaling is important for inducible Treg cell generation and for their maintenance, deficiency of SMAD3 increases IL-6 and IL-17 levels suggesting a regulatory role for SMAD3 in Th17 cell differentiation. Conclusions: While SMAD3 signaling is important for iTreg cell generation and maintenance, it is not required for Th17 cell differentiation. In addition, we find that SMAD3 signaling negatively regulates Th17 differentiation through induction of FOXP3.

Divergent effects of calcineurin Aβ on regulatory and conventional T-cell homeostasis

Calcineurin (CN) is a phosphatase that activates nuclear factor of activated T cells (NFAT). While the CN inhibitors cyclosporine A (CsA) and tacrolimus (FK506) can prevent graft rejection, they also cause inflammatory diseases. We investigated the role of calcineurin using mice deficient in the CN catalytic subunit Aβ (CNAβ). Cnab(-/-) mice exhibit defective thymocyte maturation, splenomegaly and hepatomegaly. Further, as Cnab(-/-) mice age, they exhibit spontaneous T-cell activation and enhanced production of proinflammatory cytokines (IL-4, IL-6, and IFNγ). FOXP3(+) T(reg) cells were significantly decreased in Cnab(-/-) mice likely contributing to increased T-cell activation. Interestingly, we found that CNAβ is critical for promotion of BCL-2 expression in FOXP3(+) T(reg) and for permitting TGFβ signaling, as TGFβ induces FOXP3 in control but not in Cnab(-/-) T-cells. Together, these data suggest that CNAβ is important for the production and maintenance of T(reg) cells and to ensure mature T-cell quiescence.

Impact of kyphoplasty treatment for vertebral compression fractures on pain and function in 105 patients

PURPOSE OF THE STUDY

Vertebral compression fractures are very common. Symptomatic relief with conservative therapy is often difficult to achieve. Balloon kyphoplasty is a relatively new technique which stabilises the vertebral body and restores spinal alignment in recent fractures, it achieves significant pain relief and improved functional outcome is reported. The aim of this prospective study was to determine the level of pain relief and functional outcome in patients who were initially treated conservatively for 4-6 weeks and if symptoms did not have tendency to resolve, then had kyphoplasty surgery.

MATERIAL AND METHODS

105 patients underwent balloon kyphoplasty between April 2006 and August 2010 and had 1 year follow up. Total 170 levels were augmented, 65% (n=68) of patients were female and the average age was 74 years. Pain relief was assessed using visual analogue score (VAS) and functional outcome using Oswestry Disability Index (ODI).

RESULTS

Results showed decrease of the average pre-operative VAS from 8.2 to 4.4 in the immediate postoperative period (p=0.000). This dramatic improvement remained and was 4.1 at 6 weeks, 3.3 at 6 months and 3.6 at 1 year. The average pre-operative ODI was 58. This improved to 47 in the immediate post-operative period (p=0.002). At 6 weeks this had improved further to 40 and further improvements were seen at 6 months (ODI 37) and 1 year (ODI 38). The average screening time was 2 minutes and 20 seconds. The average volume of cement used per level was 5.5 cm3. Radiographic measurements were performed by independent radiologist. The average pre-operative vertebral angle was 11.6° and 10.9° postoperatively. This was maintained throughout the follow up. This represented a negligible 6% improvement in vertebral body angle. We did not experience any clinically significant complications, we have encountered 11 minor complications which did not require any additional measures (cement leaks, penetration of the vertebral body margins by balloons or K wires and rib fractures).

DISCUSSION

Pain relief and improvement of functional outcome was sustained after one year. Limited number of patients who had 2 year follow up showed trend of minimal deterioration of both parameters (VAS and ODI). This can be explained by incidence of few adjacent segment fractures and progressive overall osteoarthritic changes in this aging population. Radiological evaluation showed maintenance of achieved alignment which did not deteriorate over time. Complication rate was low and did not require any further surgical interventions and did not have any effect on final good clinical outcome.

CONCLUSION

Balloon kyphoplasty proved to be safe surgical technique and should be considered in patients with ongoing pain following an acute vertebral compression fracture that does not improve with initial conservative treatment. It significantly improves pain and functional status in elderly patients.

Calcineurin Aβ signalling is required for Treg-cell generation and prevention of T-cell activation and B-cell lymphomagenesis (100.13)

Introduction: Calcineurin (CN), a protein phosphatase activated by Ca2+-calmodulin, is involved in activation of NFAT. CN inhibitors such as cyclosporine A (CsA) and FK506 are potent inhibitors of T-cell responses and are commonly used to prevent graft rejection. Consistently, CNAβ-deficient mice exhibit defective thymocyte maturation in young mice. However, T cells undergo spontaneous activation in older Cnab-/- mice, and succumb to B-cell lymphomas. Methods: Splenocytes are cultured in the presence of anti-CD3/CD28 beads, TGFβ1 and IL-2 for 3 days. Cytokines in culture supernatants are determined by ELISA, CBA and MSD methods. Cells are stained with CD4, CD25, CD62L and intracellular FOXP3. Results: We observed that FOXP3+ Treg cells are decreased while mature activated T cells (CD62L-CD44+) are increased in KO mice compared to control mice. While TGFβ1 induced the expression of FOXP3 in WT cultures, it failed to induce FOXP3 in KO cultures. Cytokine profiles revealed that CNAβ is required to inhibit IL-4, IL-6, IL-10, IL-17 and IFNγ by TGFβ1. IHC analyses of lymphomas revealed that the lymphomas are of B cell origin and they do not express FOXP1, a marker for activated B cells (ABCs). Discussion: These data show that CNAβ is important for the development and homeostasis of mature T cells and Treg cells. The data also suggest that in the absence of CNAβ, a defective T-cell regulation results in activation of T cells, production of inflammatory cytokines and cause cancer.

Generation of mice with a conditional allele for transforming growth factor beta 1 gene

Transforming growth factor beta1 (TGFbeta1) is a multifunctional growth factor involved in wound healing, tissue fibrosis, and in the pathogenesis of many syndromic diseases (e.g., Marfan syndrome, Camurati-Engelmann disease) and muscular, neurological, ophthalmic, cardiovascular and immunological disorders, and cancer. Since the generation of Tgfb1 knockout mice, there has been extraordinary progress in understanding its physiological and pathophysiological function. Here, we report the generation of a conditional knockout allele for Tgfb1 in which its exon 6 is flanked with LoxP sites. As proof of principle, we crossed these mice to LckCre transgenic mice and specifically disrupted Tgfb1 in T cells. The results indicate that T-cell-produced TGFbeta1 is required for normal in vivo regulation of peripheral T-cell activation, maintenance of T-cell homeostasis, and suppression of autoimmunity.

Calcineurin deficiency decreases inflammatory lesions in transforming growth factor beta1-deficient mice

Transforming growth factor (TGF) beta1) is an immunoregulatory cytokine involved in self-tolerance and lymphocyte homeostasis. Tgfb1 knock-out (KO) mice develop severe multi-focal autoimmune inflammatory lesions due to [Ca(2+)]i deregulation in T cells, and die within 3 weeks after birth. Because the calcineurin inhibitor FK506 inhibits the hyperresponsiveness of Tgfb1(-/-) thymocytes, and because calcineurin Abeta (CNAbeta)-deficient mice do not reject allogenic tumours, we have generated Tgfb1(-/-) Cnab(-/-) mice to address whether CNAbeta deficiency prevents T cell activation and inflammation in Tgfb1(-/-) mice. Here we show that in Tgfb1(-/-) Cnab(-/-) mice inflammation is reduced significantly relative to that in Tgfb1(-/-) mice. However, both CD4(+) and CD8(+) T cells in double knock-out (DKO) mice are activated, as revealed by up-regulation of CD11a lymphocyte function-associated antigen-1 (LFA-1), CD44 and CD69 and down-regulation of CD62L. These data suggest that deficiency of CNAbeta decreases inflammatory lesions but does not prevent activation of autoreactive T cells. Also Tgfb1(-/-) T cells can undergo activation in the absence of CNAbeta, probably by using the other isoform of calcineurin (CNAalpha) in a compensatory manner. CNAbeta-deficient T cells undergo spontaneous activation in vivo and are activated upon anti-T cell receptor stimulation in vitro. Understanding the role of calcineurin in T cell regulation should open up new therapeutic opportunities for inflammation and cancer.

Calcineurin Ab deficiency causes defective Treg-cell generation and enhanced effector T-cell differentiation (89.13)

Calcineurin (CN), a protein phosphatase activated by Ca2+-calmodulin, is involved in activation of NFAT by its dephosphorylation. CN inhibitors such as cyclosporine A (CsA) and FK506 are potent inhibitors of T-cell responses and are commonly used to prevent graft rejection. Consistently, CNAβ-deficient mice exhibit defective thymocyte maturation in young mice. However, T cells undergo spontaneous activation in older Cnab-/- mice, which develop splenomegaly, thymomegaly, hepatomegaly and succumb to metastatic B-cell lymphomas. We have also observed that FOXP3+ Treg cells are decreased while mature activated CD4+ and CD8+ T cells (CD62L-CD44+) are increased in Cnab-/- mice compared to age-matched control mice. These data show that CNAβ is important for the development and homeostasis of mature T cells and Treg cells. Cytokine profile analysis revealed that CNAβ signaling is required to inhibit proinflammatory cytokines (IL-4, IL-10, IL-17 and IFNγ) by TGFβ1 and TGFβ1 induced FOXP3 expression in T cells, suggesting that CNAβ signaling is required for Treg-cell generation. The data suggest that in the absence of CNAβ, a defective T-cell regulatory environment leads to accumulation of activated T cells which produce proinflammatory cytokines and cause inflammation and cancer.

Grant support: This study was supported by NIH AI067903 and CA84291 to TD, and IRG7400128 to RB.

Dual roles of immunoregulatory cytokine TGF-beta in the pathogenesis of autoimmunity-mediated organ damage

Ample evidence suggests a role of TGF-beta in preventing autoimmunity. Multiorgan inflammatory disease, spontaneous activation of self-reactive T cells, and autoantibody production are hallmarks of autoimmune diseases, such as lupus. These features are reminiscent of the immunopathology manifest in TGF-beta1-deficient mice. In this study, we show that lupus-prone (New Zealand Black and White)F(1) mice have reduced expression of TGF-beta1 in lymphoid tissues, and TGF-beta1 or TGF-beta1-producing T cells suppress autoantibody production. In contrast, the expression of TGF-beta1 protein and mRNA and TGF-beta signaling proteins (TGF-beta receptor type II and phosphorylated SMAD3) increases in the target organs, i.e., kidneys, of these mice as they age and develop progressive organ damage. In fact, the levels of TGF-beta1 in kidney tissue and urine correlate with the extent of chronic lesions that represent local tissue fibrosis. In vivo TGF-beta blockade by treatment of these mice with an anti-TGF-beta Ab selectively inhibits chronic fibrotic lesions without affecting autoantibody production and the inflammatory component of tissue injury. Thus, TGF-beta plays a dual, seemingly paradoxical, role in the development of organ damage in multiorgan autoimmune diseases. According to our working model, reduced TGF-beta in immune cells predisposes to immune dysregulation and autoantibody production, which causes tissue inflammation that triggers the production of anti-inflammatory cytokines such as TGF-beta in target organs to counter inflammation. Enhanced TGF-beta in target organs, in turn, can lead to dysregulated tissue repair, progressive fibrogenesis, and eventual end-organ damage.

TGFbeta1 deficiency does not affect the generation and maintenance of CD4+CD25+FOXP3+ putative Treg cells, but causes their numerical inadequacy and loss of regulatory function

TGFbeta1 is considered to be required for peripheral maintenance of CD4(+)CD25(+)FOXP3(+) T(reg) cells. However, we demonstrate no reduction in the percentage of such T cells in the spleens and thymi of Tgfb1(-/-) mice. Although putative T(reg) cells, characterized as CD4(+)CD25(+)FOXP3(+)CD62L(+) T cells, are increased in Tgfb1(-/-) mice, they may be inadequate to control activated T cells since the ratio of activated T cells:putative T(reg) cells is several-fold higher in Tgfb1(-/-) mice than in control mice. We further show that whereas Tgfb1(-/-) mice that express a chicken OVA-specific TCR transgene (DO11.10) have an increase in putative T(reg) cells, there are no detectable CD4(+)CD25(+) T cells in the spleens of DO11.10 Rag1(-/-) mice suggesting that T(reg)-cell generation is self-antigen dependent regardless of whether they express Tgfb1. Finally, we demonstrate that Tgfb1(-/-) T cells remain responsive to the suppressive effect of TGFbeta1 in vitro. These data suggest that TGFbeta1 is required for the regulatory function of T(reg) cells to prevent activation of T cells and autoimmunity.

TGFbeta1 and Treg cells: alliance for tolerance

Transforming growth factor beta1 (TGFbeta1), an important pleiotropic, immunoregulatory cytokine, uses distinct signaling mechanisms in lymphocytes to affect T-cell homeostasis, regulatory T (Treg)-cell and effector-cell function and tumorigenesis. Defects in TGFbeta1 expression or its signaling in T cells correlate with the onset of several autoimmune diseases. TGFbeta1 prevents abnormal T-cell activation through the modulation of Ca2+-calcineurin signaling in a Caenorhabditis elegans Sma and Drosophila Mad proteins (SMAD)3 and SMAD4-independent manner; however, in Treg cells, its effects are mediated, at least in part, through SMAD signaling. TGFbeta1 also acts as a pro-inflammatory cytokine and induces interleukin (IL)-17-producing pathogenic T-helper cells (Th IL-17 cells) synergistically during an inflammatory response in which IL-6 is produced. Here, we will review TGFbeta1 and its signaling in T cells with an emphasis on the regulatory arm of immune tolerance.

[Surgical treatment of spinal infections]

PURPOSE OF THE STUDY

Although great advances have been made in both radiological diagnosis and antibiotic therapy of microbial infections, the treatment of spinal infections remains a major clinical challenge. Many of the patients affected are referred to spinal units with long delays. The general population is ageing and the number of immunocompromised patients, as well as the number of operative procedures for spinal disorders are increasing. The aim of our study was to evaluate the clinical presentations of spinal infections, options for their diagnosis, indications for treatment and their risk factors and the results of surgery.

MATERIAL AND METHODS

The group of 112 patients evaluated after the treatment of spinal infection comprised 63 men and 49 women at an average age of 59.4 years (range, 17 to 84). The average follow-up was 3.2 years (range, 6 months to 8 years). Of these, 82 patients had primary hematogenous infection, 29 had post-operative infection,and one had an infected gun shot wound. Thirty-six patients showed neurological deficit and six were paraplegic. The diagnostic methods included FBC, CRP and EST tests, examination of blood cultures, aspirates and biopsy samples from the infected site, bone scintigraphy, MRI and CT scanning. Indications for surgery included an infection not responding to conservative treatment,with existing or impending spinal instability, and with or without neurological deficit. The surgical management involved transpedicular drainage of the abscess, wound debridement from the posterior approach and instrumented spondylodesis. Surgery which included spinal decompression with radical excision of infected tissue was augmented with posterolateral instrumented fusion and/or anterior stabilization, as indicated.

RESULTS

Of the 112 patients treated, seven died of uncontrollable sepsis after surgery; the remaining 105 were followed up. Another four patients died of causes unrelated to the spinal problem treated within 12 months. All patients recovered except for two in whom the infection persisted, but 13 required more than one surgical procedure. One patient with CSF leakage failed to heal after five interventions. The most frequently isolated infectious agents were Staphylococus aureus, Staphylococus epidermidis and E. coli. Of the 33 patients with neurological deficit, 24 improved by one or two Frankel grades. The neurological status of six paraplegic patients did not improve, but their functional findings did after stabilization of the spine. Clinical evaluation showed 47 (44.7 %) very good, 40 (38 %) good, eight (7.6 %) unchanged and 10 (9.5 %) poor outcomes.

CONCLUSION

Early diagnosis is a prerequisite for good treatment outcomes. Clinical examination, results of laboratory tests, and scintigraphy and MRI findings play the key role. When progressing osteolysis is suspected, a CT scan is necessary. Debridement should be as radical as possible, but always in compliance with the patient's health state. At an advanced stage of disease, spinal stabilization is important because it allows us to remove infected tissue. Intravenous and then oral antibiotic therapy at 2 to 4 and 6 to 12 weeks of follow-up is mandatory. The management of spinal infections is a complex process requiring good multidisciplinary cooperation.