Regulatory T cells use heparanase to access IL-2 bound to extracellular matrix in inflamed tissue

Although FOXP3+ regulatory T cells (Treg) depend on IL-2 produced by other cells for their survival and function, the levels of IL-2 in inflamed tissue are low, making it unclear how Treg access this critical resource. Here, we show that Treg use heparanase (HPSE) to access IL-2 sequestered by heparan sulfate (HS) within the extracellular matrix (ECM) of inflamed central nervous system tissue. HPSE expression distinguishes human and murine Treg from conventional T cells and is regulated by the availability of IL-2. HPSE-/- Treg have impaired stability and function in vivo, including in the experimental autoimmune encephalomyelitis (EAE) mouse model of multiple sclerosis. Conversely, endowing monoclonal antibody-directed chimeric antigen receptor (mAbCAR) Treg with HPSE enhances their ability to access HS-sequestered IL-2 and their ability to suppress neuroinflammation in vivo. Together, these data identify a role for HPSE and the ECM in immune tolerance, providing new avenues for improving Treg-based therapy of autoimmunity.

A Novel Allogeneic Rituximab-Conjugated Gamma Delta T Cell Therapy for the Treatment of Relapsed/Refractory B-Cell Lymphoma

Chimeric antigen receptor T cell (CAR-T) therapy has been applied in the treatment of B-cell lymphoma; however, CAR-T manufacturing requires virus- or non-virus-based genetic modification, which causes high manufacturing costs and potential safety concerns. Antibody-cell conjugation (ACC) technology, which originated from bio-orthogonal click chemistry, provides an efficient approach for arming immune cells with cancer-targeting antibodies without genetic modification. Here, we applied ACC technology in Vγ9Vδ2 T (γδ2 T) cells to generate a novel off-the-shelf CD20-targeting cell therapy ACE1831 (rituximab-conjugated γδ2 T cells) against relapsed/refractory B-cell lymphoma. ACE1831 exhibited superior cytotoxicity against B-cell lymphoma cells and rituximab-resistant cells compared to γδ2 T cells without rituximab conjugation. The in vivo xenograft study demonstrated that ACE1831 treatment strongly suppressed the aggressive proliferation of B-cell lymphoma and prolonged the survival of tumor-bearing mice with no observed toxicity. Mass spectrometry analysis indicated that cell activation receptors including the TCR complex, integrins and cytokine receptors were conjugated with rituximab. Intriguingly, the antigen recognition of the ACC-linked antibody/receptor complex stimulated NFAT activation and contributed to ACE1831-mediated cytotoxicity against CD20-expressing cancer cells. This study elucidates the role of the ACC-linked antibody/receptor complex in cytotoxicity and supports the potential of ACE1831 as an off-the-shelf γδ2 cell therapy against relapsed/refractory B-cell lymphoma.

FOXP3+ regulatory T cells use heparanase to access IL-2 bound to ECM in inflamed tissues

FOXP3+ regulatory T cells (Treg) depend on exogenous IL-2 for their survival and function, but circulating levels of IL-2 are low, making it unclear how Treg access this critical resource in vivo. Here, we show that Treg use heparanase (HPSE) to access IL-2 sequestered by heparan sulfate (HS) within the extracellular matrix (ECM) of inflamed central nervous system tissue. HPSE expression distinguishes human and murine Treg from conventional T cells and is regulated by the availability of IL-2. HPSE-/- Treg have impaired stability and function in vivo, including the experimental autoimmune encephalomyelitis (EAE) mouse model of multiple sclerosis. Conversely, endowing Treg with HPSE enhances their ability to access HS-sequestered IL-2 and their tolerogenic function in vivo. Together, these data identify novel roles for HPSE and the ECM in immune tolerance, providing new avenues for improving Treg-based therapy of autoimmunity.

Immunoregulatory effects of RGMb in gut inflammation

Graft-versus-host disease (GvHD) is a major complication after allogeneic hematopoietic cell transplantation (HCT). Current strategies to prevent GvHD with immunosuppressive drugs carry significant morbidity and may affect the graft-versus-tumor (GVT) effect. Inflammatory bowel disease (IBD) is an intestinal inflammatory condition that affects more than 2 million people in the United States. Current strategies to prevent colitis with immunosuppressive drugs carry significant morbidity. Recently, Repulsive Guidance Molecule b (RGMb) has been identified as part of a signaling hub with neogenin and BMP receptors in mice and humans. In addition, RGMb binds BMP-2/4 in mice and humans as well as PD-L2 in mice. RGMb is expressed in the gut epithelium and by antigen presenting cells, and we found significantly increased expression in mouse small intestine after total body irradiation HCT conditioning. We hypothesized that RGMb may play a role in GvHD and IBD pathogenesis by contributing to mucosal inflammation. Using major-mismatched HCT mouse models, treatment with an anti-RGMb monoclonal antibody (mAb) that blocks the interaction with BMP-2/4 and neogenin prevented GvHD and improved survival compared to isotype control (75% versus 30% survival at 60 days after transplantation). The GVT effect was retained in tumor models. Using an inflammatory bowel disease dextran sulfate sodium model, treatment with anti-RGMb blocking monoclonal antibody but not isotype control prevented colitis and improved survival compared to control (73% versus 33% at 21 days after treatment) restoring gut homeostasis. Anti-RGMb mAb (9D1) treatment decreased IFN-γ and significantly increased IL-5 and IL-10 in the gut of the treated mice compared to the isotype control treated mice.

[Antibody levels of measles, rubella and mumps viruses in healthy population in Shanghai from 2010 to 2020]

Objective: To determine IgG antibody levels of measles, rubella, mumps in healthy population in Shanghai from 2010 to 2020 and analyze the trend of antibody changes in different age groups. Methods: 10 828 healthy people without measles, rubella and mumps in Shanghai were included in the study from 2010 to 2020. Serum samples were collected from 12 age groups, and the serum IgG antibody of measles, rubella and mumps were detected by ELISA. The difference of antibody positive rates and antibody levels were analyzed. Results: The median age M (Q₁, Q₃) of 10 828 objects were 8 years old (9 months old, 20 years old). Males accounted for 48.34% (5 234/10 828) and females accounted for 50.92% (5 514/10 828). Unknown gender information accounted for 0.74% (80/10 828), and 27.03% (2 927/10 828) of participants had unknown MMR immunization history. The total positive rates of measles, rubella and mumps IgG antibody were 76.78%, 64.46% and 64.29% and their GMCs were 541.45 mIU/ml, 31.76 IU/ml and 133.73 U/ml respectively. There were significant differences in serum IgG antibody GMC of measles, rubella and mumps in each year (F_measles=180.74, P<0.001; F_rubella=189.95, P<0.001; F_mumps=122.40, P<0.001). The positive rate of measles antibody was higher than that of rubella and mumps, and the difference was statistically significant (χ²=518.09, P<0.001). Conclusion: The level of measles IgG antibody in healthy people in Shanghai is higher, while the level of rubella and mumps IgG antibody is slightly lower.

Abstract 5573: ACE1831: A novel allogeneic αCD20-conjugated Vδ2 gamma delta T product for non-Hodgkin’s lymphoma

Introduction Autologous CAR-T has improved clinical outcomes in hematological malignancies; however need remains to improve the toxicities, relapse rates, treatment delays and costs. ACE1831 is a novel, off-the-shelf Antibody Conjugated Effector cell therapy with aCD20 linked to gd T cells by selective proprietary DNA aptamers to activation receptors without genetic modification. Data for in vitro/in vivo pre-clinical studies are presented.

Methods γδ T cells were expanded from healthy donor PBMCs by cytokine stimulation and αβ T cell depletion. Both γδ T cells and αCD20 were covalently linked to selected DNA aptamers that enable conjugation, and cryopreserved. ACE1831 was evaluated for phenotype and antibody conjugation by flow cytometry, cytotoxicity and cytokine production by 4-hour co-culture with CD20+ Raji cells, and for in vivo anti-tumor activity and weight loss using SCID-Beige mice inoculated IV with 1 x 105 Raji cells, 4 doses of 1 x 107 ACE1831 on days 0, 3, 7, 10, and monitored for 123 days. All studies used cryopreserved ACE1831.

Results gd T cells of ACE1831 were expanded &gt;10,000 fold with &gt;95% viability, &gt;85% Vδ2 purity, and &lt;0.03% αβ T cell impurity. γδ T cells expressed high levels of CD56, CD16, NKG2D and CD69 and low levels of PD-1 and KIRs. Following αCD20 conjugation and cryopreservation, ACE1831 drug product batches retained &gt;90% viability and cytotoxicity against CD20+ Raji cells. In the presence of cell growth media, about 30% and 10% of αCD20 were retained on the cell surface at 24 and 48 hours, respectively, and at 24 and 48 hours, ACE1831 elicited 100% and 85% specific lysis against Raji cells. At 72 hours, specific lysis was 35%; however, in combination with obinutuzumab (1,000 ng/mL), ACE1831 provided 95% specific lysis against Raji cells. Co-cultured with Raji cells, ACE1831 produced 10 times more IFNγ and TNFα than unconjugated γδ T cells, but no measurable IL-6. When co-cultured with allogeneic PBMCs, ACE1831 showed no cytotoxicity towards PBMCs and the mixture showed no increase in IFNγ, TNFα, GM-CSF, IL-2, IL-4, IL-8, IL-6, and IL-10 levels compared to the PBMCs only group. ACE1831 showed persistence in vivo for &gt;14 days after a single dose of 1 x 107 AC1831 in non-tumor inoculated SCID-Beige mice. Tumor inoculated mice treated with 4 doses of ACE1831 survived 123 days without weight loss or tumor relapse based on bioluminescence and necropsy, while mice treated with γδ T survived &lt;40 days due to tumor progression.

Conclusion ACE1831, a aCD20-armed allogeneic γδ T cell product, represents a novel approach for off-the-shelf treatment for B cell malignancies. Specifically, this product candidate can offer high levels of anti-tumor activity that is extended with soluble antibody using native Fc receptor expression, and may have a low risk of GvHD and IL-6 related toxicity. These data support future clinical studies in this setting.

Citation Format: Tai-Sheng Wu, Hao-Kang Li, Ching-Wen Hsiao, Yi-Hung Ou, Zih-Fei Cheng, Hsiu-Ping Yang, Sen-Han Yang, Chia-Yun Lee, Yan-Liang Lin, Thorsten Graef, Sai-Wen Tang, Sonny Hsiao. ACE1831: A novel allogeneic αCD20-conjugated Vδ2 gamma delta T product for non-Hodgkin’s lymphoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 5573.

A novel endogenous CD16-Expressing Natural Killer Cell for cancer immunotherapy

Natural killer (NK) cells, as a potential source for off-the-shelf cell therapy, attack tumor cells with low risk of severe cytokine release syndrome (CRS) or graft-versus-host disease (GvHD). Fcγ receptor IIIA, also known as CD16, further confers NK cells with antibody-dependent cell-mediated cytotoxicity (ADCC), one mechanism of action of antibody-based immunotherapy. Here, we establish a novel human NK cell line, oNK-1, endogenously expressing CD16 along with high levels of NK activation markers and low levels of NK inhibitory markers. The long-term expansion and CD16 expression of oNK-1 cells were demonstrated. Furthermore, oNK-1 cells elicit superior cytotoxicity against cancer cells than primary NK cells. In conclusion, this study suggests that endogenous CD16-expressing oNK-1 has the potential to develop an effective NK-based therapy.

[Current status and enlightenment of teaching models in evidence-based medicine at home and abroad: a qualitative systematic review]

Objective: To summarize the different teaching models and their effects in evidence-based medicine at home and abroad by qualitative method and systematic review. Methods: We searched the following databases (from inception to 13 May, 2019): PubMed, Embase, Proquest, Cochrane, Web of Science database and the Chinese databases (CNKI, Wanfang, SinoMed and VIP). To assess data strength and validity, risk of bias assessments were undertaken. Results: A total of 52 literatures were included in this study, including 21 Chinese-language literature and 31 English-language literature. PBL teaching model, mixed teaching model and workshop teaching model were the three teaching models with the largest number of studies in 20 teaching models. Conclusion: The evidence-based medicine teaching effect was closely related to the teaching models, so it is necessary to explore more suitable teaching models for the evidence-based medicine to improve the teaching effects.

Identification of Schlafen-11 as a Target of CD47 Signaling That Regulates Sensitivity to Ionizing Radiation and Topoisomerase Inhibitors

Knockdown or gene disruption of the ubiquitously expressed cell surface receptor CD47 protects non-malignant cells from genotoxic stress caused by ionizing radiation or cytotoxic chemotherapy but sensitizes tumors in an immune competent host to genotoxic stress. The selective radioprotection of non-malignant cells is mediated in part by enhanced autophagy and protection of anabolic metabolism pathways, but differential H2AX activation kinetics suggested that the DNA damage response is also CD47-dependent. A high throughput screen of drug sensitivities indicated that CD47 expression selectively sensitizes Jurkat T cells to inhibitors of topoisomerases, which are known targets of Schlafen-11 (SLFN11). CD47 mRNA expression positively correlated with schlafen-11 mRNA expression in a subset of human cancers but not the corresponding non-malignant tissues. CD47 mRNA expression was also negatively correlated with SLFN11 promoter methylation in some cancers. CD47 knockdown, gene disruption, or treatment with a CD47 function-blocking antibody decreased SLFN11 expression in Jurkat cells. The CD47 signaling ligand thrombospondin-1 also suppressed schlafen-11 expression in wild type but not CD47-deficient T cells. Re-expressing SLFN11 restored radiosensitivity to a CD47-deficient Jurkat cells. Disruption of CD47 in PC3 prostate cancer cells similarly decreased schlafen-11 expression and was associated with a CD47-dependent decrease in acetylation and increased methylation of histone H3 in the SLFN11 promoter region. The ability of histone deacetylase or topoisomerase inhibitors to induce SLFN11 expression in PC3 cells was lost when CD47 was targeted in these cells. Disrupting CD47 in PC3 cells increased resistance to etoposide but, in contrast to Jurkat cells, not to ionizing radiation. These data identify CD47 as a context-dependent regulator of SLFN11 expression and suggest an approach to improve radiotherapy and chemotherapy responses by combining with CD47-targeted therapeutics.

Spiky electric and magnetic field structures in flux rope experiments

Magnetic flux ropes are structures that are common in the corona of the sun and presumably all stars. They can be thought of as the building blocks of solar structures. They have been observed in Earth's magnetotail and near Mars and Venus. When multiple flux ropes are present magnetic field line reconnection, which converts magnetic energy to other forms, can occur when they collide. The structure of multiple magnetic ropes, the interactions between multiple ropes, and their topological properties such as helicity and writhing have been studied theoretically and in laboratory experiments. Here, we report on spiky potential and magnetic fields associated with the ropes. We show that the potential structures are chaotic for a range of their temporal half-widths and the probability density function (PDF) of their widths resembles the statistical distribution of crumpled paper. The spatial structure of the magnetic spikes is revealed using a correlation counting method. Computer simulation suggests that the potential structures are the nonlinear end result of an instability involving relative drift between ions and electrons.

Ferrite based antennae for launching Alfvén waves

Whistler and Alfvén waves are known to scatter mirror-trapped electrons and protons into the loss cone of the earth's dipole magnetic field. An array of satellites with properly phased antennas can be used to artificially reduce the flux of energetic particles from regions where their flux has been naturally or artificially pumped. In any space based system, the power required to drive antennas is at a premium. We present here experimental evidence that the efficiency of an antenna can be greatly enhanced with the use of ferrite cores with high relative magnetic permeability μ. Ferrite-based antennas were constructed to launch Alfvén waves in a magnetized plasma. The wave magnetic field of shear Alfvén waves launched with a ferrite core was by the magnetization factor μ larger than that of a similar antenna without a ferrite. Combining multiple ferrite antennas allowed control of the injected perpendicular wavelength. This novel technique can be used to efficiently launch low frequency waves with amplitude above the threshold required for nonlinear triggering.

Transplantation of donor grafts with defined ratio of conventional and regulatory T cells in HLA-matched recipients

BACKGROUNDIn preclinical murine and early clinical studies of hematopoietic cell transplantation, engineering of donor grafts with defined ratios of CD4+CD25+FoxP3+ Tregs to conventional T cells (Tcons) results in the prevention of graft-versus-host disease and improved immune reconstitution. The use of highly purified primary graft Tregs for direct cell infusion has potential advantages over impure immunomagnetic selection or culture expansion, but has not been tested clinically. We performed a phase I study of the timed addition of CD34-selected hematopoietic stem cells and Tregs, followed by Tcons for the treatment of patients with high-risk hematological malignancies.METHODSWe present interim evaluation of a single-center open phase I/II study of administration of human leukocyte-matched Tregs and CD34-selected hematopoietic cells, followed by infusion of an equal ratio of Tcons in adult patients undergoing myeloablative hematopoietic stem cell transplantation (HCT) for high-risk or active hematological malignancies. Tregs were purified by immunomagnetic selection and high-speed cell sorting.RESULTSHere we report results for the first 12 patients who received Tregs of between 91% and 96% purity. Greater than grade II GVHD was noted in 2 patients in the first cohort of 5 patients, who received cryopreserved Tregs, but neither acute nor chronic GVHD was noted in the second cohort of 7 patients, who received fresh Tregs and single-agent GVHD prophylaxis. Patients in the second cohort appeared to have normal immune reconstitution compared with patients who underwent transplantation and did not develop GVHD.CONCLUSIONOur study shows that the use of highly purified fresh Tregs is clinically feasible and supports continued investigation of the strategy.TRIAL REGISTRATIONClinicalTrials.gov NCT01660607.FUNDINGNIH NHBLI R01 HL114591 and K08HL119590.

[Risk of bias assessment: (7) Assessing Bias in Studies of Prognostic Factors]

This paper introduces the tools related to Quality In Prognosis Studies (QUIPS) to assess the risk of bias in studies of prognostic factors and the relevant points of assessment and to illustrate the application of QUIPS in published prognostic research. The QUIPS tool identified 6 important areas to consider when evaluating validity and bias in studies of prognostic factors including participation, attrition, measurement on prognostic factors, outcomes, confounding factors, statistical analysis and reporting. It also provided a new method for evaluation on bias in the areas of prognostic research.

SLFN11 Blocks Stressed Replication Forks Independently of ATR

SLFN11 sensitizes cancer cells to a broad range of DNA-targeted therapies. Here we show that, in response to replication stress induced by camptothecin, SLFN11 tightly binds chromatin at stressed replication foci via RPA1 together with the replication helicase subunit MCM3. Unlike ATR, SLFN11 neither interferes with the loading of CDC45 and PCNA nor inhibits the initiation of DNA replication but selectively blocks fork progression while inducing chromatin opening across replication initiation sites. The ATPase domain of SLFN11 is required for chromatin opening, replication block, and cell death but not for the tight binding of SLFN11 to chromatin. Replication stress by the CHK1 inhibitor Prexasertib also recruits SLFN11 to nascent replicating DNA together with CDC45 and PCNA. We conclude that SLFN11 is recruited to stressed replication forks carrying extended RPA filaments where it blocks replication by changing chromatin structure across replication sites.

Abstract LB-244: Overcoming resistance to DNA targeted agents by epigenetic activation of Schlafen 11 (SLFN11) expression with class I histone deacetylase inhibitors

Purpose: Schlafen 11 (SLFN11), a putative DNA/RNA helicase is a dominant genomic determinant of response to DNA damaging agents and is frequently not expressed in cancer cells. Whether histone deacetylase (HDAC) inhibitors can be used to release SLFN11 and sensitize SLFN11-inactivated cancers to DNA-targeted agents is tested here. Experimental Design: SLFN11 expression was examined in The Cancer Genome Atlas (TCGA), in cancer cell line databases and in patients treated with romidepsin. Isogenic cells overexpressing or genetically inactivated for SLFN11 were used to investigate the effect of HDAC inhibitors on SLFN11 expression and sensitivity to DNA damaging agents. Results: SLFN11 expression is suppressed in a broad fraction of common cancers and cancer cell lines. In cancer cells not expressing SLFN11, transfection of SLFN11 sensitized the cells to camptothecin, topotecan, hydroxyurea and cisplatin but not to paclitaxel. SLFN11 mRNA and protein levels were strongly induced by class I (romidepsin, entinostat), but not class II (roclinostat) HDAC inhibitors in a broad panel of cancer cells. SLFN11 expression was also enhanced in peripheral blood mononuclear cells of patients with circulating cutaneous T-cell lymphoma treated with romidepsin. Consistent with the epigenetic regulation of SLFN11, camptothecin and class I HDAC inhibitors were synergistic in many of the cell lines tested. Conclusion: This study reports the prevalent epigenetic regulation of SLFN11 and the dominant stimulatory effect of HDAC inhibitors on SLFN11 expression. Our results provide a rationale for combining class I HDAC inhibitors and DNA damaging agents to overcome epigenetic inactivation of SLFN11-mediated resistance to DNA-targeted agents.

Citation Format: Azam Ghafoor, Sai-Wen Tang, Anish Thomas, Junko Murai, Jane B. Trepel, Susan E. Bates, Vinodh N. Rajapakse, Yves Pommier. Overcoming resistance to DNA targeted agents by epigenetic activation of Schlafen 11 (SLFN11) expression with class I histone deacetylase inhibitors [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr LB-244.

Resistance to PARP inhibitors by SLFN11 inactivation can be overcome by ATR inhibition

Poly(ADP-ribose) polymerase inhibitors (PARPIs) kill cancer cells by trapping PARP1 and PARP2. Talazoparib, the most potent PARPI inhibitor (PARPI), exhibits remarkable selectivity among the NCI-60 cancer cell lines beyond BRCA inactivation. Our genomic analyses reveal high correlation between response to talazoparib and Schlafen 11 (SLFN11) expression. Causality was established in four isogenic SLFN11-positive and -negative cell lines and extended to olaparib. Response to the talazoparib-temozolomide combination was also driven by SLFN11 and validated in 36 small cell lung cancer cell lines, and in xenograft models. Resistance in SLFN11-deficient cells was caused neither by impaired drug penetration nor by activation of homologous recombination. Rather, SLFN11 induced irreversible and lethal replication inhibition, which was independent of ATR-mediated S-phase checkpoint. The resistance to PARPIs by SLFN11 inactivation was overcome by ATR inhibition, mechanistically because SLFN11-deficient cells solely rely on ATR activation for their survival under PARPI treatment. Our study reveals that SLFN11 inactivation, which is common (~45%) in cancer cells, is a novel and dominant resistance determinant to PARPIs.

Overcoming Resistance to DNA-Targeted Agents by Epigenetic Activation of Schlafen 11 (SLFN11) Expression with Class I Histone Deacetylase Inhibitors

Purpose: Schlafen 11 (SLFN11), a putative DNA/RNA helicase is a dominant genomic determinant of response to DNA-damaging agents and is frequently not expressed in cancer cells. Whether histone deacetylase (HDAC) inhibitors can be used to release SLFN11 and sensitize SLFN11-inactivated cancers to DNA-targeted agents is tested here.Experimental Design:SLFN11 expression was examined in The Cancer Genome Atlas (TCGA), in cancer cell line databases and in patients treated with romidepsin. Isogenic cells overexpressing or genetically inactivated for SLFN11 were used to investigate the effect of HDAC inhibitors on SLFN11 expression and sensitivity to DNA-damaging agents.Results:SLFN11 expression is suppressed in a broad fraction of common cancers and cancer cell lines. In cancer cells not expressing SLFN11, transfection of SLFN11 sensitized the cells to camptothecin, topotecan, hydroxyurea, and cisplatin but not to paclitaxel. SLFN11 mRNA and protein levels were strongly induced by class I (romidepsin, entinostat), but not class II (roclinostat) HDAC inhibitors in a broad panel of cancer cells. SLFN11 expression was also enhanced in peripheral blood mononuclear cells of patients with circulating cutaneous T-cell lymphoma treated with romidepsin. Consistent with the epigenetic regulation of SLFN11, camptothecin and class I HDAC inhibitors were synergistic in many of the cell lines tested.Conclusions: This study reports the prevalent epigenetic regulation of SLFN11 and the dominant stimulatory effect of HDAC inhibitors on SLFN11 expression. Our results provide a rationale for combining class I HDAC inhibitors and DNA-damaging agents to overcome epigenetic inactivation of SLFN11-mediated resistance to DNA-targeted agents. Clin Cancer Res; 24(8); 1944-53. ©2018 AACR.

T cells expressing chimeric antigen receptor promote immune tolerance

Cellular therapies based on permanent genetic modification of conventional T cells have emerged as a promising strategy for cancer. However, it remains unknown if modification of T cell subsets, such as Tregs, could be useful in other settings, such as allograft transplantation. Here, we use a modular system based on a chimeric antigen receptor (CAR) that binds covalently modified mAbs to control Treg activation in vivo. Transient expression of this mAb-directed CAR (mAbCAR) in Tregs permitted Treg targeting to specific tissue sites and mitigated allograft responses, such as graft-versus-host disease. mAbCAR Tregs targeted to MHC class I proteins on allografts prolonged islet allograft survival and also prolonged the survival of secondary skin grafts specifically matched to the original islet allograft. Thus, transient genetic modification to produce mAbCAR T cells led to durable immune modulation, suggesting therapeutic targeting strategies for controlling alloreactivity in settings such as organ or tissue transplantation.

Aqueous extract of Polygonum bistorta modulates proteostasis by ROS-induced ER stress in human hepatoma cells

Hepatocellular carcinoma (HCC) remains the leading cause of cancer mortality with limited therapeutic targets. The endoplasmic reticulum (ER) plays a pivotal role in maintaining proteostasis in normal cells. However, alterations in proteostasis are often found in cancer cells, making it a potential target for therapy. Polygonum bistorta is used in traditional Chinese medicine owing to its anticancer activities, but the molecular and pharmacological mechanisms remain unclear. Using hepatoma cells as a model system, this study demonstrated that P. bistorta aqueous extract (PB) stimulated ER stress by increasing autophagosomes but by blocking degradation, followed by the accumulation of ubiquitinated proteins and cell apoptosis. In addition, an autophagy inhibitor did not enhance ubiquitinated protein accumulation whereas a reactive oxygen species (ROS) scavenger diminished both ubiquitinated protein accumulation and ligand-stimulated epidermal growth factor receptor (EGFR) expression, suggesting that ROS generation by PB may be upstream of PB-triggered cell death. Nevertheless, PB-exerted proteostasis impairment resulted in cytoskeletal changes, impairment of cell adhesion and motility, and inhibition of cell cycle progression. Oral administration of PB delayed tumour growth in a xenograft model without significant body weight loss. These findings indicate that PB may be a potential new alternative or complementary medicine for HCC.

[Study on polymorphisms of genes with susceptibility to drug induced liver injury in a cohort receiving anti-tuberculosis treatment]

OBJECTIVE

To investigate the association between the polymorphisms of genes involving in drug metabolism and transport as well as immunological reaction and the risk of anti-tuberculosis drug-induced liver injury(ATLI)in Chinese.

METHODS

This 1∶4 matched case-control study was conducted by using the data from a cohort study of Anti-tuberculosis Drugs Induced Adverse Reactions in National Tuberculosis Prevention and Control Progtam of China. Genes involving in three phase of drug metabolism and transport as well as related immunological reaction were chosen and single nucleotide polymorphisms(SNPs)were genotyped by TaqMan allele discrimination technology. Lasso regression and multivariate conditional logistic regression analysis were used to select susceptible genes.

RESULTS

A total of 33 genes with 75 SNPs were tested. The combined results of Lasso and regression logistic regression analysis showed that genetic polymorphism of SLCO1B1 rs4149014, HSPA1L rs2227956, STAT3 rs1053023 and IL-6 rs2066992 were significantly associated with the risk of ATLI(P<0.05).

CONCLUSION

SLCO1B1, HSPA1L, STAT3 and IL-6 might be the susceptibility genes of drug induced liver injury in patients receiving anti-tuberculosis treatment.

Abstract 3054: CD47 signaling regulates a DNA damage response pathway by suppressing the expression of Schlafen-11 (SLFN11)

Schlafen-11 (SLFN11) expression was recently shown to determine the sensitivity of human cancer cells to DNA damaging agents including topoisomerase inhibitors, DNA alkylating agents, and DNA synthesis inhibitors. High expression of SLFN11 in cancer cell lines results in increased sensitivity to these agents, whereas depletion of SLFN11 induces cellular protection. In addition, high expression of SHFN11 is associated with greater overall survival than low SLFN11 expression in ovarian patients treated with cisplatin. These observations suggest that SLFN11 may be an integral part of a critical DNA repair pathway. However, the pathways that regulate SLFN11 expression have not been reported. CD47 is an integrin-associated protein widely expressed on mammalian cells and frequently elevated in cancers. Its ligand, thrombospondin-1 (TSP1) induces CD47 signaling that regulates some growth factor receptors, cell fate, viability, and responses to cellular stresses such as radiation and chemotherapy. Our laboratory has previously shown that CD47 deficiency results in protection of nontransformed cells, whereas high CD47 expression sensitizes the same cells to ionizing radiation and DNA-damaging chemotherapy. We identified SLFN11 expression as a potential target of CD47 signaling by microarray analysis of a CD47-deficient mutant cell line and found that CD47 expression also correlates with that of SLFN11 in some human cancers. Thus, we sought to investigate the possible regulation of SLFN11 by CD47 by treating various cell lines with the function-modifying CD47 antibody B6H12 or its physiological ligands TSP1 and signal regulatory protein-α (SIRPα). qRT-PCR analysis revealed significant decreases in SLFN11 expression at 3 and 6 hours post-B6H12 treatment. Furthermore, treatment with TSP1 significantly decreased SHFN11 mRNA expression at the same time points, but SIRPα-Fc did not. Conversely, transient re-expression of CD47 in deficient cells elevated SLFN11 expression. These data demonstrate that pharmacological and physiological modulation of CD47 signaling acutely alters SLFN11 expression and suggests a potential mechanism by which CD47 modulates cellular sensitivity to DNA damaging chemotherapy agents. SLFN11 may in turn be a functional target and useful biomarker for the therapeutic CD47 antibodies currently in clinical trials.

Citation Format: Anthony L. Schwartz, Sukhbir Kaur, Sai-Wen Tang, Yves Pommier, David D. Roberts. CD47 signaling regulates a DNA damage response pathway by suppressing the expression of Schlafen-11 (SLFN11). [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 3054.

Abstract NS7: The Effects of a Theory-based Health Empowerment Intervention on Self-management and Functional Recovery Post-stroke

Introduction: Self-management post-stroke is challenging due to its sudden and complex sequela. Identification of an effective intervention to foster self-management post-stroke is needed. We developed a 13-week Stroke Patient Empowerment Intervention (SPEI), guided by Shearer’s Theory of Health Empowerment, to foster patients’ inner resources and social-contextual resources to enhance self-management.

Objective: To examine the effects of the SPEI (six 20-min small group sessions and 2 phone follow-ups) on self-efficacy (SE), self-management behaviour and functional recovery, compared to usual ambulatory rehabilitation care (UC).

Methods: In this randomized controlled trial, Hong Kong Chinese participants (mean age=69 years, 48% women, 72% ischemic stroke, 89% hemiparesis and 63% tactile sensory deficit) received 13-weeks of SPEI+UC (n=105) or UC only (n=105). Generalized estimating equations were used assess changes in SE (stroke-specific and illness management), self-management behaviours (cognitive symptom management, communication with physician, medication adherence, and BP self-monitoring) and functional recovery (Barthel and Lawton Indices) over time (baseline=T0, 1-week=T1, 3-months=T2 and 6-months=T3 post-intervention) between groups, using intention-to-treat.

Results: Those in the SPEI+UC group had significantly better illness management SE, self-management behaviours (cognitive symptom management, communication with physician, and BP self-monitoring), and functional recovery (Barthel and Lawton Indices), compared to UC. Changes in stroke-specific SE and medication adherence were not significantly different over time between groups (see Table 1). Attrition was low (16.7%).

Conclusions: This nurse-led SPEI was easily implemented and can readily be conducted in tandem with existing ambulatory stroke rehabilitation services, to foster self-management post-stroke and improve functional recovery.

SLFN11 Is a Transcriptional Target of EWS-FLI1 and a Determinant of Drug Response in Ewing Sarcoma

PURPOSE

SLFN11 was identified as a critical determinant of response to DNA-targeted therapies by analyzing gene expression and drug sensitivity of NCI-60 and CCLE datasets. However, how SLFN11 is regulated in cancer cells remained unknown. Ewing sarcoma, which is characterized by the chimeric transcription factor EWS-FLI1, has notably high SLFN11 expression, leading us to investigate whether EWS-FLI1 drives SLFN11 expression and the role of SLFN11 in the drug response of Ewing sarcoma cells.

EXPERIMENTAL DESIGN

Binding sites of EWS-FLI1 on the SLFN11 promoter were analyzed by chromatin immunoprecipitation sequencing and promoter-luciferase reporter analyses. The relationship between SLFN11 and EWS-FLI1 were further examined in EWS-FLI1-knockdown or -overexpressing cells and in clinical tumor samples.

RESULTS

EWS-FLI1 binds near the transcription start site of SLFN11 promoter and acts as a positive regulator of SLFN11 expression in Ewing sarcoma cells. EWS-FLI1-mediated SLFN11 expression is responsible for high sensitivity of Ewing sarcoma to camptothecin and combinations of PARP inhibitors with temozolomide. Importantly, Ewing sarcoma patients with higher SLFN11 expression showed better tumor-free survival rate. The correlated expression between SLFN11 and FLI1 extends to leukemia, pediatric, colon, breast, and prostate cancers. In addition, expression of other ETS members correlates with SLFN11 in NCI-60 and CCLE datasets, and molecular experiments demonstrate that ETS1 acts as a positive regulator for SLFN11 expression in breast cancer cells.

CONCLUSIONS

Our results imply the emerging relevance of SLFN11 as an ETS transcription factor response gene and for therapeutic response to topoisomerase I inhibitors and temozolomide-PARP inhibitor combinations in ETS-activated cancers.

Alterations of DNA repair genes in the NCI-60 cell lines and their predictive value for anticancer drug activity

Loss of function of DNA repair (DNAR) genes is associated with genomic instability and cancer predisposition; it also makes cancer cells reliant on a reduced set of DNAR pathways to resist DNA-targeted therapy, which remains the core of the anticancer armamentarium. Because the landscape of DNAR defects across numerous types of cancers and its relation with drug activity have not been systematically examined, we took advantage of the unique drug and genomic databases of the US National Cancer Institute cancer cell lines (the NCI-60) to characterize 260 DNAR genes with respect to deleterious mutations and expression down-regulation; 169 genes exhibited a total of 549 function-affecting alterations, with 39 of them scoring as putative knockouts across 31 cell lines. Those mutations were compared to tumor samples from 12 studies of The Cancer Genome Atlas (TCGA) and The Cancer Cell Line Encyclopedia (CCLE). Based on this compendium of alterations, we determined which DNAR genomic alterations predicted drug response for 20,195 compounds present in the NCI-60 drug database. Among 242 DNA damaging agents, 202 showed associations with at least one DNAR genomic signature. In addition to SLFN11, the Fanconi anemia-scaffolding gene SLX4 (FANCP/BTBD12) stood out among the genes most significantly related with DNA synthesis and topoisomerase inhibitors. Depletion and complementation experiments validated the causal relationship between SLX4 defects and sensitivity to raltitrexed and cytarabine in addition to camptothecin. Therefore, we propose new rational uses for existing anticancer drugs based on a comprehensive analysis of DNAR genomic parameters.

Wip1 and p53 contribute to HTLV-1 Tax-induced tumorigenesis

Background

Human T-cell Leukemia Virus type 1 (HTLV-1) infects 20 million individuals world-wide and causes Adult T-cell Leukemia/Lymphoma (ATLL), a highly aggressive T-cell cancer. ATLL is refractory to treatment with conventional chemotherapy and fewer than 10% of afflicted individuals survive more than 5 years after diagnosis. HTLV-1 encodes a viral oncoprotein, Tax, that functions in transforming virus-infected T-cells into leukemic cells. All ATLL cases are believed to have reduced p53 activity although only a minority of ATLLs have genetic mutations in their p53 gene. It has been suggested that p53 function is inactivated by the Tax protein.

Results

Using genetically altered mice, we report here that Tax expression does not achieve a functional equivalence of p53 inactivation as that seen with genetic mutation of p53 (i.e. a p53^−/− genotype). Thus, we find statistically significant differences in tumorigenesis between Tax⁺p53^+/+versus Tax⁺p53^−/− mice. We also find a role contributed by the cellular Wip1 phosphatase protein in tumor formation in Tax transgenic mice. Notably, Tax⁺Wip1^−/− mice show statistically significant reduced prevalence of tumorigenesis compared to Tax⁺Wip1^+/+ counterparts.

Conclusions

Our findings provide new insights into contributions by p53 and Wip1 in the in vivo oncogenesis of Tax-induced tumors in mice.

Impact of cellular autophagy on viruses: Insights from hepatitis B virus and human retroviruses

Autophagy is a protein degradative process important for normal cellular metabolism. It is apparently used also by cells to eliminate invading pathogens. Interestingly, many pathogens have learned to subvert the cell’s autophagic process. Here, we review the interactions between viruses and cells in regards to cellular autophagy. Using findings from hepatitis B virus and human retroviruses, HIV-1 and HTLV-1, we discuss mechanisms used by viruses to usurp cellular autophagy in ways that benefit viral replication.

Direct mass measurements of short-lived A=2Z-1 nuclides (63)Ge, (65)As, (67)Se, and (71)Kr and their impact on nucleosynthesis in the rp process

Mass excesses of short-lived A=2Z-1 nuclei (63)Ge, (65)As, (67)Se, and (71)Kr have been directly measured to be -46,921(37), -46,937(85), -46,580(67), and -46,320(141)  keV, respectively. The deduced proton separation energy of -90(85)  keV for (65)As shows that this nucleus is only slightly proton unbound. X-ray burst model calculations with the new mass excess of (65)As suggest that the majority of the reaction flow passes through (64)Ge via proton capture, indicating that (64)Ge is not a significant rp-process waiting point.

Nicotinamide N-methyltransferase induces cellular invasion through activating matrix metalloproteinase-2 expression in clear cell renal cell carcinoma cells

Nicotinamide N-methyltransferase (NNMT) was recently identified as one clear cell renal cell carcinoma (ccRCC)-associated gene by analyzing full-length complementary DNA-enriched libraries of ccRCC tissues. The aim of this study is to investigate the potential role of NNMT in cellular invasion. A strong NNMT expression is accompanied with a high invasive activity in ccRCC cell lines, and small interfering RNA-mediated NNMT knockdown effectively suppressed the invasive capacity of ccRCC cells, whereas NNMT overexpression markedly enhanced that of human embryonic kidney 293 (HEK293) cells. A positive correlation between the expression of NNMT and matrix metallopeptidase (MMP)-2 was found in ccRCC cell lines and clinical tissues. The treatment of blocking antibody or inhibitor specific to MMP-2 significantly suppressed NNMT-dependent cellular invasion in HEK293 cells. Furthermore, SP-1-binding region of MMP-2 promoter was found to be essential in NNMT-induced MMP-2 expression. The specific inhibitors of PI3K/Akt signaling markedly decreased the binding of SP1 to MMP-2 promoter as shown by chromatin immunoprecipitation assay. We also demonstrated that PI3K/Akt pathway plays a role in NNMT-dependent cellular invasion and MMP-2 activation. Moreover, short hairpin RNA-mediated knockdown of NNMT expression efficiently inhibited the growth and metastasis of ccRCC cells in non-obese diabetic severe combined immunodeficiency mice. Taken together, the present study suggests that NNMT has a crucial role in cellular invasion via activating PI3K/Akt/SP1/MMP-2 pathway in ccRCC.

Is surgery always indicated in older women with breast cancer?

Although surgery has long been considered the main form of curative treatment for breast cancer, its use in older women may not always be indicated. Whilst surgery has been shown to provide superior local control for breast cancer, there is conflicting evidence on whether surgery offers a significant improvement on overall survival in these patients. The more indolent tumour biology commonly seen in older women with breast cancer, coupled with competing causes of death may alter the goals of treatment. The differing needs of older patients should be thoroughly assessed to consider their comorbidities, functional status and quality of life. A comprehensive geriatric assessment and quality of life assessment could identify pretreatment risk factors and guide clinical decision making, improving morbidity and prognosis. Alternatives to surgery include primary endocrine therapy and primary radiotherapy. Further research is required to identify different patient or tumour factors which can be used to individualize treatment for breast cancer in older women and to develop holistic assessment tools which take into account their individual quality of life, geriatric syndromes and functional needs. A dedicated multidisciplinary-led clinic may provide a suitable platform for the assessment, review and management of this distinctive set of patients.

Depression literacy among Chinese stroke survivors

OBJECTIVES

Mental health literacy is fundamental to the pursuit of health. Little is known about patients' literacy levels regarding depression even though it is common among elderly stroke survivors. This paper will report the level of mental health literacy and thematic constructs of depression interpreted by a group of stroke survivors.

METHOD

Qualitative data on patients' understanding of 'depression' in Chinese were translated and analyzed by an academic and a researcher separately to identify emerging constructs using a thematic approach. Out of 214 ischemic stroke older adults, aged 50+, 85 were able to explain the term in their own words after their first stroke attack.

RESULTS

The majority of stroke patients (60%, 129 out of 214) had never heard of depression and only four referred to it as a medical disease. Only a third would like to learn more about depression. Older Chinese adults depicted depression mainly by using words in the cognitive and affective domains, but the descriptors used were mostly non-specific and might not match the diagnostic criteria for depression or the commonly used screening tools.

CONCLUSION

Low mental health literacy among older patients indicated that much more work needs to be done in health promotion and education on depression literacy.

Up-regulation of vascular endothelial growth factor-D expression in clear cell renal cell carcinoma by CD74: a critical role in cancer cell tumorigenesis

Elevation of CD74 is associated with a number of human cancers, including clear cell renal cell carcinoma (ccRCC). To understand the role of CD74 in the oncogenic process of ccRCC, we ectopically expressed CD74 in human embryonic kidney 293 cells (HEK/CD74) and evaluated its oncogenic potential. Through overexpression of CD74 in HEK293 and Caki-2 cells and down-regulation of CD74 in Caki-1 cells, we show that vascular endothelial growth factor-D (VEGF-D) expression is modified accordingly. A significant, positive correlation between CD74 and VEGF-D is found in human ccRCC tissues (Pearson's correlation, r = 0.65, p < 0.001). In HEK/CD74 xenograft mice, CD74 significantly induced the formation of tumor masses, increased tumor-induced angiogenesis, and promoted cancer cell metastasis. Blockage of VEGF-D expression by small interference RNA resulted in a decrease in cell proliferation, invasion, and cancer cell-induced HUVEC migration enhanced by CD74. Furthermore, we provide evidence that the intracellular signaling cascade responsible for VEGF-D up-regulation by CD74 is both PI3K/AKT- and MEK/ERK-dependent, both of which are associated with NF-kappaB nuclear translocation and DNA-binding activity. These results suggest that VEGF-D is crucial for CD74-induced human renal carcinoma cancer cell tumorigenesis.

MYC pathway is activated in clear cell renal cell carcinoma and essential for proliferation of clear cell renal cell carcinoma cells

Clear cell renal cell carcinoma (ccRCC) is the major and aggressive subtype of RCC. Previously, we identified 383 differentially expressed genes by analyzing full-length cDNA libraries of ccRCC and normal kidney tissues. In this study, we applied functional network analysis to the differentially expressed genes for identifying deregulated molecular pathways in ccRCC, and the results indicated that MYC showed a prominent role in the highest scoring network. The upregulation of MYC expression was validated in ccRCC tissues and cell lines. Furthermore, Knockdown of MYC expression by MYC-specific siRNA significantly inhibited the abilities of uncontrolled proliferation, anchorage-independent growth and arrested cell cycle in the G0/G1 phase in ccRCC cells. Moreover, we found that 37 differentially expressed genes were shown to be MYC-target genes, and the upregulation of the MYC-target genes BCL2, CCND1, PCNA, PGK1, and VEGFA were demonstrated. The expression of these MYC-target genes was significantly correlated with the expression of MYC in ccRCC tissues, and knockdown of MYC also suppressed the expression of these MYC-target genes in ccRCC cells. The recruitment of MYC to the promoter regions of BCL2, CCND1, PCNA, PGK1, and VEGFA was shown by Chromatin immunoprecipitation assay. These results suggest that MYC pathway is activated and plays an essential role in the proliferation of ccRCC cells.

The smiley as a simple screening tool for depression after stroke: A preliminary study

In Hong Kong, there is a paucity of evidence to support which tool is superior in measuring depression after stroke (DAS). A simple, non-language-based, culturally neutral, non-verbal and easy to apply tool that is not highly dependent on training will be desirable.

OBJECTIVES

The present study aimed to examine the clinical utility of three smiley pictures in detecting DAS for older Chinese patients at 1 month after first-ever ischemic stroke.

METHODS

This was a cross-sectional study. A total of 253 stroke patients were interviewed by a research nurse at 1-month follow-up.

RESULTS

Taking Diagnostic and Statistic Manual (DSM IV) as the gold standard, the measurement properties of emoticon (sad) in terms of sensitivity, specificity, positive and negative predictive values, as well as Kappa's value were found comparable to Geriatric Depression Scale (GDS). The emoticon (happy) demonstrated a highly significant inverse relationship with all depression assessment tools (p<0.001). It was also found that the emoticon (flat) could capture 98% of all depressed subjects identified by DSM IV, although its predictive values were less satisfactory.

CONCLUSIONS

The smiley pictures seemed to fulfil the requirements for early and prompt screening among older patients. Cultural implication regarding emotions dissipation among Chinese patients should be further studied.

Identification of differentially expressed genes in clear cell renal cell carcinoma by analysis of full-length enriched cDNA library

Renal cell carcinoma (RCC) is the most common malignancy in adult kidney, and accounts for 3% of malignancies worldwide with increasing incidence. Clear cell RCC (ccRCC) is the major type in RCC. Resection by surgery is the main treatment because the response of ccRCC to traditional therapies is very poor. To identify the tumor-associated genes for better understanding the molecular mechanism of ccRCC, the full-length enriched cDNA libraries of ccRCC and normal kidney tissues were constructed by the oligo-capping method. Nucleotide sequences of the cDNA libraries of ccRCC and normal kidney tissues were sequenced. From the sequence analysis of 19,425 and 12,400 clones of ccRCC and normal kidney tissues, 4356 and 3055 genes were identified, respectively. By comparing the gene-expression patterns of ccRCC and normal tissues, the up- or down-regulated genes were identified. Among these identified genes, the differential expression of annexin A2 and argininosuccinate synthetase genes were further confirmed by quantitative real-time PCR and Western blot analysis.

Master-slave robotic system for therapeutic gastrointestinal endoscopic procedures

Flexible endoscopy is used to inspect and treat disorders of the gastrointestinal (GI) tract without the need for creating an artificial opening on the patient's body. Simple surgical procedures (like polypectomy and biopsy) can be performed by introducing a flexible tool via a working channel to reach the site of interest at the distal end. More technically demanding surgical procedures like hemostasis for arterial bleeding, or suturing to mend a perforation cannot be effectively achieved with flexible endoscopy. The proposed robotic system enables the endoscopist to perform technically demanding therapeutic procedures (currently possible only with open surgery) in conjunction with conventional flexible endoscopes. The robotic system consists of a master console and a slave. The latter is a cable driven flexible robotic manipulator that can be inserted into tool channel of existing endoscopes or attached in tandem to the endoscopes. Together with the real time endoscopic view, the endoscopist would be capable of performing more intricate and difficult surgical procedures.

The Japanese version of the Barratt Impulsiveness Scale, 11th version (BIS-11): its reliability and validity

No instrument for assessing impulsiveness has been developed in Japan. After translating the Barratt Impulsiveness Scale 11th version (BIS-11) into Japanese, we investigated reliability and validity in student (n = 34) and worker (n = 416) samples. To assess test-retest reliability, the intraclass coefficient between test and retest was calculated in the student sample. Internal consistency was examined by calculating Cronbach's alpha in the worker sample. To see factor validity, we examined by confirmatory factor analysis whether the three-factor model, proposed by a previous report, fit the data. The results showed that the Japanese version of the BIS-11 had excellent test-retest reliability and acceptable internal consistency reliability. In addition, the Japanese version was judged to have similar factor structure to the original one. The Japanese version of the BIS-11 is a reliable and valid measure and has possible utility for assessing impulsiveness.