Andre Lieber

Publications of Andre Lieber

• Co-administration of epithelial junction opener JO-1 improves the efficacy and safety of chemotherapeutic drugs.

  Authors: Ines Beyer, Hua Cao, Jonas Persson, Hui Song, Qinghua Feng, Roma Yumul, Ruan van Rensburg, Zongyi Li, Ronald Berenson, Darrick Carter, Steve R Roffler, Charles M Drescher, Maximilian Richter, Andre Lieber

  Clinical cancer research : an official journal of the American Association for Cancer Research. 04/2012;

  PURPOSE: Epithelial junctions between tumor cells inhibit the penetration of anti-cancer drugs into tumors. We previously reported on recombinant adenovirus serotype 3 derived protein (JO-1), whichPURPOSE: Epithelial junctions between tumor cells inhibit the penetration of anti-cancer drugs into tumors. We previously reported on recombinant adenovirus serotype 3 derived protein (JO-1), which triggers transient opening of intercellular junctions in epithelial tumors through binding to desmoglein 2 (DSG2), and enhances the anti-tumor effects of several therapeutic monoclonal antibodies. The goal of this study was to evaluate whether JO-1 co-therapy can also improve the efficacy of chemotherapeutic drugs. EXPERIMENTAL DESIGN: The effect of intravenous application of JO-1 in combination with several chemotherapy drugs including paclitaxel/TaxolTM, nanoparticle albumin bound paclitaxel/AbraxaneTM, liposomal doxorubicin/DoxilTM and irinotecan/CamptosarTM, was tested in xenograft models for breast, colon, ovarian, gastric and lung cancer. Because JO-1 does not bind to mouse cells, for safety studies with JO-1, we also used human DSG2 (hDSG2) transgenic mice with tumors that overexpressed human DSG2. RESULTS: JO-1 increased the efficacy of chemotherapeutic drugs, and in several models overcame drug resistance. JO-1 treatment also allowed for the reduction of drug doses required to achieve anti-tumor effects. Importantly, JO-1 co-admininstration protected normal tissues, including bone marrow and intestinal epithelium, against toxic effects that are normally associated with chemotherapeutic agents. Using the hDSG2 transgenic mouse model, we demonstrated that JO-1 predominantly accumulates in tumors. Except for a mild, transient diarrhea, intravenous injection of JO-1 (2mg/kg) had no critical side effects on other tissues or hematological parameters in hDSG2-transgenic mice.CONCLUSIONS: Our preliminary data suggest that JO-1 co-therapy has the potential to improve the therapeutic outcome of cancer chemotherapy.

• Biodistribution and retargeting of FX-binding ablated adenovirus serotype 5 vectors.

  Authors: Raul Alba, Angela C Bradshaw, Lynda Coughlan, Laura Denby, Robert A McDonald, Simon N Waddington, Suzanne M K Buckley, Jenny A Greig, Alan L Parker, Ashley M Miller, Hongjie Wang, Andre Lieber, Nico van Rooijen, John H McVey, Stuart A Nicklin, Andrew H Baker

  Blood. 10/2010; 116(15):2656-64.

  A major limitation for adenoviral transduction in vivo is the profound liver tropism of adenovirus type 5 (Ad5). Recently, we demonstrated that coagulation factor X (FX) binds to Ad5-hexon protein atA major limitation for adenoviral transduction in vivo is the profound liver tropism of adenovirus type 5 (Ad5). Recently, we demonstrated that coagulation factor X (FX) binds to Ad5-hexon protein at high affinity to mediate hepatocyte transduction after intravascular delivery. We developed novel genetically FX-binding ablated Ad5 vectors with lower liver transduction. Here, we demonstrate that FX-binding ablated Ad5 predominantly localize to the liver and spleen 1 hour after injection; however, they had highly reduced liver transduction in both control and macrophage-depleted mice compared with Ad5. At high doses in macrophage-depleted mice, FX-binding ablated vectors transduced the spleen more efficiently than Ad5. Immunohistochemical studies demonstrated transgene colocalization with CD11c(+), ER-TR7(+), and MAdCAM-1(+) cells in the splenic marginal zone. Systemic inflammatory profiles were broadly similar between FX-binding ablated Ad5 and Ad5 at low and intermediate doses, although higher levels of several inflammatory proteins were observed at the highest dose of FX-binding ablated Ad5. Subsequently, we generated a FX-binding ablated virus containing a high affinity Ad35 fiber that mediated a significant improvement in lung/liver ratio in macrophage-depleted CD46(+) mice compared with controls. Therefore, this study documents the biodistribution and reports the retargeting capacity of FX binding-ablated Ad5 vectors in vitro and in vivo.

• Adenovirus vector vaccination induces expansion of memory CD4 T cells with a mucosal homing phenotype that are readily susceptible to HIV-1.

  Authors: Adel Benlahrech, Julian Harris, Andrea Meiser, Timos Papagatsias, Julia Hornig, Peter Hayes, Andre Lieber, Takis Athanasopoulos, Veronique Bachy, Eszter Csomor, Rod Daniels, Kerry Fisher, Frances Gotch, Len Seymour, Karen Logan, Romina Barbagallo, Linda Klavinskis, George Dickson, Steven Patterson

  Proceedings of the National Academy of Sciences of the United States of America. 11/2009;

  In the recently halted HIV type 1 (HIV-1) vaccine STEP trial, individuals that were seropositive for adenovirus serotype 5 (Ad5) showed increased rates of HIV-1 infection on vaccination with an Ad5In the recently halted HIV type 1 (HIV-1) vaccine STEP trial, individuals that were seropositive for adenovirus serotype 5 (Ad5) showed increased rates of HIV-1 infection on vaccination with an Ad5 vaccine. We propose that this was due to activation and expansion of Ad5-specific mucosal-homing memory CD4 T cells. To test this hypothesis, Ad5 and Ad11 antibody titers were measured in 20 healthy volunteers. Dendritic cells (DCs) from these individuals were pulsed with replication defective Ad5 or Ad11 and co-cultured with autologous lymphocytes. Cytokine profiles, proliferative capacity, mucosal migration potential, and susceptibility to HIV infection of the adenovirus-stimulated memory CD4 T cells were measured. Stimulation of T cells from healthy Ad5-seropositive but Ad11-seronegative individuals with Ad5, or serologically distinct Ad11 vectors induced preferential expansion of adenovirus memory CD4 T cells expressing alpha(4)beta(7) integrins and CCR9, indicating a mucosal-homing phenotype. CD4 T-cell proliferation and IFN-gamma production in response to Ad stimulation correlated with Ad5 antibody titers. However, Ad5 serostatus did not correlate with total cytokine production upon challenge with Ad5 or Ad11. Expanded Ad5 and Ad11 memory CD4 T cells showed an increase in CCR5 expression and higher susceptibility to infection by R5 tropic HIV-1. This suggests that adenoviral-based vaccination against HIV-1 in individuals with preexisting immunity against Ad5 results in preferential expansion of HIV-susceptible activated CD4 T cells that home to mucosal tissues, increases the number of virus targets, and leads to a higher susceptibility to HIV acquisition.

• A recombinant adenovirus type 35 fiber knob protein sensitizes lymphoma cells to rituximab therapy.

  Authors: Hongjie Wang, Ying Liu, Zong-Yi Li, Xiaolong Fan, Akseli Hemminki, Andre Lieber

  Blood. 11/2009;

  Many tumors, including lymphomas, upregulate expression of CD46 to escape destruction by complement. Tumor cells are therefore relatively resistant to therapy by monoclonal antibodies, which actMany tumors, including lymphomas, upregulate expression of CD46 to escape destruction by complement. Tumor cells are therefore relatively resistant to therapy by monoclonal antibodies, which act through complement-dependent cytotoxicity (CDC). From an E.coli expression library of adenovirus type 35 fiber knob mutants, we selected a variant (Ad35K++) that had a higher affinity to CD46 than the natural Ad35 fiber knob. We demonstrated that incubation of lymphoma cells with recombinant Ad35K++ protein resulted in transient removal of CD46 from the cell surface. Pre-incubation of lymphoma cells with Ad35K++ sensitized cells to CDC triggered by the CD20-specific monoclonal antibody rituximab. In xenograft models with human lymphoma cells, pre-injection of Ad35K++ dramatically increased the therapeutic effect of rituximab. Blood cell counts and organ histology were normal after intravenous injection of Ad35K++ into mice that express human CD46. The presence of polyclonal anti-Ad35K++ antibodies did not affect the ability of Ad35K++ to enhance rituximab-mediated CDC in in vitro assays. The Ad35K++-based approach has potential implications in monoclonal antibody therapy of maligancies beyond the combination with rituximab.

• Anti-4-1BB scFv immunogene therapy and low dose cyclophosphamide exhibit a synergistic antitumor effect in established murine lung tumors.

  Authors: Fang Liu, Chao Fang, Xun Ye, Qin Lu, De-Hong Yu, Wei-Wei Zhang, Hong Qi, Jing Xie, Andre Lieber, Hong-Zhuan Chen

  Cancer biology & therapy. 05/2009; 8(8):707-13.

  T-cell costimulatory molecules such as 4-1BB may provide a distinct and important signal for promoting positive immune regulation. 4-1BB is thought to have potential use as a cancer immunotherapeuticT-cell costimulatory molecules such as 4-1BB may provide a distinct and important signal for promoting positive immune regulation. 4-1BB is thought to have potential use as a cancer immunotherapeutic drug. In our previous study, a nonreplicative adenovirus (Ad.4-1BB scFv) carrying single-chain Fv fragments (scFv) specific for the 4-1BB gene (anti-4-1BB scFv) possessed remarkable in vivo anti-hepatoma efficacy. However, monotherapy achieved by triggering 4-1BB signaling was not sufficient to induce eradicative antitumor activities in low immunogenic tumors. It is of great interest to explore any possible synergistic antitumor effect of 4-1BB signaling combined with low dose cyclophosphamide (CTX), which is well documented to inhibit the suppressive capability of regulatory T-cells in mice and humans. In the present study, recombinant nonreplicative adenoviruses carrying an anti-4-1BB scFv gene were generated, characterized and explored for their stimulation of antilung tumor (TC-1) immunity in immunocompetent C57BL/6 mice. Compared to adenovirus and cyclophosphamide alone, adenovirus-mediated anti-4-1BB scFv in combination with low dose CTX treatment could obviously augment the antitumor activity, in which some established TC-1 tumors were eradicated and the survival of mice was significantly extended. This synergistic antitumor effect could be largely attributed to the depletion of T regulatory cells induced by low dose CTX. These findings may provide a new and promising strategy for immunogene therapy against cancer.

• Towards a stem cell gene therapy for breast cancer.

  Authors: Zongyi Li, Ying Liu, Sebastian Tuve, Ye Xun, Xiaolong Fan, Liang Min, Qinghua Feng, Nancy Kiviat, Hans-Peter Kiem, Mary Leonora Disis, Andre Lieber

  Blood. 04/2009;

  Current approaches for treatment of late-stage breast cancer rarely result in a long-term cure. In part this is due to tumor stroma that prevents access of systemically or intratumorally appliedCurrent approaches for treatment of late-stage breast cancer rarely result in a long-term cure. In part this is due to tumor stroma that prevents access of systemically or intratumorally applied therapeutics. We propose a stem cell gene therapy approach for controlled tumor stroma degradation that utilizes the patho-physiological process of recruitment of inflammatory cells into the tumor. This approach involves genetic modification of hematopoietic stem cells (HSCs) and their subsequent transplantation into tumor-bearing mice. We show that inducible, intratumoral expression of relaxin (Rlx) either by transplanting tumor cells that contained the Rlx gene or by transplantation of mouse HSCs transduced with an Rlx-expressing lentivirus vector delays tumor-growth in a mouse model of breast cancer. The antitumor effect of Rlx was mediated through degradation of tumor stroma, which provided increased access of infiltrating anti-tumor immune cells to their target tumor cells. Furthermore, we demonstrated in a human/mouse chimeric model that genetically modified HSCs expressing a transgene can access the tumor site. Our findings are relevant for cancer gene- and immunotherapy.

• Transduction of liver metastases after intravenous injection of Ad5/35 or Ad35 vectors with and without factor X-binding protein pretreatment.

  Authors: Ying Liu, Hongjie Wang, Roma Yumul, Wentao Gao, Andrea Gambotto, Takashi Morita, Andrew Baker, Andre Lieber

  Human gene therapy. 03/2009;

  Inefficient tumor transduction with targeted adenovirus vectors is largely due to unspecific virus sequestration by blood components, including coagulation factor X, and Kupffer cell scavenging. InInefficient tumor transduction with targeted adenovirus vectors is largely due to unspecific virus sequestration by blood components, including coagulation factor X, and Kupffer cell scavenging. In this study, we show that pre-injection of the snake venom X-bP (factor X-binding protein) reduces hepatocyte transduction and increases the circulation time in blood of an intravenously injected, fiber-chimeric Ad5/35 vector. X-bp pre-treatment resulted in improved Ad5/35 transduction of liver metastases and increased the anti-tumor efficacy of an Ad5/35-based oncolytic adenovirus. Furthermore, we demonstrate that a vector based on adenovirus serotype 35, which is less sequestered by factor X, is efficient in tumor targeting. This gives a rationale for using Ad35-based vectors in virotherapy of cancer.

• Cancer gene therapy of adenovirus-mediated anti-4-1BB scFv in immunocompetent mice.

  Authors: Fang Liu, Qin Lu, Xun Ye, Chao Fang, Yi Zhao, Min Liang, Fang Hu, Andre Lieber, Hong-Zhuan Chen

  Cancer biology & therapy. 04/2008; 7(3):448-53.

  The use of immunostimulatory molecule genes aiming at enhancing anti-tumor immunity has emerged as a new approach to treat cancers. 4-1BB signaling, an important costimulatory pathway delivering aThe use of immunostimulatory molecule genes aiming at enhancing anti-tumor immunity has emerged as a new approach to treat cancers. 4-1BB signaling, an important costimulatory pathway delivering a signal for T cell activation, survival and growth, has become one of the most promising targets for cancer immunotherapy. In this work, a recombinant nonreplicative adenovirus (Ad.4-1BB scFv) carrying a single-chain Fv fragments (scFv) specific for 4-1BB gene (anti-4-1BB scFv) was generated, haracterized and explored for its stimulation of anti-tumor immunity in immunocompetent C57BL/6 mice. Ad.4-1BB scFv could efficiently infect murine hepatoma Hepa 1-6 cells and induce anti-4-1BB scFv expression on the cell surface. Moreover, Ad.4-1BB scFv did not cause obvious cytotoxicity effect on human and murine tumor cell lines (A549, PLC/PRF/5, Hepa 1-6 and TC-1) even at a high MOI, which suggested Ad.4-1BB scFv had no direct effect on tumor cells. Intratumoral injection of Ad.4-1BB scFv to established Hepa 1-6 tumors significantly suppressed the tumor growth in C57BL/6 mice. The anti-tumor effect might be mainly attributed to the anti-4-1BB scFv-mediated immune activity, as evidenced by enhanced interferon-gamma-producing splenic cells and increased lymphocytes infiltration in the tumor microenvironment. These results indicated that nonreplicative adenovirus carrying the anti-4-1BB scFv gene possessed powerful in vivo anti-tumor efficacy and might be a valuable tool for cancer immunotherapy.

• Directed evolution generates a novel oncolytic virus for the treatment of colon cancer.

  Authors: Irene Kuhn, Paul Harden, Maxine Bauzon, Cecile Chartier, Julie Nye, Steve Thorne, Tony Reid, Shaoheng Ni, Andre Lieber, Kerry Fisher, Len Seymour, Gabor M Rubanyi, Richard N Harkins, Terry W Hermiston

  PLoS ONE. 01/2008; 3(6):e2409.

  BACKGROUND: Viral-mediated oncolysis is a novel cancer therapeutic approach with the potential to be more effective and less toxic than current therapies due to the agents selective growth andBACKGROUND: Viral-mediated oncolysis is a novel cancer therapeutic approach with the potential to be more effective and less toxic than current therapies due to the agents selective growth and amplification in tumor cells. To date, these agents have been highly safe in patients but have generally fallen short of their expected therapeutic value as monotherapies. Consequently, new approaches to generating highly potent oncolytic viruses are needed. To address this need, we developed a new method that we term "Directed Evolution" for creating highly potent oncolytic viruses. METHODOLOGY/PRINCIPAL FINDINGS: Taking the "Directed Evolution" approach, viral diversity was increased by pooling an array of serotypes, then passaging the pools under conditions that invite recombination between serotypes. These highly diverse viral pools were then placed under stringent directed selection to generate and identify highly potent agents. ColoAd1, a complex Ad3/Ad11p chimeric virus, was the initial oncolytic virus derived by this novel methodology. ColoAd1, the first described non-Ad5-based oncolytic Ad, is 2-3 logs more potent and selective than the parent serotypes or the most clinically advanced oncolytic Ad, ONYX-015, in vitro. ColoAd1's efficacy was further tested in vivo in a colon cancer liver metastasis xenograft model following intravenous injection and its ex vivo selectivity was demonstrated on surgically-derived human colorectal tumor tissues. Lastly, we demonstrated the ability to arm ColoAd1 with an exogenous gene establishing the potential to impact the treatment of cancer on multiple levels from a single agent. CONCLUSIONS/SIGNIFICANCE: Using the "Directed Evolution" methodology, we have generated ColoAd1, a novel chimeric oncolytic virus. In vitro, this virus demonstrated a >2 log increase in both potency and selectivity when compared to ONYX-015 on colon cancer cells. These results were further supported by in vivo and ex vivo studies. Furthermore, these results have validated this methodology as a new general approach for deriving clinically-relevant, highly potent anti-cancer virotherapies.

• Tumor cells expressing anti-CD137 scFv induce a tumor-destructive environment.

  Authors: Yi Yang, Shilin Yang, Zhengmao Ye, Jade Jaffar, Yifeng Zhou, Erin Cutter, Andre Lieber, Ingegerd Hellström, Karl Erik Hellström

  Cancer research. 04/2007; 67(5):2339-44.

  For immunotherapy to become more effective, there is a need to maximize the antitumor response at the tumor site as well as to eliminate tumor cell variants that lack a given tumor antigen or theFor immunotherapy to become more effective, there is a need to maximize the antitumor response at the tumor site as well as to eliminate tumor cell variants that lack a given tumor antigen or the ability to present it. We have previously shown that wild-type (WT) cells from the K1735 melanoma (K1735-WT) are rejected following vaccination with cells (K1735-1D8) transfected to express scFv from the anti-CD137 monoclonal antibody 1D8, and that CD4(+) T cells and natural killer (NK) cells are needed for this rejection. We now show that tumors harvested 4 to 10 days after mice had been transplanted with K1735-1D8 cells or a mixture of K1735-1D8 and K1735-WT cells contained more NK cells and that they had an increased percentage of CD4(+) T lymphocytes producing IFNgamma or tumor necrosis factor-alpha. We further show that the percentage of NK cells was higher in B16-1D8 melanomas expressing anti-CD137 scFv than in the WT tumors and that the percentage of FoxP3(+) cells was lower. Admixture of 10% K1735-1D8 cells prevented the progressive growth of transplanted K1735-WT cells in syngeneic mice and also of cells from the antigenically different sarcoma Ag104. Inhibition of WT tumor cells by tumor cells transfected to express anti-CD137 scFv was shown also with the TC1 carcinoma and B16 melanoma. Furthermore, injection of an adenovirus vector, Ad-1D8, which encodes anti-CD137 scFv into established B16 melanomas, significantly prolonged the survival of tumor-bearing mice and could induce regression. Our data suggest that targeting of anti-CD137 scFv to tumors should be explored for therapy for some human cancers.

• New serotypes of adenoviral vectors.

  Authors: Daniel Stone, Andre Lieber

  Current opinion in molecular therapeutics. 11/2006; 8(5):423-31.

  Since it was first demonstrated that recombinant adenovirus (Ad) vectors could be generated by inserting foreign genes into Ad genomes, they have been extensively used as eukaryotic expressionSince it was first demonstrated that recombinant adenovirus (Ad) vectors could be generated by inserting foreign genes into Ad genomes, they have been extensively used as eukaryotic expression vectors and therapeutic gene delivery vehicles. Originally, Ad vectors were based on the human Ad5 serotype and while most currently used Ad vectors are still based on Ad5, recent research has highlighted a series of problems that limit the efficacy and safety of these vectors. To circumvent the problems associated with Ad5-based vectors, new vectors have utilized various Ads of both human and nonhuman origin. In this review we introduce the recent advances made in the development of non-Ad5-based vectors.

• Multiple vitamin K-dependent coagulation zymogens promote adenovirus-mediated gene delivery to hepatocytes.

  Authors: Alan L Parker, Simon N Waddington, Campbell G Nicol, Dmitry M Shayakhmetov, Suzanne M. Buckley, Laura Denby, Geoffrey Kemball-Cook, Shaoheng Ni, Andre Lieber, John H McVey, Stuart A Nicklin, Andrew H Baker

  Blood. 11/2006; 108(8):2554-61.

  Upon local delivery, adenovirus (Ad) serotype 5 viruses use the coxsackie and Ad receptor (CAR) for cell binding and alpha(v) integrins for internalization. When administered systemically, however,Upon local delivery, adenovirus (Ad) serotype 5 viruses use the coxsackie and Ad receptor (CAR) for cell binding and alpha(v) integrins for internalization. When administered systemically, however, their role in liver tropism is limited because CAR-permissive and mutated viruses show similar biodistribution, a finding recently attributed to blood coagulation factor (F) IX or complement protein C4BP binding to the adenovirus fiber and "bridging" to either low-density lipoprotein receptor-related protein or heparan sulfate proteoglycans. Here, we show that hepatocyte transduction in vitro can be enhanced by the vitamin K-dependent factors FX, protein C, and FVII in addition to FIX but not by prothrombin (FII), FXI, and FXII. This phenomenon was not dependent on proteolytic activation or cell signaling activity and for FX was mediated by direct virus-factor binding. Human FX substantially enhanced hepatocyte transduction by CAR-permissive and mutated viruses in an ex vivo liver perfusion model. In vivo, global down-regulation of vitamin K-dependent zymogens by warfarin significantly diminished liver uptake of CAR-deleted Ads; however, this phenomenon was fully rescued by acute infusion of human FX. Our results indicate a common and pivotal role for distinct vitamin K-dependent coagulation factors in mediating hepatocyte transduction by adenoviruses in vitro and in vivo.

• Discovery of novel methylation biomarkers in cervical carcinoma by global demethylation and microarray analysis.

  Authors: Pavel Sova, Qinghua Feng, Gary Geiss, Troy Wood, Robert Strauss, Vania Rudolf, Andre Lieber, Nancy Kiviat

  Cancer epidemiology, biomarkers & prevention : a publication of the American Association for Cancer Research, cosponsored by the American Society of Preventive Oncology. 02/2006; 15(1):114-23.

  A genome-wide screening study for identification of hypermethylated genes in invasive cervical cancer (ICC) was carried out to augment our previously discovered panel of three genes found to beA genome-wide screening study for identification of hypermethylated genes in invasive cervical cancer (ICC) was carried out to augment our previously discovered panel of three genes found to be useful for detection of ICC and its precursor neoplasia. Putatively hypermethylated and silenced genes were reactivated in four ICC cell lines by treatment with 5-aza-2'-deoxycytidine and trichostatin A and identified on expression microarrays. Thirty-nine of the 235 genes up-regulated in multiple ICC cell lines were further examined to determine the methylation status of associated CpG islands. The diagnostic use of 23 genes that were aberrantly methylated in multiple ICC cell lines were then analyzed in DNA from exfoliated cells obtained from patients with or without ICC. We show, for the first time, that aberrant methylation of six genes (SPARC, TFPI2, RRAD, SFRP1, MT1G, and NMES1) is present in a high proportion of ICC clinical samples but not in normal samples. Of these genes, SPARC and TFPI2 showed the highest frequency of aberrant methylation in ICC specimens (86.4% for either) and together were hypermethylated in all but one ICC cases examined. We conclude that expression profiling of epigenetically reactivated genes followed by methylation analysis in clinical samples is a powerful tool for comprehensive identification of methylation markers. Several novel genes identified in our study may be clinically useful for detection or stratification of ICC and/or of its precursor lesions and provide a basis for better understanding of mechanisms involved in development of ICC.

• Insulation from viral transcriptional regulatory elements enables improvement to hepatoma-specific gene expression from adenovirus vectors.

  Authors: Xun Ye, Min Liang, Xia Meng, XiaoWei Ren, Hongzhuan Chen, Zong-Yi Li, Shaoheng Ni, Andre Lieber, Fang Hu

  Biochemical and biophysical research communications. 09/2003; 307(4):759-64.

  We previously reported that the HS-4 insulator, derived from the chicken beta-globin locus, was able to shield a downstream inducible promoter from viral enhancers or silencers present in the genomeWe previously reported that the HS-4 insulator, derived from the chicken beta-globin locus, was able to shield a downstream inducible promoter from viral enhancers or silencers present in the genome of adenovirus vectors. In this study, we constructed two recombinant adenoviruses (Ad) that express an alkaline phosphatase (AP) reporter gene driven by an alpha-fetoprotein (AFP) enhancer/promoter with and without HS-4 insulator (Ad.HS4.AFP-AP and Ad.AFP-AP). The insulated vector, Ad.HS4.AFP-AP, conferred significantly higher AP expression than Ad.AFP-AP in all AFP-producing hepatocellular carcinoma cell lines (HepG2, Hep3B, and HuH7) examined. AP expression from Ad.HS4.AFP-AP was specific to hepatoma cells and barely detectable in AFP-negative tumor cell lines and normal human cells, including human hepatocytes. Intravenous infusion of viral vectors into mice with liver metastasis derived from Hep3B hepatoma cells resulted in AP expression exclusively localized to tumor cells. The number of tumor cells with detectable AP expression was significantly higher in mice infused with Ad.HS4.AFP-AP than in mice that received the non-insulated vector. This study demonstrates that the HS-4 insulator in the context of an Ad vector can increase the activity of the AFP promoter, while maintaining its tumor-specificity in vitro and in vivo. Considering that the anti-tumor activity of oncolytic vectors often depends on the level of pro-apoptotic or suicide gene expression, insulators might be a useful tool to improve the efficacy and specificity of these vectors.

• Advances in gene transfer into haematopoietic stem cells by adenoviral vectors.

  Authors: Frank C Marini, Dmitry Shayakhmetov, Helen Gharwan, Andre Lieber, Michael Andreeff

  Expert opinion on biological therapy. 01/2003; 2(8):847-56.

  Until recently, the cells of haematopoietic origin were not considered good adenoviral (Adv) targets, primarily because they lacked the specific Adv receptors required for productive and efficientUntil recently, the cells of haematopoietic origin were not considered good adenoviral (Adv) targets, primarily because they lacked the specific Adv receptors required for productive and efficient Adv infections. In addition, because of limitations inherent in Adv infections, such as short-term expression and a non-integrating nature, their application has been precluded from haematopoietic stem cell (HSC) and bone marrow transduction protocols where long-term expression has been required. Therefore, limited research utilising Adv-mediated gene transfer into haematopoietic cells had been conducted. With recent insights into the critical interactions between adenovirus (Adv) and cells, new Adv-mediated gene transduction strategies have now been reported that may overcome these limitations. These new strategies include Adv possessing synthetic polymer coatings, genetically modified capsid proteins or antibody-redirected fibres that can efficiently redirect and retarget Adv to transfer genes into HSC. Additionally, new hybrid Advs, engineered with both modified capsid proteins and novel cis-acting integration sequences, are also being developed which can efficiently deliver and integrate Adv delivered genes into HSC. This is an area of research that is now rapidly gaining momentum in terms of techniques and applications. Here we review the current status of adenovirus-based vectors as a means to achieve high-level gene transfer into haematopoietic cell types.

• 123. Adenovirus Type 11 Based Vectors as a Platform for Treatment of Metastatic and Hematopoietic Disease

  Authors: Daniel Stone, Andre Lieber

• 411. Trapping of Adenovirus Vectors in Blood

  Authors: Daniel Stone, Shaoheng Ni, Zong-Yi Li, Dmitry M Shayakhmetov, Andre Lieber

• 376. Hepatic Tropism of Adenoviral Type 5 Vectors Can Be Mediated by Multiple Coagulation Factors

  Authors: Alan L Parker, Campbell G Nicol, Simon N Waddington, Suzanne M. Buckley, Dmitry M Shayakhmetov, Shaoheng H. Ni, Andre Lieber, John H McVey, Laura Denby, Stuart A Nicklin, Andrew H Baker

• Insulation from viral transcriptional regulatory elements enables improvement to hepatoma-specific gene expression from adenovirus vectors

  Authors: Xun Ye, Min Liang, Xia Meng, XiaoWei Ren, HongZhuan Chen, Zong-Yi Li, ShaoHeng Ni, Andre Lieber, Fang Hu

  Biochemical and Biophysical Research Communications.

  We previously reported that the HS-4 insulator, derived from the chicken β-globin locus, was able to shield a downstream inducible promoter from viral enhancers or silencers present in the genome ofWe previously reported that the HS-4 insulator, derived from the chicken β-globin locus, was able to shield a downstream inducible promoter from viral enhancers or silencers present in the genome of adenovirus vectors. In this study, we constructed two recombinant adenoviruses (Ad) that express an alkaline phosphatase (AP) reporter gene driven by an α-fetoprotein (AFP) enhancer/promoter with and without HS-4 insulator (Ad.HS4.AFP-AP and Ad.AFP-AP). The insulated vector, Ad.HS4.AFP-AP, conferred significantly higher AP expression than Ad.AFP-AP in all AFP-producing hepatocellular carcinoma cell lines (HepG2, Hep3B, and HuH7) examined. AP expression from Ad.HS4.AFP-AP was specific to hepatoma cells and barely detectable in AFP-negative tumor cell lines and normal human cells, including human hepatocytes. Intravenous infusion of viral vectors into mice with liver metastasis derived from Hep3B hepatoma cells resulted in AP expression exclusively localized to tumor cells. The number of tumor cells with detectable AP expression was significantly higher in mice infused with Ad.HS4.AFP-AP than in mice that received the non-insulated vector. This study demonstrates that the HS-4 insulator in the context of an Ad vector can increase the activity of the AFP promoter, while maintaining its tumor-specificity in vitro and in vivo. Considering that the anti-tumor activity of oncolytic vectors often depends on the level of pro-apoptotic or suicide gene expression, insulators might be a useful tool to improve the efficacy and specificity of these vectors.

• 1100. Baculovirus Vectors for Malaria Vaccination

  Authors: Robert Strauss, Andreas Huser, Shaoheng Ni, Salif Sow, Nancy Kiviat, Christian Hofmann, Andre Lieber