Humanized liver chimeric mice (PXB-mice) are generated by the transplantation of human hepatocytes into mice that have severe combined immunodeficiency and express an albumin-promoted urokinase-type plasminogen activator (cDNA-uPA/SCID) transgene. Human hepatocytes cannot synthesize ascorbic acid (AA; commonly called vitamin C) and humans require supplementation to prevent vitamin C deficiency. PXB-mouse livers contain up to approximately 95% human hepatocytes, which likely affects AA synthesis. To determine whether dietary AA supplementation prevents scurvy-like symptoms and death in PXB-mice, a 12 week study that compared nonsupplemented and supplemented PXB-mice was conducted. Approximately 4 weeks into the study, PXB-mice without dietary supplementation of AA displayed weight loss and clinical signs of hypovitaminosis C, including hunched posture, unkempt appearance, and lameness. Pathologic evaluation of nonsupplemented PXB-mice revealed lesions consistent with hypovitaminosis C. Mean serum AA concentrations in the nonsupplemented PXB-mice were below the limit of quantitation (0.5 μg/mL) and were substantially less than those of controls. AA was also measured in a number of tissues, including adrenal gland, brain, liver, and testis; low AA concentrations were similarly observed in tissues obtained from the nonsupplemented PXB-mice. Collectively, these findings support AA supplementation in PXB-mice to prevent the development of hypovitaminosis C and the potential utility of nonsupplemented PXB-mice as an animal model of scurvy.

Chronic hepatitis B virus (HBV) infection is a major public health problem. New treatment approaches are needed because current treatments do not target covalently closed circular DNA (cccDNA), the template for HBV replication, and rarely clear the virus. We harnessed adeno-associated virus (AAV) vectors and CRISPR-Staphylococcus aureus (Sa)Cas9 to edit the HBV genome in liver-humanized FRG mice chronically infected with HBV and receiving entecavir. Gene editing was detected in livers of five of eight HBV-specific AAV-SaCas9-treated mice, but not control mice, and mice with detectable HBV gene editing showed higher levels of SaCas9 delivery to HBV+ human hepatocytes than those without gene editing. HBV-specific AAV-SaCas9 therapy significantly improved survival of human hepatocytes, showed a trend toward decreasing total liver HBV DNA and cccDNA, and was well tolerated. This work provides evidence for the feasibility and safety of in vivo gene editing for chronic HBV infections, and it suggests that with further optimization, this approach may offer a plausible way to treat or even cure chronic HBV infections.

Chronic hepatitis B virus infection cannot be cured by current therapies, so new treatments are urgently needed. We recently identified novel inhibitors of the hepatitis B virus ribonuclease H that suppress viral replication in cell culture. Here, we employed immunodeficient FRG KO mice whose livers had been engrafted with primary human hepatocytes to ask whether ribonuclease H inhibitors can suppress hepatitis B virus replication in vivo. Humanized FRG KO mice infected with hepatitis B virus were treated for two weeks with the ribonuclease H inhibitors #110, an α-hydroxytropolone, and #208, an N-hydroxypyridinedione. Hepatitis B virus viral titers and S and e antigen plasma levels were measured. Treatment with #110 and #208 caused significant reductions in plasma viremia without affecting hepatitis B virus S or e antigen levels, and viral titers rebounded following treatment cessation. This is the expected pattern for inhibitors of viral DNA synthesis. Compound #208 suppressed viral titers of both hepatitis B virus genotype A and C isolates. These data indicate that Hepatitis B virus replication can be suppressed during infection in an animal by inhibiting the viral ribonuclease H, validating the ribonuclease H as a novel target for antiviral drug development.

BACKGROUND & AIMS: The incidence of nonalcoholic steatohepatitis (NASH) is increasing. The pathophysiological mechanisms of NASH and the sequence of events leading to hepatic fibrosis are incompletely understood. The aim of this study was to gain insight into the dynamics of key molecular processes involved in NASH and to rank early markers for hepatic fibrosis. METHODS: A time-course study in low-density lipoprotein-receptor knockout. Leiden mice on a high-fat diet was performed to identify the temporal dynamics of key processes contributing to NASH and fibrosis. An integrative systems biology approach was used to elucidate candidate markers linked to the active fibrosis process by combining transcriptomics, dynamic proteomics, and histopathology. The translational value of these findings were confirmed using human NASH data sets. RESULTS: High-fat-diet feeding resulted in obesity, hyperlipidemia, insulin resistance, and NASH with fibrosis in a time-dependent manner. Temporal dynamics of key molecular processes involved in the development of NASH were identified, including lipid metabolism, inflammation, oxidative stress, and fibrosis. A data-integrative approach enabled identification of the active fibrotic process preceding histopathologic detection using a novel molecular fibrosis signature. Human studies were used to identify overlap of genes and processes and to perform a network biology-based prioritization to rank top candidate markers representing the early manifestation of fibrosis. CONCLUSIONS: An early predictive molecular signature was identified that marked the active profibrotic process before histopathologic fibrosis becomes manifest. Early detection of the onset of NASH and fibrosis enables identification of novel blood-based biomarkers to stratify patients at risk, development of new therapeutics, and help shorten (pre) clinical experimental time frames.

ABSTRACT Syrian hamsters are permissive for the replication of species C human adenoviruses (HAdV-C). The virus replicates to high titers in the liver of these animals after intravenous infection, while respiratory infection results in virus replication in the lung. Here we show that two types belonging to species C, HAdV-C5 and HAdV-C6, replicate to significantly different extents and cause pathology with significantly different severities, with HAdV-C6 replicating better and inducing more severe and more widespread lesions. The virus burdens in the livers of HAdV-C6-infected hamsters are higher than the virus burdens in HAdV-C5-infected ones because more of the permissive hepatocytes get infected. Furthermore, when hamsters are infected intravenously with HAdV-C6, live, infectious virus can be isolated from the lung and the kidney, which is not seen with HAdV-C5. Similarly to mouse models, in hamsters, HAdV-C6 is sequestered by macrophages to a lesser degree than HAdV-C5. Depletion of Kupffer cells from the liver greatly increases the replication of HAdV-C5 in the liver, while it has only a modest effect on the replication of HAdV-C6. Elimination of Kupffer cells also dramatically increases the pathology induced by HAdV-C5. These findings indicate that in hamsters, pathology resulting from intravenous infection with adenoviruses is caused mostly by replication in hepatocytes and not by the abortive infection of Kupffer cells and the following cytokine storm. IMPORTANCE Immunocompromised human patients can develop severe, often lethal adenovirus infections. Respiratory adenovirus infection among military recruits is a serious problem, in some cases requiring hospitalization of the patient. Furthermore, adenovirus-based vectors are frequently used as experimental viral therapeutic agents. Thus, it is imperative that we investigate the pathogenesis of adenoviruses in a permissive animal model. Syrian hamsters are susceptible to infection with certain human adenoviruses, and the pathology accompanying these infections is similar to what is observed with adenovirus-infected human patients. We demonstrate that replication in permissive cells in a susceptible host animal is a major part of the mechanism by which systemic adenovirus infection induces pathology, as opposed to the chiefly immune-mediated pathology observed in nonsusceptible hosts. These findings support the use of compounds inhibiting adenovirus replication as a means to block adenovirus-induced pathology.

Oncolytic vectors based on human species C adenovirus type 5 (Ad5) are being developed for cancer gene therapy. Studies on wild-type Ad5 in animal models are likely to provide important insights into the behavior of these vectors in patients. The most frequently used permissive immunocompetent animal model for Ad5 infection is the Syrian hamster. Ad5 (and Ad6) replicates in these animals and causes pathology that is similar to that seen with humans. Here, we report findings with a new Syrian hamster strain in which the STAT2 gene was functionally knocked out (KO) by site-specific CRISPR/Cas9-mediated gene targeting. STAT2 is a critical element of the Type I and Type III interferon signal transduction pathways. STAT2 KO hamsters infected intravenously with Ad5 demonstrated an accentuated pathology compared to the wild-type control animals, and the virus load in the organs (liver, lung, kidney) of STAT2 KO animals was 100- to 1000-fold higher than that in wild-type hamsters. We show that the Type I interferon pathway is disrupted in these hamsters, inasmuch as the interferon response genes PKR, OAS, and Mx2 were induced by Ad5 in the liver of wild-type but not STAT2 KO hamsters, revealing a critical role of interferon-stimulated genes in controlling Ad5 infection. Notably, the adaptive immune response to Ad5 is not adversely affected in STAT2 KO hamsters, and surviving hamsters cleared the infection by 7 to 10 days post challenge. In fact, anti-Ad5 neutralizing antibodies were 10-fold higher at 7 days postinfection in the STAT2 KO hamsters than in wild-type hamsters. T cell infiltration into the liver was similar at 3 and 7 days in the STAT2 KO and wild-type hamsters. Treatment of Ad5-infected STAT2 KO hamsters with high dose cyclophosphamide resulted in markedly increased mortality, pathogenesis, and virus replication in the liver (~1011 TCID50/g liver) at 10 days postinfection, likely because the adaptive immune response as well as other aspects of the innate response were abolished. This is the first study to report findings with a genetically modified Syrian hamster infected with human adenovirus. Further, this is the first study to show that the Type I interferon pathway plays a role in inhibiting Ad5 replication in a permissive animal model. This conclusion is in accord with a previous study in which we showed using a custom microarray platform that there is a robust up-regulation of genes involved in the innate immune response (e.g. OAS, PKR, IFN-inducible protein 10) in the liver at 18 h post-intravenous infection of wild-type Syrian hamsters with Ad5 (Ying, B. et al., Virology 485, 305, 2015). Besides providing an insight into adenovirus infection in humans, our results underscore the usefulness of Syrian hamsters as a permissive model for the study of species C human adenovirus and adenovirus-based vectors. In future studies, STAT2 KO hamsters bearing tumors could be used to explore the role of Type I and Type III interferon signaling on the efficacy of oncolytic adenovirus vectors.

Human adenoviruses have been studied extensively in cell culture and have been a model for studies in molecular, cellular, and medical biology. However, much less is known about adenovirus replication and pathogenesis in vivo in a permissive host because of the lack of an adequate animal model. Presently, the most frequently used permissive immunocompetent animal model for human adenovirus infection is the Syrian hamster. Species C human adenoviruses replicate in these animals and cause pathology that is similar to that seen with humans. Here, we report findings with a new Syrian hamster strain in which the STAT2 gene was functionally knocked out by site-specific gene targeting. Adenovirus-infected STAT2 knockout hamsters demonstrated an accentuated pathology compared to the wild-type control animals, and the virus load in the organs of STAT2 knockout animals was 100- to 1000-fold higher than that in wild-type hamsters. Notably, the adaptive immune response to adenovirus is not adversely affected in STAT2 knockout hamsters, and surviving hamsters cleared the infection by 7 to 10 days post challenge. We show that the Type I interferon pathway is disrupted in these hamsters, revealing the critical role of interferon-stimulated genes in controlling adenovirus infection. This is the first study to report findings with a genetically modified Syrian hamster infected with a virus. Further, this is the first study to show that the Type I interferon pathway plays a role in inhibiting human adenovirus replication in a permissive animal model. Besides providing an insight into adenovirus infection in humans, our results are also interesting from the perspective of the animal model: STAT2 knockout Syrian hamster may also be an important animal model for studying other viral infections, including Ebola-, hanta-, and dengue viruses, where Type I interferon-mediated innate immunity prevents wild type hamsters from being effectively infected to be used as animal models.

Vaccines against mucosally invasive, intracellular pathogens must induce a myriad of immune responses to provide optimal mucosal and systemic protection, including CD4+ T cells, CD8+ T cells, and Ab-producing B cells. In general, CD4+ T cells are known to provide important helper functions for both CD8+ T cell and B cell responses. However, the relative importance of CD4+ T cells, CD8+ T cells, and B cells for mucosal protection is less clearly defined. We have studied these questions in detail using the murine model of Trypanosoma cruzi infection. Despite our initial hypothesis that mucosal Abs would be important, we show that B cells are critical for systemic, but not mucosal, T. cruzi protective immunity. B cell–deficient mice developed normal levels of CD8+ effector T cell responses early after mucosal T. cruzi infection and T. cruzi trans-sialidase vaccination. However, after highly virulent systemic challenge, T. cruzi immune mice lacking T. cruzi–specific B cells failed to control parasitemia or prevent death. Mechanistically, T. cruzi–specific CD8+ T cells generated in the absence of B cells expressed increased PD-1 and Lag-3 and became functionally exhausted after high-level T. cruzi systemic challenge. T. cruzi immune serum prevented CD8+ T cell functional exhaustion and reduced mortality in mice lacking B cells. Overall, these results demonstrate that T. cruzi–specific B cells are necessary during systemic, but not mucosal, parasite challenge.

Adenovirus infections of immunocompromised pediatric hematopoietic stem cell transplant patients can develop into serious and often deadly multi-organ disease. There are no drugs approved for adenovirus infections. Cidofovir (an analog of 2-deoxycytidine monophosphate) is used at times but it can be nephrotoxic and its efficacy has not been proven in clinical trials. Brincidofovir, a promising lipid-linked derivative of cidofovir, is in clinical trials. Ganciclovir, an analog of 2-deoxyguanosine, has been employed occasionally but with unknown efficacy in the clinic. In this study, we evaluated valganciclovir against disseminated adenovirus type 5 (Ad5) infection in our permissive immunosuppressed Syrian hamster model. We administered valganciclovir prophylactically, beginning 12 h pre-infection or therapeutically starting at Day 1, 2, 3, or 4 post-infection. Valganciclovir significantly increased survival, reduced viral replication in the liver, and mitigated the pathology associated with Ad5 infection. In cultured cells, valganciclovir inhibited Ad5 DNA replication and blocked the transition from early to late stage of infection. Valganciclovir directly inhibited Ad5 DNA polymerase in vitro, which may explain, at least in part, its mechanism of action. Ganciclovir and valganciclovir are approved to treat infections by certain herpesviruses. Our results support the use of valganciclovir to treat disseminated adenovirus infections in immunosuppressed patients.

Adenocarcinoma in the human stomach evolves in the setting of Helicobacter pylori-induced oxyntic atrophy and chronic mucous cell metaplasia.Two types of metaplasia associated with development of intestinal-type cancers are observed in the human stomach: intestinal metaplasia (IM; intestinal type goblet cells in the stomach) and Spasmolytic Polypeptide (TFF2) Expressing Metaplasia (SPEM; with the presence of antral type TFF2-expressing mucous cells in the oxyntic region).Our previous study showed that SPEM developed from transdifferentiation of mature chief cells, rather than originating from aberrant differentiation of resident progenitor cells.Recent investigations have noted evidence for increased Ras activity in up to a third of gastric cancers.Thus, we have hypothesized that activated Ras, specifically induced in mature chief cells, elicits transdifferentiation of chief cells into SPEM and progression of SPEM to more intestinalized metaplasia.To test this hypothesis, we have examined a novel mouse model of metaplasia in the stomach in Mist1-CreERT2Tg/+;LSL-K-Ras(G12D)Tg/+;mT/mGTg/+ mice.Tamoxifen (TAM) treatment induces the expression of activated K-Ras specifically in mature chief cells and marks the K-Ras-induced chief cells with GFP as a lineage tracer.This mouse model rapidly develops SPEM and IM within 3 months, following TAM induction of activated K-Ras expression in mature chief cells.At 1 week post TAM treatment, we found several groups of metaplastic glands between normal oxyntic glands that were positive for SPEM markers.At 3 months post TAM treatment, oxyntic glands were replaced with metaplastic glands that showed highly proliferative mucous cell populations at the bases and the cells in the metaplastic glands were strongly positive for clusterin and TFF3 with distinct goblet cell morphologies, and also positive for Pdx1.Some glands were positive for IM markers such as villin and Cdx1.The mice at 4 months post TAM treatment developed severe inflammation, metaplasia, dysplasia and the invasive adenocarcinoma.Consistent with active K-Ras expression, cells with nuclear expression of phospho-ERK1/2 were also observed at the bases of metaplastic glands.Interestingly, we observed that the metaplastic glands were positive for GFP, indicating that they were derived from transdifferentiation of Cre-induced chief cells.Therefore, the induction of activated Ras specifically in mature chief cells initially leads to transdifferentiation of chief cells into SPEM followed by evolution of goblet cell IM and eventual neoplastic lesions.These studies demonstrate that expression of activated Ras in Chief cells can lead to the development of the entire spectrum of metaplastic and neoplastic lineages leading to gastric cancer.

Chronic inflammation is a major risk factor for cancer, including gastric cancers and other gastrointestinal cancers. For example, chronic inflammation caused by autoimmune gastritis (AIG) is associated with an increased risk of gastric polyps, gastric carcinoid tumors, and possibly adenocarcinomas. In this study, we characterized the progression of gastric cancer in a novel mouse model of AIG. In this model, disease was caused by CD4(+) T cells expressing a transgenic T-cell receptor specific for a peptide from the H(+)/K(+) ATPase proton pump, a protein expressed by parietal cells in the stomach. AIG caused epithelial cell aberrations that mimicked most of those seen in progression of human gastric cancers, including chronic gastritis followed by oxyntic atrophy, mucous neck cell hyperplasia, spasmolytic polypeptide-expressing metaplasia, dysplasia, and ultimately gastric intraepithelial neoplasias. Our work provides the first direct evidence that AIG supports the development of gastric neoplasia and provides a useful model to study how inflammation drives gastric cancer.

Interleukin-12 is a potent activator and initiator of type-1 T cell development, and can be used as an adjuvant to bias for the development of vaccine-induced Th1 immune responses. During vaccination of MHC class I deficient beta-2 microglobulin knockout mice (beta M-2(-/-)) with an IL-12/alpha IL-4 Th1 biasing procedure, all of the mice died. None of the IL-12/alpha IL-4 treated wild type mice developed any noticeable complications. We hypothesized that NI( cells may be activated by IL-12 treatment in these beta M-2(-/-) mice, leading to necrosis and eventual death. IL-12/alpha IL-4 treatment of beta M-2(-/-) mice resulted in increased NK cell numbers and activation status (IFN-gamma(+), CD69(+)). Finally, in vivo depletion of NK cells reversed the pathology induced by IL-12/alpha IL-4 treatment in beta M-2 deficient mice. These results indicate that IL-12 combined with alpha IL-4 irreversibly activates NM cells leading to a disseminated inflammatory pathology and death in beta M-2(-/-) mice. (c) 2013 Elsevier Ltd. All rights reserved.

The human population is currently faced with the potential use of natural or recombinant variola and monkeypox viruses as biological weapons. Furthermore, the emergence of human monkeypox in Africa and its expanding environs poses a significant natural threat. Such occurrences would require therapeutic and prophylactic intervention with antivirals to minimize morbidity and mortality of exposed populations. Two orally-bioavailable antivirals are currently in clinical trials; namely CMX001, an ether-lipid analog of cidofovir with activity at the DNA replication stage and ST-246, a novel viral egress inhibitor. Both of these drugs have previously been evaluated in the ectromelia/mousepox system; however, the trigger for intervention was not linked to a disease biomarker or a specific marker of virus replication. In this study we used lethal, intranasal, ectromelia virus infections of C57BL/6 and hairless SKH1 mice to model human disease and evaluate exanthematous rash (rash) as an indicator to initiate antiviral treatment. We show that significant protection can be provided to C57BL/6 mice by CMX001 or ST-246 when therapy is initiated on day 6 post infection or earlier. We also show that significant protection can be provided to SKH1 mice treated with CMX001 at day 3 post infection or earlier, but this is four or more days before detection of rash (ST-246 not tested). Although in this model rash could not be used as a treatment trigger, viral DNA was detected in blood by day 4 post infection and in the oropharyngeal secretions (saliva) by day 2-3 post infection - thus providing robust and specific markers of virus replication for therapy initiation. These findings are discussed in the context of current respiratory challenge animal models in use for the evaluation of poxvirus antivirals. (c) 2012 Elsevier B.V. All rights reserved.

Exposure to moderately selective p38 alpha mitogen-activated protein kinase (MAPK) inhibitors in the Beagle dog results in an acute toxicity consisting of mild clinical signs (decreased activity, diarrhea, and fever), lymphoid necrosis and depletion in the gut-associated lymphoid tissue (GALT), mesenteric lymph nodes and spleen, and linear colonic and cecal mucosal hemorrhages. Lymphocyte apoptosis and necrosis in the GALT is the earliest and most prominent histopathologic change observed, followed temporally by neutrophilic infiltration and acute inflammation of the lymph nodes and spleen and multifocal mucosal epithelial necrosis and linear hemorrhages in the colon and cecum. These effects are not observed in the mouse, rat, or cynomolgus monkey. To further characterize the acute toxicity in the dog, a series of in vivo, in vitro, and immunohistochemical studies were conducted to determine the relationship between the lymphoid and gastrointestinal (GI) toxicity and p38 MAPK inhibition. Results of these studies demonstrate a direct correlation between p38 alpha MAPK inhibition and the acute lymphoid and gastrointestinal toxicity in the dog. Similar effects were observed following exposure to inhibitors of MAPK-activated protein kinase-2 (MK2), further implicating the role of p38 alpha MAPK signaling pathway inhibition in these effects. Based on these findings, the authors conclude that p38 alpha MAPK inhibition results in acute lymphoid and GI toxicity in the dog and is unique among the species evaluated in these studies.

ABSTRACT Monkeypox virus (MPXV) is an orthopoxvirus closely related to variola, the etiological agent of smallpox. In humans, MPXV causes a disease similar to smallpox and is considered to be an emerging infectious disease. Moreover, the use of MPXV for bioterroristic/biowarfare activities is of significant concern. Available small animal models of human monkeypox have been restricted to mammals with poorly defined biologies that also have limited reagent availability. We have established a murine MPXV model utilizing the STAT1-deficient C57BL/6 mouse. Here we report that a relatively low-dose intranasal (IN) infection induces 100% mortality in the stat1 − / − model by day 10 postinfection with high infectious titers in the livers, spleens, and lungs of moribund animals. Vaccination with modified vaccinia virus Ankara (MVA) followed by a booster vaccination is sufficient to protect against an intranasal MPXV challenge and induces an immune response more robust than that of a single vaccination. Furthermore, antiviral treatment with CMX001 (HDP-cidofovir) and ST-246 protects when administered as a regimen initiated on the day of infection. Thus, the stat1 − / − model provides a lethal murine platform for evaluating therapeutics and for investigating the immunological and pathological responses to MPXV infection.

Chagas' disease, induced by Trypanosoma cruzi, is a common cause of infectious myocarditis. Recent clinical treatment trials and vaccine studies indicate that chagasic immunopathology is directed against the parasite and not self-antigens. Therefore, vaccines may have the potential to protect against disease progression. Certain combinations of mouse and parasite strains produce significant histopathology and can be used for safety analyses of new vaccination strategies. The goals of this study were to determine (1) whether the development of chagasic cardiomyopathy in the murine model could be identified by electrocardiogram (ECG); and (2) whether these potential chagasic ECG changes would correlate with histopathologic findings. Groups of BALB/c, C57BL/6, and C3H mice were infected with different parasite strains (Tulahuén, Brazil, or Sylvio-X10/4) and evaluated weekly by ECG. Selected tissues from subsets of mice were harvested periodically for blinded histologic evaluation. Significantly increased proportions of BALB/c mice infected with Brazil and Tulahuén strain parasites displayed prolonged QT intervals. Prolonged mean QT intervals detected in infected BALB/c mice significantly correlated with chagasic histopathologic changes. These results indicate that ECG can be used as a non-invasive method to screen for immune-mediated damage resulting in chagasic cardiomyopathy in the murine model.

BCL-2/E1B-19 kDa-interacting protein 3 (BNIP3) is a BH3-only mitochondrial protein. Expression of BNIP3 is strongly stimulated by hypoxia. Up-regulation of BNIP3 has been detected in several human carcinomas including carcinomas of the lung and breast. The significance of BNIP3 overexpression in these cancers is not known. To determine whether BNIP3 plays a role in tumor growth, we generated A549 lung carcinoma cells that overexpressed BNIP3 and examined their ability to form tumors in the mouse xenograft model. All cell lines that overexpressed BNIP3 formed larger tumors compared to the parental or vector-transformed A549 cells. Breast carcinoma cell lines that overexpressed BNIP3 also induced tumors in athymic mice in the absence of hormone administration, while the parental cell line did not. Stable shRNA-mediated knockdown of endogenous BNIP3 severely impaired the tumorigenic activity of A549 cells. The tumor growth-enhancing activity was reduced by deletion of the BH3 domain of BNIP3. Expression of a dominant-negative mutant of BNIP3 lacking the C-terminal transmembrane domain also inhibited the tumorigenic potential of A549 cells. These results suggest that BNIP3 plays a fundamental role in the development of certain solid tumors such as the lung and breast carcinomas.

Syrian hamster is a practical animal model for studying the systemic effects of oncolytic vectors derived from adenovirus serotype 5 (Ad5). Ad5 replicates well in Syrian hamster tissues, and Syrian hamster cell lines are available that are known to support Ad5 replication. In this study, we established four new Syrian hamster cell lines from transplantable pancreatic, renal, hepatic and lung tumors. The pancreatic cell line (SHPC6) and the renal cell line were highly permissive for Ad5 replication. The SHPC6 cell line formed disseminated intraperitoneal tumors when cells were injected into the peritoneal cavity. INGN 007, an oncolytic Ad5-based vector, completely reversed the growth of disseminated intraperitoneal SHPC6 tumor nodules following intraperitoneal injection of the vector, leading to 100% survival of the treated animals. SHPC6 cells also formed subcutaneous tumors, whose growth was suppressed by INGN 007 following intratumoral injection. INGN 007 replicated in both the intraperitoneal and subcutaneous SHPC6 tumors. Following intraperitoneal injection, INGN 007 did not replicate in the livers of hamsters with intraperitoneal SHPC6 tumors, and was not hepatotoxic. These studies suggest that the SHPC6 cell line may be useful as a model for disseminated pancreatic cancer, and that INGN 007 may be a safe and effective vector to treat these tumors.