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Preliminary reports suggest that patients with primary biliary cirrhosis (PBC) have evidence of human betaretrovirus infection. The aim of this study was to determine whether antiviral therapy impacts on the disease process. We conducted two consecutive open-labeled, nonrandomized, 1-yr pilot studies; the first with lamivudine 150 mg/day and the second with Combivir combination therapy using lamivudine 150 mg and zidovudine 300 mg twice a day. Eleven PBC patients enrolled in each study, seven patients were entered into both studies, and one patient was withdrawn from each study due to side effects. Evaluation of liver biopsies before and after lamivudine therapy showed a 4-5 increase in necroinflammatory score, a 1-1.5 elevation in bile duct injury, with little change in the percentage of portal tracts with bile ducts (50-52%). None of the patients in the lamivudine study normalized alkaline phosphatase. Histological assessment following Combivir therapy revealed a 6 to 4 improvement in necroinflammatory score (p < 0.03, 95% CI: 0.53-2.33), a 3 to 1 reduction in bile duct injury (p < 0.02, 95% CI: 1.08-2.07), and a 45-75% increase in portal tracts with bile ducts (p < 0.05, 95% CI: 0.02-0.29). In the Combivir cohort, five patients normalized alkaline phosphatase and four developed normal AST, ALT, and alkaline phosphatase. Histological and biochemical endpoints were achieved in the Combivir pilot study suggesting a larger placebo-controlled trial is required as a proof of principle to assess whether antiviral therapy impacts the PBC disease process.

Background: Although ∼20% of human cancers are caused by microorganisms, only suspicion exists for a microbial cause of lung cancer. Potential infectious agents were investigated in non-small cell lung cancer (NSCLC) and non-neoplastic lung. Methods: Seventy NSCLC tumours (33 squamous cell carcinomas, 17 adenocarcinomas, 10 adenocarcinomas with lepidic spread, and 10 oligometastases) and 10 non-neoplastic lung specimens were evaluated for molecular evidence of microorganisms. Tissues were subjected to the Lawrence Livermore Microbial Detection Array, an oncovirus panel of the International Agency for Research on Cancer, and human papillomavirus (HPV) genotyping. Associations were examined between microbial prevalence, clinical characteristics, and p16 and EGFR expression. Results: Retroviral DNA was observed in 85% squamous cell carcinomas, 47% adenocarcinomas, and 10% adenocarcinomas with lepidic spread. Human papillomavirus DNA was found in 69% of squamous cell carcinomas with 30% containing high-risk HPV types. No significant viral DNA was detected in non-neoplastic lung. Patients with tumours containing viral DNA experienced improved long-term survival compared with patients with viral DNA-negative tumours. Conclusions: Most squamous cell carcinomas and adenocarcinomas contained retroviral DNA and one-third of squamous cell carcinomas contained high-risk HPV DNA. Viral DNA was absent in non-neoplastic lung. Trial results encourage further study of the viral contribution to lung carcinogenesis.

Background Immunity against pathogens evolved through complex mechanisms that only for sake of simplicity are defined as innate immunity and adaptive immunity. Indeed innate and adaptive immunity are strongly intertwined each other during evolution. The complexity is further increased by intrinsic mechanisms of immunity that rely on the action of intracellular molecules defined as restriction factors (RFs) that, particularly in virus infections, counteract the action of pathogen gene products acting at different steps of virus life cycle. Main body and conclusion Here we provide an overview on the nature and the mode of action of restriction factors involved in retrovirus infection, particularly Human T Leukemia/Lymphoma Virus 1 (HTLV-1) infection. As it has been extensively studied by our group, special emphasis is given to the involvement of the MHC class II transactivator CIITA discovered in our laboratory as regulator of adaptive immunity and subsequently as restriction factor against HIV-1 and HTLV-1, a unique example of dual function linking adaptive and intrinsic immunity during evolution. We describe the multiple molecular mechanisms through which CIITA exerts its restriction on retroviruses. Of relevance, we review the unprecedented findings pointing to a concerted action of several restriction factors such as CIITA, TRIM22 and TRIM19/PML in synergizing against retroviral replication. Finally, as CIITA profoundly affects HTLV-1 replication by interacting and inhibiting the function of HTLV-1 Tax-1 molecule, the major viral product associated to the virus oncogenicity, we also put forward the hypothesis of CIITA as counteractor of HTLV-1-mediated cancer initiation.

BackgroundAlthough existing studies show that reactivation of the human endogenous retrovirus (HERVs) plays a leading role in multiple sclerosis (MS) progression, the practitioners are yet to establish effective approaches for managing MS without jeopardizing the patients’ immune systems.AimTo provide up-to-date knowledge on the specific roles played by the reactivation of the HERVs in the pathogenesis of MS.Materials and methodsA systematic review of 70 peer-reviewed journals accessed via PubMed was conducted. The searches generated more than 600 sources that were evaluated based on three step in and exclusion criteria. The selected sources were critically analyzed vis-à-vis the paper’s hypothesis which posits that the HERVs reactivation does not directly cause the MS, but triggers a demyelination process by promoting the pathogenic effects of the retroviruses. The paper further documents the advancements in the therapeutic applications resulting from the immunohistological analysis and pathological studies aimed at minimizing the adverse consequences of the HERVs reactivation.Results and discussionsOnly three out of the 70 reviewed sources did not find provide evidence linking the reactivation of HERV and MS progression. On the other hand, overwhelming pieces of evidence confirm that the reactivations often drive the demyelinating plaques by initiating microglial inflammation. Pathological examinations reveal that the inflammatory monocytes (Ly6ChiCCR2 + CX3CR1lo) trigger the reactivation of the malignant T cells that are responsible for the progression of MS. These findings are promoting new discoveries as far as managing MS is concerned.

Breast cancer is the most frequent malignancy affecting women worldwide. It has been suggested that infection by Epstein Barr Virus (EBV), Mouse Mammary Tumor Virus or a similar virus, MMTV-like virus (MMTV-LV), play a role in the etiology of the disease. However, studies looking at the presence of these viruses in breast cancer have produced conflicting results and this possible association remains controversial. Here, we used polymerase chain reaction assay to screen specific sequences of EBV and MMTV-LV in 86 tumor and 65 adjacent tissues from Mexican women with breast cancer. Neither tumor samples nor adjacent tissue were positive for either virus in a first round PCR and only 4 tumor samples were EBV positive by a more sensitive nested PCR. Considering the study's statistical power, these results do not support the involvement of EBV and MMTV-LV in the etiology of breast cancer.

The most common neurological complication in patients receiving successful combination antiretroviral therapy (cART) is peripheral neuropathic pain. Data show that distal symmetric polyneuropathy (DSP) also develops along with murine acquired immunodeficiency syndrome (MAIDS) after infection with the LP-BM5 murine retrovirus mixture. Links between cannabinoid receptor 2 (CB2R) and peripheral neuropathy have been established in animal models using nerve transection, chemotherapy-induced pain, and various other stimuli. Diverse types of neuropathic pain respond differently to standard drug intervention, and little is currently known regarding the effects of modulation through CB2Rs. In this study, we evaluated whether treatment with the exogenous synthetic CB2R agonists JWH015, JWH133, Gp1a, and HU308 controls neuropathic pain and neuroinflammation in animals with chronic retroviral infection. Hind-paw mechanical hypersensitivity in CB2R agonist-treated versus untreated animals was assessed using the MouseMet electronic von Frey system. Multicolor flow cytometry was used to determine the effects of CB2R agonists on macrophage activation and T-lymphocyte infiltration into dorsal root ganglia (DRG) and lumbar spinal cord (LSC). Results demonstrated that, following weekly intraperitoneal injections starting at 5 wk p.i., JWH015, JWH133, and Gp1a, but not HU308 (5 mg/kg), significantly ameliorated allodynia when assessed 2 h after ligand injection. However, these same agonists (2x/wk) did not display antiallodynic effects when mechanical sensitivity was assessed 24 h after ligand injection. Infection-induced macrophage activation and T-cell infiltration into the DRG and LSC were observed at 12 wk p.i., but this neuroinflammation was not affected by treatment with any CB2R agonist. Activation of JAK/STAT3 has been shown to contribute to development of neuropathic pain in the LSC and pretreatment of primary murine microglia (2 h) with JWH015-, JWH133-, or Gp1a-blocked IFN-gamma-induced phosphorylation of STAT1 and STAT3. Taken together, these data show that CB2R agonists demonstrate acute, but not long-term, antiallodynic effects on retrovirus infection-induced neuropathic pain.

Endogenous retroviruses (ERVs) are genomic elements that are present in a wide range of vertebrates and have been implicated in a variety of human diseases, including cancer. However, the characteristic expression patterns of ERVs, particularly in virus-induced tumours, is not fully clear. DNA methylation was analysed by bisulfite pyrosequencing, and gene expression was analysed by RT-qPCR. In this study, we first found that the endogenous avian retrovirus ALVE1 was highly expressed in some chicken tissues (including the heart, bursa, thymus, and spleen) at 2 days of age, but its expression was markedly decreased at 35 days of age. In contrast, the CpG methylation level of ALVE1 was significantly lower in heart and bursa at 2 days than at 35 days of age. Moreover, we found that the expression of ALVE1 was significantly inhibited in chicken embryo fibroblast cells (CEFs) and MSB1 cells infected with avian leukosis virus subgroup J (ALVJ) and reticuloendotheliosis virus (REV) at the early stages of infection. In contrast, the expression of the ALVE1 env gene was significantly induced in CEFs and MSB1 cells infected with Marek’s disease virus (MDV). However, the methylation and expression levels of the ALVE1 long terminal repeat (LTR) did not show obvious alterations in response to viral infection. The present study revealed the expression patterns of ALVE1 in a variety of chicken organs and tissues and in chicken cells in response to avian tumour virus infection. These findings may be of significance for understanding the role and function of ERVs that are present in the host genome.

Introduction Matrix metalloproteinase-8 (MMP-8; neutrophil collagenase) is an important regulator of innate immunity that has oncosuppressive actions in numerous tumor types. Methods We have intercrossed Mmp8 -null mice with the Polyoma virus middle T oncogene-driven (MMTV-PyMT) mouse model of mammary cancer to explore the effects of loss of MMP-8 on the incidence and progression of mammary carcinomas. Results In this aggressive mouse model of breast cancer, loss of MMP-8 accelerated tumor onset even further, such that 90% of MMTV-PyMT ; Mmp8 -null female mice were tumor-bearing at the time of weaning. Throughout the 14 weeks of the model, tumor burden increased in homozygous Mmp8 -null mice compared to Mmp8 -wild-type and -heterozygote animals. Likewise, lung metastasis dramatically increased in the MMTV-PyMT ; Mmp8 -null mice. Immunohistochemistry revealed that tumors in wild-type, Mmp8 -heterozygotes and -null animals had similar vascular density at 8 weeks, but at 10 weeks Mmp8 -wild-type tumors had a lower vascularity than their heterozygote and null counterparts. No differences in macrophage infiltration were apparent throughout primary tumor development, though at 10 weeks a drop in neutrophil infiltrates was observed in Mmp8 -wild-type tumors. Using quantitative real-time RT-PCR, we tracked the expression of the entire Mmp and Timp gene families, observing a significant decrease in Mmp3 expression in Mmp8 -null tumors compared to wild-type and heterozygotes throughout the time course of the model, which was confirmed at the protein level. Conclusions These findings provide novel insight into the suppressive action of MMP-8 on mammary tumorigenesis and metastasis, and indicate that the loss of MMP-8 likely has pleiotropic effects on innate immunity and angiogenesis that are reflected in changes in the protease web.

Retroviruses have been foundational in cancer research since early studies identified proto-oncogenes as targets for insertional mutagenesis. Integration of murine gamma-retroviruses into the host genome favours promoters and enhancers and entails interaction of viral integrase with host BET/bromodomain factors. We report that this integration pattern is conserved in feline leukaemia virus (FeLV), a gamma-retrovirus that infects many human cell types. Analysis of FeLV insertion sites in the MCF-7 mammary carcinoma cell line revealed strong bias towards active chromatin marks with no evidence of significant post-integration growth selection. The most prominent FeLV integration targets had little overlap with the most abundantly expressed transcripts, but were strongly enriched for annotated cancer genes. A meta-analysis based on several gamma-retrovirus integration profiling (GRIP) studies in human cells (CD34+, K562, HepG2) revealed a similar cancer gene bias but also remarkable cell-type specificity, with prominent exceptions including a universal integration hotspot at the long non-coding RNA MALAT1. Comparison of GRIP targets with databases of super-enhancers from the same cell lines showed that these have only limited overlap and that GRIP provides unique insights into the upstream drivers of cell growth. These observations elucidate the oncogenic potency of the gamma-retroviruses and support the wider application of GRIP to identify the genes and growth regulatory circuits that drive distinct cancer types.

Background Conflicting results regarding the association of MMTV with human breast cancer have been reported. Published sequence data have indicated unique MMTV strains in some human samples. However, concerns regarding contamination as a cause of false positive results have persisted. Methods We performed PCR assays for MMTV on human breast cancer cell lines and fresh frozen and formalin fixed normal and malignant human breast epithelial samples. Assays were also performed on peripheral blood mononuclear cells from volunteer blood donors and subjects at risk for human retroviral infections. In addition, assays were performed on DNA samples from wild and laboratory mice. Sequencing of MMTV positive samples from both humans and mice were performed and phylogenetically compared. Results Using PCR under rigorous conditions to prevent and detect “carryover” contamination, we did detect MMTV DNA in human samples, including breast cancer. However, the results were not consistent and seemed to be an artifact. Further, experiments indicated that the probable source of false positives was murine DNA, containing endogenous MMTV, present in our building. However, comparison of published and, herein, newly described MMTV sequences with published data, indicates that there are some very unique human MMTV sequences in the literature. Conclusion While we could not confirm the true presence of MMTV in our human breast cancer subjects, the data indicate that further, perhaps more traditional, retroviral studies are warranted to ascertain whether MMTV might rarely be the cause of human breast cancer.