Papillomaviruses (PVs) induce papillomas, premalignant lesions, and carcinomas in a wide variety of species. PVs are classified first based on their host and tissue tropism and then their genomic diversities. A laboratory mouse papillomavirus, MmuPV1 (formerly MusPV), was horizontally transmitted within an inbred colony of NMRI-Foxn1nu/Foxn1nu (nude; T cell deficient) mice of an unknown period of time. A ground-up, filtered papilloma inoculum was not capable of infecting C57BL/6J wild-type mice; however, immunocompetent, alopecic, S/RV/Cri-ba/ba (bare) mice developed small papillomas at injection sites that regressed. NMRI-Foxn1nu and B6.Cg-Foxn1nu, but not NU/J-Foxn1nu, mice were susceptible to MmuPV1 infection. B6 congenic strains, but not other congenic strains carrying the same allelic mutations, lacking B- and T-cells, but not B-cells alone, were susceptible to infection, indicating that mouse strain and T-cell deficiency are critical to tumor formation. Lesions initially observed were exophytic papillomas around the muzzle, exophytic papillomas on the tail, and condylomas of the vaginal lining which could be induced by separate scarification or simultaneous scarification of MmuPV1 at all four sites. On the dorsal skin, locally invasive, poorly differentiated tumors developed with features similar to human trichoblastomas. Transcriptome analysis revealed significant differences between the normal skin in these anatomic sites and in papillomas versus trichoblastomas. The primarily dysregulated genes involved molecular pathways associated with cancer, cellular development, cellular growth and proliferation, cell morphology, and connective tissue development and function. Although trichoepitheliomas are benign, aggressive tumors, few of the genes commonly associated with basal cell carcinoma or squamous cells carcinoma were highly dysregulated.

Molecular imaging has gained attention as a possible approach for the study of the progression of inflammation and disease dynamics. Herein we used [18F]-2-deoxy-2-fluoro-D-glucose ([18F]-FDG) as a radiotracer for PET imaging coupled with CT (FDG-PET/CT) to gain insight into the spatiotemporal progression of the inflammatory response of ferrets infected with a clinical isolate of a pandemic influenza virus, H1N1 (H1N1pdm). The thoracic regions of mock- and H1N1pdm-infected ferrets were imaged prior to infection and at 1, 2, 3 and 6 days post-infection (DPI). On 1 DPI, FDG-PET/CT imaging revealed areas of consolidation in the right caudal lobe which corresponded with elevated [18F]-FDG uptake (maximum standardized uptake values (SUVMax), 4.7–7.0). By days 2 and 3, consolidation (CT) and inflammation ([18F]-FDG) appeared in the left caudal lobe. By 6 DPI, CT images showed extensive areas of patchy ground-glass opacities (GGO) and consolidations with the largest lesions having high SUVMax (6.0–7.6). Viral shedding and replication were detected in most nasal, throat and rectal swabs and nasal turbinates and lungs on 1, 2 and 3 DPI, but not on day 7, respectively. In conclusion, molecular imaging of infected ferrets revealed a progressive consolidation on CT with corresponding [18F]-FDG uptake. Strong positive correlations were measured between SUVMax and bronchiolitis-related pathologic scoring (Spearman’s ρ = 0.75). Importantly, the extensive areas of patchy GGO and consolidation seen on CT in the ferret model at 6 DPI are similar to that reported for human H1N1pdm infections. In summary, these first molecular imaging studies of lower respiratory infection with H1N1pdm show that FDG-PET can give insight into the spatiotemporal progression of the inflammation in real-time.

A papillomavirus (PV) that naturally infects laboratory mice will provide an extremely valuable tool for PV research. We describe here the isolation, cloning and molecular analysis of the first novel laboratory-mouse PV, designated MusPV. This agent, recently identified in the tissues from florid and asymmetrical papillomas on the face of nude mice (NMRI-Foxn1

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Abstract. Expression and secretion of procathepsin D (pCD) increases proliferation, metastasis and progression of breast cancer but the structural moiety by which pCD exerts these effects is still ambiguous. Here, we present data on a series of pCD stable mutants to identify the pCD region that mediates this mitogenic effect. Mutations affecting the region of the activation peptide (AP) were studied together with catalytic and glycosylation mutants. Mitogenic effect was evaluated using in vitro invasion and proliferation assays and in vivo by determining the tumorigenic potential. The catalytic mutants and glycosylation mutants of pCD continued to display enhanced cell proliferation, invasion and tumorigenicity similar to stable transfectants of native pCD, suggesting that neither the proteolytic activity nor the sugar moieties contribute to the mitogenic effect. However, stable transfectants of pCD lacking its AP and with various mutations in the 27-44 amino acid region of AP, failed to show enhanced cell proliferation or invasion in vitro and tumor growth in vivo, establishing the importance of AP region. Our study concludes that the entire 27-44 amino acid region of AP is necessary for the stimulatory actions of pCD on breast cancer cells.

Elevated level of procathepsin D (pCD), a zymogen of lysosomal aspartic proteinase cathepsin D, is associated with highly invasive neoplasms that include breast cancer. Independent studies have established that secreted pCD functions as a growth factor acting both in an autocrine and paracrine manner. Therefore, to explore whether pCD can be employed as a therapeutic target, the present study evaluates the impact of pCD knockdown using RNA interference technology. Of the three siRNA oligos tested, siRNA-3 exhibited a 90% inhibitory effect on pCD gene expression. Stable attenuation of pCD in breast cancer cells MDA-MB-231 was achieved by using a plasmid vector-based shRNA system. Pronounced suppression of pCD expression was accompanied by a significant reduction in invasion and proliferation of MDA-MB-231 cells stably transfected with functional shRNA. Importantly, in the athymic nude mice model, downregulation of pCD in breast cancer cells significantly reduced their metastatic potential. In addition, we observed a reduction in Cdc42 and NFkB2 expression in MDA-MB-231 cells with decreased pCD expression. When combined, our in vitro and in vivo experiments demonstrate that targeting pCD through RNAi technology represents a potential therapeutic tool for developing a therapy against breast cancer.

Abstract. Procathepsin D (pCD), a zymogen of lysosomal aspartic peptidase cathepsin D, overexpression is correlated with highly invasive malignancies, including breast cancer. Recently, different studies have shown the role of secreted pCD as mitogen acting both in an autocrine and a paracrine manner. The aim of the present study is to examine the antitumor effects elicited by a decrease in the protein level of pCD by ribozyme and to explore the therapeutic potential of this specific targeting. Using the mFold program, we designed seven anti-pCD ribozymes and checked the accessibility to target pCD mRNA by RNase H cleavage experiment in a cell-free system. The sequences of the 4 most effective ribozymes were cloned and stably transfected in a highly metastatic human breast cancer cell line, MDA-MB-231, to knock down the expression of pCD. Downregulation of pCD due to ribozyme expression was observed by Western blotting and real-time RT-PCR. Stably transfected cells with antipCD ribozymes exhibited a significant lowering of in vitro invasion (p<0.001) and reduction in lung colonization potential in nude mice when compared to control ribozyme transfected cells. We also found that downregulation of pCD by ribozyme promotes apoptosis of MDA-MB-231 cells on serum deprivation. These results suggest that we have generated a biologically functional ribozyme against pCD with possible therapeutic implications in breast cancer cells.

The inflammatory response is modulated through interactions among the nervous, endocrine, and immune systems. Intercommunication between immune cells and the autonomic nervous system is a growing area of interest. Spatial and temporal information about inflammatory processes is relayed to the central nervous system (CNS) where neuroimmune modulation serves to control the extent and intensity of the inflammation. Over the past few decades, research has revealed various routes by which the nervous system and the immune system communicate. The CNS regulates the immune system via hormonal and neuronal pathways, including the sympathetic and parasympathetic nerves. The immune system signals the CNS through cytokines that act both centrally and peripherally. This review aims to introduce the concept of neuroimmune interaction and discuss its potential clinical application, in an attempt to broaden the awareness of this rapidly evolving area and open up new avenues that may aid in the treatment of inflammatory diseases.