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Helicobacter pylori has acquired great importance during the last two decades, after being recognized as an important pathogen that infects a great portion of the human population. This microorganism is recognized as the main causal agent of chronic gastritis and duodenal ulcers, and it is associated with the subsequent development of gastric carcinoma. The pathogenic mechanisms of H. pylori and their relation to gastric ailments have not been clearly defined. However, at present it is well established that urease, vacuolating cytotoxin VacA, and the pathogenicity island (cag PAI) gene products, are the main factors of virulence of this organism. Thus, individuals infected with strains that express these virulence factors probably develop a severe local inflammation that may induce the development of peptic ulcer and gastric cancer. The way the infection spreads throughout the world suggests the possibility that there are multiple pathways of transmission. Due to the importance that H. pylori has acquired as a human pathogen, laboratories worldwide are attempting to develop a vaccine that confers long-term immunological protection against infection by this microorganism. Hence, the objective of this review is to present the most relevant findings of the biology of H. Pylori and its interaction with the human host. The full version of this paper is available too at: http://www.insp.mx/salud/index.html

Interferon tau (IFN-τ) is a promising alternative antiviral and immunotherapeutic agent in a wide variety of diseases including infectious, neurodegenerative, autoimmune and cancer due to its low toxicity in comparison with other type I interferon´s. The objective of our study was established the effect of the bovine IFN-τ on human (SiHa) and murine (BMK-16/myc) cells transformed with HPV 16 and evaluates the antitumor effect in a murine tumor model HPV 16 positive. We determine that bovine IFN-τ has antiproliferative effects, pro-apoptotic activity and induces repression of viral E6 and E7 oncogenes (time- and dose-dependent) on human and murine cells transformed with HPV 16 similar to the effects of IFN-β. However, IFN-τ induces greater antiproliferative effect, apoptosis and repression of both oncogenes in BMK-16/myc cells compared to SiHa cells. The differences were explained by the presence and abundance of the type I interferon receptor (IFNAR) in each cell line. On the other hand, we treated groups of tumor-bearing mice (HPV16 positive) with IFN-τ and showed the inhibition tumor growth effect in vivo . Our finding indicates that bovine IFN-τ may be a good candidate for immunotherapy against cervical cancer., Competing Interests: The authors declare no conflict of interest.

Human papillomavirus (HPV) is a DNA virus that infects epithelial cells and has been implicated in the development of cervical cancer. Few therapeutic strategies have been designed for the treatment of cervical intraepithelial neoplasia, a precursor of cervical cancer. In these early stages, the HPV E2 protein is the most important viral factor involved in viral gene expression and plays crucial roles during the vegetative viral cycle in epithelial cells. Papillomavirus E2 binds specifically to palindromic ACCN 6 GGT sequences, referred to as the E2 binding sites (E2BS), which are concentrated within the viral long control region, and which are responsible for regulation of the HPV protein's expression. Here, we consider E2BS as a candidate sequence to induce the expression of antiviral therapeutic genes selectively in HPV-infected cells expressing the E2 protein. This study focuses on the use of an HPV-specific promoter comprised of four E2BS to drive the expression of IL-12, leading to an antitumor effect in an HPV-positive murine tumor model. The therapeutic strategy was implemented via viral gene therapy using adenoviral vectors with recombinant E2 and IL-12 genes and E2BS-IL-12. We demonstrate that the HPV-specific promoter E2BS is functional in vitro and in vivo through transactivation of HPV E2 transcription factor., Competing Interests: The authors declare no conflict of interest.

The Helicobacter pylori infection of gastric mucosa is one of the most common infectious diseases and is associated with a variety of clinical outcomes, including peptic ulcer disease and gastric cancer. Helicobacter pylori-induced damage to gastric mucosal cells is controlled by bacterial virulence factors, which include VacA and CagA. Outer membrane vesicles are constantly shed by the bacteria and can provide an additional mechanism for pathogenicity by releasing non-secretable factors which can then interact with epithelial cells. The present report shows that external membrane vesicles are able to induce apoptosis not mediated by mitochondrial pathway in gastric (AGS) epithelial cells, as demonstrated by the lack of cytochrome c release with an activation of caspase 8 and 3. Apoptosis induced by these vesicles does not require a classic VacA+ phenotype, as a negative strain with a truncated and therefore non-secretable form of this protein can also induce cell death. These results should be taken into account in future studies of H. pylori pathogenicity in strains apparently VacA-.