Virological Mechanisms in the Coinfection between HIV and HCV.

Due to shared transmission routes, coinfection with Hepatitis C Virus (HCV) is common in patients infected by Human Immunodeficiency Virus (HIV). The immune-pathogenesis of liver disease in HIV/HCV coinfected patients is a multifactorial process. Several studies demonstrated that HIV worsens the course of HCV infection, increasing the risk of cirrhosis and hepatocellular carcinoma. Also, HCV might increase immunological defects due to HIV and risk of comorbidities. A specific cross-talk among HIV and HCV proteins in coinfected patients modulates the natural history, the immune responses, and the life cycle of both viruses. These effects are mediated by immune mechanisms and by a cross-talk between the two viruses which could interfere with host defense mechanisms. In this review, we focus on some virological/immunological mechanisms of the pathogenetic interactions between HIV and HCV in the human host.

Nasopharyngeal carcinoma: review of the literature with a focus on therapeutical implications.

Nasopharyngeal carcinoma (NPC) is a rare neoplasm which is associated with Epstein-Barr virus (EBV). First of all, we reviewed the literature on NPC treatment. Radio/chemotherapy is currently the gold standard but unfortunately is affected by rates of failure ranging from 7% up to 58%. Because NPC development is promoted by the EBV latent life cycle, EBV-targeted treatments were investigated. Firstly, forcing cytolytic virus activation through administration of gemcitabine and/or valproic acid before administration of a nucleoside analogue showed anti-tumoral activity in vitro as well as in murine model and it was also well tolerated in humans. Secondly, the association of autologous EBV-specific cytotoxic T lymphocytes with chemotherapy correlated with an improved median survival and was safe but not effective versus metastatic lesions. Thirdly, suppression of late membrane protein-1 in the clinic proved controversial because it gave resistance to chemotherapy and, on the other hand, increased radiosensitivity. Finally, we suggest future perspectives for clinical research which should include both prospective and observational cohort studies to assess the role of different risk factors in the development of NPC and the effectiveness of new investigational treatments.

Back to the origin of HCV 2c subtype and spreading to the Calabria region (Southern Italy) over the last two centuries: a phylogenetic study.

Circulation of HCV genotype 2 has been described in European Countries where numerous subtypes and unclassified HCV 2 lineages have been reported. In Italy, subtype 1b is the most prevalent, followed by genotype 2. In the present study, phylogeny of HCV 2c was investigated. The phylogeny of HCV 2c isolated from 54 Italian patients in the Calabria region (Southern Italy) was investigated by analyzing a fragment of the NS5B gene. Patients came from 5 metropolitan areas and a small village (Sersale). These areas were geographically dispersed throughout the entire region. A Bayesian coalescent-based framework was used to estimate origin and spreading of HCV 2c in this region. Phylogenetic analysis showed that 28 Italian sequences were intermixed with foreign HCV 2c reference sequences and grouped into 3 major clades: A, B, and C. Nineteen inter-clade sequences were associated uniquely with surgery as risk factor for HCV acquisition. By contrast, a sub-cluster within clade B was associated with blood transfusion. Moreover, sequences from Sersale village grouped in the Italian sub-cluster and were intermixed with 10 sequences from metropolitan areas. The three isolates with the longest branch came from Sersale and belonged to patients who had glass syringes as risk factor. HCV 2c isolates from the Calabria region shared a common ancestor whose origin was traced back to 1889. Our results suggest that, after its introduction - possibly as a result of population movements between Italy and African Countries during Italian colonialism - HCV 2c spread through multiple risk factors, not including intravenous drug use. So, transmission chains followed a pathway different from other European Countries. Although HCV incidence is decreasing, these ways are still ongoing, possibly justifying stability in the relative prevalence of HCV 2c.

Receptor recognition of and immune intracellular pathways for Veillonella parvula lipopolysaccharide.

Veillonella parvula is an anaerobic gram-negative coccus that is part of the normal flora of the animal and human mouth and gastrointestinal and genitourinary tracts. Oral V. parvula is involved in the development of early periodontal disease as well as different types of serious infections. Present data on molecular mechanisms responsible for innate immune response against Veillonella are very scanty. The aim of this study was to investigate the Toll-like receptor (TLR) pathways responsible for V. parvula lipopolysaccharide (LPS) and to identify the intracellular pathways induced by this recognition. V. parvula LPS stimulated tumor necrosis factor alpha (TNF-alpha) and interleukin-6 (IL-6) release in human peripheral blood mononuclear cells (PBMC) in a dose-dependent manner. Pretreatment of cells with a TLR4 antagonist significantly reduced TNF-alpha and IL-6 production in PBMC stimulated with either Veillonella or Escherichia coli LPS. However, V. parvula LPS was 10- to 100-fold less active than E. coli LPS for cytokine induction. TNF-alpha, IL-1beta, IL-6, and IL-10 were released in wild-type and TLR2(-/-), but not TLR4(-/-), mouse macrophage cultures. V. parvula LPS was able to activate the human PBMC p38 mitogen-activated protein kinase (MAPK). A specific p38 MAPK inhibitor strongly inhibited V. parvula LPS-induced TNF-alpha, IL-1beta, IL-6, and IL-10. In conclusion, V. parvula LPS is able to induce cytokine production in both human and murine in vitro models, although it is less effective than Enterobacteriaceae LPS. V. parvula LPS-stimulated cytokine induction, as well as p38 MAPK activation, are TLR4-dependent features.