University of Cagliari

About: University of Cagliari is a education organization based out in Cagliari, Italy. It is known for research contribution in the topics: Population & Dopamine. The organization has 11029 authors who have published 29046 publications receiving 771023 citations. The organization is also known as: Università degli Studi di Cagliari & Universita degli Studi di Cagliari.

Clinical significance of hepatitis C virus genotypes and quasispecies.

Abstract: Hepatitis C virus (HCV) is a major cause of morbidity and mortality worldwide. The infection becomes chronic in about 85% of infected individuals, in the face of a strong humoral and cellular immune response. One of the most important features of HCV is its high degree of genetic variability, which is due to the inherent low fidelity of the viral replication machinery. As a consequence, HCV circulates in vivo as a population of divergent, albeit closely related, genomes exhibiting a distribution that follows the model referred to as a quasispecies. The genetic variability of HCV is complex and has been classified into four hierarchical strata: genotypes, subgenotypes, isolates, and quasispecies. Over the past few years, an extraordinary interest has been focused on the biologic and clinical implications of the genetic variability of HCV. Although there is consensus that the genotypes may influence the out come of antiviral therapy, their clinical significance in the natural history of the disease, as well as in transmission, infectivity, and pathogenesis of HCV infection, remains elusive. Conversely, evidence has accumulated that the quasispecies nature of HCV provides a large reservoir of biologically different viral variants that may have important clinical implications for viral persistence by immune escape mechanisms, for the generation of antiviral drug resistance, and for the development of an effective vaccine. This article reviews the state of the art on the biologic and clinical implications of the genetic variability of HCV.

HIV and the chemokine system: 10 years later.

Abstract: The unexpected encounter, 10 years ago, between human immunodeficiency virus (HIV) and the chemokine system has dramatically advanced our understanding of the pathogenesis of AIDS, opening new perspectives for the development of effective prophylactic and therapeutic measures. To initiate infection, the HIV-1 external envelope glycoprotein, gp120, sequentially interacts with two cellular receptors, CD4 and a chemokine receptor (or coreceptor) like CCR5 or CXCR4. This peculiar two-stage receptor-interaction strategy allows gp120 to maintain the highly conserved coreceptor-binding site in a cryptic conformation, protected from neutralizing antibodies. The differential use of CCR5 and CXCR4 defines three HIV-1 biological variants (R5, R5X4, X4), which vary in their prevalence during the disease course. The evolutionary choice of HIV-1 to exploit chemokine receptors as cellular entry gateways has turned their chemokine ligands into endogenous antiviral factors that variably modulate viral transmission, disease progression and vaccine responses. Likewise, the natural history of HIV-1 infection is influenced by specific polymorphisms of chemokine and chemokine-receptor genes. The imminent clinical availability of coreceptor-targeted viral entry inhibitors raises new hope for bridging the gap towards a definitive cure of HIV infection.