Proteomic analysis of Human Respiratory Syncytial Virus Group B (HRSVB) (GB3 and BA-like genotypes) using mass spectrometry

Abstract

The human respiratory syncytial virus (HRSV) is the most important cause of lower respiratory tract infection in babies and elderly with annual epidemics occurring in late fall and winter in temperate climates. In Brazil, 30-50% of outpatient consultations and more than 50% of hospitalizations are attributed to acute lower-respiratory tract infections (ALRI). The human respiratory syncytial virus (HRSV) is classified into two groups, HRSV-A and HRVSV-B according to their genetic and antigenic characteristics. The two subgroups share 81% of genomic nucleotide homology and 88% of amino acid sequence identity, and the G protein is the most divergent. Both groups are classified into different genotypes that can co-circulate during the same epidemic, with one or two dominant genotypes, that can shift over the years. The emergence of isolates of HRSVB with a 60-nt duplication in the G protein were first described in Buenos Aires, Argentine, in 1999, and later in several other places, spreading throughout the world. These viruses clustered in a new genotype named BA and was the most prevalent across the world in the last years. In addition to the rapid spread of the BA-like genotype it was related to the development of more severe pathology in children under 6 months of age. Currently there are no vaccines or effective therapeutic treatment and the mechanisms by which HRSV causes epithelial infection and injury are not entirely clear, although there is strong evidence that much of the pathogenesis not only due the virus strain, but is due to the host immune response to the infection. Studies involving the interaction of viruses from both groups, A and B, with the host cells were performed using the technique of cDNA microarray and SILAC coupled to liquid chromatography and mass spectrometry (LC-MS/MS). These studies allowed the understanding of changes in the cellular proteome and revealed the multiple effects of the virus into the host cell, including for example, the regulation of immune response genes, apoptosis and cytoskeleton organization. The knowledge of the phenotypic differences of the virus and the interaction of viruses with host cells at the molecular level are essential for the development of new therapeutic and preventive strategies. The goals of this study will be to realize the proteomic on HRSVB proteins belonging to the genotype GB-3 and BA-Like purified from HEp-2 cell cultured using mass spectrometry as principal device. (AU)