Influenza virus infection of lymphoid tissues

Abstract

Influenza viruses are orthomyxoviruses belonging to three distinc genera, Influenzavirus A, B e C. They are enveloped viruses with genome consisting of 8 segments of single-stranded negative-sense RNA for influenza viruses A and B, and 7 for influenza C. The infection may cause typical symptoms of influenza, or severe acute respiratory syndrome, being an important cause of morbidity and mortality globally. The sporadic appearance of new influenza virus lineages of animal origin, with ability to infect humans and cause pandemics, highlights the importance of these agents in public health and implementation of health care policies. The detection of viral proteins and virus genomes in lymphoid tissues from experimentally infected mice and asymptomatic humans, indicates that there is replication of influenza virus in these tissues, opening new possibilities to consider viral dissemination from lymphoid tissues, and the possibility of persistence in these sites. In this regard, the present project aims at investigating influenza virus infection in lymphoid tissues in an effort to understand pathogenesis of its persistence in these tissues. The objectives are to investigate infection of lymphoid tissue by influenza vírus by means of detection of viral proteins, Messenger RNAs, complementary RNA (anti-genome), characterization of phenotypes of infected cells, isolation and molecular characterization of virus lineages obtained from different infected tissue sites, and experimental infection in a mouse model to evaluate prolonged virus presence in tissues months after infection.