Reatividade cruzada entre Dengue virus e outrosvírus do gênero Flavivirus

Abstract

Flaviviridae virus family is a group of enveloped virus with single strand and positive sense RNA genome. It is composed of Flavivirus, Pestivirus and Hapacivirus genera. Flavivirus genus contains more than 70 distinct viral species, such as Japanese Encephalitis virus, Tick-borne Encephalitis virus, West Nile virus, Yellow Fever virus and Dengue virus, which are responsible for several human diseases. Among all polypeptides which occur in viral particles, E glicoprotein is the majorknown antigenic determinant. Several cross-reactivity events occur between the virus in the Flavivirus genus, what is possibly caused by humoral immune response to antigenic epitopes located in E glycoprotein, that are conserved and common to all virus from Flavivirus genus. This problem is of special importance for specie-specificsorological diagnosis, especially in areas where several distinct Flavivirus species coexist in a tempora and spatial way. Since, due to historical reasons, serological tests are the main evidence for laboratorial diagnosis of Flavivirus infection and, consequently, for public health policies, this study aims to gather, by bibliographic surveying of specialized scientific literature, the cross-reactivity characteristicsdetected between DENV and others virus from Flavivirus genus. The existence of cross-reactivity has been frequently documented as a problem for the laboratorial diagnostic of dengue. The alignment and post analysis of the sequences of the E protein showed that the value of identity of the aa sequence varied between 97,7% and 36,7% among the Flavivirus samples analysed. The DENV1 and DENV3 samples showed the biggest identity value between themselves - 76,5% - whileDENV2 and DENV4 showed a identity value of 63,8%. When compared to others Flavivirus, the DENV showed smaller aa identity values, that varied between 36,7% and 50%.