The laboratory of Molecular Virology (Faculty of Science, U.L.B.) is studying the transcriptional regulation of three retroviruses, HIV-1 (Human Immunodeficiency Virus type 1), HTLV-I (Human T-cell leukemia virus I) and BLV (Bovine Leukemia Virus), with a special emphasis on the role played by chromatin structure and by histone and non-histone protein modifications.
Infection by these retroviruses is characterized by viral latency in the large majority of infected cells and by the absence of viremia (in the cases of HTLV-I and BLV). These features are thought to be due to the transcriptional repression of viral expression in vivo, but the molecular mechanisms involved in such a repression are not fully elucidated.
These three retroviruses encode a protein called Tat, TaxHTLV-I and TaxBLV, respectively, involved in trans-activation of long terminal repeat (LTR)-directed gene expression.
This laboratory is studying the role played by epigenetic modifications (histone acetylation, histone methylation and DNA methylation) in transriptional latency and reactivation of HIV-1, BLV and HTLV-I. These epigenetic modifications could be one mechanism by which these viruses escape the host immune response and, in the case of HTLV-I/BLV, allow tumor development.