Department of Biochemistry, Microbiology and Immunology
University of Ottawa Faculty of Medicine
United States of America
Dr Marc-André Langlois discusses his research into the immune response to retroviruses, as well as his new technique for screening DNA for rare mutated proviral sequences. International Innovation. Laboratory of Molecular Virology and Intrinsic Immunity Intrinsic immunity represents the collection of continuously active mechanisms that protect a host from viral pathogens. This unique feature of intrinsic immunity sets it apart from conventional adaptive and innate immune responses in that it does not require priming by the recognition of viral epitopes or pathogen associated molecular patterns (PAMPS), nor does it require a downstream cascade of signaling events. Host-encoded intrinsic restriction factors are proteins that constitute the first line of defense against viral pathogens. Retroviruses pose a unique threat because they permanently insert their genetic material into the genome of their host during the infection. In addition to the disease that may be caused by the virus, integration can lead to gene deregulation and cancer. APOBEC3 proteins are potent intrinsic restriction factors expressed in lymphocytes, macrophages and dendritic cells, all of which play important roles in the infection cycle of retroviruses. Humans express 7 APOBEC3 proteins with APOBEC3G (A3G) being the best-studied member of the APOBEC3 family. To prevent the spread of retroviruses, A3G can mutate retroviral DNA prior to its integration into the host’s genome. A3G can also inhibit the early stages of the retroviral infection by hindering replication and preventing retroviral integration. The sum of these antiviral effects will result in a dramatic decrease in viral DNA being integrated into the host’s genome and in damage to the genetic code of progeny retroviruses that have come into contact with A3G.
Retroviruses HIV APOBEC3G Molecular Virology Intrinsic Immunity Retroviral Restriction Factors Flow virometry Microbiology