Janet Douglas, Ph.D.
Viruses and their hosts are in a constant evolutionary arms race to survive. Studying this intricate battle provides us with new insights into understanding anti-viral immunity and new targets for developing anti-viral therapies. My research focuses on the interplay between the host’s defense mechanism to prevent viral release from cells and the various viral countermeasures that have co-evolved.
A major aspect of my work involves characterizing the mechanism of how the HIV-1 protein Vpu counteracts the host restriction factor BST-2/Tetherin to allow efficient viral egress. We are specifically investigating how Vpu and BST-2 interact and how Vpu uses the host’s own ubiquitin system (for normal protein trafficking and degradation) to circumvent BST-2. In addition, the lab is employing various screening methodologies to identify additional host factors that may be necessary for BST-2 function and/or adaptors important for Vpu’s ability to downmodulate BST-2.
The viral release restriction imposed by BST-2 is not limited to HIV, but may represent an innate immune mechanism that functions to limit the spread of many, if not all enveloped viruses. The filovirus family is composed of both Marburg and Ebola viruses, which are negative-strand RNA viruses that encode only seven ORFs. Despite their simplicity, human infection results in highly transmissible hemorrhagic fevers with mortality rates approaching 90%. Currently there are no treatments or vaccines for Ebola virus. Like HIV, Ebola virus appears to have evolved a countermeasure to BST-2 in the form of its envelope protein GP. Therefore, we are extending our studies to determine how Ebola virus GP is able to overcome the BST-2 restriction. The GP/BST-2 interaction has the potential to be a new target for the design of effective anti-Ebola strategies.
Although it is becoming increasingly apparent that BST-2 functions as a broad spectrum, antiviral innate immune mechanism, there are some enveloped viruses, such as the flaviviruses that bud from cells quite differently than HIV and Ebola and therefore may avoid the BST-2 restriction. My lab is also interested in determining whether a member of the flaviviruses, Dengue is also restricted by BST-2 and if so, if it has evolved a counteracting mechanism.
After receiving a B.S. in biology at Eckerd College, Janet entered graduate school at the University of Tennessee in Memphis where she received her Ph.D. in 1995 for characterizing the immortalizing and transforming potential of the Adenovirus E1A gene. As a postdoctoral fellow in Dr. Victor Garcia’s laboratory at St. Jude Children’s Hospital in Memphis, TN she developed an HIV-based lentiviral gene delivery system for the transduction of non-dividing human lymphocytes and hematopoietic stem cells. This foray into gene therapy led her into more applied biology, which she pursued at the biotechnology company Systemix in Palo Alto, CA. Here, she extended her work on gene therapy to include a humanized mouse model for assessing the efficacy of lentiviral vectors. Keeping her focus on virology she left the field of gene therapy in 2001 and began working in drug discovery for Gilead Sciences in Foster City, CA. There, she participated in a multi-disciplinary team of scientists attempting to identify novel small molecule inhibitors of respiratory syncytial virus (RSV) fusion and later inhibitors of HIV-1 reverse transcriptase. In 2004 she returned to academic science and began working with Dr. Ashlee Moses at the Vaccine and Gene Therapy Institute (VGTI) at OHSU where they investigated the cellular transformation mechanisms induced by KSHV/HHV-8 infection, as well as determining how the HIV-1 accessory protein Vpu functions to enhance the release of viral particles by counteracting the host immunomodulatory protein BST-2. Currently, as an assistant scientist at the VGTI she is continuing her research on the host’s viral egress restriction and has extended it to other viruses.