Dr. Roan has had a long-standing interest in understanding the effect of host factors on microbial pathogens of the genital mucosa. Her current research focuses in three major areas:

First, she is investigating the molecular basis by which small amounts of HIV can initiate infection in the mucosa. Her lab has discovered that genital and rectal fibroblasts, amongst the most abundant cells of the mucosa, potently increase HIV infection of T cells. In contrast to fibroblasts, mucosal epithelial cells, which line the mucosa, inhibit HIV infection by apically secreting antiviral factors. These findings suggest that abrasions in the genital and rectal epithelium may increase HIV transmission in part by allowing HIV to escape an antiviral environment to access the infection-favorable environment of the stromal fibroblasts. Ongoing research in the lab seeks to determine the molecular mechanisms by which stromal fibroblasts increase HIV infection of T cells, and conversely the mechanisms by which mucosal epithelial cells limit infection rates, using ex vivo tissue models. The effects of seminal plasma components, which the lab previously demonstrated markedly enhance HIV infection, along with sex steroids and microbicide candidates, are also being investigated in these model systems.

Second, she is using mass cytometry to characterize susceptibility of cells to latent and productive infection by HIV. Her lab conducted a 38-parameter characterization of HIV entry and productive infection of tissue CD4+ T cells by mass cytometry, and used an analytical approach that takes advantage of the high-dimensional nature of CyTOF datasets to distinguish receptors modulated during infection from those differentially expressed on preferentially infected cells. These studies identified a subset of memory CD4+ T cells susceptible to HIV entry but not productive infection. Ongoing work in the lab seeks to characterize the molecular basis of this post-entry restriction, and to use CyTOF and a variety of high-dimensional CyTOF data analysis tools to characterize the types of cells that are productively and latently infected with HIV.

Lastly, Dr. Roan is investigating how various components of human seminal plasma can affect infection by STDs and fertility. Semen, in contrast to other human bodily fluids, contains multiple types of amyloid fibrils under non-diseased conditions. Dr. Roan previously demonstrated that these fibrils potently enhance infection by HIV and other sexually transmitted viruses, and characterized the mechanisms by which they do so. The lab is conducting studies to characterize the physiological function of these fibrils, by assessing how they signal to sperm cells and cells of the female reproductive tract. The effects of seminal plasma components other than semen fibrils are also being characterized both for their effects on HIV infection and reproductive health, as well as to serve as biomarkers of human disease.

Postdoctoral fellows and graduate students who have experience in microbiology and/or immunology are encouraged to apply for postdoctoral training in the lab of Dr. Nadia Roan. Interested applicants should send their CV and names of three references to: [email protected]