Thursday, October 4, 2012

Introducing Assistant Professor N. Luisa Hiller

The Department of Biological Sciences is proud to announce Dr. N. Luisa Hiller has joined the faculty as an assistant professor. Hiller comes to Carnegie Mellon University from a postdoctoral research position at another Pittsburgh institution, the Center for Genomic Sciences at Allegheny-Singer Research Institute. She also received her doctorate in immunology and microbial pathogenesis from the Northwestern University Medical School.

Tell us a little about the research that you plan to conduct at Carnegie Mellon.

I am interested in bacteria within the context of chronic infection and human health. Currently, I’m focused on the role of pneumococcus on chronic ear infections in children. Many chronic infections are caused by organized communities of bacteria termed biofilms. These biofilms can be populated by one bacterial clone (one group of genetically identical cells), multiple strains from the same species (cells that are all part of one species, but still differ significantly in their genomic content), or even multiple species. Furthermore, cells in these biofilms often have fascinating features, such as physical connections between cells, extensive exchange of genetic material, and chemical communication across the cell. I think of biofilms as bacterial cities.

My goal is to understand the behavior of bacteria within these biofilms. What strains and species are present in an infection? How genetically different are these strains from one another? How much and how quickly do strains change their genetic composition over the course of an infection or an epidemic? What molecules do cells use to communicate with each other and with their host (us)?

What are some potential implications from your work?

The healthy human body contains more bacterial cells than human ones. I hope we’ll start to gain a better understanding of which bacteria to target and which bacteria not to target.  This may be resolved not at the level of which bacterial species, but instead which strains or even which genes should be targets. Ultimately, this type of knowledge will be applied to diagnosis, treatment and prevention of disease.

In general, where is your field of research heading?

Bacterial infections can, of course, be very harmful and pathogenic, but bacteria can also be very beneficial to the human host.  Intriguingly, there is potential for the same species to be beneficial, indifferent, or detrimental to its host depending on the exact genes carried by strain, by the host, and by other microbes in the human body.  The field is developing a new understanding of bacteria’s role within the human body – the ecology of the human body.  Stunning new high-throughput technologies now allow us to identify the composition of bacteria in our bodies, as well as the genes, proteins, and metabolites these microbes are using. Ultimately, we should be able to understand in enormous detail not only the role of bacteria in disease, but also its role in human health.

Can you tell us about any current collaborations as well as your plans for future collaborations?

I am already collaborating closely with Dr. Dannie Durand. Using phylogenic tools she and her group have developed, we are investigating gene exchange across bacterial species in the human nasopharynx. Also, although the work of Dr. Aaron Mitchell is on fungal pathogens and mine on bacteria, there is significant overlap. I’m currently planning experiments with him, using a very powerful new technology (NanoString), to determine which bacterial genes are turned on specifically during the infectious process. At the Center for Genomic Sciences, I continue to work closely with my post-doctoral mentor, Dr. Garth Ehlrich, to further understand the variability and plasticity within bacterial species.

What part of coming to Pittsburgh, Carnegie Mellon and the Department of Biological Sciences are you the most excited about?

I am excited about being in such a scientifically stimulating environment. Not only are the collaboration opportunities that I just mentioned available, but also the potential for other collaborations exists, such as working with Dr. Jonathan Minden or Dr. Marcel Bruchez.  Furthermore, drawing together the Department of Biological Sciences and the Center for Genomic Sciences offers stimulating new opportunities.

When you are not in the research lab, what do you do?

I’m the mother of two young daughters, when I can find them under all the books and toys; we spend time exploring Pittsburgh and its dinosaurs.