Understanding Tuberculosis

gillian-beamerGillian Beamer, VMD, PhD, DACVP, works on tuberculosis (TB) and the bacterial pathogen that causes it, Mycobacterium tuberculosis. TB is rare in the United States, but it is rampant in Asia, Africa, and some parts of Russia. One of the most successful pathogens at evading the host immune system and establishing itself in lung tissue, Mycobacterium tuberculosis annually kills an estimated 1.5 million people worldwide.

Beamer joined the Department of Infectious Disease and Global Health at Cummings School of Veterinary Medicine in January 2012. She earned her VMD at the University of Pennsylvania and her PhD (immunology) at Ohio State University. She is also a diplomate of the American College of Veterinary Pathologists (DACVP). Prior to joining Tufts, she was a senior research scientist at Ohio State University, working on Mycobacterium tuberculosis infection.

Offering collaboration in
  • mouse models of TB
  • mouse neutrophils
  • Seeking collaboration in
  • testing compounds against TB in mouse models
  • The pathology of tuberculosis is complex and not fully understood. “My focus is on how TB develops following a controlled infection,” says Beamer. “The mechanisms involve protective immunity and lung-damaging inflammation. Understanding the balance or factors that tip the balance between immunity and inflammation may help us develop better treatments or predictive tests. We use the mouse as a model of infection and disease because it can replicate many of the immune and disease responses that are present in humans.”

    “Recently there’s been interest in neutrophils, one of the immune cells in our bodies, as markers of TB disease,” says Beamer. Neutrophils may play a role in protecting the host from the TB bacterium during the early stages of infection. In later stages, however, neutrophils may contribute to the damaging inflammation of the disease. Active research is attempting to unravel the complex interactions between TB bacteria, neutrophils, and other host immune agents.

    Beamer’s research group is generating neutrophils in tissue culture from mouse neutrophil progenitor cells, which are like stem cells that only differentiate into neutrophils. The group will use these cells to investigate the role neutrophils may play in the pathology of TB. A more thorough understanding of the pathology could open new avenues for prevention and treatment. For example, if research shows that neutrophils contribute to TB at some point during disease progression, drugs that specifically inhibit these immune cells could be tested in conjunction with existing antibiotics.

    Beamer is also collaborating with others to test new antibiotics and other pharmaceuticals against TB, and she would like to expand this work. The current antibiotic treatment regimen is difficult and requires administration of multiple antibiotics over 6 to 9 months. New treatments are also needed to combat the increasing prevalence of multidrug-resistant TB.  “To have a direct impact on patients, we need to identify and test antibiotics that work better,” says Beamer. All of her research on infectious TB bacteria is carried out in the New England Regional Biosafety Laboratory, which has facilities for working with biosafety level 3 pathogens in rodents and other animal models. “Moving experimental compounds into mouse models for preclinical testing is important and a particular strength of our school,” she says. “We are actively seeking collaborations in this realm. We can do all the infectious work and provide insight into potential adverse effects.”

    “I’m also interested in understanding host genetics related to TB and linking those data sets to imaging of TB infected lungs and computer modeling,” says Beamer. “New genetically diverse mice are now available to help answer those questions. In humans, certain haplotypes and immunologic molecules are associated with higher incidence of TB. Nice work by others has identified genetic loci that contribute to TB disease in mice, but there is much more to learn.”

    For more information, please see http://vet.tufts.edu/facpages/beamer_g.html.