UND researchers have discovered age-associated changes in host immune responses to plague, beginning as early as the human equivalent of very early middle age. These findings will allow the research team of David S. Bradley and Matthew L. Nilles to understand the mechanisms that result in increased age-associated susceptibility to plague, and likely immune responses to other microbes. Up until now, most studies of age-related losses of immune response have focused on the very elderly, at which time the host’s immunity is usually significantly suppressed and the mechanisms leading to this suppression are difficult to elucidate.
Plague is caused by the extremely virulent pathogen Yersinia pestis. Most known for its widespread and devastating effects during the Dark Ages, plague naturally cycles through periods of quiescence that may last decades. However, it can manifest its ugly and deadly effects quickly—the last urban epidemic in the United States was in Los Angeles in 1924–1925, and an outbreak in India in 1994 drew world attention because it was the pneumonic form, passed from person to person, unlike the plague during the Dark Ages in Europe that was primarily bubonic, carried by ticks from rats. Plague remains endemic in the western United States, including the prairie dog population in western North Dakota.
Nathaniel D. Lambert, Deanna M. Langfitt, Matthew L. Nilles, and David S. Bradley from the Department of Microbiology and Immunology at the UND School of Medicine and Health Sciences were the authors of the research paper describing their findings about plague. Nilles, an internationally recognized expert on the Yersinia pestis bacterium, leads the plague research effort at the School, and Bradley, chair of the department and leader of the larger infectious disease research focus at UND, is an internationally recognized expert on host immune responses to microbes and related vaccines and immunotherapeutics. Bradley and Nilles have a long collaborative research relationship, reaching back more than 13 years, in studying interactions between hosts and pathogens. Their research paper can be found at the American Society for Microbiology’s website at http://bit.ly/qvirK2.