Jae-Kwang Yoo, PhD

How Immune Cells Come to the Rescue Against Influenza

Influenza viruses cause considerable illness and death. Each year, 5% to 20% of the population in the United States contracts influenza. Approximately 200,000 people are hospitalized and as many as 36,000 die from complications associated with seasonal flu. Jae-Kwang Yoo, Ph.D., is trying to gain a better understanding of how the body’s immune system fights the influenza virus. “We can use this information to improve the efficiencies of the vaccine for the seasonal flu, and potentially for a pandemic flu,” he says.

“We can use this information to improve the efficiencies of the vaccine for the seasonal flu, and potentially for a pandemic flu.”
When a person is infected with the influenza virus, the immune system responds using B cells. These cells produce neutralizing antibodies that are essential both to prevent reinfection and to eliminate the infection from the respiratory tract. Once they are activated, B cells proliferate and differentiate, or become specialized. B cells are dependent on immune cells called CD4+ T cells to help with this process. A type of CD4+ T cells called T follicular helper cells (TFH) provide B cells with assistance in fighting influenza, but how these helper cells are generated against influenza is not well understood.

During his PhD training in the lab of Dr. Eleanor N. Fish at the University of Toronto, Dr. Yoo and colleagues identified a new cell involved in fighting against viruses called late activator antigen presenting cell (LAPC). This cell regulates the body’s antibody response, especially in influenza virus infection. Now at the University of Virginia, working with Dr. Thomas J. Braciale, Dr. Yoo has found that LAPCs are potent inducers of TFH response in influenza virus infection. However, the exact way in which the immune system controls this process is still not clear. This is what he aims to understand.

“With the prestigious support from the American Lung Association Research Award, we can be one step closer to be able to provide insights into how our immune system controls antibody response in pulmonary viral infection,” Dr. Yoo says. “Hopefully, my American Lung Association-funded research may provide a framework for the identification of novel targets for therapeutic vaccine development to prevent influenza A virus infection. This will ultimately help save lives.”