A study conducted by Taiwanese researchers suggests that the reason newborns are more susceptible than adults to influenza is because their natural killer (NK) cells, a component of the innate immune system, are easily compromised by flu viruses.
“We found that infants’ NK cells — the body’s natural weapon against flu — are very vulnerable to the flu virus,” Lin Syh-jae (林思偕), a doctor at Chang Gung Children’s Hospital and the leader of the research team, said at a press conference yesterday.
“Not only do infants’ NK cells die out faster than adult ones, their functions become compromised through the process of infection,” he said, adding that NK cells perform equally well in newborns and adults prior to any flu infection.
In research conducted over the past three years, Lin first derived NK cells from fresh umbilical cord blood, injected influenza A viruses into the cells and studied the infection mechanism. To counter the flu infection process, Lin introduced interleukin-15, an immune hormone, and found that it could effectively increase NK cells’ anti-viral function.
“There is a possibility that interleukin-15 could be used in the future to treat children with serious influenza complications,” he said.
Kuo Ming-ling (郭敏玲), a professor at Chang Gung University’s Graduate Institute of Biomedical Sciences and a team member, said the more scientists know about the human immune system, the better chances they have of finding ways to prevent the onset of diseases.
“Our findings can serve as useful references for the health food industry because they might want to probe the efficiency of adding interleukin-15 to their food supplements,” Kuo said. “The relationship between children’s NK cells and influenza infection is a very new topic.”
The study was published in the March edition of the Journal of Infectious Diseases.