A geneticist’s perspective on how smoking affects the immune response of the human immune system and cytokine responses to infection and vaccination

It would be valuable to learn more about how smoking influences immune cell function, and, in turn, what the body’s responses to infection and vaccination are, says Luo. “That could offer valuable insights into the broader health consequences of smoking.”

How well your immune system responds to something is the most important factor in determining its health. The immune response the body prefers is small and not too strong, but enough to heal wounds and fight infections, but not so much that the body starts to attack itself.

Immune responses vary greatly from person to person, and an effort is being made to understand why. In addition to cigarette smoking, the study found that having a higher body mass index and having previously been infected with a typically benign virus called cytomegalovirus also affect the immune response.

The authors combined all of the results and personal information to come up with 136 characteristics. They found that three traits stood out as having particularly strong associations with cytokine responses: cigarette smoking, body mass index and previous cytomegalovirus infection.

“It is a very important piece of work,” says Vinod Kumar, a geneticist at Radboud University Medical Center in Nijmegen, the Netherlands, not only because of the specific results about smoking, but also because of the overall effort to track sources of variability in immune responses. The study found that individual environmental factors, for example, can affect different cytokines to different degrees. “It makes me wonder how much detail we should consider when we are looking at targeted therapy or personalized medicine,” he says.

It was clear from the data that smoking was related to many factors, including age, sex and genetics. And these effects lingered for years after participants had given up cigarettes. The factors correlated with the chemical tags that were added to the cell’s DNA. The addition of such groups can affect the activity of genes.

Stability of Senegal and Hong Kong populations for a long-term study of AIDS in Central Asia, with special emphasis on human epochs

But the study still needs to be repeated to ensure that the results are generalizable, says Saint-André. And, in future, it should include a more ethnically and racially diverse group of participants. The team has now expanded their study to include participants from Senegal and Hong Kong, she says. The researchers have also gone back to the original participants, and have collected fresh blood samples from 415 of them ten years after the original samples were taken.