A scientist at St. Joseph’s Healthcare Hamilton has uncovered how T-cells communicate with the brain, noting that the effects of T-cells on the brain may be contributing to differences in the ways that males and females experience stress. Led by Dr. Jane Foster, researcher at St. Joseph’s Healthcare Hamilton and Associate Professor at McMaster University, the study was published in Brain, Behavior and Immunity.

T-cells are a type of white blood cells that play an important role in attacking viruses and cancer cells. However, researchers have found that T-cells also communicate with the brain, and are linked to learning, memory and stress response.

“We know that the profile of the immune system is different in males and females including differences in T-cells,” explains Dr. Foster. “A lot of the drugs we have available for mood disorders affect the immune system. If we could target areas of the immune system based on sex, we could have new ways of treating mood disorders specific for males and females.”

“In our study, we removed T-cells from mice to see how this would affect brain and behaviour,” states Dr. Foster. “Mice without T-cells didn’t show the same sex differences with regards to behaviour that wild type mice did. This suggests to us that the T-cells have an important role in the development of sex differences and how males and females experience anxiety.”

The study notes how sex differences result in distinct clinical features across mood and anxiety-related disorders. The lifetime risk for major depressive disorder is also twice as high for females compared to males.

Dr. Foster, her research team, and her collaborators at SickKids Hospital in Toronto hope to continue their research by examining the development of the immune system early in life, as well as continuing to uncover how T-cells communicate with the brain.