Two specific types of immune system cell that attack invaders - CD4 T-cells and natural killer cells - increased in number with age, with a higher rate of increase in women than in men.
Their experiments on mice showed the virus impaired the ability of a specific part of the immune system, called regulatory T cells, to calm inflammation.
His specific areas of study include how our immune systems play a key role in our emotional lives and using compassion meditation to prevent depression in college students by reducing stress-related inflammatory activity.