In this study researchers explored the mechanisms in which acupuncture modulates the immune system. In particular they discuss collections of mast cells around the common acupuncture points. Increases in macrophages from the stimulation of certain acupuncture points. They discuss the increases in natural killer cells that appear with the stimulation of certain acupuncture points such as ST 36 and discuss the regulatory effects of acupuncture on T cells and their subsets. They further get into certain pathways such as vagal-adrenal, brain-gut, etc. that are modulated by acupuncture and end up with immunomodulatory effects.
The researchers conclude with "in addition to dramatically regulating immune cells and molecules, including innate and adaptive immune responses, acupuncture can stimulate and support immunological responses that are anti-inflammatory and anti-infectious".