In this study acupuncture was shown to improve immunological function by modulating expression of the Cx43 gene. The mechanism by which acupuncture induced activation of the gene was not explored, however they did show that acupuncture improved white blood cell count as well as the activity of the thymus and spleen (points used were CV 4 and St 36 for 7 days consecutively).
Zhen Ci Yan Jiu. 2007 Oct;32(5):291-5.