Division of Rheumatology, Allergy & Immunology, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, and the Nutritional Science Research Institute, Boston, Massachusetts, USA
Correspondence:JF Bukowski, Division of Rheumatology, Allergy & Immunology, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, MA 02115, USA. E-mail: email@example.com; Phone: +1-508-485-1226
Human γδ T lymphocytes are a subset of T cells and are a first line of defense against microbes and tumors. These γδ T cells can be primed by nitrogen-containing bisphosphonates, and certain short-chain alkylamines. These primed γδ T cells have an enhanced capacity to proliferate and to secrete cytokines upon ex vivo exposure to a wide variety of microbes and tumor cells. The largest dietary source of alkylamines is L-theanine, an amino acid unique to tea beverages that is catabolized to ethylamine. Supplementation of subjects with capsules containing L-theanine and catechins has recently been shown to decrease the incidence of cold and flu symptoms, while enhancing γδ T cell function.