Bioactive food components that enhance γδ T cell function may play a role in cancer prevention

Abstract

γδ T cells are found largely within the epithelium and recognize antigens differently than their αβ T cell counterparts. TCR δ-/- knock out mice exhibit a rapid tumor onset, along with increased tumor incidence. Although limited, research demonstrates that nutrients and bioactive food components can influence γδ T cell cytotoxicity, cytokine secretion, and proliferative capacity, and the results are nonetheless intriguing. Among other functions, γδ T cells play a role in immunosurveillance againstmalignant cells, as shown by the T cell receptor (TCR)δ-/- knock out mice that exhibit a rapid tumor onset and increased tumor incidence. Somecommon dietarymodifiers of γδ T cell numbers or activity are apple condensed tannins, dietary nucleotides, fatty acids, and dietary alkylamines. A recent clinical study demonstrated that ingesting a fruit and vegetable juice concentrate increased the number of circulating γδ T cells. Clinical studies also document that the oral consumption of a tea component, L-theanine, enhances γδ T cell proliferation and interferon-γ secretion. The significance of these studies awaits additional examination of the influence of exposures and duration on these and other food components. Adoptive transfer and TCRδ-/- knock outmicemodels should be used more extensively to determine the physiological impact of the number and activity of these cells as a function of dietary component exposures. While clarifying the diet and γδ T interrelationship may not be simple, the societal implications are enormous. © 2008 American Society for Nutrition.