Differential regulation of CD11b on gammadelta T cells and monocytes in response to unripe apple polyphenols.
Leukocyte adhesion and migration are mediated partially by CD11b/CD18 (membrane-activated complex-1, CR3). Earlier studies have demonstrated a role for green tea polyphenols in down-regulating CD11b on CD8(+) T cells and monocytes. We have shown recently a stimulatory effect of unripe apple polyphenols (APP) on gammadelta T cells. Thus, we compared the effect of APP on bovine gammadelta T cell and monocyte CD11b expression. Purified bovine monocytes and monocyte-depleted PBLs were cultured with APP. CD11b levels decreased on monocytes in response to APP. In contrast, a gammadelta T cell subset responded to APP by up-regulating CD11b. The CD11b regulation was not seen on gammadelta T cells or monocytes treated with APP fractions depleted of tannins. The APP-induced down-regulation of CD11b on monocytes was inhibited by an anti-CD11b mAb, consistent with previous studies showing that polyphenols bind CD11b. As expected, the anti-CD11b mAb had no effect on the APP response in resting gammadelta T cells, as these cells lacked CD11b. Consistent with the changes in surface CD11b expression, APP-treated gammadelta T cells showed increased adherence to plastic, whereas monocyte adhesion was reduced. APP also induced cytokine gene expression in gammadelta T cells. Some polyphenols are thought of as anti-inflammatory agents; however, these data, as well as other ongoing studies, indicate they have a proinflammatory effect on gammadelta T cells. In vivo, plant polyphenols may enhance gammadelta T cell migration and function at sites of inflammation, where they could induce rapid, immune-regulatory and innate-like immune responses.
Graff
Jill C
JC
Veterinary Molecular Biology, Montana State University, 960 Technology Blvd., Bozeman, MT 59718, USA.
Jutila
Mark A
MA
D000818:Animals; D039481:CD11b Antigen / Q000378:metabolism*; D002417:Cattle; D002448:Cell Adhesion; D002478:Cells, Cultured / Q000187:drug effects / Q000378:metabolism; D005419:Flavonoids / Q000494:pharmacology*; D007962:Leukocytes / Q000187:drug effects / Q000378:metabolism; D008213:Lymphocyte Activation; D027845:Malus / Q000737:chemistry*; D009000:Monocytes / Q000187:drug effects* / Q000378:metabolism*; D010636:Phenols / Q000494:pharmacology*; D059808:Polyphenols; D016692:Receptors, Antigen, T-Cell, gamma-delta / Q000378:metabolism*; D016176:T-Lymphocyte Subsets / Q000187:drug effects / Q000378:metabolism
D039481:CD11b Antigen; D005419:Flavonoids; D010636:Phenols; D059808:Polyphenols; D016692:Receptors, Antigen, T-Cell, gamma-delta