Direct Costimulatory Effect of TLR3 Ligand Poly(I:C) on Human γδ T Lymphocytes

Daniela Wesch, Susann Beetz, Hans-Heinrich Oberg, Matthias Marget, Kirsten Krengel, Dieter Kabelitz

doi:10.4049/jimmunol.176.3.1348

Direct Costimulatory Effect of TLR3 Ligand Poly(I:C) on Human γδ T Lymphocytes

Daniela Wesch

Institute of Immunology, Universitätsklinikum Schleswig-Holstein Campus Kiel, Kiel, Germany
Susann Beetz

Institute of Immunology, Universitätsklinikum Schleswig-Holstein Campus Kiel, Kiel, Germany
Hans-Heinrich Oberg

Institute of Immunology, Universitätsklinikum Schleswig-Holstein Campus Kiel, Kiel, Germany
Matthias Marget

Institute of Immunology, Universitätsklinikum Schleswig-Holstein Campus Kiel, Kiel, Germany
Kirsten Krengel

Institute of Immunology, Universitätsklinikum Schleswig-Holstein Campus Kiel, Kiel, Germany
Dieter Kabelitz

Institute of Immunology, Universitätsklinikum Schleswig-Holstein Campus Kiel, Kiel, Germany

説明

<jats:title>Abstract</jats:title><jats:p>TLR3 recognizes viral dsRNA and its synthetic mimetic polyinosinic-polycytidylic acid (poly(I:C)). TLR3 expression is commonly considered to be restricted to dendritic cells, NK cells, and fibroblasts. In this study we report that human γδ and αβ T lymphocytes also express TLR3, as shown by quantitative real-time PCR, flow cytometry, and confocal microscopy. Although T cells did not respond directly to poly(I:C), we observed a dramatic increase in IFN-γ secretion and an up-regulation of CD69 when freshly isolated γδ T cells were stimulated via TCR in the presence of poly(I:C) without APC. IFN-γ secretion was partially inhibited by anti-TLR3 Abs. In contrast, poly(I:C) did not costimulate IFN-γ secretion by αβ T cells. These results indicate that TLR3 signaling is differentially regulated in TCR-stimulated γδ and αβ T cells, suggesting an early activation of γδ T cells in antiviral immunity.</jats:p>