TLR2 is expressed on activated T cells as a costimulatory receptor.
Toll is the founder of a group of pattern recognition receptors that play a critical role in the innate immunity in Drosophila. At least 10 distinct Toll-like receptors (TLRs), recognizing pathogen-associated molecular patterns, have now been identified in humans. Most investigations on TLRs have focused on cells of the innate system. We report here that naïve human T cells expressed high levels of cell-surface TLR2 after activation by anti-T cell receptor antibody and IFN-alpha. Activated cells produced elevated levels of cytokines in response to the TLR2 ligand, bacterial lipopeptide. Furthermore, CD4(+)CD45RO(+) memory T cells from peripheral blood constitutively expressed TLR2 and produced IFN-gamma in response to bacterial lipopeptide, which also markedly enhanced the proliferation and IFN-gamma production by CD45RO(+) T cells in the presence of IL-2 or IL-15. Thus, TLR2 serves as a costimulatory receptor for antigen-specific T cell development and participates in the maintenance of T cell memory. This suggests that pathogens, via their pathogen-associated molecular patterns, may contribute directly to the perpetuation and activation of long-term T cell memory in both antigen-dependent and independent manner.
Division of Immunology, Infection, and Inflammation, University of Glasgow, Glasgow G11 6NT, United Kingdom.
Mousa
M
Komai-Koma
Louise
L
Jones
Graham S
GS
Ogg
Damo
D
Xu
Foo Y
FY
Liew
D000818:Animals; D000938:Antigen-Presenting Cells / Q000276:immunology; D001483:Base Sequence; D017931:DNA Primers; D005312:Fetal Blood / Q000276:immunology; D005434:Flow Cytometry; D006801:Humans; D007156:Immunologic Memory; D007231:Infant, Newborn; D008213:Lymphocyte Activation / Q000276:immunology; D008562:Membrane Glycoproteins / Q000172:deficiency / Q000235:genetics*; D051379:Mice; D018345:Mice, Knockout; D016133:Polymerase Chain Reaction; D011956:Receptors, Cell Surface / Q000172:deficiency / Q000235:genetics* / Q000276:immunology; D013601:T-Lymphocytes / Q000276:immunology*; D051195:Toll-Like Receptor 2; D051193:Toll-Like Receptors
D017931:DNA Primers; D008562:Membrane Glycoproteins; D011956:Receptors, Cell Surface; C495342:TLR2 protein, human; D051195:Toll-Like Receptor 2; D051193:Toll-Like Receptors