Expression and function of Toll-like receptor on T cells.
Toll is the founder of a group of pattern recognition receptors, which play a critical role in the innate immunity in Drosophila. At least 13 distinct Toll-like receptors (TLRs), recognising pathogen-associated molecular pattern (PAMPs), 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 (TCR) antibody and interferon-alpha. Activated cells produced elevated levels of cytokines in response to the TLR2 ligand, bacterial lipopeptide (BLP). Furthermore, CD4(+)CD45RO(+) memory T cells from peripheral blood constitutively expressed TLR2 and produced IFNgamma in response to BLP. BLP also markedly enhanced the proliferation and IFNgamma production by CD45RO(+) T cells in the presence of IL-2 or IL-15. Thus, TLR2 serves as a co-stimulatory receptor for antigen-specific T cell development and participates in the maintenance of T cell memory. This suggests that pathogens, via their PAMPs, may contribute directly to the perpetuation and activation of long term T cell memory in both antigen dependent and independent manner.
Xu
Damo
D
Division of Immunology, Infection and Inflammation, University of Glasgow, Glasgow G11 6NT, Scotland, UK.
Komai-Koma
Mousa
M
Liew
Foo Y
FY
D000818:Animals; D015496:CD4-Positive T-Lymphocytes / Q000166:cytology / Q000276:immunology* / Q000378:metabolism; D006801:Humans; D007156:Immunologic Memory; D008562:Membrane Glycoproteins / Q000096:biosynthesis* / Q000235:genetics / Q000502:physiology*; D011956:Receptors, Cell Surface / Q000096:biosynthesis* / Q000235:genetics / Q000502:physiology*; D051195:Toll-Like Receptor 2; D051193:Toll-Like Receptors
D008562:Membrane Glycoproteins; D011956:Receptors, Cell Surface; C495342:TLR2 protein, human; D051195:Toll-Like Receptor 2; D051193:Toll-Like Receptors