Cutting edge: T cells respond to lipopolysaccharide innately via TLR4 signaling.
LPS, a molecule produced by Gram-negative bacteria, is known to activate both innate immune cells such as macrophages and adaptive immune B cells via TLR4 signaling. Although TLR4 is also expressed on T cells, LPS was observed not to affect T cell proliferation or cytokine secretion. We now report, however, that LPS can induce human T cells to adhere to fibronectin via TLR4 signaling. This response to LPS was confirmed in mouse T cells; functional TLR4 and MyD88 were required, but T cells from TLR2 knockout mice could respond to LPS. The human T cell response to LPS depended on protein kinase C signaling and involved the phosphorylation of the proline-rich tyrosine kinase (Pyk-2) and p38. LPS also up-regulated the T cell expression of suppressor of cytokine signaling 3, which led to inhibition of T cell chemotaxis toward the chemokine stromal cell-derived factor 1alpha (CXCL12). Thus, LPS, through TLR4 signaling, can affect T cell behavior in inflammation.
Zanin-Zhorov
Alexandra
A
Department of Immunology, Weizmann Institute of Science, Rehovot 76100, Israel.
Tal-Lapidot
Guy
G
Cahalon
Liora
L
Cohen-Sfady
Michal
M
Pevsner-Fischer
Meirav
M
Lider
Ofer
O
Cohen
Irun R
IR
D000818:Animals; D002448:Cell Adhesion / Q000276:immunology; D002464:Cell Migration Inhibition; D002465:Cell Movement / Q000276:immunology; D054377:Chemokine CXCL12; D019743:Chemokines, CXC / Q000037:antagonists & inhibitors / Q000502:physiology; D002634:Chemotaxis, Leukocyte / Q000276:immunology; D005260:Female; D005353:Fibronectins / Q000502:physiology; D006801:Humans; D007113:Immunity, Innate; D008070:Lipopolysaccharides / Q000494:pharmacology*; D051379:Mice; D008809:Mice, Inbred C3H; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D053594:Myeloid Differentiation Factor 88 / Q000502:physiology; D015398:Signal Transduction / Q000276:immunology*; D013601:T-Lymphocytes / Q000166:cytology / Q000276:immunology* / Q000378:metabolism; D051197:Toll-Like Receptor 4 / Q000037:antagonists & inhibitors / Q000502:physiology*
C515255:CXCL12 protein, human; D054377:Chemokine CXCL12; D019743:Chemokines, CXC; C515256:Cxcl12 protein, mouse; D005353:Fibronectins; D008070:Lipopolysaccharides; D053594:Myeloid Differentiation Factor 88; D051197:Toll-Like Receptor 4