title: Interleukin-10 anti-inflammatory response to Borrelia burgdorferi, the agent of Lyme disease: a possible role for suppressors of cytokine signaling 1 and 3.
abstract: It has been established that interleukin-10 (IL-10) inhibits inflammatory cytokines produced by macrophages in response to Borrelia burgdorferi or its lipoproteins. The mechanism by which IL-10 exerts this anti-inflammatory effect is still unknown. Recent findings indicate that suppressors of cytokine signaling (SOCS) proteins are induced by cytokines and Toll-like receptor (TLR)-mediated stimuli, and in turn they can down-regulate cytokine and TLR signaling in macrophages. Because it is known that SOCS are induced by IL-10 and that B. burgdorferi and its lipoproteins most likely interact via TLR2 or the heterodimers TLR2/1 and/or TLR2/6, we hypothesized that SOCS are induced by IL-10 and B. burgdorferi and its lipoproteins in macrophages and that SOCS may mediate the inhibition by IL-10 of concomitantly elicited cytokines. We report here that mouse J774 macrophages incubated with IL-10 and added B. burgdorferi spirochetes (freeze-thawed, live, or sonicated) or lipidated outer surface protein A (L-OspA) augmented their SOCS1/SOCS3 mRNA and protein expression, with SOCS3 being more abundant. Pam(3)Cys, a synthetic lipopeptide, also induced SOCS1/SOCS3 expression under these conditions, but unlipidated OspA was ineffective. Neither endogenous IL-10 nor the translation inhibitor cycloheximide blocked SOCS1/SOCS3 induction by B. burgdorferi and its lipoproteins, indicating that the expression of other genes is not required. This temporally correlated with the IL-10-mediated inhibition of the inflammatory cytokines IL-1beta, IL-6, IL-12p40, IL-18, and tumor necrosis factor alpha. Our data are evidence to suggest that expression of SOCS is part of the mechanism of IL-10-mediated inhibition of inflammatory cytokines elicited by B. burgdorferi and its lipoproteins.
authors.affiliation: Division of Bacteriology and Parasitology, Tulane National Primate Research Center, 18703 Three Rivers Rd., Covington, LA 70433, USA. vida@tulane.edu
authors.forename: Vida A
authors.initials: VA
authors.lastname: Dennis
authors.forename: Ayanna
authors.initials: A
authors.lastname: Jefferson
authors.forename: Shree R
authors.initials: SR
authors.lastname: Singh
authors.forename: Frédéric
authors.initials: F
authors.lastname: Ganapamo
authors.forename: Mario T
authors.initials: MT
authors.lastname: Philipp
mesh_terms: D000818:Animals; D000954:Antigens, Surface / Q000276:immunology / Q000494:pharmacology; D001425:Bacterial Outer Membrane Proteins / Q000276:immunology / Q000494:pharmacology; D001428:Bacterial Vaccines / Q000276:immunology / Q000494:pharmacology; D025065:Borrelia burgdorferi; D002478:Cells, Cultured; D016207:Cytokines / Q000235:genetics / Q000378:metabolism*; D015536:Down-Regulation; D016753:Interleukin-10 / Q000494:pharmacology*; D008074:Lipoproteins / Q000276:immunology / Q000494:pharmacology; D008193:Lyme Disease / Q000276:immunology*; D008264:Macrophages / Q000187:drug effects* / Q000276:immunology; D051379:Mice; D015398:Signal Transduction; D000071222:Suppressor of Cytokine Signaling 1 Protein; D000071223:Suppressor of Cytokine Signaling 3 Protein; D050826:Suppressor of Cytokine Signaling Proteins / Q000235:genetics / Q000502:physiology*; D014158:Transcription, Genetic; D015854:Up-Regulation
chemical_list: D000954:Antigens, Surface; D001425:Bacterial Outer Membrane Proteins; D001428:Bacterial Vaccines; D016207:Cytokines; D008074:Lipoproteins; C072045:OspA protein; C491590:Socs1 protein, mouse; C491411:Socs3 protein, mouse; D000071222:Suppressor of Cytokine Signaling 1 Protein; D000071223:Suppressor of Cytokine Signaling 3 Protein; D050826:Suppressor of Cytokine Signaling Proteins; D016753:Interleukin-10