title: Induction of cytokines by heat shock proteins and endotoxin in murine macrophages.
abstract: Extensive studies in the past 10 years have suggested that heat shock protein 60 (Hsp60) and Hsp70 may be potent activators of the innate immune system capable of inducing pro-inflammatory cytokine production by macrophages. However, we have recently demonstrated that the reported pro-inflammatory cytokine-inducing effect of Hsp60 and Hsp70 was due to contaminating lipopolysaccharide (LPS) and LPS-associated molecules. In the current study, we determined whether highly purified, essentially LPS-free recombinant human Hsp60 (rhHsp60) and rhHsp70 had any cytokine-inducing effect. Using gene expression array, we demonstrated that at 2 and 4h after treatment, while LPS (1 ng/ml) markedly enhanced the expression of a number of cytokine genes, rhHsp60 and rhHsp70 (5 microg/ml) had no effect on any of the 96 common cytokine genes. Reverse transcriptase-polymerase chain reaction analysis and enzyme-linked immunosorbent assay of tumor necrosis factor-alpha (TNFalpha) and interleukin-1beta (IL-1beta) supported the above observation. These data suggest that rhHsp60 and rhHsp70 do not activate cytokine genes in murine macrophages.
authors.affiliation: Institute for Clinical Research, Washington, DC 20422, USA. baochong.gao@med.va.gov
authors.forename: Baochong
authors.initials: B
authors.lastname: Gao
authors.forename: Min-Fu
authors.initials: MF
authors.lastname: Tsan
mesh_terms: D002460:Cell Line; D018834:Chaperonin 60 / Q000235:genetics / Q000494:pharmacology*; D016207:Cytokines / Q000096:biosynthesis* / Q000235:genetics; D004731:Endotoxins / Q000494:pharmacology*; D015870:Gene Expression / Q000187:drug effects*; D020869:Gene Expression Profiling; D018840:HSP70 Heat-Shock Proteins / Q000235:genetics / Q000494:pharmacology*; D006801:Humans; D007375:Interleukin-1 / Q000096:biosynthesis; D008070:Lipopolysaccharides / Q000494:pharmacology; D008264:Macrophages / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D020411:Oligonucleotide Array Sequence Analysis; D011994:Recombinant Proteins / Q000235:genetics / Q000494:pharmacology; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014409:Tumor Necrosis Factor-alpha / Q000096:biosynthesis
chemical_list: D018834:Chaperonin 60; D016207:Cytokines; D004731:Endotoxins; D018840:HSP70 Heat-Shock Proteins; D007375:Interleukin-1; D008070:Lipopolysaccharides; D011994:Recombinant Proteins; D014409:Tumor Necrosis Factor-alpha