Induction of cytokines by heat shock proteins and endotoxin in murine macrophages.
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.
Gao
Baochong
B
Institute for Clinical Research, Washington, DC 20422, USA. baochong.gao@med.va.gov
Tsan
Min-Fu
MF
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
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