HSP70 peptidembearing and peptide-negative preparations act as chaperokines.
We recently elucidated a novel function for the 70-kDa heat shock protein (HSP70) as a chaperone and a cytokine, a chaperokine in human monocytes. Here we show that peptide-bearing and peptide-negative HSP70 preparations isolated from EMT6 mammary adenocarcinoma cells (EMT6-HSP70) act as chaperokines when admixed with murine splenocytes. EMT6-HSP70 bound with high affinity to the surface of splenocytes recovered from naive BALB/c mice. The [Ca2+]i inhibitor BAPTA dose dependently inhibited HSP70- but not LPS-induced NF-kappaB activity and subsequent augmentation of proinflammatory cytokine TNF-alpha, IL-1beta, and IL-6 production. Taken together, these results suggest that presence of peptide in the HSP70 preparation is not required for spontaneous activation of cells of the innate immune system.
Asea
A
A
Department of Adult Oncology, Dana-Farber Cancer Institute, Harvard Medical School, Boston, MA 02115, USA.
Kabingu
E
E
Stevenson
M A
MA
Calderwood
S K
SK
D000230:Adenocarcinoma; D000818:Animals; D002118:Calcium / Q000378:metabolism; D002614:Chelating Agents / Q000494:pharmacology; D004533:Egtazic Acid / Q000031:analogs & derivatives / Q000494:pharmacology; D005260:Female; D018840:HSP70 Heat-Shock Proteins / Q000276:immunology / Q000493:pharmacokinetics*; D007375:Interleukin-1 / Q000378:metabolism; D015850:Interleukin-6 / Q000378:metabolism; D008070:Lipopolysaccharides / Q000494:pharmacology; D008325:Mammary Neoplasms, Experimental; D051379:Mice; D008807:Mice, Inbred BALB C; D018832:Molecular Chaperones / Q000276:immunology / Q000493:pharmacokinetics*; D009000:Monocytes / Q000276:immunology / Q000378:metabolism*; D016328:NF-kappa B / Q000378:metabolism; D011485:Protein Binding / Q000187:drug effects / Q000276:immunology; D015398:Signal Transduction / Q000276:immunology; D013154:Spleen / Q000166:cytology / Q000276:immunology / Q000378:metabolism; D014407:Tumor Cells, Cultured; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism
D002614:Chelating Agents; D018840:HSP70 Heat-Shock Proteins; D007375:Interleukin-1; D015850:Interleukin-6; D008070:Lipopolysaccharides; D018832:Molecular Chaperones; D016328:NF-kappa B; D014409:Tumor Necrosis Factor-alpha; D004533:Egtazic Acid; C025603:1,2-bis(2-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid; D002118:Calcium