Hsp70 release from peripheral blood mononuclear cells.
There are an increasing number of studies reporting the presence of Hsps in human serum. We have investigated the release of Hsp70 into blood and culture medium from peripheral blood mononuclear cells (PBMCs), and whether this release is due to cell damage or active secretion from the cells. Intact Hsp70 was released from cells within whole blood and from purified PBMCs under normal culture conditions. Hsp70 release was rapid (0.1 ng/10(6) cells/h) over the first 2 h of culture and continued at a reduced rate up to 24 h (<0.025 ng/10(6) cells/h). Using viable cell counts and lactate dehydrogenase release we were able to confirm that the release of Hsp70 was not due to cellular damage. Hsp70 release was inhibited by monensin, methyl-beta-cyclodextrin, and methylamine, but not by brefeldin A. These data suggest that Hsp70 is released from cells via a non-classical pathway, possibly involving lysosomal lipid rafts.
Chester Centre for Stress Research, Biological Sciences, University College Chester, Parkgate Road, Chester CH1 4BJ, United Kingdom.
Claire
C
Hunter-Lavin
Emma L
EL
Davies
Maria M F V G
MM
Bacelar
Michael J
MJ
Marshall
Sarah M
SM
Andrew
John H H
JH
Williams
D001402:B-Lymphocytes / Q000378:metabolism; D015153:Blotting, Western; D020126:Brefeldin A / Q000494:pharmacology; D002470:Cell Survival; D003470:Culture Media / Q000494:pharmacology; D018840:HSP70 Heat-Shock Proteins / Q000097:blood* / Q000378:metabolism; D006801:Humans; D007770:L-Lactate Dehydrogenase / Q000378:metabolism; D007963:Leukocytes, Mononuclear / Q000166:cytology* / Q000378:metabolism; D008247:Lysosomes / Q000378:metabolism; D021962:Membrane Microdomains / Q000378:metabolism; D008744:Methylamines / Q000737:chemistry; D008985:Monensin / Q000378:metabolism; D011500:Protein Synthesis Inhibitors / Q000494:pharmacology; D012333:RNA, Messenger / Q000378:metabolism; D013601:T-Lymphocytes / Q000378:metabolism; D013696:Temperature; D013997:Time Factors; D047392:beta-Cyclodextrins / Q000378:metabolism
D003470:Culture Media; D018840:HSP70 Heat-Shock Proteins; D008744:Methylamines; D011500:Protein Synthesis Inhibitors; D012333:RNA, Messenger; D047392:beta-Cyclodextrins; D020126:Brefeldin A; D008985:Monensin; C027451:methylamine; D007770:L-Lactate Dehydrogenase; C031215:betadex