Study on the relationship between heat shock protein 70 and toll-like receptor-4 of monocytes.
To explore the relation between human heat shock protein 70 (hsp70) and TLR4 in human monocytes in vitro, human monocytes were stimulated with various concentrations of HSP70, and TNF-alpha production in supernatants was measured by ELISA. Pre-incubated with or without anti-TLR4 mAb, and stimulated with hsp70 (5.0 microg/ml), NF-kappaB p65 of human monocytes in different time points were detected by immunohistochemistry and monocyte surface expression of TLR4 was measured by flow cytometry. After the human monocytes were pre-incubated with various concentrations of anti-TLR4 and stimulated with hsp70 (5.0 microg/ml), TNF-alpha production in supernatants was measured. The results showed that hsp70 enhanced NF-kappaB activation, which was clearly inhibited by anti-TLR4, with the positive cell ratios being 67.44%, 39.17%, 31.56% and 28.05 %, respectively. TLR4 was rapidly down-regulated in the presence of hsp70. MFI of TLR4 on monocytes in different time points were 87.77 +/- 5.38, 78.16 +/- 6.01 and 45.17 +/- 4.97 (P<0.05), 26.98 +/- 5.83 (P<0.01), respectively. Moreover, hsp70-induced TNF-alpha production by human monocytes was inhibited by anti-TLR4. It is suggested that TLR4 is involved in the hsp70-mediated activation of innate immunity.
Chen
Xinzhong
X
Department of Cardiovascular Surgery, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022, China.
Sun
Zongquan
Z
Du
Xinling
X
Liu
Chao
C
Liu
Yi
Y
Wu
Long
L
D018840:HSP70 Heat-Shock Proteins / Q000378:metabolism*; D006801:Humans; D066298:In Vitro Techniques; D009000:Monocytes / Q000378:metabolism*; D051197:Toll-Like Receptor 4 / Q000378:metabolism; D051996:Transcription Factor RelA / Q000378:metabolism*; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism*
D018840:HSP70 Heat-Shock Proteins; C495345:TLR4 protein, human; D051197:Toll-Like Receptor 4; D051996:Transcription Factor RelA; D014409:Tumor Necrosis Factor-alpha