Direct association of thioredoxin-1 (TRX) with macrophage migration inhibitory factor (MIF): regulatory role of TRX on MIF internalization and signaling.
Thioredoxin-1 (TRX) is a small (14 kDa) multifunctional protein with the redox-active site Cys-Gly-Pro-Cys. Macrophage migration inhibitory factor (MIF) is a 12 kDa cytokine belonging to the TRX family. Historically, when we purified TRX from the supernatant of ATL-2 cells, a 12 kDa protein was identified along with TRX, which was later proved to be MIF. Here, we show that TRX and MIF form a complex in the cell and the culture supernatant of ATL-2 cells. Using a BIAcore assay, we confirmed that TRX has a specific affinity with MIF. We also found that extracellular MIF was more effectively internalized into the ATL-2 cells expressing TRX on the cell surface, than the Jurkat T cells which do not express surface TRX. Moreover, anti-TRX antibody blocked the MIF internalization, suggesting that the cell surface TRX is involved in MIF internalization into the cells. Furthermore, anti-TRX antibody inhibited MIF-mediated enhancement of TNF-alpha production from macrophage RAW264.7 cells. These results suggest that the cell surface TRX serves as one of the MIF binding molecules or MIF receptor component and inhibits MIF-mediated inflammatory signals.
Son
Aoi
A
Department of Biological Responses, Institute for Virus Research, Kyoto University, Kyoto 606-8507, Japan.
Kato
Noriko
N
Horibe
Tomohisa
T
Matsuo
Yoshiyuki
Y
Mochizuki
Michika
M
Mitsui
Akira
A
Kawakami
Koji
K
Nakamura
Hajime
H
Yodoi
Junji
J
D000818:Animals; D002460:Cell Line; D004705:Endocytosis / Q000502:physiology; D006801:Humans; D008070:Lipopolysaccharides / Q000494:pharmacology; D008263:Macrophage Migration-Inhibitory Factors / Q000235:genetics / Q000378:metabolism*; D008264:Macrophages / Q000166:cytology / Q000187:drug effects / Q000276:immunology; D051379:Mice; D010084:Oxidation-Reduction; D011485:Protein Binding; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism; D015398:Signal Transduction / Q000502:physiology*; D020349:Surface Plasmon Resonance; D013879:Thioredoxins / Q000378:metabolism*; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism
D008070:Lipopolysaccharides; D008263:Macrophage Migration-Inhibitory Factors; D011994:Recombinant Proteins; D014409:Tumor Necrosis Factor-alpha; D013879:Thioredoxins