Exercise-induced extracellular 72 kDa heat shock protein (Hsp72) stimulates neutrophil phagocytic and fungicidal capacities via TLR-2.
This study evaluated the role of toll like receptor 2 (TLR-2) in the interaction of 72 kDa extracellular heat shock protein (Hsp72, a stress-inducible protein) with neutrophils and the participation on TLR-2 in the stimulation of neutrophil phagocytic and fungicidal capacities by post-exercise physiological concentrations of Hsp72. Human peripheral blood neutrophils were incubated with fluorescein isothiocyanate-conjugated Hsp72, and were analyzed by immunofluorescence microscopy and flow cytometry. Both methods revealed an interaction of Hsp72 with neutrophils. In addition, when neutrophils were pre-incubated with an anti-TLR-2 antibody this interaction was clearly decreased. Post-exercise circulating concentration of Hsp72 (8.6 ng/ml) stimulated the phagocytic and fungicidal capacities of neutrophils and this effect could be also blocked using an antibody against TLR-2. Phosphatidylinositol-3-kinase (PI3K), extracellular signal-regulated kinase (ERK) and the nuclear transcription factor kappa beta (NF-kappabeta) were found to be involved in the signaling process, confirming the participation of TLR-2 in the stimulation of neutrophil function by Hsp72. In conclusion, TLR-2 is involved at least in part, in the stimulation of neutrophil phagocytic and fungicidal capacities induced by post-exercise physiological concentrations of Hsp72.
Giraldo
Esther
E
Department of Physiology, Faculty of Sciences, University of Extremadura, 06071, Badajoz, Spain.
Martin-Cordero
Leticia
L
Garcia
Juan Jose
JJ
Gehrmann
Mathias
M
Gerhmann
Mathias
M
Multhoff
Gabriele
G
Ortega
Eduardo
E
D000328:Adult; D002176:Candida albicans / Q000502:physiology; D002478:Cells, Cultured; D015444:Exercise / Q000502:physiology*; D005260:Female; D050884:HSP72 Heat-Shock Proteins / Q000378:metabolism*; D006801:Humans; D009504:Neutrophils / Q000166:cytology / Q000276:immunology* / Q000378:metabolism; D010587:Phagocytosis / Q000502:physiology*; D015398:Signal Transduction; D051195:Toll-Like Receptor 2 / Q000378:metabolism*
D050884:HSP72 Heat-Shock Proteins; C495342:TLR2 protein, human; D051195:Toll-Like Receptor 2