Fig. 8.
Schematic diagram of WBC response to metHb + LTA. Haemolytic bacterial infection e.g. by S. aureus, releases Fe3 + metHb into the plasma, which is highly redox-active and interacts with LTA. Neutrophils respond highly sensitively to metHb + LTA complexes by activating unconventional TLR2-mediated signal transduction. Amongst the other leukocytes, monocytes and T cells are activated by metHb, LTA and metHb + LTA by expressing adhesion and costimulatory molecules leading to modulation of neutrophil's responses. The detailed molecular mechanism (denoted as “?” on dashed arrows) of TLR2 signal transduction induced by Hb + TLR ligand complex remains to be elucidated.