Figure 4. Heat-sensitive S. aureus Hla activates nociceptors and contributes to infection-induced hyperalgesia.
(a) Hla application evoked DRG neuron calcium flux (arrows, traces), (b-c) dose-dependent calcium flux (n=3/condition) and acute pain (n=5-10/group). *p<0.05, ***p<0.001. (d) Heat pre-treatment abolishes Hla-induced pain (1 μg, n=7/group). (e) Hla, HLAH35L evoked DRG neuron action potentials (arrow, Hla application, n=3/condition). (f) Hla (1 μg, n=6) but not HlaH35L (1 μg, n=5) induced acute pain. (g) Hla 100 ng (n=8), 330 ng (n=8), saline (n=8) injection induced hypersensitivity. 100 ng vs. saline: ***p<0.001; 330 ng vs. saline: #p<0.05, ##p<0.01, ###p<0.001. (h) S. aureus lacking Hla (n=12) produced less mechanical (p=0.0056), heat (p=0.0193), acetone (p=0.0118) hypersensitivity than WT S. aureus (n=13). *p<0.05; **p<0.01; ***p<0.001. Error bars, mean±s.e.m.