Sulfide influence on polymorphonuclear functions: a possible role for Ca2+ involvement.
Polymorphonuclear cells (PMN) of gingival sulcus play an important role in host defense against periodontal tissue-invading bacteria, but their phagocytic activity is conditioned by several virulence factors released by oral pathogens. In this report we have studied the influence of sulfide, a toxic bacterial metabolite, on the main PMN functions: chemotaxis, degranulation and oxidative burst. PMN exposed to sodium sulfide (up to 2 mM) used as a source of H2S showed a depression of the calcium-dependent cytoskeleton activities such as chemotaxis and azurophilic granule release induced by FMLP. No effect was observed on the calcium-independent specific granule release obtained by PMA. These data were in agreement with the sulfide inhibition of cytosolic free Ca2+ concentration [Ca2+]i increase normally induced by ionomycin. On the other hand, hydrogen sulfide was able to prime PMN for a stronger oxidative response both to calcium-dependent or calcium-independent stimulation. This finding may account for a more efficient oxidative killing under reoxygenation of the anaerobic infectious areas.
Mariggiò
M A
MA
Department of Biomedical Sciences and Human Oncology, Faculty of Medicine, University of Bari, Italy.
Pettini
F
F
Fumarulo
R
R
D002118:Calcium / Q000502:physiology*; D015550:Cell Degranulation / Q000187:drug effects / Q000276:immunology; D002634:Chemotaxis, Leukocyte / Q000187:drug effects / Q000276:immunology; D006801:Humans; D009504:Neutrophils / Q000187:drug effects* / Q000276:immunology; D016897:Respiratory Burst / Q000187:drug effects / Q000276:immunology; D012441:Saccharomyces cerevisiae; D013440:Sulfides / Q000494:pharmacology*
D013440:Sulfides; D002118:Calcium; C033479:sodium sulfide