An in vitro study of neutrophils obtained from the normal gingival sulcus

Abstract

Neutrophils (PMN) are considered to be key components in the protection of the periodontium against pathogenic bacteria. We therefore compared five of the major characteristics of peripheral blood PMN (PB‐PMN) (adherence, chemotaxis, phagocytosis, oxidaiive metabolism, and lysosomal granules) to those of normal crevicular neutrophils (CR‐PMN) isolated from the same individuals. The data indicate that the presence of Fc and C3b receptors, and the production of superoxide are similar in CR‐PMN and PB‐PMN. In addition, healthy gingival sulci harbor a high percentage of stimulated PMN as determined by the nitroblue tetrazolium (NBT) reduction assay. The percentage of CR‐PMN which phagocytized opsonized red blood cells (RBC) was lower than that of PB‐PMN. The in vitro migration of CR‐PMN was reduced as compared to that of PB‐PMN. Crevicular neutrophils also have a diminished ability to adhere to glass surfaces which may be related to a direct non‐cytotoxic effect of gingival fluid component(s) on CR‐PMN. In addition, morphologic evidence indicates that specific granules are more depleted than azurophil granules in CR‐PMN. Interpretation of studies of neutrophil functions in periodontal diseases must consider the observed differences between normal peripheral blood and crevicular neutrophils.

Effects of leukotriene B4 in the human lung. Recruitment of neutrophils into the alveolar spaces without a change in protein permeability.

“…When we studied superoxide anion production, we found that the lung PMN retained their capacity to produce superoxide anion in response to a maximal concentration of PMA (100 ng/ml), consistent with studies of gingival PMN, showing normal production of superoxide anion in response to PMA (10 ng/ml) (51). When PMA is used as the trigger, superoxide anion production is mediated by protein kinase C translocated from the cytosol to the cell membrane (59).…”

“…The data indicate that PMN can migrate across the tight epithelial barrier of the lungs without a major loss in function. The PMN lose some of their smaller secondary granules during transit, which has been observed in PMN from skin blisters and gingival tissue (51,54,55). This effect is not necessarily specific for LTB4, inasmuch as the PMN from the NaCl-and the LTB4-treated sides had similar granule size distributions.…”

“…These observations apply to normal circulating PMN; we have not tested the possibility that when PMN are activated in the circulation before migration, their migration into the lungs in response to LTB4 might be associated with microvascular injury and an increase in permeability (49). Although other studies have measured the function of human PMN in periodontal tissue (50,51), joint fluids (52,53) and skin blisters (54), this is the first study that has measured the function of newly emigrated PMN in human lungs, and the first study to investigate both PMN activity and the effects of PMN migration on the permeability of the epithelial barrier in the human lung. The data indicate that PMN can migrate across the tight epithelial barrier of the lungs without a major loss in function.…”

Exudation primes human and guinea pig neutrophils for subsequent responsiveness to the chemotactic peptide N-formylmethionylleucylphenylalanine and increases complement component C3bi receptor expression.

“…They showed that PMN preincubated with activated complement have an irreversibly reduced chemotactic response toward the same stimulus. Later, chemotactic deactivation was shown to occur in vivo in different clinical situations (10)(11)(12). Deactivation is not limited to chemotaxis.…”

An in vivo study of degranulation of azurophil granules in the neutrophils during phagocytosis of cationized ferritin in the gingival sulcus.

“…Leffell and Spitznagel (10) stated that the specific granular contents are released into the extracellular spaces, whereas azurophil granular contents are released into the phagosomes. Charon et al (4) indicated at the electron level that in crevicular neutrophils specific granules are more rapidly depleted than azurophil granules. On the other hand, Baehni et al (2) reported that the late stage of gingivitis is more potent than the early stage of gingivitis in exocytosis of specific granules.…”