Differential expression of CR3, FcɛRll and FcγRlll on Polymorphonuclear leukocytes in gingival crevicular fluid

Polymorphonuclear leukocytes (PMNLs) are the most numerous cell population among the cellular infiltrates in gingival crevicular fluid (GCF) and play important roles in the host-defensive system in the gingival crevices. We determined the percentage of neutrophils, cosinophils and basophils in total PMNLs by light microscopic observation using Randolph-methylene blue staining, then assessed flow cytometric differences in the expression of CR3, FcγRIII, FcɛRII. LFA-1α, and LFA-Iβ on PMNL in GCF and peripheral blood (PB) from 21 patients with adult periodontius (AP) and 13 healthy donors. Percentages of basophils and eosinophils were higher in GCF than in PB. In both AP patients and healthy subjects, expression of CR3 and FcɛRll was higher while FeγRIII was lower in GCF than in PB. The statistical analysis showed that the expressions of FcγRIII and FcɛRII on GCF PMNLs were lower in AP patients than in healthy subjects. Expressions of LFA-1α and β on GCF were similar to those on PB PMNLs. PB PMNLs stimulated in vitro with Porphyromonas gingivalts culture supernatant and fMLP displayed an expression pattern of CR3, FcγRIII and FcɛRII on GCF PMNLs. However, C5a and IL-I failed to induce changes in FcγRIII and FcɛRII. The results indicate that GCF neutrophils are activated, present enhanced adhesion and a decreased IgG-binding ability which would reflect that they are at the terminal stage of activation, and that GCF contains a larger eosinophil fraction than in PB. Moreover, these GCF eosinophils appear to be activated.