KINETICS OF CD11B EXPRESSION ON NEUTROPHILS ISOLATED FROM SUBJECTS WITH HEALTHY GINGIVAE AND PATIENTS WITH ADVANCED PERIODONTITIS

The adhesion molecule, CD11b/CD18, plays a role in host defense agains t bacterial infections owing to its involvement in cell migration and phagocytosis. We examined the kinetics of CD11b expression on neutroph ils isolated from peripheral blood (PB-PMNs) and gingival crevicular f luid (CF-PMNs) in subjects with healthy gingivae and in patients with advanced periodontitis in order to assess if CF-PMNs respond different ly in regard to CD11b expression from PB-PMNs isolated from healthy or periodontitis subjects. CF-PMNs or formylmethionylleucylphenylalanine (fMLP)-stimulated PB-PMNs were incubated in buffer with or without di valent cations for 60, 90, or 110 minutes. Plasma membrane (surface) C D11b as measured by flow cytometry was found to be reduced with time w hen cells (PB-PMNs or CF-PMNs) from either controls or patients were t reated with calcium- and magnesium-free buffer. However, when CF-PMNs were treated with buffer containing Ca++/Mg++, surface CD11b expressio n increased on cells from both controls and patients. The reduction in CD11b expression on PB-PMNs is significantly greater than that measur ed on CF-PMNs over time. Therefore, CF-PMNs respond differently from P B-PMNs which have been artifically stimulated with fMLP in regard to k inetics of CD11b expression on the plasma membrane.