CYTOSKELETAL ACTIN REORGANIZATION IN NEUTROPHILS FROM PATIENTS WITH LOCALIZED JUVENILE PERIODONTITIS

LOCALIZED JUVENILE PERIODONTITIS (LJP) is an early-onset periodontal d isease associated with a polymorphonuclear neutrophil (PMN) defective migratory response. Kinetics of actin polymerization-depolymerization determine the shape changes occurring in the plasma membrane-associate d cytoskeleton and provide the driving force for directed cell migrati on (chemotaxis). Therefore, we investigated the relation between an ab normality in LJP PMN chemotaxis and an altered reorganization of the a ctin filament network. PMNs isolated from peripheral blood of LJP pati ents (n=14) and matching control subjects (n=12) were evaluated for ra ndom and directed migration in a Boyden chamber assay, and the kinetic s of actin polymerization were studied by flow cytometry. Three groups of LJP patients could be distinguished on the basis of their PMN-chem otactic response compared to their matched control: depressed (n=6), n ormal (n=4), and elevated (n=4). The abnormal (depressed or elevated) chemotaxis was generally not related to abnormal random migratory resp onse, except for two patients. Since the kinetics of formyl-methionyl- leucyl-phenylalanine-induced F-actin response were highly variable fro m one subject to another, means were calculated at each timepoint with the values obtained from each group of subjects and compared by a gen eral factorial design analysis. No statistically significant differenc es were detected between the control group and the LJP patient group. Furthermore, the data did not show a correlation between the kinetics of actin polymerization-depolymerization and the abnormal chemotactic response observed in LJP PMNs. Hence, the chemotaxis defect in LJP PMN appears to be mediated by signaling events that carry their effect in dependently of an intact cytoskeleton.