The adhesion molecule CD11b/CD18 (CR3, C3bi receptor) is expressed on the surface of neutrophils (PMNs) and is known to function in phagocytosis of C3bi opsonized cells such as RBC and Staphylococci. Surface expression of CD11b/CD18 is increased on crevicular fluid PMNs (CF-PMNs) from periodontal sites as compared to healthy sites. The BROAD, LONG-TERM OBJECTIVE of this study is to develop the means to enhance eradication of periodontal pathogens by modulating neutrophils locally in the gingival crevice.
The SPECIFIC AIMS of this study are to test the hypothesis that l). the high level of CD11b surface expression on CF-PMNs is due to a relative increase in CD11b transcription (Specific Aim l), 2). the increase in CD11b transcription accounts for the increased surface expression (Specific Aim 2) and 3). PB-PMNs from periodontitis patients differ from those of control subjects in their capacity for CD11b transcription. METHODS: To determine the level of CD11b transcription, RNA will be purified from CF-PMNs as well as unstimulated and stimulated peripheral blood PMNs. CF-PMNs will be obtained from periodontitis sites in periodontitis patients and healthy sites from control subjects. PB-PMNs will be isolated from these same patients. CD11b mRNA will be quantitated using a polymerase chain reaction assay that will utilize primers specific for CD11b. To correlate the increase in CD11b mRNA expression with the level of CD11b expressed on the PMN surface, flow cytometric analysis of the level of surface CD11b will be conducted. HEALTH RELATEDNESS: The results from this study will lead to a local therapy which will enhance phagocytosis of periodontal pathogens. Modulation of CD11b upregulation at the gene level in the crevicular environment will eventually eliminate timely and costly procedures such as subgingival cleaning and periodontal surgery, as well as the use of antibiotics.
| Watanabe, K; Blew, B; Scherer, M et al. (1997) CD11b mRNA expression in neutrophils isolated from peripheral blood and gingival crevicular fluid. J Clin Periodontol 24:814-22 |
