Document Type

Thesis

Date of Degree

Spring 2011

Degree Name

MS (Master of Science)

Degree In

Oral Science

First Advisor

Kim A. Brogden

Abstract

Histatins, a group of proteins produced by human salivary glands, have a variety of innate immune functions including the ability to: kill oral microorganisms, neutralize toxins, inactivate protease/collagenase activities, inhibit co-aggregation of oral bacteria, and inhibit lipopolysaccharide mediated activities. Hemagglutinin B (HagB), a virulence factor of the periodontal pathogen Porphyromonas gingivalis, induces a robust cytokine and chemokine response in human myeloid dendritic cells. In this study, I hypothesize that histatin 5 can attenuate a HagB-induced chemokine response. Objectives: To characterize an expanded cytokine and chemokine response induced in human myeloid dendritic cells by HagB, and to determine if prior incubation of HagB with histatin 5 attenuates these responses. Methods: In my first experiment, 0.040 M HagB was mixed with dilutions of histatin 5 and histatin 8 (Sigma, 0.04 to 40.0 M), incubated at 37C for 30 minutes, and added to 2 x 104 human myeloid dendritic cells (Lonza, Walkersville, MD). At 24 hours, culture media was removed, and 6 cytokines and chemokines (pg/ml) were determined in cell-free supernatants (Millipore, Billerica, MA) using the Luminex 100 IS instrument (Luminex, Austin, TX). In my second experiment, 0.040 M HagB was mixed with 40.0 M histatin 5 only (e.g., 1:1000), incubated at 37C for 30 minutes, and added to 2 x 104 human myeloid dendritic cells. At 0, 1, 2, 4, 8, 16, and 24 hours post-inoculation, culture media was removed, and 26 cytokines and chemokines (pg/ml) were determined in cell-free supernatants. Results: In both experiments, human myeloid dendritic cells incubated with HagB produced Th1, Th2, and Th17 cytokines (IL-2, IL-12(p70), IFN-, IL-3, IL-4, IL-5, , IL-15, IL-17); pro-inflammatory cytokines (IL-1, IL-1, IL-6, TNF-, IL-12(p40); anti-inflammatory v cytokines (IL-10, IL-13, IFN2); chemokines (CXCL8/IL-8, CXCL10/IP-10, CCL2/MCP-1, CCL3/MIP-1, MIP-1b, CCL11/eotaxin); and colony stimulating factors (IL-7, G-CSF, GM-CSF). Histatin 5 significantly attenuated (p < 0.05) the IL-8 response induced by HagB at 8 - 16 hours and to a lesser extent, the IL-6, GM-CSF, MCP-1, MIP-1α, MIP-1β, and TNF-α response. Conclusion: Histatin 5 is an important salivary component capable of attenuating an IL-8 response. Together with human beta defensin 3, another peptide previously shown to attenuate pro-inflammatory cytokines, histatin 5 may help control and contain oral infection and inflammation by down regulating IL-8 chemotactic response.

Keywords

antiinflammatory, cytokine, Histatin, IL-8, P. gingivalis, saliva

Pages

viii, 65 pages

Bibliography

Includes bibliographical references (pages 56-65).

Copyright

Copyright 2011 Derek Steven Borgwardt

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