Document Type

Thesis

Date of Degree

Spring 2011

Degree Name

MS (Master of Science)

Degree In

Oral Science

First Advisor

Kim A. Brogden

First Committee Member

Kim Brogden

Second Committee Member

David Drake

Third Committee Member

Paula Weistroffer

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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