Publication Date

2008

Document Type

Thesis

Committee Members

Larry Arlian (Advisor), Barbara Hull (Committee Member), Courtney Sulentic (Committee Member)

Degree Name

Master of Science (MS)

Abstract

House dust mites are microscopic arthropods that can trigger moderate allergic symptoms such as sneezing, watery eyes, itching, and wheezing in sensitized individuals. People with more serious allergies to house dust mites can develop allergic diseases like atopic dermatitis and asthma. The effects of house dust mites on allergy sufferers make house dust mites and the study of their effects on the human body of great medical and economic importance. A majority of the research that has been done on house dust mite's effects on humans has dealt with the lungs and relevant disease like asthma. Little work has been done on the inflammatory response of the skin to the house dust mite. Since the human microvascular dermal endothelial cell(HMVEC-d) is a major regulator in the inflammatory response of the skin, my research attempted to look at the in vitro effects of house dust mite extract on the expression of inflammatory molecules that are important in inflammatory cell trafficking and activation.

HMVEC-d were exposed to extracts of the two most common house dust mite species Dermatophagoides farinae and Dermatophagoides pteronyssinus at four different concentrations. The expression level of the cytokines IL-1alpha, IL-1beta, IL-6, macrophage inflammatory protein 1alpha (MIP-1alpha), granulocyte-macrophage colony stimulating factor (GM-CSF), and eotaxin, as well as the chemokines IL-8 and macrophage chemoattractant protein 1 (MCP-1) were analyzed using a sandwich ELISA technique. The expression level of the chemokine receptors CXCR-1, CXCR-2, and CCR-5, and the adhesion molecules intracellular adhesion molecule 1 (ICAM-1), vascular cellular adhesion molecule 1 (VCAM-1), and E-selectin were analyzed using the indirect ELISA technique. Expression of all of the molecules was determined at 12 hours and 24 hours post exposure to house dust mite extract. The effects of house dust mite extract on dermal endothelial cells after stimulation with TNF-alpha was also tested.

The results showed an extensive upregulation in the expression of several of the molecules that were tested for. The adhesion molecule ICAM-1 had a significant dose dependent increase in expression but the adhesion molecules VCAM-1 and E-selectin showed a much smaller yet still significant dose dependent increase in expression. The cytokines and chemokines IL-6, GM-CSF, IL-8, and MCP-1 all showed a significant dose dependent increase in expression by the HMVEC-d. The chemokine receptors were unaffected by the extract and the cytokines IL-1alpha, IL-1beta, MIP-1alpha, and eotaxin were not detected. The results clearly show that the two species of house dust mite extracts caused an increase in the expression level of several specific inflammatory molecules by HMVEC-d. The variation in the effects that the two species of house dust mites had on HMVEC-d indicates that the uncharacterized non-allergic components of the two extracts may also play a role in the activation of the allergic response of the skin.

Page Count

98

Department or Program

Microbiology and Immunology

Year Degree Awarded

2008

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