The COX-2 Gene and the Immune System

This is a cross-sectional, controlled study designed to investigate the association of single nucleotide polymorphisms (SNPs) in the cyclooxygenase-2 (COX2) gene, also called prostaglandin endoperoxidase synthase 2 (PTGS2), on T-cell differentiation and function. Specifically, the impact of the promoter-region SNP 765G>C (rs20417) and the 3 untranslated region (UTR) SNP 8473T>C (rs5275) on T helper cell (Th) 2, Th9, and Th17 differentiation and function will be examined. Non-Hispanic, White or Black/African American, non-pregnant adults, aged 18-65 years, who are wild type (WT), with respect to both the 765G>C and 8473T>C SNPs, WT with respect to 765G>C and homozygous for 8473T>C, and homozygous for both 765G>C and 8473T>C will be recruited into a total of three genotype groups. Potential participants will be identified from the Environmental Polymorphisms Registry, contacted by recruitment letter and pre-screened for eligibility. Pre-screened individuals will provide verbal consent to withhold certadata analysis, a urine collection cup, and pre-visit instructions. Participants will attend a single study visit that will take place at the National Institute of Environmental Health Sciences (NIEHS) Clinical Research Unit (CRU). During this visit, written informed consent will be obtained, and there will be a final screening and eligibility determination, medical history review, vital signs, physical examination and blood and urine samples will be collected. From peripheral blood, lymphocyte subsets, prostaglandin levels, and cytokine levels will be determined; stable prostaglandin metabolites, creatinine, total protein and albumin will be measured in urine. Lymphocytes will be isolated from peripheral blood for ex vivo analyses. Demographic characteristics (i.e., age) will be compared between the groups, and when possible, recruitment will be targeted to achieve an approximate match of race and gender across the groups. The primary objective of the study is to determine whether the 765G>C or 8473T>C SNPs exhibit altered Th2, Th9 and Th17 cell differentiation by examining lymphocyte subsets in vivo. The study will also examine the impact of these two SNPs on circulating Th2/Th9/Th17 cytokine levels and prostaglandins in vivo, on differentiation of naive CD4+T-cells to Th cell subsets in vitro, and on lymphocyte production of cytokines and prostaglandins in vitro.

• INCLUSION CRITERIA:
• Participant of the Environmental Polymorphisms Registry and current contact information available
• Genotype information available for relevant 765G>C and 8473T>C COX2 polymorphisms, which indicates:

• Individuals who are WT with respect to both 765G>C and 8473T>C (N=31)
• Individuals who are WT with respect to 765G>C and homozygous for 8473T>C (N=31)
• Individuals who are homozygous for both 765G>C and 8473T>C (N=31)
• Age 18- 65 years
• Race self-identified as White or Black and Non-Hispanic ethnicity
• Willing and able to provide informed consent
• Able to comply with all protocol procedures

Exclusion criteria

• History of infection within the preceding 1 week or an oral temperature >38 degrees C
• Current daily or chronic use of corticosteroids (systemic, inhaled and topical).
• Any current conditions known to impact peripheral white blood cell count (e.g., leukemia, lymphopenia, AIDS, other immunodeficiency disorders)
• Current daily or chronic use of systemic immunosuppressants.
• Current pregnancy or lactation
• Unwilling or unable to:

• Fast (including alcohol and caffeine-containing products) and discontinue tobacco use for 12 hours prior to the study visit
• Withhold all prescribed and over-the-counter medications and supplements the morning of the study visit, until after the visit is completed
• Refrain from taking the following medications and supplements for 7 days prior to the study visit:

• NSAIDs
• Corticosteroids (nasal, inhaled, topical or systemic)
• Fish oil and niacin supplements
• For blood draws that exceed 200ml, a hematocrit of <34% for women or <36% for men, or >56% for either gender.
• For blood draws exceeding 200ml, blood or plasma donation in the last 8 weeks