Mapping of disease-associated expression polymorphisms in primary peripheral blood CD4+ lymphocytes

Analysis of expression quantitative trait loci (eQTLs) using RNA derived from freshly harvested peripheral blood CD4+ lymphocytes from 200 asthmatics collected in clinical settings. RNA was obtained from peripheral blood CD4+ lymphocytes at four study centers. Peripheral blood (17 cc) was collected into BD Vacutainer CPT tubes (BD Diagnostics, Franklin Lakes, New Jersey) and placed on ice. Samples were centrifuged within 1 hour of collection for 20 minutes at 1700RCF, followed by mononuclear cell layer isolation and suspension in 10 ml of PBS. We isolated CD4+ lymphocytes using anti-CD4+ microbeads by column separation (Miltenyi Biotec, Auburn, CA) using 20 µl anti-CD4+ Micro beads per 106 total cells