Blood donors and PBMC isolation
Peripheral blood samples were obtained from healthy donors and patients
of the Charité - Universitätsmedizin Berlin, Medical Department,
Division of Gastroenterology, Infectiology and Rheumatology. All blood
donors gave informed consent and the study was approved by the ethical
committee of the Charité - Universitätsmedizin Berlin. PBMC were freshly
isolated from 20 mL blood by density gradient centrifugation (Biocoll;
Biochrom, Berlin, Germany). Heparinized whole blood was layered on the
Biocoll Separation Solution and centrifuged at 1200 g for 25 min at
21 °C. PBMC were collected from the interphase, washed and resuspended
in RPMI1640 (Gibco, Life Technologies, Darmstadt, Germany) supplemented
with 5% human AB-serum (Sigma-Aldrich, St. Louis, MO, USA).