Human basophil expression profiles (in vitro) (Ref12)

Human basophils were examined in vitro for changes in their mRNA expression profiles during stimulation under a variety of conditions. Basophils were obtained from two sources prior to purification, residual cell packs from leukapheresis procedures (which represent the 80% of the sample results) or by venipuncture. For cells obtained by leukapheress, purification included application of elutration, 2-step Percoll gradients and negative selection on Miltenyi columns using StemSep basophil isolation antibodies (see J. Immunol. Methods, 385:51, 2012). For cells obtained by venipuncture, purification included application of 2-step Percoll gradients following by negative selection on Miltenyi columns using StemSep basophil isolation antibodies. The time from subject donation to the start of an in vitro study (first lysis for mRNA) ranged from 6-7 hours for leukapheresis packs to 4-5 hours for venipuncture. Basophil purities averaged 99% for these studies. For most of the studies, purified basophils were incubated in RPMI-1640 media supplemented with human serum albumin (0.03%), 20 µg/ml gentamycin and glutamine (as glutamax) for several hours to 3 days depending on the stimulus. For most experiments, the day 0 lysis acted as the initial control in order to examine profiles for changes due to simple culture. The study included stimulation with interleukin-3, inteleukin-33, interleukin-5, interleukin-2, nerve growth factor, anti-IgE antibody (6061P, Hybridoma Labs, Maryland) or fmet-leu-phe (FMLP) and the sample title indicates the mode and length of stimulation. Basophils were isolated from peripheral blood, purified to high homegeneity (99%), and stimulated in vitro.