ALT (G/G) clones, RNA was extracted from clones using a Monarch Total RNA
extraction kit (NEB). cDNA was synthesized using MaximaH RT (NEB) enzyme
following manufacturer’s protocol and oligoDT primers. cDNA was diluted 1
in 4 with HLA-DQB1 (Assay ID:Hs00409790) and
actinB (Assay ID:Hs01060665) probes and Taqman MasterMix
(Thermofisher). Samples were run on an ARIAmx qPCR machine (Agilent) and data
analyzed with Aria 1.5 (Agilent) software. Expression is represented as
2-delta(HLA-DQB1 Ct - ActinBCt). For analysis of protein expression, clones that survived after
3–4 months of culture were washed with PBS and stained with FITC
anti-HLA-DQ (Biolegend, Clone: HLADQ1) for 30 minutes on ice and cell surface
expression assessed by flow cytometry. Data was analyzed using Flowjo and
Graphpad PRISM.