SYBR green quantitative PCR with gene-specific primers from IDT Technologies (Coralville, IA) for IFN-γ, TGF-β, IL-21 (fwd 5'-CTATGTGTTCTAGGAGAGATGCTG-3', rev 5'-GGAGGAAAGAAACAGAAGCACA-3'), and CXCL9 mRNAs and 18s rRNA was performed on ABI StepOnePlus Real-Time PCR System (ThermoFisher Scientific) using previously published primer sequences [87] [88] [89] [90] .