UBE2G2 and UBE2J2 regulate US2-induced immunoreceptor downregulation. (A,B) U937 (A) or THP-1 (B) cells expressing US2 were lentivirally transduced with a CRISPR/Cas9 vector targeting TRC8 (gRNA #1), UBE2G2 (gRNA #1) or UBE2J2 (gRNA #1). At 2 days after infection, gRNA-expressing cells were selected using puromycin. Cell surface expression of integrin-α4 (ITGA4), thrombomodulin (THBD) and HLA-I (HLA-A2 for THP-1 cells, HLA-A3 for U937 cells) was assessed by flow cytometry at 10 days (U937) or 15 days (THP-1) post infection. (C) THP-1 cells expressing US2 were lentivirally transduced with two CRISPR gRNAs (#4 and #5) targeting UBE2G2. At 2 days after infection, gRNA-expressing cells were selected using puromycin, and expression of integrin α1 (ITGA1), integrin α2 (ITGA2) or IL12 receptor β1-subunit (IL12R-B1) was assessed by flow cytometry at 7 dpi. (D) Lysates from cells used in B were prepared and subjected to immunoblotting analysis for total protein expression levels of ITGA2, ITGA4, thrombomodulin, and HLA-I (HCA2). US11-expressing cells were included as a control. Actin was used as a loading control. The asterisk marks an unspecific band.