Cell surface expression of PDI and/or Thioredoxin. PM-1 T cells (panel A), primary human MDM (panel B) and PBLs (panel C) were isolated and cultured as described in Methods. Subsequently, the cells were fixed with 1.6% paraformaldehyde and treated with NH4Cl to quench the reactive aldehyde groups before labeling. The PDI and Trx levels on the cell surface were detected by a combination of directly labeled anti-PDI-FITC and anti-Trx-APC mAbs from the same clones used in the HIV-1 infection experiments. In addition, the unstimulated and PHA-P stimulated PBLs were labeled with anti-CD4-Pacific blue conjugated mAb, and the PDI and Trx expression were analyzed on the CD4+ lymphocyte (Ly) population. The results were analyzed and the final graphs were created using FlowJoe software.