CD8+FOXP3+T cells from renal transplant recipients in quiescence induce immunoglobulin-like transcripts-3 and -4 on dendritic cells from their respective donors.

In previous studies, CD8+FOXP3+ T cells have been shown to upgrade the inhibitory receptors on dendritic cells (DC) in heart transplantation patients. The inhibitory receptor were immunoglobulin-like transcripts (ILT)-3 and ILT-4, which were highly expressed on tolerogenic dendritic cells. Our study focused on the CD8+FOXP3+ T cells from allogeneic renal transplant recipients, seeking to dissert their function in inducing ILT-3- and ILT-4-expressing dendritic cells. We analyzed 11 quiescent renal transplant recipients and their respective donors. Reverse transcriptase polymerase chain reaction analysis showed that the levels of Foxp3 mRNA in CD8+ T cells after renal transplantation were significantly higher than those in CD8+ T cells before transplantation. We further investigated the capacity of allospecific CD8+FOXP3+ T cells to induce upregulation of the inhibitory receptors ILT-3 and ILT-4 on DC. Data from FACS showed that CD8+FOXP3+ T cells induced greater expression of ILT-3 and ILT-4 on DC in an allospecific fashion. This study confirmed that Foxp3 gene expression was enhanced among quiescent renal transplant patients, suggesting that CD8+FOXP3+ T cells play an important role in unresponsiveness related to upregulated ILT-3 and ILT-4 receptors on DC.