It is known that CD83 is expressed on human T cells after stimulation and is detectable on circulating T cells from patients with acute GVHD (31). of xenogeneic GVHD. CD83 CAR T cells are also capable of treating xenogeneic GVHD. We show that human acute myeloid leukemia (AML) expresses CD83 and that myeloid leukemia cell lines are readily killed by CD83 CAR T cells. Human CD83 CAR T cells are a promising cell-based approach to preventing 2 critical complications of allo-HCT GVHD and relapse. Thus, the use of human CD83 CAR T cells for GVHD prevention and treatment, as well as for targeting CD83+ AML, warrants clinical investigation. = 2C3 independent donor experiments). (D and E) The amount of IFN- and IL-2 released by mock-transduced or CD83 CAR T cells after stimulation with CD83+ DCs. (F) GW0742 CD83 CAR T cells or mock-transduced T cells were cocultured with CD83+ DCs and cytotoxicity was measured on a real-time cell analysis system. The data are presented (mean SEM) as the average normalized cell index over time for duplicate wells. Normalized cell index is calculated as cell index at a given time point divided by cell index at the normalized time point, which is day 1 after addition of T cells. One representative experiment of 2 is shown. (G) CD83 CAR T cells or mock-transduced T GW0742 cells were stimulated by CD83+ DCs and the absolute number of T cells (mean SEM) was calculated weekly over a 14-day period. One representative experiment of 2 shown. ANOVA (DCG). ***= 0.0001C0.001; ****< 0.0001. The CD83 CAR construct exhibited a high degree of transduction efficiency, with more than 60% of T cells expressing the EGFP-tagged CAR construct (Figure 1B). While CD4 expression was similar among both groups, a reduction in GW0742 CD8 expression was observed among CD83 CAR T cells compared with mock-transduced T cells (Figure 1C). However, the CD83 CAR T cells demonstrated robust IFN- and IL-2 production when cultured with CD83+ target cells such as cytokine-matured human monocyte-derived DCs (moDCs) (Figure 1, D and E). Additionally, CD83 CAR T cells demonstrated potent killing of and proliferation against CD83+ moDCs compared with mock-transduced T cells (Figure 1, F and G). The target moDCs in these experiments were allogeneic to the T cells. Therefore, the lysis and proliferation by mock-transduced T cells represent baseline alloreactivity (Figure 1, F and G). CD83 is differentially expressed on activated human Tconvs compared with Tregs. CD83 is an established marker of human DC maturation and is also expressed on activated human B cells (37, 38). Using a CD83 reporter mouse system, it was previously shown that activated murine T cells also express CD83 (39). It is known that CD83 is expressed on human T cells GW0742 after stimulation and is detectable on circulating T cells from patients with acute GVHD (31). However, the precise expression of CD83 on CD4+ Tregs versus CD4+ Tconvs or CD8+ T cells is unclear. We confirmed that human T cell expression of CD83 occurs with stimulation, including allogeneic DCs or CD3/CD28 beads (Figure 2, A and B). Importantly, we demonstrate Mouse monoclonal antibody to TCF11/NRF1. This gene encodes a protein that homodimerizes and functions as a transcription factor whichactivates the expression of some key metabolic genes regulating cellular growth and nucleargenes required for respiration,heme biosynthesis,and mitochondrial DNA transcription andreplication.The protein has also been associated with the regulation of neuriteoutgrowth.Alternate transcriptional splice variants,which encode the same protein, have beencharacterized.Additional variants encoding different protein isoforms have been described butthey have not been fully characterized.Confusion has occurred in bibliographic databases due tothe shared symbol of NRF1 for this gene and for “”nuclear factor(erythroid-derived 2)-like 1″”which has an official symbol of NFE2L1.[provided by RefSeq, Jul 2008]” that CD83 is differentially expressed on human CD4+ Tconvs (CD127+, CD25+) compared with immune suppressive CD4+ Tregs (CD127-, CD25+, Foxp3+) or cytolytic CD8+ T cells in response to DC alloactivation (Figure 2A). CD4+ Tconv expression of CD83 peaks at 4C8 hours of DC allostimulation and declines to baseline levels by 48 hours in vitro, with minimal amounts observed on Tregs or CD8+ T cells (Figure 2A). The expression of CD83 is more abundant with supraphysiologic CD3/CD28 bead stimulation, which also causes a late increase in CD83 expression on Tregs and CD8+ T cells by 48 hours of activation (Figure 2B). Among GW0742 CD4+ T cells, Th1 (CD4+, T-Bet+), and Th2 (CD4+, GATA3+) cells exhibit significantly increased CD83 expression compared with Th17s (CD4+, RORt+) following DC allostimulation (Figure 2C). Given that CD83 expression is shared among proinflammatory mature DCs as well as alloreactive Tconvs, we investigated whether the CD83 CAR T cell could deplete either of these target cells in culture. Human CD83 CAR or mock T cells were cultured with autologous peripheral blood mononuclear cells (PBMCs) stimulated by allogeneic moDCs, and the amount of CD83+ target cells was evaluated at 8 hours of culture. CD83 CAR T cells significantly reduced the amount of CD83+ T cell and nonCT cell targets in vitro (Figure 2D). Next, we evaluated the expression of CD83 on the EGFP+ CAR T cells over 48 hours. CD83 expression on the CAR T cells was scant, and an increase in the proportion of EGFP+ CAR T cells was still observed by 48 hours of culture (Figure 2E), providing evidence that the CD83 CAR T cells do not overtly succumb to CD83-mediated fratricide. Consistent with the expression of CD83 on human T cells after 8 hours of.