The role of endoplasmic reticulum aminopeptidase 2 in modulating immune detection of choriocarcinoma†

Abstract

Gestational choriocarcinomas are derived from placental trophoblast cells, with HLA-C being the only class I polymorphic molecule expressed. However, choriocarcinomas have not been profiled for endoplasmic reticulum aminopeptidase 2 (ERAP2) expression. ERAP2 trims peptides presented by human leukocyte antigens (HLA) that have shown to modulate immune response. Over 50% of choriocarcinomas we screened lack ERAP2 expression, which suggests that the absence of ERAP2 expression allows immune evasion of choriocarcinoma cells. We demonstrate that the ability of choriocarcinoma cells to activate lymphocytes was lowest with cells lacking ERAP2 (JEG-3) or HLA-C (JAr). This observation suggests that activation is dependent on expression of both ERAP2 and HLA-C molecules. In addition, an ERAP2 variant in which lysine is changed to asparagine (K392N) results in increased trimming activity (165-fold) for hydrophobic peptides and biologically never been detected. We hypothesize that homozygosity for the N392 ERAP2 variant is prohibited because it modulates the immune recognition of placental trophoblasts. We demonstrate that NK-cell activation and killing were significantly dependent on forced expression of the N392 ERAP2 isoform in JEG-3 cells. Cytotoxicity was confirmed by 7AAD killing assays showing that N392 ERAP2-isoform expressing JEG-3 cells had the highest percentage of apoptotic cells independent of the expression level of CD11a on lymphocytes. This is the first report showing that N392 ERAP2 promotes an immune clearance pathway for choriocarcinoma cells, and provides an explanation for why embryonic homozygosity for the N392 ERAP2 variant is not detected in any population.

The Differential Expression of ERAP1/ERAP2 and Immune Cell Activation in Pre-eclampsia

“…Subsequently, the CD56+ NK cells were differentiated into Dim/Bright ratio, with CD16 to distinguish the cytotoxicity. Most importantly, the ratio of activated NK cells characterized by CD69+/CD56 Dim /CD16+, where the cytotoxicity of this population has been demonstrated in a previous in vitro study, was almost doubled in PE (12.7 vs. 23%; Figure 4C) (12). This suggests that activated and more cytotoxic NK cells are circulating in women with PE.…”

“…Collection and preparation were previously described (12). Red blood cells were lysed using ice-cold deionized water for 30 s. White blood cells were then resuspended in FACs buffer [1× phosphate buffered saline (PBS), 2% heat-inactivated fetal bovine serum (FBS)], counted, and blocked for 10 min in FACS Buffer and Human Trustain FcX Fc receptor blocking solution (Biolegend; #422302) at room temperature, followed by staining with CD3-APC/Fire750 (BioLegend; #344840), CD56-PE (BioLegend; #318306), CD8-PerCP (BioLegend; #344708), CD11a-PE/Cy7 (BioLegend; #301220), CD16-FITC (BioLegend; #302006), CD69-APC (BioLegend; #310910).…”

“…JEG-3 cells were transfected with ERAP2K as previously described (12) prior to the addition of the isolated PMBCs. After a 24-h incubation period, the cytokine profile of the collected supernatant was determined using the PathScan R Th1/Th2/Th17 Cytokine Antibody Array Kit according to the manufacturer's protocol (Cell Signaling Technology; #13047).…”

Association of the genetic variants in the Endoplasmic reticulum aminopeptidase 2 gene with ankylosing spondylitis susceptibility

“…Lack of ERAP2 expression in haplotype B is because of the ERAP2 gene rs2248374 polymorphism that in uences on the RNA stability (15). It has been reported that there is a strong LD between haplotypes A and B of ERAP2 SNPs, which can be involved in the immune evasion of trophoblasts (30). Lack of ERAP2 expression has been proposed to be protective in AS and other in ammatory disorders (31).…”

PTEN inhibitor VO-OHpic attenuates inflammatory M1 macrophages and cardiac remodeling in doxorubicin-induced cardiomyopathy

“…9661L, Cell Signaling) (24,53,55), and ␤-actin (as a loading control, 1:1,000, catalog no. 4967L, Cell Signaling) (12,32,54) for 3 h at room temperature or overnight at 4°C. Membranes were then washed and incubated with the appropriate secondary antibody for 1 h at room temperature.…”