Table 2.
Phenotypic, biochemical, molecular, and functional properties of SLE LDNs and PMN‐MDSCsa
| SLE LDNs | PMN‐MDSCs | |
|---|---|---|
| Physical characteristic | ||
| Density | Low | Low |
| Morphology | Promyelocytes, myelocytes, metamyelocytes, bands and segmented neutrophils | Metamyelocytes, bands, and segmented neutrophils |
| Surface marker | ||
| FSC | NA | High |
| CD11b | +++ | ++ |
| CD14 | −/+ | − |
| CD15 | +++ | +++ |
| CD66b | +++ | +++ |
| LOX‐1 | +/++/+++ | + |
| Biomarker | ||
| ROS | + | +++ |
| ARG1 | ++ | ++ |
| PD‐L1 | + | + |
| Immunometabolic status | ||
| ER stress | ++ | ++ |
| Functional test | ||
| Inhibition of T cell proliferation | No | Yes |
| Inhibition of IFNγ production | No | Yes |
a
Positive and negative signs indicate the level of expression of relevant markers in SLE LDNs or polymorphonuclear myeloid‐derived suppressor cells (PMN‐MDSCs). NA = not applicable; LOX‐1 = lectin‐like oxidized low‐density lipoprotein receptor 1; ROS = reactive oxygen species; ARG1 = arginase 1; PD‐L1 = programmed death ligand 1; ER = endoplasmic reticulum (see Table 1 for other definitions).