Table 1 ∣.
Microglia-derived and monocyte-derived TAM subsets identified by single-cell technologies
| Technique | Reported subsets | Disease or Model | Functional or prognostic evaluation |
|---|---|---|---|
| Monocyte-derived TAMs (MDMs) | |||
| scRNA-seq and CITE-seq16 | Transitory/differentiating; phagocytic/lipid metabolic; hypoxic/glycolytic; SEPP1low/microglia-like; interferon-induced | ND and recurrent GBM; GL261 (GBM model) | No |
| SEPP1high/anti-inflammatory | Recurrent GBM, GL261 (GBM model) | ||
| CyTOF7 | MDM2 | IDHwt glioma, melanoma BrM, carcinoma BrM | Positive correlation with OS in WHO grade II and III glioma |
| MDM3 | IDHwt and IDHmut glioma, melanoma BrM, carcinoma BrM | ||
| MDM4 | IDHwt glioma | No | |
| scRNA-seq95 | Microglia-like; glioma-associated; actively differentiating; interferon-induced | U87 (GBM model) | No |
| scRNA-seq and CyTOF8 | CD73hi ICI-resistant, hypoxic, immunosuppressive | GBM | Negative correlation with survival (TCGA GBM); Cd73 KO in GL261 mice improved survival in combination with ICI |
| CyTOF223 | Macrophages-monocytes; microglia-like; SIGLECF+ macrophages | GL261 (GBM model) | No |
| scRNA-seq47 | MDM; radiation-induced MDM | H2030 (lung cancer BrM model) | No |
| CyTOF and CITE-seq23 | Ly6Chigh BrM-enriched; Ly6Clow microglia-like; Ly6Chigh MDM | E0771 (breast cancer BrM model) | No |
| Microglia-derived TAMs | |||
| scRNA-seq16 | Phagocytic/lipid metabolic; IFNγ-induced | ND and recurrent GBM, GL261 GBM model | No |
| Hypoxic | Recurrent GBM and GL261 GBM model | ||
| scRNA-seq95 | Homeostatic; glioma-associated; cycling/proliferating; undefined; glioma-associated; MHC II high | U87 (GBM model) | No |
| scRNA-seq and CyTOF22 | Glioma-associated; ageing-associated and glioma-associated; homeostatic | IDHwt GBM | No |
| CyTOF223 | Two undefined | GL261 (GBM model) | No |
| scRNA-seq47 | TAM microglia; radiation-induced TAM microglia | H2030 (lung cancer BrM model) | No |
| CyTOF and CITE-seq23 | Homeostatic; primed; TNF+ inflammatory state; undefined inflammatory state; migratory; migratory and inflammatory; S100+ LGALS1+, LGALS3+ | E0771 (breast cancer BrM model) | No |
| VISTA+ PDL1+ BrM-promoting CNS myeloid cells | Targetable with anti-VISTA and anti-PDL1 | ||
| scRNA-seq100 | Homeostatic; transcriptionally active; MHC I and MHC II high; proliferative | GL261 (GBM model) | No |
Studies where TAM compartments were not further subclustered beyond all tumour-associated MDMs or microglia are not shown, although their single-cell data may be a useful resource7,43,100. Further populations of myeloid cells that are not shown include immature/less differentiated monocytes, intermediate macrophages, mature macrophages and border-associated macrophages23,100,223. BrM, brain metastasis; CITE-seq, cellular indexing of transcriptomes and epitopes by sequencing; CyTOF, cytometry by time of flight; GBM, glioblastoma; ICI, immune-checkpoint inhibitor; IDHmut, isocitrate dehydrogenase mutant; IDHwt, isocitrate dehydrogenase wild type; KO, knockout; MDMs, monocyte-derived macrophages; MHC, major histocompatibility complex; ND, newly diagnosed; OS, overall survival; scRNA-seq, single-cell RNA sequencing; TAMs, tumour-associated macrophages; TCGA, The Cancer Genome Atlas.