Table 3 Summary of the critical findings of preclinical CAR-M studies
From: The CAR macrophage cells, a novel generation of chimeric antigen-based approach against solid tumors
Targeted- cancer or cell line | Genetic enhancement | CAR structure | Results | Ref |
|---|---|---|---|---|
Melanoma Neuroblastoma | CRISPR/cas9 | hPSCs-derived GD2 targeted with CD3ζ-CD28-OX40 | In-vitro results showed substantial anti-tumor activity The neuroblastoma tumor burden is reduced in the xenograft mouse model with minimal adverse effects | [121] |
Ovarian cancer Pancreatic cancer Leukemia Lymphoma | Lentiviral | iPSCs-derived CD19-targeted CD86-FcγRI or iPSCs-derived mesothelin-targeted-4-1BB-CD3ζ | In-vitro CAR-iMacs showed cytokines expression and phagocytosis in an antigen-dependent manner and polarized them toward an M1 state in-vivo result CAR-iMacs showed some anti-tumor effect on leukemia cells expressing and high mesothelin-expressing ovarian cancer cell line | [129] |
Lung tumors Plural effusion malignant cells | Lentiviral | THP-1 derived-MUC1 CAR-M CD3ζ-CD28-OX40 | In-vitro results showed potent anti-tumor function by phagocytosis and secretion of pro-inflammatory cytokines such as IL-1β, IL-8, and TNFα | [177] |
Breast cancer | Lentiviral | HER2-targeting-CD147 CAR-M | in-vitro, CAR-147 macrophages did not inhibit the growth of tumor cells in-vivo significantly inhibited tumor growth, remodeled the tumor ECM, and promoted T-cell infiltration, resulting in tumor growth | [178] |
Ovarian cancer | Adenoviral vector (Ad5f35) | THP-1 derived HER2 CAR-M | In-vitro sustainable M1 phenotype and polarize M2 toward M1 phenotype. CAR-Ms phagocyte and eliminate tumor cells in an antigen-dependent manner Significantly decrease tumor burden and improve overall survival in xenograft mice models | [105] |
Mesothelin-positive tumor cells | Adenoviral vector (Ad5f35) | PBMC-derived mesothelin CAR-M with CD3ζ (CT-1119) | In-vitro: high CAR expression, possesses M1 phenotype with relative resistance to M2 shift, and exhibits robust tumor cell-killing capability and pro-inflammatory cytokines Substantially decreased tumor burden in a murine xenograft model of lung cancer | [179] |
Neuroblastoma | Nano complex | Anti-ALK CAR-M with- CD3ζ-CD28- IFN-γ gene | In-vitro: Transfection with MPEI/pCAR-IFN-γ did not very significantly polarize macrophage toward the M1 phenotype The MPEI/pCAR-IFN-γ injection into Neuro-2a tumor-bearing mice reduced tumor growth, decreased the Treg cell, and increased the function of activated CD8+ T cells in the tumors | [123] |
Glioma | Nano complex | Anti-CD133 CAR-M with- CD3ζ | NP-pCAR induces M1 polarization and increases the secretion of IL-1β and TNF-α of targeted macrophages in-vitro. Also, it decreases the number of CD133-positive tumor cells and causes tumor regression without traceable toxicity in the orthotropic mouse glioma model | [125] |
Brain stem glioma | Nano complex | Anti-HER2 CAR-Ms | In-vitro: PCD68/PB/N/R nanoparticles produce CAR-Ms with M1 phenotype and greater phagocytic and cytotoxic ability in an antigen-dependent manner. Intratumoral injection of P/PB/N/R nanoparticles generates Anti-HER2 CAR-Ms, causes phagocyte tumor cells, enhances immune system response, and tumor regression in mice without any notable side effects | [124] |
EGFRvIII positive cells | Lentiviral | IPSCs derived anti-EGFRIII CAR M with different intracellular domains, including CD3ζ, TIR, and CD3ζ-TIR | CAR-iMACs demonstrate significant anti-tumor activity, but TIR-CAR-iMACs showed more pro-inflammatory activity, killing persistence, and greater anti-tumor activity in-vivo. In addition, the CD3ζ-TIR-CAR-iMACs could increase anti-tumor activity and contribute to retaining M1 polarization of CAR-iMACs, more robust anti-tumor capability compared to alone them in-vivo | [128] |
4T1 tumor cells (breast cancer) | Lentiviral | RAW264.7-derived anti-CCR7 CAR M with domain derived from TLR2, TLR4, TLR6, MerTK or 4-1BB-CD3ζ | MerTK-CAR-M displays targeted anti-tumor function in both in-vitro and in-vivo and exhibits most phagocytic and anti-tumor activity against tumor cells by reducing tumor burden, increasing median survival time and creating the inflammatory environment by increasing the levels of proinflammatory cytokines in serum In-vivo | [131] |
Raji B cells | Lentiviral | J774A.1 cell line Anti-CD19/CD22 CAR-P with different intracellular domain including Megf10, FcRγ, Bai1, and MerTK with/without PI3K | CAR-Ms with the Megf10 or FcRγ intracellular domains demonstrate the greater phagocytic capacity of CD19-positive cells compared to others PI3K CAR-P induced some whole-cell phagocytosis, comparable to the CAR-P-FcRγ. Also, CAR-P tandem macrophages notably decreased the number of tumor cells. However, the CAR-P tandem was much more efficient at whole-cell phagocytosis than the CAR-P-FcRγ | [106] |
CT26-HER2 cell line | Adenoviral vector (Ad5f35) | BM-derived anti-HER2 CAR M cells | CAR M cells showed anti-tumor activity and phagocyte HER2-overexpressing tumor cells and boosted the cytotoxicity of CD8+ T cells by inducing MHC-I expression on tumor cells. In-vivo, CAR-M causes significant tumor regression, improves overall survival, increases infiltration rate of CD4+ and CD8+ T, NK, and DC cells in the TME, and ameliorates epitope spreading, improving T-cell reaction to TAA | [180] |
Raji cells | Lentiviral | BM-derived anti-CD19 CAR M with different intracellular domains, including Megf10, PI3K, and FcRγ | CAR-M PI3K and CAR-M FcRγ exhibit more phagocytic capacity; CAR-M FcRγ possesses more substantial cytotoxic and phagocytic ability. Also, the utilization of CAR-M FcRγ and CAR-T cells together showed substantially greater cytotoxic power than CAR-M FcRγ or CAR-T cells alone, and inflammatory factors such as IL-1β, IL-6, IFN-γ, CXCL1, MCP-1, and MIP-2 have notably increased in-vitro. CAR-T cells Secrete Inflammatory factors like IFN-γ and GM-CSF, which increase CD80/86 expression and probably induce M1 polarization of CAR-Ms. Upregulated CD80/86 on CAR-Ms may ameliorate CAR-T cell activation and fitness | [130] |
Lung cancer brain metastasis cell (H2030BrM) | - | Anti-MSLN CAR-M with MyD88 signaling molecule | In the humanized mouse model, CAR-Ms penetrated BBB and significantly reduced brain metastasis growth. The CAR-Ms exhibit antigen-specific phagocytosis activity against MSLN-positive tumor cells. Also, CAR-M demonstrates much fewer neuron toxicities and liver compared to CAR-T | [181] |
Mammary gland squamous carcinoma cell line (HCC-1806) | - | RAW 264.7 derived Anti-MSLN CAR-M with TLR4 and TLR2-based toll-like receptor signaling domains | In-vitro, MOTO-CARs effectively kill cancer cells and secrete notable levels of TNF-α, which displays that MOTO-CARs polarize toward the M1 phenotype upon target recognition In-vivo, the MOTO-CARs can traffic effectively to the tumor site and substantially reduce tumor burden compared to the mock control | [182] |
Non-small cell lung carcinoma NCI-H460 and A549 cell lines | lentiviral or adenoviral (Ad5f35) | Human monocyte-derived anti-TK1 CAR M with TIR signaling | In-vitro, after transduction, MOTO-CARs exhibit sustainable M1 phenotype and express low levels of CD163 and high levels of CD14, CD80, and CD206. MOTO-CARs demonstrated a nearly fourfold increase in killing activity against cancer cells compared with the controls | [183] |
HT1080 cells | Lentiviral | CB-HSPCs, THP-1 and MONO-MAC-6 anti-CEA CAR-M with different intracellular domains including 2B4-DAP12, CD28-CD3ζ | Ex vivo, the CAR gene was transduced to CB-derived HSPCs successfully and generated CAR-Ms have stable CAR expression. Also, any evidence of that CAR expression might alter CD34 positive cell-derived macrophage morphology, phenotype, or basic anti-bacterial phagocytic function, but it was not observed. Both anti-CEA-CARs showed antigen-specific function by increased cytokine secretion, and CD3ζ CAR-expressingTHP-1-derived macrophages showed enhanced antigen-specific phagocytosis of target cells | [143] |