Cell-based molecularly targeted therapy: targeting oncoproteins with T cell receptor gene therapy

Peptides of tetraspanin oncoprotein CD151 trigger active immunity against primary tumour and experimental lung metastasis

BACKGROUND

Active immunotherapy is an effective, long-lasting, cheap, and safe approach to suppress cancer progression; however, the key issue is to develop appropriate tumour vaccines. Oncoproteins are up-regulated under various stress conditions and promote cell survival. Oncoproteins and their immunogenic domains could serve well as tumour vaccines and prime the hosts' active anti-tumour immunity.

METHODS

Proteomic and bioinformatic analyses were performed to identify potential tumour associated antigens (TAAs). Then, peptides derived from CD151 were designed and synthesized according to the major histocompatibility complex (MHC) I binding and immunogenicity. Cytotoxicity assay, flow cytometry, immunohistochemistry, and in vivo bioluminescence imaging were performed to assess the active anti-tumour immunity triggered by CD151 peptides in H22 primary hepatoma and experimental 4T1 breast cancer lung metastasis models.

FINDINGS

CD151 was identified as an ideal TAA based on proteomic and bioinformatic analyses. CD151 peptides as tumour vaccines triggered active anti-tumour immunity against H22 hepatoma and the lung metastasis of 4T1 breast cancer in two mouse models through the activation of CD8+IFNγ+ lymphocytes and the subsequent targeted cytotoxicity. Further, the peptides suppressed the negative regulators, myeloid-derived suppressor cells. Survival was prolonged for mice with lung metastases from CD151 peptide-immunised groups.

INTERPRETATION

The up-regulated oncoproteins in 8 Gy-irradiated tumour cells are good candidates for designing immunogenic peptides as tumour vaccines. Anti-tumour active immunity primed by peptides from CD151 may be an effective and safe approach to suppress cancer progression.

Direct and antibody-dependent cell-mediated cytotoxicity of head and neck squamous cell carcinoma cells by high-affinity natural killer cells

High affinity natural killer cells (haNKs) are a cell therapy product capable of mediating both direct and antibody-dependent cell-mediated cytotoxicity (ADCC). These cells may be particularly useful in tumors that escape T-cell anti-tumor immunity by harboring antigen processing and presentation defects. Here, we demonstrated that haNKs directly kill both HPV-positive and negative head and neck squamous cell carcinoma cells. Variable tumor cell sensitivity to haNK direct cytotoxicity did not correlated with MHC class I chain-related protein A or B (MICA or MICB) expression. Importantly, haNK killing was significantly enhanced via ADCC mediated by cetuximab or avelumab in cells with higher baseline EGFR or PD-L1 expression, respectively. The ability of IFNγ to induce tumor cell PD-L1 expression correlated with enhanced PD-L1-specific ADCC. IFNγ induced neither tumor cell EGFR expression nor EGFR-specific ADCC. Although a single dose of 8 Gy IR did not appear to directly enhance susceptibility to haNK killing alone, enhanced PD-L1- and EGFR-mediated ADCC after IR correlated with increased PD-L1 and EGFR expression in one of four models. This pre-clinical evidence supports the investigation of haNK cellular therapy in combination with ADCC-mediating mAbs, with or without IR, in the clinical trial setting for patients with advanced HNSCCs. Given the MHC-unrestricted nature of this treatment, it may represent an opportunity to treat patients with non-T-cell inflamed tumors.