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Updated: Jul 8, 2026
Experimental Melanoma Immunotherapy Model Using Tumor Vaccination with a Hematopoietic Cytokine
Published on: February 24, 2023
T-cell receptor gene therapy of established tumors in a murine melanoma model
John D Abad1, Claudia Wrzensinski, Willem Overwijk
1Surgery Branch, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA.
Abstract:
Adoptive cell transfer therapy using tumor-infiltrating lymphocytes for patients with metastatic melanoma has demonstrated significant objective response rates. One major limitation of these current therapies is the frequent inability to isolate tumor-reactive lymphocytes for treatment. Genetic engineering of peripheral blood lymphocytes with retroviral vectors encoding tumor antigen-specific T-cell receptors (TCRs) bypasses this restriction. To evaluate the efficacy of TCR gene therapy, a murine treatment model was developed. A retroviral vector was constructed encoding the pmel-1 TCR genes targeting the B16 melanoma antigen, gp100. Transduction of C57BL/6 lymphocytes resulted in efficient pmel-1 TCR expression. Lymphocytes transduced with this retrovirus specifically recognized gp100-pulsed target cells as measured by interferon-gamma secretion assays. Upon transfer into B16 tumor-bearing mice, the genetically engineered lymphocytes significantly slowed tumor development. The effectiveness of tumor treatment was directly correlated with the number of TCR-engineered T cells administered. These results demonstrated that TCR gene therapy targeting a native tumor antigen significantly delayed the growth of established tumors. When C57BL/6 lymphocytes were added to antigen-reactive pmel-1 T cells, a reduction in the ability of pmel-1 T cell to treat B16 melanomas was seen, suggesting that untransduced cells may be deleterious to TCR gene therapy. This model may be a powerful tool for evaluating future TCR gene transfer-based strategies.
Insights
T-cell receptor (TCR) gene therapy shows promise for metastatic melanoma by engineering T cells to target tumor antigens. This approach successfully slowed tumor growth in a mouse model, offering a potential new avenue for cancer treatment.
Area of Science:
- Immunology
- Oncology
- Gene Therapy
Background:
- Adoptive cell transfer (ACT) using tumor-infiltrating lymphocytes (TILs) shows efficacy in metastatic melanoma.
- A key limitation of TIL therapy is the difficulty in isolating tumor-reactive lymphocytes.
- T-cell receptor (TCR) gene therapy offers a potential solution by genetically engineering peripheral blood lymphocytes.
Purpose of the Study:
- To develop and evaluate a murine model for assessing TCR gene therapy efficacy against melanoma.
- To investigate the potential of genetically engineered lymphocytes targeting a native tumor antigen.
Main Methods:
- Constructed a retroviral vector encoding the pmel-1 TCR targeting the B16 melanoma antigen gp100.
- Transduced C57BL/6 lymphocytes with the retroviral vector for efficient pmel-1 TCR expression.
- Assessed specific recognition of gp100-pulsed target cells via interferon-gamma secretion assays.
- Administered genetically engineered lymphocytes into B16 tumor-bearing mice to evaluate therapeutic effects.
Main Results:
- Transduced lymphocytes efficiently expressed the pmel-1 TCR and specifically recognized gp100-pulsed target cells.
- Transfer of TCR gene-engineered lymphocytes significantly slowed tumor development in B16 melanoma-bearing mice.
- Therapeutic effectiveness correlated directly with the number of administered TCR-engineered T cells.
- The addition of untransduced lymphocytes diminished the therapeutic efficacy of pmel-1 T cells.
Conclusions:
- TCR gene therapy targeting a native tumor antigen can significantly delay the growth of established tumors.
- This murine model serves as a valuable tool for evaluating future TCR gene transfer strategies.
- Untransduced peripheral blood lymphocytes may negatively impact the efficacy of TCR gene therapy.
