Targeting the melanoma-associated antigen CSPG4 with HLA-C*07:01-restricted T-cell receptors
Korbinian N Kropp1, Martina Fatho1, Enes Huduti1
1Internal Medicine III, University Cancer Center (UCT), Research Center for Immunotherapy (FZI), University Medical Center (UMC) of the Johannes Gutenberg University and German Cancer Consortium (DKTK), Partner Site Frankfurt/Mainz, Mainz, Germany.
Intorduction:
Chondroitin sulfate proteoglycan 4 (CSPG4), also known as high molecular weight-melanoma associated antigen, is expressed in melanoma but also other tumor entities and constitutes an attractive target for immunotherapeutic approaches. While recent preclinical reports focused on anti-CSPG4 chimeric antigen receptors (CAR), we here explore T-cell receptor (TCR)-based approaches targeting CSPG4.
Methods:
The TCRs of two CSPG4-reactive T-cell clones (11C/73 and 2C/165) restricted by the highly prevalent HLA-C*07:01 allele were isolated and the respective αβTCR pairs were retrovirally expressed in CRISPR/Cas9-edited TCR-knockout T cells for functional testing. We also combined alpha and beta TCR chains derived from 11C/73 and 2C/165 in a cross-over fashion to assess for hemichain dominance. CSPG4+ melanoma, glioblastoma and lung cancer cell lines were identified and, if negative, retrovirally transduced with HLA-C*07:01.
Results:
Functional tests confirmed specific recognition of CSPG4+HLA-C*07:01+ target cells by the αβTCR retrieved from the parental T-cell clones and in part also by the cross-over TCR construct 2Cα-11Cβ. Despite high surface expression, the 11Cα-2Cβ combination, however, was not functional.
Discussion:
Collectively, 11C/73- and 2C/165-expressing T cells specifically and efficiently recognized CSPG4+HLA-C*07:01+ cancer cells which warrants further preclinical and clinical evaluation of these TCRs.
Insights
T-cell receptor (TCR) approaches targeting chondroitin sulfate proteoglycan 4 (CSPG4) show promise for cancer immunotherapy. Engineered T cells expressing specific TCRs efficiently recognized CSPG4-positive cancer cells, warranting further clinical evaluation.
Area of Science:
- Immunology and Cancer Therapeutics
- Molecular Biology and Genetic Engineering
Background:
- Chondroitin sulfate proteoglycan 4 (CSPG4) is a tumor-associated antigen found in melanoma and other cancers.
- CSPG4 presents an attractive target for immunotherapeutic strategies, with recent focus on chimeric antigen receptors (CARs).
Purpose of the Study:
- To explore T-cell receptor (TCR)-based immunotherapeutic approaches targeting CSPG4.
- To isolate and functionally characterize CSPG4-reactive TCRs for potential cancer treatment.
Main Methods:
- Isolated TCRs from CSPG4-reactive T-cell clones (11C/73 and 2C/165) restricted by HLA-C*07:01.
- Retrovirally expressed TCR pairs in CRISPR/Cas9-edited TCR-knockout T cells for functional assessment.
- Constructed and tested cross-over TCR combinations (e.g., 2Cα-11Cβ) and transduced cancer cell lines with HLA-C*07:01.
Main Results:
- Specific recognition of CSPG4+ HLA-C*07:01+ target cells by parental TCR constructs (11C/73 and 2C/165).
- Partial functional recognition observed with the cross-over TCR construct 2Cα-11Cβ.
- The 11Cα-2Cβ combination showed no functional activity despite high CSPG4 surface expression.
Conclusions:
- T cells engineered with 11C/73 and 2C/165 TCRs demonstrate specific and efficient recognition of CSPG4+ HLA-C*07:01+ cancer cells.
- These findings support the further preclinical and clinical evaluation of these TCR-based immunotherapies.
