Anti-melanoma activity of T cells redirected with a TCR-like chimeric antigen receptor

Area of Science:

• Immunology
• Oncology
• Biotechnology

Background:

• Adoptive T cell therapy using genetically modified T cells (TCRs or CARs) shows clinical success.
• Limitations include TCR mismatching and the need for surface tumor antigens, hindering broader application.
• Existing CARs often target surface antigens, limiting their use for intracellular tumor antigens.

Purpose of the Study:

• To develop a novel TCR-like chimeric receptor (CAR) targeting the intracellular melanoma-associated gp100/HLA-A2 complex.
• To evaluate the efficacy of T cells engineered with this TCR-like CAR (GPA7-28z) against melanoma.

Main Methods:

• A TCR-like antibody (GPA7) was fused with CD28 and CD3-ζ signaling endodomains to create the GPA7-28z CAR.
• Human T cells were genetically modified to express the GPA7-28z CAR.
• In vitro cytotoxicity assays were performed against HLA-A2-positive melanoma cells.
• In vivo efficacy was assessed using a melanoma xenograft mouse model.

Main Results:

• GPA7-28z-engineered T cells demonstrated potent cytotoxic activity against HLA-A2-positive melanoma cells in vitro.
• Infusion of GPA7-28z-transduced T cells significantly suppressed melanoma progression in a xenograft mouse model.
• The TCR-like CAR effectively redirected T cell specificity towards the gp100/HLA-A2 complex.

Conclusions:

• TCR-like CARs represent a promising alternative to TCR-mediated therapy for melanoma.
• This approach overcomes limitations of traditional CARs by targeting intracellular antigens presented by HLA molecules.
• TCR-like CARs offer a versatile platform for targeting diverse tumor antigens in adoptive T cell therapy.