Memory T Cells Expressing an NKG2D-CAR Efficiently Target Osteosarcoma Cells.

Area of Science:

• Immunology
• Oncology
• Biotechnology

Background:

• NKG2D ligands (NKG2DL) are present on osteosarcoma and immunosuppressive cells, making them targets for cancer therapy.
• NKG2D receptors on immune cells like NK cells and CD8+ T cells are crucial for eliminating tumor-initiating cells.

Purpose of the Study:

• To optimize an immunotherapy strategy for osteosarcoma by leveraging NKG2D-NKG2DL interactions.
• To evaluate the safety and efficacy of CD45RA- memory T cells engineered with an NKG2D-4-1BB-CD3z chimeric antigen receptor (CAR) against osteosarcoma.

Main Methods:

• CD45RA- T cells from healthy donors were genetically modified with NKG2D CARs.
• NKG2D CAR expression was confirmed via flow cytometry.
• In vitro cytotoxicity assays and an in vivo orthotopic osteosarcoma mouse model were used to assess efficacy.

Main Results:

• Lentiviral transduction successfully increased NKG2D CAR expression on CD45RA- T cells, maintaining genetic stability.
• NKG2D-CAR+ memory T cells exhibited enhanced in vitro cytolytic activity against osteosarcoma cells without harming healthy cells.
• Significant in vivo anti-tumor activity was observed in the osteosarcoma mouse model with NKG2D-CAR+ T cells, unlike untransduced T cells.

Conclusions:

• NKG2D-4-1BB-CD3z CAR-redirected memory T cells effectively target NKG2DL-expressing osteosarcoma cells.
• This CAR T-cell therapy represents a promising immunotherapeutic strategy for osteosarcoma patients.