CMV-specific TCR-transgenic T cells for immunotherapy.

Area of Science:

• Immunology
• Transplantation Immunology
• Molecular Biology

Background:

• Cytomegalovirus (CMV) reactivation is a significant threat post-allogeneic hemopoietic stem cell transplantation (HSCT).
• Adoptive T cell therapy is effective for CMV-positive donor recipients, but a therapeutic gap exists for CMV-negative donor recipients due to unavailability of CMV-specific T cells.
• This unmet need highlights the importance of developing novel strategies for CMV-specific T cell generation in this high-risk population.

Purpose of the Study:

• To develop a novel adoptive T cell therapy for patients receiving transplants from CMV-negative donors.
• To engineer CMV-specific T cells by transferring T cell receptor (TCR) genes encoding CMV specificity.
• To assess the functionality and stability of these engineered T cells for potential clinical application.

Main Methods:

• Generated CMV-specific T cell clones with defined HLA restrictions recognizing the pp65 antigen.
• Cloned the genes of four TCRs and transferred them into primary T cells from CMV-negative donors, creating CMV-TCR-transgenic T cells.
• Assessed effector functions including IFN-gamma and IL-2 secretion, cytotoxicity, and proliferation in response to CMV pp65 antigen.
• Enriched and expanded engineered T cells using antigen-specific stimulation to evaluate stability and functional enhancement.

Main Results:

• Engineered CMV-TCR-transgenic T cells exhibited broad effector functions, including cytokine secretion, cytotoxicity, and proliferation upon stimulation with endogenously processed pp65.
• The specificity of the transferred TCR was stable and fully functional, as indicated by enhanced effector functions during expansion.
• Engineered T cells could be effectively enriched and expanded through antigen-specific stimulation, demonstrating feasibility for therapeutic manufacturing.

Conclusions:

• CMV-TCR-transgenic T cells engineered from CMV-negative donors possess potent antiviral effector functions.
• This approach offers a promising strategy to address the lack of CMV-specific T cells in recipients from CMV-negative donors.
• These engineered T cells are expected to be effective in controlling CMV disease and establishing long-term antiviral memory after HSCT.