Generation of CD8(+) T cells expressing two additional T-cell receptors (TETARs) for personalised melanoma therapy

Area of Science:

• Immunology
• Oncology
• Biotechnology

Background:

• Adoptive T-cell therapy faces challenges due to tumor immune evasion via antigen loss.
• Equipping T cells with multiple specificities could overcome single-antigen loss by cancer cells.

Purpose of the Study:

• To generate and evaluate dual-specific T cells (TETARs) expressing two T-cell receptors (TCRs).
• To assess the functionality and potential interference of co-expressed TCRs.
• To investigate strategies for enhancing TCR expression and efficacy in adoptive T-cell therapy.

Main Methods:

• Generated TETARs by RNA electroporation of CD8(+) T cells with two TCRs.
• Equipped TETARs with TCRs targeting the common melanoma antigen gp100 and a patient-specific CCT6A mutation (CCT6A(m)).
• Assessed T-cell function, including cytokine secretion and lytic activity, upon antigen stimulation.
• Investigated the effect of TCR 'murinisation' on expression and function.

Main Results:

• Dual-specific CD8(+) T cells (TETARs) demonstrated functional cytokine secretion and lytic activity against both gp100 and CCT6A(m) antigens.
• Some reciprocal inhibition between the two TCRs was observed.
• Murinisation of the CCT6A(m) TCR enhanced its expression, prolonged its presence, and boosted T-cell lytic capacity.

Conclusions:

• Functional dual-specific T cells targeting a common and a patient-specific melanoma antigen were successfully generated.
• This approach holds potential for personalized adoptive T-cell therapy, with transient TCR expression enhancing safety.
• Repetitive RNA-transfected cell injections are proposed to maintain therapeutic effect, while treatment cessation allows receptor clearance.