Rapamycin-resistant effector T-cell therapy

Area of Science:

• Immunology
• Pharmacology
• Transplantation Biology

Background:

• Mechanistic target of rapamycin (mTOR) inhibition stresses tumor and T cells.
• Cells employ survival mechanisms like alternative signaling and autophagy.
• Rapamycin-resistant effector T (T-Rapa) cells exhibit enhanced function.

Purpose of the Study:

• To investigate the therapeutic potential of ex vivo rapamycin-modified T cells (T-Rapa).
• To evaluate the ability of T-Rapa cells to modulate immune responses in transplantation.
• To assess the balance between graft-versus-host disease (GVHD) and graft-versus-tumor (GVT) effects.

Main Methods:

• Ex vivo rapamycin treatment of T cells with polarizing cytokines and antigen-presenting-cell-free costimulation.
• Generation of T-helper 1 (Th1) or T-helper 2 (Th2)-type effector cells.
• Murine models and Phase I/II clinical trials in allogeneic hematopoietic cell transplantation.

Main Results:

• Murine Th2-skewed T-Rapa cells potently prevented graft rejection and GVHD while balancing GVHD and GVT.
• Human T-Rapa cells in a Phase II trial showed a mixed Th2/Th1 phenotype, promoting donor chimerism and a favorable GVHD/GVT balance.
• A Phase I trial evaluating autologous Th1/Tc1-skewed T-Rapa cells is ongoing.

Conclusions:

• Ex vivo rapamycin modulation of effector T cells is a flexible therapeutic strategy.
• T-Rapa cells offer a promising approach to optimize immune balance in transplantation.
• This method may improve outcomes by mitigating GVHD while preserving GVT effects.