Mitochondrial Membrane Potential Identifies Cells with Enhanced Stemness for Cellular Therapy.

Area of Science:

• Immunology
• Cell Biology
• Metabolic Engineering

Background:

• Adoptively transferred T cell efficacy relies on metabolic fitness for long-term survival and antitumor immunity.
• Current methods for isolating metabolically robust T cells for therapeutic use are not well-established.

Purpose of the Study:

• To develop and validate a method for isolating metabolically fit CD8(+) T cells based on mitochondrial membrane potential.
• To assess the in vivo therapeutic potential of metabolically selected T cells.

Main Methods:

• Utilized tetramethylrhodamine methyl ester (TMRM), a lipophilic cationic dye, to sort T cells based on mitochondrial membrane potential (ΔΨm).
• Conducted comprehensive metabolomic and gene expression profiling of sorted T cell populations.
• Evaluated in vivo persistence and antitumor efficacy of transferred low-ΔΨm versus high-ΔΨm CD8(+) T cells.

Main Results:

• Low-ΔΨm-sorted CD8(+) T cells exhibited global features of improved metabolic fitness.
• Transfer of low-ΔΨm T cells resulted in superior long-term in vivo persistence.
• Low-ΔΨm T cells demonstrated an enhanced capacity to eradicate established tumors compared to high-ΔΨm cells.
• ΔΨm-based sorting successfully enriched for metabolically superior cells in CD4(+) T cells and long-term hematopoietic stem cells.

Conclusions:

• Mitochondrial membrane potential, assessed by TMRM, is a reliable marker for isolating metabolically fit T cells.
• Metabolism-based cell selection using ΔΨm holds promise for enhancing cell therapies.
• This approach may be broadly applicable to lymphocyte and hematopoietic stem cell therapies for cancer and viral diseases.