Primary T cells for mRNA-mediated immunotoxin delivery

Area of Science:

• Immunology
• Cancer Therapy
• Molecular Biology

Background:

• Chimeric protein toxins are used in cancer therapy but have severe side effects.
• Immune cells are being explored as targeted delivery systems for these toxins.

Purpose of the Study:

• To investigate the use of human primary T cells for delivering immunotoxins via mRNA transfection.
• To develop and optimize protocols for transient mRNA transfection in T cells and HEK293 cells.

Main Methods:

• Constructed chimeric immunotoxins targeting cancer neovasculature (VEGF-PE38, VEGF-PE38D).
• Established transient mRNA transfection protocols for HEK293 cells and primary human T cells.
• Analyzed immunotoxin expression, secretion, and translocation using mass spectrometry.
• Assessed cytotoxic activity of T cells secreting immunotoxins in co-culture models.

Main Results:

• Efficient expression and secretion of immunotoxins (e23-PE38, VEGF-PE38, VEGF-PE38D) were achieved through mRNA transfection.
• Mass spectrometry confirmed proper endoplasmic reticulum translocation of VEGF-PE38D.
• Immunotoxin-secreting T cells demonstrated cytotoxic activity against ovarian cancer cells in the presence of a bispecific antibody.

Conclusions:

• Primary human T cells can be effectively engineered via mRNA transfection to secrete functional immunotoxins.
• This mRNA-mediated delivery system shows promise for targeted cancer therapy, potentially reducing systemic toxicity.