Engineered Mesenchymal Cells Improve Passive Immune Protection Against Lethal Venezuelan Equine Encephalitis Virus...

Area of Science:

• Immunology
• Gene Therapy
• Cell-Based Therapies

Background:

• Mesenchymal stromal cells (MSCs) are explored as gene delivery vectors for therapeutic applications.
• Venezuelan equine encephalitis virus (VEEV) poses a significant threat with no current human vaccine or antiviral.
• Direct antibody administration offers immediate but short-lived protection against pathogens.

Purpose of the Study:

• To evaluate engineered human umbilical cord perivascular cells (HUCPVCs) as a gene delivery platform for passive immunity.
• To compare the protective efficacy of engineered MSCs against VEEV with purified neutralizing antibodies.

Main Methods:

• HUCPVCs were engineered to express a VEEV-neutralizing antibody transgene.
• Engineered HUCPVCs and purified antibodies were administered to athymic mice.
• Serum antibody titers, half-life, and protection against lethal VEEV challenge were assessed.

Main Results:

• Engineered HUCPVCs produced protective anti-VEEV antibody titers for 21-38 days, with detectable levels at 109 days post-transplantation.
• The half-life of purified anti-VEEV antibody was only 3.7 days, limiting protection to 2-3 days.
• Mice pretreated with engineered HUCPVCs were protected against lethal VEEV exposure 24 hours and 10 days post-injection.

Conclusions:

• Engineered MSCs serve as effective gene delivery vehicles for sustained passive immunity.
• This cell-based approach offers a superior, single-dose prophylaxis strategy compared to repeated antibody administration.
• The study demonstrates the potential of engineered MSCs for protection against endemic and biowarfare pathogens.