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Updated: Apr 14, 2026
Author Spotlight: Improved Method for Production and Purification of Adeno-Associated Viral Vectors
Published on: April 5, 2024
Adeno-associated virus mediated delivery of an engineered protein that combines the complement inhibitory properties
Derek Leaderer1, Siobhan M Cashman1, Rajendra Kumar-Singh1
1Department of Developmental, Molecular and Chemical Biology, Program in Genetics, Sackler School of Graduate Biomedical Sciences, Tufts University School of Medicine, Boston, MA, USA.
Insights
Gene therapy using adeno-associated virus (AAV) vectors delivered combined complement regulators (SACT and DTAC) to protect liver vasculature from complement-mediated damage. This approach shows promise for treating complement-related disorders.
Area of Science:
- Immunology
- Gene Therapy
- Molecular Biology
Background:
- Complement activation is implicated in various disorders.
- CD46, CD55, and CD59 are key membrane-bound complement regulators.
- Previous studies showed independent gene transfer of these regulators protects tissues.
Purpose of the Study:
- To investigate combining CD46, CD55, and CD59 regulatory functions into single gene products.
- To express these combined regulators using adeno-associated virus (AAV) vectors in a soluble form.
Main Methods:
- Minigenes for CD46, CD55, CD59 (SACT) or CD55, CD59 (DTAC) were cloned into AAV vectors.
- In vitro activity of SACT and DTAC was assessed.
- Recombinant AAV vectors were administered to mice to evaluate protection of liver vasculature against human complement.
Main Results:
- SACT and DTAC demonstrated expected regulatory activities in vitro.
- AAV-mediated delivery of SACT and DTAC reduced human membrane attack complex (MAC) deposition in murine liver vasculature by 63.2% and 56.7%, respectively.
Conclusions:
- SACT and DTAC delivered via AAV vectors effectively limit complement-mediated damage in vivo.
- These constructs warrant further investigation as potential gene therapies for complement-mediated diseases.
Background:
A variety of disorders are associated with the activation of complement. CD46, CD55 and CD59 are the major membrane associated regulators of complement on human cells. Previously, we have found that independent expression of CD55, CD46 or CD59 through gene transfer protects murine tissues against human complement mediated attack. In the present study, we investigated the potential of combining the complement regulatory properties of CD46, CD55 and CD59 into single gene products expressed from an adeno-associated virus (AAV) vector in a soluble non-membrane anchored form.
Methods:
Minigenes encoding the complement regulatory domains from CD46, CD55 and CD59 (SACT) or CD55 and CD59 (DTAC) were cloned into an AAV vector. The specific regulatory activity of each component of SACT and DTAC was measured in vitro. The recombinant AAV vectors were injected into the peritoneum of mice and the efficacy of the transgene products for being able to protect murine liver vasculature against human complement, specifically the membrane attack complex (MAC), was measured.
Results:
SACT and DTAC exhibited properties similar to CD46, CD55 and CD59 or CD55 and CD59, respectively, in vitro. AAV mediated delivery of SACT or DTAC protected murine liver vasculature from human MAC deposition by 63.2% and 56.7%, respectively.
Conclusions:
When delivered to mice in vivo via an AAV vector, SACT and DTAC are capable of limiting human complement mediated damage. SACT and DTAC merit further study as potential therapies for complement mediated disorders when delivered via a gene therapy approach.
