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Updated: Sep 3, 2025
Engineering and Evolution of Synthetic Adeno-Associated Virus AAV Gene Therapy Vectors via DNA Family Shuffling
Published on: April 2, 2012
Directed evolution of adeno-associated virus for efficient gene delivery to microglia
Rui Lin1, Youtong Zhou2,3, Ting Yan2,4,5
1National Institute of Biological Sciences (NIBS), Beijing, China. linrui@nibs.ac.cn.
Abstract:
As the resident immune cells in the central nervous system (CNS), microglia orchestrate immune responses and dynamically sculpt neural circuits in the CNS. Microglial dysfunction and mutations of microglia-specific genes have been implicated in many diseases of the CNS. Developing effective and safe vehicles for transgene delivery into microglia will facilitate the studies of microglia biology and microglia-associated disease mechanisms. Here, we report the discovery of adeno-associated virus (AAV) variants that mediate efficient in vitro and in vivo microglial transduction via directed evolution of the AAV capsid protein. These AAV-cMG and AAV-MG variants are capable of delivering various genetic payloads into microglia with high efficiency, and enable sufficient transgene expression to support fluorescent labeling, Ca2+ and neurotransmitter imaging and genome editing in microglia in vivo. Furthermore, single-cell RNA sequencing shows that the AAV-MG variants mediate in vivo transgene delivery without inducing microglia immune activation. These AAV variants should facilitate the use of various genetically encoded sensors and effectors in the study of microglia-related biology.
Insights
Researchers developed new adeno-associated virus (AAV) variants for efficient gene delivery into microglia, the brain's immune cells. These AAV-MG variants enable studying microglia function and disease without triggering immune responses.
Area of Science:
- Neuroscience
- Immunology
- Molecular Biology
Background:
- Microglia are key immune cells in the central nervous system (CNS), crucial for neural circuit regulation.
- Microglial dysfunction is linked to various CNS diseases, highlighting the need for tools to study them.
- Efficient and safe methods for delivering genetic material into microglia are essential for advancing research.
Purpose of the Study:
- To discover novel adeno-associated virus (AAV) variants for effective microglial transduction.
- To enable in vitro and in vivo delivery of genetic payloads into microglia.
- To facilitate the study of microglia biology and disease mechanisms.
Main Methods:
- Directed evolution of AAV capsid proteins to identify microglial-targeting variants.
- Testing AAV-cMG and AAV-MG variants for in vitro and in vivo microglial transduction efficiency.
- Utilizing single-cell RNA sequencing to assess immune activation post-transduction.
Main Results:
- Identified AAV-cMG and AAV-MG variants with high efficiency for microglial gene delivery.
- Demonstrated successful transgene expression for labeling, imaging (Ca2+ and neurotransmitters), and genome editing in microglia.
- Confirmed that AAV-MG variants do not induce microglia immune activation in vivo.
Conclusions:
- Novel AAV variants (AAV-cMG, AAV-MG) provide efficient tools for microglial gene delivery.
- These variants support various genetic applications in microglia, including imaging and editing.
- The developed AAV vectors are suitable for studying microglia-related biology and diseases without immune side effects.
