What Is a Viral Vector? AAV vs. Lentivirus for Gene Therapy Delivery

In the realm of gene therapy, viral vectors stand as crucial tools for delivering genetic material into cells. These delivery systems are engineered viruses that have been modified to be safe, efficient, and effective in transferring therapeutic genes. Among the various types of viral vectors, Adeno-Associated Virus (AAV) and Lentivirus are two of the most widely used in clinical and research settings. Both have unique characteristics that make them suitable for different applications in gene therapy.

Adeno-Associated Virus (AAV) is a small virus that infects humans and some other primate species. It is not known to cause disease, which makes it an attractive candidate for use in gene therapy. AAV vectors are particularly favored for their safety profile and their ability to infect both dividing and non-dividing cells, making them versatile for a range of therapeutic applications. One of the key advantages of AAV is its stable integration into the host genome at a specific site, reducing the risk of insertional mutagenesis, a process that could potentially trigger cancer if the gene inserts disrupt a critical gene. However, AAV vectors have a relatively small packaging capacity, limiting the size of the therapeutic gene they can deliver. This limitation means that some larger genes cannot be packaged into AAV vectors, which can restrict their use in certain therapeutic contexts.

Lentivirus, on the other hand, is a type of retrovirus that can integrate into the host cell genome, which allows for long-term, stable expression of the therapeutic gene. Derived from Human Immunodeficiency Virus (HIV), lentiviruses are modified to remove their pathogenicity, making them safe for use in therapeutic applications. Lentiviral vectors can efficiently transduce both dividing and non-dividing cells, similar to AAV, but they have a larger packaging capacity, which allows for the delivery of bigger genes. This feature makes lentiviral vectors suitable for a broader range of genetic therapies, particularly those that require the delivery of larger genes or multiple genes at once. However, their ability to integrate randomly into the host genome raises concerns about insertional mutagenesis, which requires careful consideration and design of the vector.

When deciding between AAV and lentiviral vectors for gene therapy delivery, several factors must be considered. The choice often depends on the specific requirements of the therapy, including the size of the gene to be delivered, the target cell type, the desired duration of expression, and safety considerations. AAV vectors might be preferred when a safe, non-integrating vector is desired, especially in applications where the immune system's response to the vector can be managed. Conversely, lentiviral vectors are often chosen for applications that require the delivery of larger genetic payloads or long-term expression in dividing cells.

In summary, both AAV and lentiviral vectors are powerful tools in the field of gene therapy, each with its own strengths and limitations. Understanding the characteristics of these vectors and the specific requirements of the therapeutic application is crucial in designing effective and safe gene therapy strategies. As the field progresses, ongoing research and development are likely to further enhance the capabilities of these viral vectors, expanding their potential to treat a wide array of genetic disorders and diseases.

Discover Eureka LS: AI Agents Built for Biopharma Efficiency

Stop wasting time on biopharma busywork. Meet Eureka LS - your AI agent squad for drug discovery.

▶ See how 50+ research teams saved 300+ hours/month

From reducing screening time to simplifying Markush drafting, our AI Agents are ready to deliver immediate value. Explore Eureka LS today and unlock powerful capabilities that help you innovate with confidence.