Infectivity of adeno-associated virus serotypes in mouse testis

Area of Science:

• Gene therapy
• Molecular biology
• Virology

Background:

• Recombinant adeno-associated viruses (AAVs) are promising vectors for gene therapy and research.
• Understanding AAV serotype tropism in specific tissues is crucial for effective delivery.
• The study investigates AAV infectivity in the murine testis.

Purpose of the Study:

• To evaluate the tropism of various AAV serotypes in the mouse testis following direct injection.
• To identify specific cell types transduced by different AAV serotypes.
• To assess the potential of AAVs as gene therapy vectors in the testicular environment.

Main Methods:

• Direct testicular injection of multiple AAV serotypes (AAV2, 5, 8, 9, AAVrh10) in mice.
• Analysis of reporter gene expression to determine cell transduction.
• Comparison of wildtype AAV2 tropism with a modified AAV2 (AAV2 TM) mutant.

Main Results:

• AAV2 and AAV9 preferentially transduced Leydig cells in the mouse testis.
• AAV2 TM mutant showed altered tropism, transducing Sertoli cells and infiltrating seminiferous tubules.
• No tested AAV serotypes infected spermatogonial cells, the sperm progenitors.

Conclusions:

• The tested AAV serotypes did not infect sperm progenitors, supporting their safety as gene therapy vectors.
• Further investigation into the presence of rAAV genomic DNA in germ cells is needed to fully assess risks.
• AAV tropism in the testis is serotype-specific, with potential for targeting specific cell populations like Leydig and Sertoli cells.