Follow the following 10 steps to check one by one. If any one is not satisfied, change to the next candidate.
- Clear the target cell type (not an organ, but a specific cell, such as hepatocyte/motor neuron/photoreceptor/RPE).
- Check the receptor/co-receptor expression of the cell in the target species (AAVR must have; attachment receptor? Ly6A? PDGFR? Galactose? TfR1?).
- Check the evidence that the serotype already exists in this cell + this species + the proposed pathway, and give priority to Level A evidence.
- Preliminarily screen 2-3 candidate serotypes (find the organization + the pathway "high" in the 6.2 matrix, giving priority to 8/9/rh10/rh74/MyoAAV, which is conserved across species).
- Verify the tropism based on the route of administration - the tropism of different routes for the same serotype may be different.
- Check that the promoter cooperates with the capsid (whether the promoter can be transcribed after the capsid enters the cell, do not expect the promoter to make up for the capsid).
- Determine dose window (effective dose vs toxic dose, considering liver/DRG off-target and immune burden).
- Set study endpoints (vg→mRNA→protein→functional multilayer, single cell resolution, sampling time to match expression kinetics).
- Assess risk of species extrapolation (distinguish conservative vs. non-conserved serotypes; key conclusions need to be reviewed in NHP or humanized models).
- Set controls (empty vector, non-target tissue sampling, head-to-head comparison of different serotypes; check the original text before using combinations marked "to be verified" in the matrix).