So we know that there is a first gene therapy drug in the market out there called Alipogene tiparvovec to address lipoprotein lipase deficiency (LPLD) at a genetic level. Does this genetic drug target all cell types (except germline) that expresses the LPL gene in the human body or simply the parenchymal cells that process fat? I have not been able to find information specific to Glybera.
Glybera doesn't target all cells, and doesn't target fat processing cells. Glybera is adeno-associated virus 1, which normally infects skeletal muscles. Glybera is delivered by intramuscular injection, so the virus easily infects the muscle tissue. The infected muscle cells produce a variant of lipoprotein lipase that has better activity than normal LPL and secrete it into the bloodstream. Once in the blood LPL can interact with chylomicrons and make them smaller.
Here is a paper about viral gene therapy for LPL deficiency, specifically about glybera, but I don't think it's open access.