Enhanced long-term transduction and engraftment of CD34+ human hematopoietic stem cells transduced with tyrosine-modified recombinant adeno-associated virus serotypes 2 and 6

Thesis (M.S.) California State University, Los Angeles, 2012Committee members: Sandra Sharp, Edith Porter, Kirsten Fisher, Saswati Chatterjee, Nancy McQueenAAV, Beta Thalassemia, HSC, Tyrosine-modifiedThere is significant therapeutic promise in the clinical application of stem cell gene therapy, but it remains limited by problems related to available gene transfer vectors. Recombinant adeno-associated virus (rAAV) vectors are promising for gene transfer into human hematopoietic stem cells (HSCs). However, exposed tyrosine residues on the rAAV vector capsid are involved in premature proteasomal degradation of the vector, reducing overall efficiency of gene transfer. Previous studies show that rAAV vectors (serotypes 2, 8, 9) have greatly improved transduction efficiency by mutating the tyrosine (Y) residues to phenylalanine (F) residues to prevent early degradation. Among the rAAV vectors being examined for gene transfer into HSCs are rAAV serotypes 2 and 6, which differ in tropism and gene transfer efficiency. This thesis reports that novel tyrosine-modified rAAV6 vectors transduce human cord blood-derived HSCs capable of significant transgene expression both <italic>in vitro</italic> and <italic>in vivo</italic>.Biological Science