Pilot Project Abstract - Taylor, Jason, PhD

Taylor, Jason, MD, PhD, Assistant Professor, Dept.of Hematology and Medical Oncology, OHSU

“Genetic modification of T-cells in a simian model for HIV”

Genetic modification of rhesus macaque T-cells with foamy viral vectors to develop an in vivo simian model for HIV

Simian immunodeficiency virus (SIV) is used in primates as a large animal model for human immunodeficiency virus (HIV). With both viruses, CD4-positive T-cells are one of the critical cell types that are infected and depleted during infection. One of the untapped potentials of the SIV model is the ability to modify and track T-cells within individual animals. This would allow researchers to determine how modifications affect T-cell homing, survival and turn-over which are critical to both better understand the pathophysiology and develop therapeutic treatment for HIV. However, to date, this avenue of research has been hampered by the inability to efficiently genetically modify (transduce) large numbers of primary T-cells. In a preliminary study, we tested several vector systems and were able to effectively transduce primary rhesus macaque T-cells using a foamy virus (FV) vector. Proposal The purpose of this study is two-fold: 1) Optimize rhesus macaque T-cell transduction and ex vivo expansion conditions; 2) Develop foamy viral vectors expressing non-antigenic selectable surface markers. Method We will initially optimize the transduction and expansion of primary macaque T-cells using a marker gene (green fluorescent protein [GFP]). Simultaneously, we will engineer non-antigenic cell surface markers of transduction so that transduced cells can be followed in vivo without being immunogenic. Once the conditions have been optimized, we will transduce, expand, and purify large numbers of rhesus macaque T-cells with the non-immunogenic FV vectors as proof-of-principle for this approach.