The Sindbis viral vector platform was engineered from Sindbis virus, a RNA virus that is naturally transmitted in blood and can survive in the blood stream. Consequently, Sindbis vector can be systemically injected – an advantage over other vectors that are inactivated in plasma.
Sindbis viral vectors target and kill cancer cells through dual mechanisms:
- Tumor specific targeting and killing: Sindbis virus naturally binds to the high affinity laminin receptors (LAMR) that are over-expressed in tumor cells and trigger apoptosis (programmed cell-death)
- Vector-induced immune activation: Sindbis viral vectors transit through the lymph nodes where they also actuate and recruit an immune response to trigger cell death of tumor cells through activated NK cells, macrophages and tumor antigen specific CD8+ T cells. In addition, Sindbis-mediated apoptosis and cell death releases tumor associated antigens (TAAs) from tumor cells, leading to epitope spreading.