A prokaryotic-eukaryotic hybrid viral vector for delivery of large cargos of genes and proteins into human cells

Development of safe and efficient nanoscale vehicles that can deliver large molecular cargos into human cells could transform future human therapies and personalized medicine. Here, we design a hybrid viral vector composed of a prokaryotic virus (bacteriophage T4) and a eukaryotic virus [adeno-associated virus (AAV)]. The small 25-nm AAV is attached to the large 120 nm x 86 nm T4 head through avidin-biotin cross-bridges using the phage decoration proteins Soc and Hoc. AAV piggy-backed on T4 capsid, by virtue of its natural ability to enter human cells acted as an efficient driver, delivering the largest payloads of foreign DNA (up to 170 kb) and protein (up to 1025 molecules) reported to date, and elicited robust immune responses in mice against flu and plague pathogens and conferred complete protection against lethal pneumonic plague challenge. The T4-AAV represents a unique platform for assembly of natural building blocks into potential therapeutics against genetic and infectious diseases.