In collaboration with researchers at the Mount Sinai School of Medicine in New York, CBST has produced the first real-time video images of direct, cell-to-cell transmission of human immunodeficiency virus (HIV).

Prof. Benjamin Chen from the Division of Infectious Disease at Mt. Sinai was recently successful in fusing green fluorescent protein (GFP) to Gag - a key structural protein of HIV. In contrast to previous attempts to engineer similar proteins, the resultant virus proved to be competent - able to infect other CD4+ lymphocytes. Using conventional fluorescence microscopy, Dr. Chen was able to demonstrate HIV transmission through direct cell contact -- challenging the current belief that free virus is the principal mode of infection.

Using the 3D spinning disk confocal microscope at CBST, we are able to observe this process in much greater detail (more than 10 times the useful information in terms of spatial and temporal resolution), and reconstruct video images to focus on the structure and behavior of the virological synapse, which forms at the interface of cells in contact. By uncovering the different modes of Gag movements in the donor cell, we may be able to identify new targets or strategies for antiviral therapy.