Watercolour and ink on paper illustration of a cross section through an HIV virus particle (upper; red and purple) attaching to a host target cell (lower; blue and green) e.g. a CD4 T cell, a type of white blood cell found in the immune system. Both the virus and the target cell are surrounded by separate membranes (white/grey; circular shape) and blood plasma is visible between the two (yellow and brown). Three HIV envelope glycoproteins (purple; extend out from the virus and look like trees rooted in the membrane) bind to proteins (receptor CD4 and co-receptor CCR5) on the surface of the target cell. This causes a change in conformation that inserts fusion peptides into the cellular membrane. Width of image is approximately 100 nm.
This image forms part of a series of illustrations which capture HIV at eight different points in the viral life cycle as it infects a cell and replicates.