Retroviruses, such as human immunodeficiency virus 1 (HIV-1), contain capsids that enclose the viral RNA genome, enzymes, and accessory proteins. The assembly, maturation, and stability of the viral capsid are critical to the viral replication life cycle. Furthermore, the surface of the viral capsid serves as a primary interaction interface between the virus and the host cell, for both host defense proteins and virus dependence factors. I will describe HIV-1 capsid assembly and interactions with host factor IP6 and cyclophilin A, highlighting unexpected novel interactions that are critical for these host factors to stabilize the HIV-1 capsid. I will present our recent in situ studies of nuclear import of intact HIV-1 capsid and the architecture of native chromatin fibers in T-cells.