HIV-1 adaptation to HLA: a window into virus-host immune interactions.

•Human leukocyte antigen (HLA) class I-restricted immune responses exert strong selection pressures on HIV-1, driving viral evolution through immune escape.•The mutational pathways and time-course of HIV-1 immune escape are specific and reproducible in the context of host HLA class I alleles.•Viral diversity and immune escape are barriers to sustained host control of HIV-1 and the design of effective HIV-1 vaccines.•Study of HLA-driven viral adaptation has yielded important insights that can be harnessed into HIV vaccine design strategies.