Although impressive advances have been made towards unraveling the structural and functional aspects of proteins that mediate the entry of HIV into cells, the molecular nature of the events at the "instant" of recognition and fusion remain shrouded in mystery. There is also a poor structural understanding of how HIV often escapes antibody-mediated neutralization. These two questions form the biological focus of the studies we are carrying out with HIV using emerging tools in cryo electron tomography. We are using advanced 3D imaging technologies to determine the structure of individual virions, to understand the molecular interactions that define strongly and weakly neutralizing antibodies, and to define the structural basis of viral recognition and entry.
Image of isolated SIV particles (kindly provided by Dr. Jeff Lifson, NCI) and a cultured macrophage. Both images were recorded on frozen hydrated samples at liquid nitrogen temperatures.