Single Molecule Imaging-based design of HIV-1 vaccines

ongoing

The HIV-1 vaccine research has re-emerged in the last few years due to the identification of antibodies that neutralize most HIV-1 circulating strains. A deeper understanding of the mechanistic mode of target recognition for these antibodies represents a big hope in the field. This project aims at understanding and characterizing polyclonal antibody responses to aid rational vaccine design via radically new technologies on light microscopy. The molecular mechanism of time-resolved HIV-1 fusion will be visualized and quantified on the surface of living cells by combining real-time single virus tracking, fluorescence fluctuation spectroscopy and 3D single molecule localization microscopy (SMLM) imaging. The implementation of a new technology that allows three-dimensional nanometre localization of single particles will allow us to multiplex single molecule experiments with functional readouts for single-virus HIV-1 fusion simultaneously. Here, I will systematically establish the mechanism of action of different families of neutralizing antibodies and how they disrupt the three-step HIV fusion reaction, conserved among different HIV tropism, recently discovered by our group. I will unveil the molecular insights on the precise Env-induced, time-resolved stoichiometry of CD4 and co-receptors (CCR5 or CXCR4) in the presence and absence of different combinations of bNAbs and study their impact on HIV transmission. FUSION will open new avenues to design putative drugs that target host-specific receptor and co-receptor oligomeric states to block HIV-1 fusion. This project systematically applies cutting-edge time-resolved imaging approaches as a gold standard to ascertain how different combinations of bNAbs perturb the HIV fusion mechanism in CD4+ T cells and macrophages. I will establish a world-class laboratory in HIV-1 and single molecule microscopy. I will decipher several key virus–host cell interactions at molecular level and contribute to rational vaccine and drug desig