Innovative nanobodies for medical diagnostics – NVDIAG

The NVDIAG joint laboratory (generation of Nano-antibodies using extracellular Vesicles for DIAGnostic purposes) is a bilateral partnership between the Laboratoire d'Ingénierie des Systèmes Macromoléculaires (LISM) and BioCytex, both based in Marseille. The LISM is a joint research unit of the CNRS and the University of Aix-Marseille, conducting fundamental research at the frontiers of microbiology, biochemistry and cell biology. LISM's research themes focus on the study of biological membranes, and consequently on membrane proteins (MPs), with very strong skills in structural biology (crystallography and electron microscopy). BioCytex is a biotechnology company founded in the early 90s and specialized in the development and standardization of diagnostic tests based on quantitative flow cytometry and ELISA.
The NVDIAG LabCom aims to develop innovative technologies via the engineering of extracellular vesicles (EVs) to present complex antigens, in native conformation, for the generation of camelid monoclonal antibodies (Nano-antibodies) dedicated to applications in the field of flow cytometry and ELISA diagnostics.
Most of the markers used in medical diagnostics are surface PMs. LISM has developed a methodology for producing, purifying and characterizing EVs coated with PM of interest. The laboratory has demonstrated through structural studies using electron microscopy that the use of VEs enables PM to be obtained in a native oligomerized state. In parallel, LISM operates a platform dedicated to the generation of nano-antibodies derived from camelid single variable domain heavy chains (VHH).
The first objective of LabCom NVDIAG is to demonstrate that PM expressed recombinantly on the surface of EVs possess the same properties as those naturally present on cells. To this end, nano-antibodies will be generated by LISM using EVs, then characterized by flow cytometry at BioCytex on vesicles on the one hand, and on human biological samples on the other. Similar behavior will demonstrate identical conformation of the molecules. PM produced in this way in native conformation will reveal original epitopes that do not exist when, for example, soluble extracellular domains are used. These new epitopes will be used to develop nano-antibodies against difficult targets. A particular focus will be on the development of nano-antibodies that are non-competitive with therapeutic antibodies, which could then be used as companion diagnostic tests for monitoring treatment, particularly in cancer immunotherapy.
The second objective will be to prove that the methodology developed by NVDIAG can be used to produce complex molecular assemblies made up of several PM in native conformation. Vesicles obtained by co-transfection will be characterized by electron microcopy at LISM to ensure the presence of the various protein partners. Nano-antibodies will be generated by LISM and their specificities will be characterized on biological samples (whole blood) by BioCytex. These nano-antibodies recognizing conformational epitopes will meet unmet needs for a number of complex antigens.
Ultimately, the functional antibodies will be commercialized by BioCytex to meet healthcare needs in the fields of hemostasis and cancer.