Résumé
Background and aims: Macrophages (MPs) are overwhelmingly present in atheroma plaques and play a pivotal role in atherogenesis. Within atherosclerotic lesions, distinct subsets of MPs coexist including inflammatory MPs (infMPs) and foam cell MPs (FMs), which signify disease progression and regulatory MPs (regMPs), indicative of plaque regression. A growing body of litterature suggests that promoting MP polarization towards the regMP phenotype using chemical or naturally derived compounds can significantly contribute to the reduction of atherosclerotic plaques. This research aims to engineer biomimetic lipoprotein complexes (LPC) as a targeted therapeutic approach for atherosclerosis. LPCs are designed to incorporate conjugated linoleic acid (CLA) to limit foam cell formation and alleviate inflammation while being functionalized with human antibodies (HuAbs) specifically targeting FMs. Methods: The HuAbs were obtained through a dual in vivo/in vitro phage-display selection, firstly in an atheromatous animal model and secondly using a human pathophysiological FM model. Following a prescreening ELISA assay conducted with individual HuAb clones, VH and VL sequences were analyzed using IMGT V-Quest software after Sanger sequencing. These sequences were compared to a Next-Generation Sequencing (NGS) library derived from the in vivo-selected HuAbs. Antibody reactivity was validated (1) by flow cytometry using FMs and unstimulated MPs and (2) by immunohistochemistry on aortic sections from Apoe-/- mice. Results: Three rounds of in vitro selection on FMs yielded 1.9 × 107 HuAbs. Of 192 HuAbs shortlisted via ELISA from 1,000 individualized clones, 93 had VH/VL sequences accurately identified in the IMGT database. The top 10 HuAbs, based on their reactivity in flow cytometry, immunohistochemistry and occurrence in the NGS library, were selected. Conclusions: This innovative in vivo/in vitro phage display method successfully identified HuAbs specific to FMs. The next step involves reformatting these top 10 candidates into soluble HuAb fragments for conjugation onto LPCs, enabling precise delivery of the therapeutic agents directly to the atherosclerotic plaques.