Identification of IgG1 isotype phosphorylcholine antibodies for the treatment of inflammatory cardiovascular diseases
Résumé
Phosphorylcholine (PC) is an important pro‐inflammatory damage associated molecular pattern. Previous data has shown that natural IgM anti‐PC protect against cardiovascular disease. We aimed to develop a monoclonal PC IgG antibody with anti‐inflammatory and anti‐atherosclerotic properties.
A chimeric anti‐PC (PC‐mAb(T15), consisting of a human IgG1 Fc and a mouse T15/E06 Fab) was produced, this was shown to bind specifically to epitopes in human atherosclerotic tissues. Inflammation‐driven accelerated atherosclerosis was induced by femoral‐artery‐cuff‐placement in ApoE3*Leiden mice. This results in rapid induction of inflammatory genes and altered expression of genes associated with ER stress and choline metabolism in the lesions. Treatment with PC‐mAb(T15) reduced accelerated atherosclerosis via reduced expression of endoplasmic reticulum‐stress markers and CCL2 production.
Recombinant anti‐PC Fab fragments were identified by phage display and cloned into fully human IgG1 backbones creating a human monoclonal IgG1 anti‐PC (PC‐mAbs) that specifically bind PC, apoptotic cells and oxLDL. Based on preventing macrophage oxLDL‐uptake and CCL2 production, 4 monoclonal PC‐mAbs were selected which to various extent reduced vascular inflammation and lesion development. Additional optimization and validation of 2 PC‐mAb antibodies resulted in selection of PC‐mAb X19‐A05, which inhibited accelerated atherosclerosis. Clinical grade production of this antibody (ATH3G10) significantly attenuated vascular inflammation and accelerated atherosclerosis and was tolerated in safety studies in rats and cynomolgus monkeys.
In conclusion
Chimeric anti‐PCs can prevent accelerated atherosclerosis by inhibiting vascular inflammation directly and through reduced macrophage oxLDL‐uptake resulting in decreased lesions. PC‐mAb represents a novel strategy for cardiovascular disease prevention.