Background Phosphorylcholine (PC) is an important pro-inflammatory damage-associated molecular pattern. Previous data have shown that natural IgM anti-PC protects against cardiovascular disease. We... Show moreBackground Phosphorylcholine (PC) is an important pro-inflammatory damage-associated molecular pattern. Previous data have shown that natural IgM anti-PC protects against cardiovascular disease. We aimed to develop a monoclonal PC IgG antibody with anti-inflammatory and anti-atherosclerotic properties.Methods Using various techniques PC antibodies were validated and optimized. In vivo testing was performed in a femoral artery cuff model in ApoE3*Leiden mice. Safety studies are performed in rats and cynomolgus monkeys.Results A chimeric anti-PC (PC-mAb(T15), consisting of a human IgG1 Fc and a mouse T15/E06 Fab) was produced, and this was shown to bind specifically to epitopes in human atherosclerotic tissues. The cuff model 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, four monoclonal PC-mAbs were selected, which to various extent reduced vascular inflammation and lesion development. Additional optimization and validation of two 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.Conclusions 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. Show less
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... Show morePhosphorylcholine (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. Show less
Venous grafts are often used to bypass occlusive atherosclerotic lesions; however, poor patency leads to vein graft disease. Deficiency of TLR4, an inflammatory regulator, reduces vein graft... Show moreVenous grafts are often used to bypass occlusive atherosclerotic lesions; however, poor patency leads to vein graft disease. Deficiency of TLR4, an inflammatory regulator, reduces vein graft disease. Here, we investigate the effects of the accessory molecule and TLR4 analogue RadioProtective 105 (RP105) on vein graft disease. RP105 deficiency resulted in a 90% increase in vein graft lesion area compared to controls. In a hypercholesterolemic setting (LDLr−/−/RP105−/− versus LDLr−/− mice), which is of importance as vein graft disease is usually characterized by excessive atherosclerosis, total lesion area was not affected. However we did observe an increased number of unstable lesions and intraplaque hemorrhage upon RP105 deficiency. In both setups, lesional macrophage content, and lesional CCL2 was increased. In vitro, RP105−/− smooth muscle cells and mast cells secreted higher levels of CCL2. In conclusion, aggravated vein graft disease caused by RP105 deficiency results from an increased local inflammatory response. Show less
Venous grafts are often used to bypass occlusive atherosclerotic lesions; however, poor patency leads to vein graft disease. Deficiency of TLR4, an inflammatory regulator, reduces vein graft... Show moreVenous grafts are often used to bypass occlusive atherosclerotic lesions; however, poor patency leads to vein graft disease. Deficiency of TLR4, an inflammatory regulator, reduces vein graft disease. Here, we investigate the effects of the accessory molecule and TLR4 analogue RadioProtective 105 (RP105) on vein graft disease. RP105 deficiency resulted in a 90% increase in vein graft lesion area compared to controls. In a hypercholesterolemic setting (LDLr(-/-)/RP105(-/-) versus LDLr(-/-) mice), which is of importance as vein graft disease is usually characterized by excessive atherosclerosis, total lesion area was not affected. However we did observe an increased number of unstable lesions and intraplaque hemorrhage upon RP105 deficiency. In both setups, lesional macrophage content, and lesional CCL2 was increased. In vitro, RP105(-/-) smooth muscle cells and mast cells secreted higher levels of CCL2. In conclusion, aggravated vein graft disease caused by RP105 deficiency results from an increased local inflammatory response. Show less
Wezel, A.; Velden, D. van der; Maassen, J.M.; Lagraauw, H.M.; Vries, M.R. de; Karper, J.C.; ... ; Quax, P.H.A. 2015
Atherosclerosis, restenosis and cardiac remodeling after myocardial infarction can cause serious clinical problems that greatly contribute to both high morbidity and mortality. In all these... Show moreAtherosclerosis, restenosis and cardiac remodeling after myocardial infarction can cause serious clinical problems that greatly contribute to both high morbidity and mortality. In all these processes, the inflammatory responses caused by activation of the immune system play a very prominent role. This thesis elaborates on the role of specific components of the immune system and the therapeutic possibilities that lay hidden therein. This was done by focussing on the pathophysiological process in which Damage Associated Molecular Patterns (DAMPs) are released upon cell stress and cell death or other tissue damage, and may play an important role via different mechanisms. The data in this thesis illustrates specific involvement of DAMPs recognizing factors such as Toll-like Receptors in vascular remodeling and the therapeutic potential that lies within these findings. We show that endogenous activation of the immune s ystem plays an important role in the post-interventional vascular remodeling process. Multiple DAMPs such as HMGB1 are absent before intervention however they were found highly up regulated locally in the vessel wall after intervention indicating a specific relation with the intervention procedure. The presence and involvement of a variety of Toll Like Receptors in different models of vascular remodeling is interesting since these receptors are considered to be important recognizers of the DAMPs locally found in the vessel wall. Different intracellular signalling pathways and TLR accessory molecules seem to mediate the outcome of the specific DAMP-TLR interactions on vascular remodeling majorly. Protective effects of TLR3 and different outcomes of RP105 deficiency on vascular remodeling processes indicate the complexity of the underlying pathophysiological processes. These results can be partly explained by downstream TLR signalling and involvement of specific cell subtypes. The exploration of these underlying mechanisms offers new opportunities for biomarker selection and therapy development. Show less
Background RP105 (CD180) is TLR4 homologue lacking the intracellular TLR4 signaling domain and acts a TLR accessory molecule and physiological inhibitor of TLR4-signaling. The role of RP105 in... Show moreBackground RP105 (CD180) is TLR4 homologue lacking the intracellular TLR4 signaling domain and acts a TLR accessory molecule and physiological inhibitor of TLR4-signaling. The role of RP105 in vascular remodeling, in particular post-interventional remodeling is unknown. Methods and Results TLR4 and RP105 are expressed on vascular smooth muscle cells (VSMC) as well as in the media of murine femoral artery segments as detected by qPCR and immunohistochemistry. Furthermore, the response to the TLR4 ligand LPS was stronger in VSMC from RP105−/− mice resulting in a higher proliferation rate. In RP105−/− mice femoral artery cuff placement resulted in an increase in neointima formation as compared to WT mice (4982±974 µm2 vs.1947±278 µm2,p = 0.0014). Local LPS application augmented neointima formation in both groups, but in RP105−/− mice this effect was more pronounced (10316±1243 µm2 vs.4208±555 µm2,p = 0.0002), suggesting a functional role for RP105. For additional functional studies, the extracellular domain of murine RP105 was expressed with or without its adaptor protein MD1 and purified. SEC-MALSanalysis showed a functional 2:2 homodimer formation of the RP105-MD1 complex. This protein complex was able to block the TLR4 response in whole blood ex-vivo. In vivo gene transfer of plasmid vectors encoding the extracellular part of RP105 and its adaptor protein MD1 were performed to initiate a stable endogenous soluble protein production. Expression of soluble RP105-MD1 resulted in a significant reduction in neointima formation in hypercholesterolemic mice (2500±573 vs.6581±1894 µm2,p<0.05), whereas expression of the single factors RP105 or MD1 had no effect. Conclusion RP105 is a potent inhibitor of post-interventional neointima formation. Show less
