Phage display selection of peptides that home to atherosclerotic plaques: IL‐4 receptor as a candidate target in atherosclerosis

Abstract

Imaging or drug delivery tools for atherosclerosis based on the plaque biology are still insufficient. Here, we attempted to identify peptides that selectively home to atherosclerotic plaques using phage display. A phage library containing random peptides was ex viv screened for binding to human atheroma tissues. After three to four rounds of selection, the DNA inserts of phage clones wer sequenced. A peptide sequence, CRKRLDRNC, was the most frequently occurring one. Intravenously injected phage displaying the CRKRLDRNC peptide was observed to home to atherosclerotic aortic tissues of low-density lipoprotein receptor-deficient (Ldlr−/–) mice at higher levels than to normal aortic tissues of wild-type mice. Moreover, a fluorescein- or radioisotope-conjugated synthetic CRKRLDRNC peptide, but not a control peptide, homed in vivo to atherosclerotic plaques in Ldlr−/– mice, while homing of the peptide to other organs such as brain was minimal. The homing peptide co-localized with endothelial cells, macrophages and smooth muscle cells a mouse and human atherosclerotic plaques. Homology search revealed that the CRKRLDRNC peptide shares a motif of interleukin-receptor (IL-4) that is critical for binding to its receptor. The peptide indeed co-localized with IL-4 receptor (IL-4R) at atherosclerotic plaques. Moreover, the peptide bound to cultured cells expressing IL-4R on the cell surface and the binding was inhibited by the knock-down of IL-4R. These results show that the CRKRLDRNC peptide homes to atherosclerotic plaques through binding to IL-4R as its target and may be a useful tool for selective drug delivery and molecular imaging of atherosclerosis.

Specific penetration and accumulation of a homing peptide within atherosclerotic plaques of apolipoprotein E-deficient mice

“…LyP-1 penetration into the plaque interior is a unique feature not seen with previously reported plaque homing peptides, which primarily bind to the luminal surface of plaques or to cells close to the luminal surface (5,6,(8)(9)(10)(11)). An example of such peptides is the CREKA peptide in this study, which almost exclusively delivers its payload to the luminal surface of plaques.…”

“…In vivo phage display (4) has been used with some success to identify reagents with improved specificity for plaque targeting (5)(6)(7)(8)(9)(10)(11). We have shown that the pentapeptide CREKA, which binds to fibrin-fibronectin complexes in clotted plasma (12), homes to plaques (10).…”

Engineered Exosomes With Ischemic Myocardium‐Targeting Peptide for Targeted Therapy in Myocardial Infarction

“…Rabies viral glycoprotein peptide (YTIWMPENPRPGTPCDIFTNSRGKRASNG) displayed on the external part of exosomes can specifically bind to acetylcholine receptor 39. In terms of the cardiovascular system, several homing peptides have been identified and applied to targeted therapy, including atherosclerosis,40, 41, 42 pulmonary arterial hypertension,43 and ischemia/reperfusion injured cardiomyocytes 44. In research by Won et al,44 they presented that a polymeric gene carrier conjugated with IMTP (CSTSMLKAC) was capable of targeting ischemic myocardium, resulting in high localization within the ischemic zone of the LV of an ischemia/reperfusion rat model on systemic administration.…”

Treating glioblastoma multiforme with selective high-dose liposomal doxorubicin chemotherapy induced by repeated focused ultrasound

“…7 These findings show that therapeutic agents that bind to interleukin-4 receptors may be a useful approach to tumor treatment. 8 Our previous work has demonstrated that the concentration of Evans blue in tumors and the tumorto-normal brain ratio of Evans blue in the brain is elevated after blood-brain barrier disruption induced by pulsed-high intensity focused ultrasound (HIFU) in the presence of microbubbles. In these circumstances, repeated pulsed HIFU exposure is able to increase further the efficiency of Evans blue delivery into the brain.…”

“…18,19 Here, we designed a ligand from atherosclerotic plaque-specific peptide-1 (AP-1) selected from phage display libraries and can locate atherosclerotic plaque tissue and bind to the interleukin-4 receptor because it has the same binding motif to the interleukin-4 protein. 8 Specifically, in order to allow more specific and efficient delivery of liposomal doxorubicin to brain tumors, an AP-1 actively targeted liposomal antitumor drug specific for interleukin-4 receptors, which is present on the cell membrane of malignant tumors, has been developed. Previous work has demonstrated that AP-1-labeled nanoparticles can be used for targeted drug delivery to tumor tissue.…”