Identification Of A Novel Peptide Recognizes Rhesus Monkey Neural Stem Cells By Phage Display

Labeling and targeting stem cells call for new markers that can selectively bind to them. Since the exact pathways involved in the early human development and organogenesis still remains unknown, and also does the process of the replication of ES cells model in vitro, the possible clinical applications are limited. Cells communicate with each other through surface receptors, as well as with their immediate niche, and certain changes in the repertoire of these receptors are likely to be specified for particular lineages, thus to find out which receptors are responsible for differentiation of ES cells into each lineage is crucial to investigate the relative pathways, to identify, isolate, expand and characterize specific cell lineages derived from ES cells.In the study, we detected OCT4, Nanog, SOX2 expression by using RT-PCR, and confirmed ES cells condition by AKP analysis. Induced by RA+B27 defined medium, we obtained neural stem cells derived from Rhesus monkey embryonic stem cells through EB fromation. neural stem cells derived from Rhesus monkey embryonic stem cells were confirmed by using immunofluoresence analysis and RT-PCR to test the expression of Nestin, SOX2, Mushasi-1. With different enzyme treatment method we got pure NS cells.Five novel peptides with specific binding ability to neural stem cells derived from Rhesus monkey embryonic stem cells was successfully screened out by using Ph.D-12 peptide phage display library. HGE and APW were shown in enzyme linked immunosorbent assay with the high affinity and specificity if the NS cells and confirmed by immunofluoresence analysis. Competed with a chemically synthesized peptide whose sequence is identical to that displayed by phage indicating the binding capability is endowed by the peptide sequence. Further results of quantum dots labeling and western blot showed that the HGE peptide bound on membrane of neural stem cells through a protein-protein interaction. APW also shows affinity and specificity to NS cells.APW shows affinity both to maraca ES cells and NS cells, according to another research by Lu Shuai of our lab. Further toxicity test indicates that APW is not toxic for ES cells in vitro culture. And bioinformatics research suggests that APW binds to ES cells via the non-bonding forces.The finding from this work holds promise to be an imagination or targeting agent for the neural stem cells and may also be a research tool for the study of other cell lineages derived from ES cells.