Identification of antigenic peptide recognized by the anti-JL1 leukemia-specific monoclonal antibody from combinatorial peptide phage display libraries

PURPOSE: In the present study an antigen-mimetic peptide of the anti-JL1 leukemia-specific monoclonal antibody (mAb) was identified and characterized. METHODS: From combinatorial peptide phage display libraries displaying the random linear heptapeptides and dodecapeptides, we selected clones with affinity to anti-JL1 mAb through repeated rounds of panning on a mAb-coated ELISA plate. The antigenicity and immunogenicity of the peptide epitopes were then studied using chemically synthesized peptides. RESULTS: The selected clones had the LXPSIP consensus sequence. Two synthetic peptides LPPSIPFGLTVGGGGS and LLPSIPNQAYLGGGGS specifically reacted with anti-JL1 mAb in ELISA. These two peptides were found to inhibit the interaction between anti-JL1 mAb and JL1 antigen-positive Molt-4 cells. Although the immune sera raised against the keyhole limpet hemocyanin-conjugated peptides failed to react with Molt-4 cells, it showed strong reactivity to the peptide epitope. However, one mAb raised by peptide immunization successfully bound to Molt-4 cells. CONCLUSION: An epitope-mimetic peptide of anti-JL1 mAb was found using combinatorial peptide phage display libraries. It induced strong humoral response against itself, but only a limited fraction of this humoral response was cross-reactive with the original JL1 antigen

MiRGator v3.0: A microRNA portal for deep sequencing, expression profiling and mRNA targeting

Biogenesis and molecular function are two key subjects in the field of microRNA (miRNA) research. Deep sequencing has become the principal technique in cataloging of miRNA repertoire and generating expression profiles in an unbiased manner. Here, we describe the miRGator v3.0 update (http://mirgator.kobic.re.kr) that compiled the deep sequencing miRNA data available in public and implemented several novel tools to facilitate exploration of massive data. The miR-seq browser supports users to examine short read alignment with the secondary structure and read count information available in concurrent windows. Features such as sequence editing, sorting, ordering, import and export of user data would be of great utility for studying iso-miRs, miRNA editing and modifications. miRNA-target relation is essential for understanding miRNA function. Coexpression analysis of miRNA and target mRNAs, based on miRNA-seq and RNA-seq data from the same sample, is visualized in the heat-map and network views where users can investigate the inverse correlation of gene expression and target relations, compiled from various databases of predicted and validated targets. By keeping datasets and analytic tools up-to-date, miRGator should continue to serve as an integrated resource for biogenesis and functional investigation of miRNAs