Identification of anti-CD98 antibody mimotopes for inducing antibodies with antitumor activity by mimotope immunization.
Bottom Line: In this study, we isolated linear and constrained mimotopes from HBJ127, a tumor-suppressing anti-CD98 heavy chain mAb, and determined their abilities for induction of antitumor activity equal to that of the parent antibody.Functional and structural analysis of retrieved Fab clones revealed that they were almost identical to the parent antibody.From these results, we confirmed that mimotope immunization was promising for retrieving antitumor antibodies equivalent to the parent antibody, although the co-administration of adjuvant compounds such as T-cell epitope peptides and Toll-like receptor 4 agonist peptides is likely to be necessary for inducing stronger antitumor immunity than mimotope injection alone.
Affiliation: Department of Clinical Pharmacology and Genetics, School of Pharmaceutical Sciences, University of Shizuoka, Shizuoka, Japan.Show MeSH
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Mentions: We first determined the reactivity of A18, B3, and C17 against live HeLa cells by IIF. All rFabs strongly stained the surfaces of HeLa cells (Fig. 1). We then determined the reactivity against HeLa cell lysates using these rFabs for antigen capture and human CD98-specific mAb for detection in sandwich ELISA. A18, B3, and C17 reacted with CD98 in HeLa cell lysates (Fig. 2). Next, we determined in vitro tumor growth inhibitory activity of A18, B3, and C17 using CD98-expressing HeLa cells. HeLa cells were treated with rFabs then cross-linked with rabbit anti-mouse IgG F(ab')2. After 72 h, the viability of cells was determined by alamarBlue assay. As shown in Figure 3, all rFab clones showed cell growth inhibition activity comparable to HBJ127. These results implied that mimotope-induced rFabs reacted with human CD98 antigen and showed the biological activities as comparable to HBJ127.
Affiliation: Department of Clinical Pharmacology and Genetics, School of Pharmaceutical Sciences, University of Shizuoka, Shizuoka, Japan.