The Application Of BLyS-binding Peptides From Different Sources And Their Peptibodies As BLyS Antagonists

In the progress to explore more promising treatments for autoimmune disorders, an indispensable survival factor for B cells, termed B lymphocyte stimulator(BLyS), has been verified to be a prominent target. BLyS, a member of the tumor necrosis factor(TNF) family, displays a vital regulator in the control of B cell proliferation, differentiation, maturation and homeostasis. By binding to three transmembrane receptors, BlyS activates divers signal pathways to approach its function. As it reported, excessive BLyS has been testified in the patients suffering from SS, SLE, RA and B cell malignancies. Therefore, various BLyS antagonists are becoming hot spots with broad therapeutic prospects.In this study, BLyS affinity peptides 814 and 219 were obtained from phage display library. Peptides 3-TA and 3-TC were designed by computer-aided modeling based on BLyS-TACI complex’s structure. To overcome the peptides’ instability in spatial conformation and bioactivity, human IgG1 Fc segment was linked to peptide to evolve peptide-Fc fusion proteins, steady and noval peptibodies. The feasibility of peptides and their peptibodies being BLyS antagonists were analyzed and compared. Findings are as follows:1 Fusion genes p ET30a-814-Fc and pET30a-219-Fc were constructed and expressed. Peptibody 814-Fc displayed strong inhibiting activity on the BLyS-TACI interaction as peptide 814 did.2 Fusion genes p ET30a-3-TA-Fc and pET30a-3-TC-Fc were constructed and expressed. Peptibody 3-TA-Fc and 3-TC-Fc behaved better BLyS affinity than TA-Fc and TC-Fc did.3 Fusion proteins 814-Fc and TA-Fc existed as homodimer. 814 or 814-Fc showed two- fold inhibition effect than TA or TA-Fc did. Meanwhile, 814 and TA have different binding orientation with BLyS.