sBAFF mutants induce neutralizing antibodies against BAFF.
B cell activating factor belonging to the TNF family (BAFF) is a novel member of the tumor necrosis factor (TNF) ligand family and plays an important role in B lymphocyte maturation and survival. Overexpression of BAFF is closely involved in the pathogenesis and progression of many kinds of autoimmune disorders; therefore, BAFF has been considered as an ideal therapeutic target for these conditions. In this study, we generated several candidate immune inhibitors of human BAFF by conjugating foreign immunodominant T-helper cell (Th) epitopes to the N- or C-terminus of five BAFF mutants. The recombined proteins were successfully expressed in Escherichia coli (E. coli) and purified by Ni-NTA chromatography. BALB/c mice immunized with the recombinant proteins produced high levels of anti-BAFF antibodies, and their sera inhibited the lymphocyte proliferation-inducing activity of recombinant soluble BAFF and natural soluble BAFF. Moreover, antibodies cross-reactive with BAFF were detected in sera from hu-SCID mice immunized with the recombinant proteins. These results indicated that the recombinant BAFF mutants modified with Th epitopes could induce neutralizing antibodies against BAFF in vivo. This study may provide a valuable strategy for treating BAFF-associated autoimmune diseases.
Gao
Huiguang
H
Department of Biochemistry and Molecular Biology, Third Military Medical University, Chongqing 400038, China.
Bian
Aina
A
Zheng
Yingru
Y
Li
Rongfen
R
Ji
Qing
Q
Huang
Gang
G
Hu
Daqiang
D
Zhang
Li
L
Gong
Wei
W
Hu
Ying
Y
He
Fengtian
F
D000818:Animals; D000906:Antibodies / Q000097:blood / Q000494:pharmacology*; D053264:B-Cell Activating Factor / Q000037:antagonists & inhibitors* / Q000276:immunology*; D049109:Cell Proliferation / Q000187:drug effects; D005260:Female; D006801:Humans; D007114:Immunization; D007074:Immunoglobulin G / Q000097:blood; D017710:Lymphocyte Transfusion; D008214:Lymphocytes / Q000166:cytology / Q000187:drug effects; D051379:Mice; D008807:Mice, Inbred BALB C; D016513:Mice, SCID; D050505:Mutant Proteins / Q000276:immunology*; D009500:Neutralization Tests; D011994:Recombinant Proteins / Q000096:biosynthesis / Q000235:genetics / Q000302:isolation & purification; D012995:Solubility
D000906:Antibodies; D053264:B-Cell Activating Factor; D007074:Immunoglobulin G; D050505:Mutant Proteins; D011994:Recombinant Proteins; C505719:TNFSF13B protein, human