The protective antibodies induced by a novel epitope of human TNF-alpha could suppress the development of collagen-induced arthritis.
Tumor necrosis factor alpha (TNF-alpha) is a major inflammatory mediator that exhibits actions leading to tissue destruction and hampering recovery from damage. At present, two antibodies against human TNF-alpha (hTNF-alpha) are available, which are widely used for the clinic treatment of certain inflammatory diseases. This work was undertaken to identify a novel functional epitope of hTNF-alpha. We performed screening peptide library against anti-hTNF-alpha antibodies, ELISA and competitive ELISA to obtain the epitope of hTNF-alpha. The key residues of the epitope were identified by means of combinatorial alanine scanning and site-specific mutagenesis. The N terminus (80-91 aa) of hTNF-alpha proved to be a novel epitope (YG1). The two amino acids of YG1, proline and valine, were identified as the key residues, which were important for hTNF-alpha biological function. Furthermore, the function of the epitope was addressed on an animal model of collagen-induced arthritis (CIA). CIA could be suppressed in an animal model by prevaccination with the derivative peptides of YG1. The antibodies of YG1 could also inhibit the cytotoxicity of hTNF-alpha. These results demonstrate that YG1 is a novel epitope associated with the biological function of hTNF-alpha and the antibodies against YG1 can inhibit the development of CIA in animal model, so it would be a potential target of new therapeutic antibodies.
Dong
Jie
J
Beijing Institute of Basic Medical Sciences, Beijing, China.
Gao
Yaping
Y
Liu
Yu
Y
Shi
Jinxia
J
Feng
Jiannan
J
Li
Zhanguo
Z
Pan
Heping
H
Xue
Yanning
Y
Liu
Chuan
C
Shen
Beifen
B
Shao
Ningsheng
N
Yang
Guang
G
D000595:Amino Acid Sequence; D000818:Animals; D000906:Antibodies / Q000276:immunology*; D001169:Arthritis, Experimental / Q000139:chemically induced / Q000517:prevention & control*; D001483:Base Sequence; D003094:Collagen / Q000008:administration & dosage*; D017931:DNA Primers; D004797:Enzyme-Linked Immunosorbent Assay; D000939:Epitopes / Q000737:chemistry / Q000276:immunology*; D006801:Humans; D051379:Mice; D008969:Molecular Sequence Data; D016297:Mutagenesis, Site-Directed; D011817:Rabbits; D017386:Sequence Homology, Amino Acid; D014409:Tumor Necrosis Factor-alpha / Q000235:genetics / Q000276:immunology*
D000906:Antibodies; D017931:DNA Primers; D000939:Epitopes; D014409:Tumor Necrosis Factor-alpha; D003094:Collagen