Mechanistic studies of the immunochemical termination of self-tolerance with unnatural amino acids.
For more than 2 centuries active immunotherapy has been at the forefront of efforts to prevent infectious disease [Waldmann TA (2003) Nat Med 9:269-277]. However, the decreased ability of the immune system to mount a robust immune response to self-antigens has made it more difficult to generate therapeutic vaccines against cancer or chronic degenerative diseases. Recently, we showed that the site-specific incorporation of an immunogenic unnatural amino acid into an autologous protein offers a simple and effective approach to overcome self-tolerance. Here, we characterize the nature and durability of the polyclonal IgG antibody response and begin to establish the generality of p-nitrophenylalanine (pNO(2)Phe)-induced loss of self-tolerance. Mutation of several surface residues of murine tumor necrosis factor-alpha (mTNF-alpha) independently to pNO(2)Phe leads to a T cell-dependent polyclonal and sustainable anti-mTNF-alpha IgG autoantibody response that lasts for at least 40 weeks. The antibodies bind multiple epitopes on mTNF-alpha and protect mice from severe endotoxemia induced by lipopolysaccharide (LPS) challenge. Immunization of mice with a pNO(2)Phe(43) mutant of murine retinol-binding protein (RBP4) also elicited a high titer IgG antibody response, which was cross-reactive with wild-type mRBP4. These findings suggest that this may be a relatively general approach to generate effective immunotherapeutics against cancer-associated or other weakly immunogenic antigens.
Grünewald
Jan
J
Department of Chemistry, The Scripps Research Institute, La Jolla, CA 92037, USA.
Hunt
Grady S
GS
Dong
Liqun
L
Niessen
Frank
F
Wen
Ben G
BG
Tsao
Meng-Lin
ML
Perera
Roshan
R
Kang
Mingchao
M
Laffitte
Bryan A
BA
Azarian
Sassan
S
Ruf
Wolfram
W
Nasoff
Marc
M
Lerner
Richard A
RA
Schultz
Peter G
PG
Smider
Vaughn V
VV
D000596:Amino Acids / Q000235:genetics* / Q000276:immunology; D000818:Animals; D000917:Antibody Formation; D001323:Autoantibodies; D001324:Autoantigens / Q000235:genetics; D007074:Immunoglobulin G; D007167:Immunotherapy / Q000379:methods*; D051379:Mice; D010649:Phenylalanine / Q000031:analogs & derivatives / Q000235:genetics; D015202:Protein Engineering / Q000379:methods*; D017634:Self Tolerance / Q000276:immunology*; D013601:T-Lymphocytes / Q000276:immunology; D014409:Tumor Necrosis Factor-alpha / Q000235:genetics
D000596:Amino Acids; D001323:Autoantibodies; D001324:Autoantigens; D007074:Immunoglobulin G; D014409:Tumor Necrosis Factor-alpha; C040239:4-nitrophenylalanine; D010649:Phenylalanine