title: Human CD4-internal antigen anti-idiotypic monoclonal antibody: induction of a CD4-specific response in humans.
abstract: We previously showed that anti-idiotypic mAb (mAb2) F16-16D7 (16D7) to the paratope (or paratope-related idiotope) of the anti-CD4 mAb HP2/6 induces anti-CD4 Abs in BALB/c mice. In view of the potential ability of 16D7 to induce anti-CD4 Ab in humans and the potential benefits of anti-CD4 Abs in the treatment of autoimmune diseases, we evaluated the immunologic response to and assessed the safety of four 2-mg 16D7 s.c. injections in one patient with systemic lupus erythematosus (SLE) and one with rheumatoid arthritis (RA). 16D7 induced anti-isotypic and anti-anti-idiotypic Abs (Ab3), which were almost exclusively of the IgG isotype. Ab3 specifically reacted with 16D7 as they inhibited its binding to mAb HP2/6. Although Ab3 did not react with cellular or recombinant CD4 (rCD4), single-cell enzyme-linked immunospot assays of anti-CD4 Ab production revealed many more spot-forming cells in rCD4- and 16D7-coated wells than in wells coated with BSA or 16D7 isotype-matched MK2-23. Spot-forming anti-CD4 Abs were specifically induced by 16D7, since rCD4-dependent spot formation 1) was not observed with PBL from one patient with SLE, one with mixed connective tissue disease, and one with melanoma immunized with MK2-23; and 2) was inhibited by 16D7 and not by MK2-23. Spot-forming anti-CD4 Abs recognize a CD4 epitope identical (or closely related) to that seen by HP2/6, since this specifically inhibited spot formation. A substantial, although transient, CD4+ T cell depletion was only observed in the RA patient. Local and/or general toxicity and laboratory and/or clinical signs indicative of immunodepression or diseases relapse were not observed during an 18-month follow-up.
authors.affiliation: Department of Biomedical Sciences and Human Oncology (DIMO), University of Bari Medical School, Italy.
authors.forename: F
authors.initials: F
authors.lastname: Perosa
authors.forename: M
authors.initials: M
authors.lastname: Scudeletti
authors.forename: M A
authors.initials: MA
authors.lastname: Imro
authors.forename: F
authors.initials: F
authors.lastname: Dammacco
authors.forename: F
authors.initials: F
authors.lastname: Indiveri
mesh_terms: D000328:Adult; D000818:Animals; D000888:Antibodies, Anti-Idiotypic / Q000009:adverse effects / Q000096:biosynthesis* / Q000627:therapeutic use; D000911:Antibodies, Monoclonal / Q000276:immunology*; D000918:Antibody Specificity; D001172:Arthritis, Rheumatoid / Q000276:immunology / Q000628:therapy; D015704:CD4 Antigens / Q000276:immunology*; D000939:Epitopes / Q000276:immunology*; D005260:Female; D006801:Humans; D008180:Lupus Erythematosus, Systemic / Q000276:immunology / Q000628:therapy; D051379:Mice; D008875:Middle Aged; D016176:T-Lymphocyte Subsets / Q000276:immunology
chemical_list: D000888:Antibodies, Anti-Idiotypic; D000911:Antibodies, Monoclonal; D015704:CD4 Antigens; D000939:Epitopes