title: Construction of a recombinant non-mitogenic anti-human CD3 antibody.
abstract: IOR-T3, a mouse monoclonal antibody specific for human CD3, has been successfully used in the treatment of acute transplant rejection due to its potential as T-cell immunosuppressant. In the present work we report the construction of a human IgG1 chimeric variant of IOR-T3, named T3q. In order to reduce the T-cell activating capacity of the newly obtained chimeric molecule, the two leucine residues at positions 234 and 235 of the CH2 region were replaced by alanines, obtaining the T3q(Ala/Ala) molecule. In vitro evaluation of T3q and T3q(Ala/Ala) showed that there were no differences in the recognition of human CD3 in comparison with murine IOR-T3. However, the Fc-mutated version T3q(Ala/Ala) displayed a much weaker FcgammaR binding capacity than the unmutated chimeric molecule T3q, as well as a reduced ability to induce T-cell proliferation, proinflammatory cytokine release (TNFalpha and IL-6), and early activation surface marker expression (CD25 and CD69). We also found that, unlike treatment with T3q, the reduction in T-cell proliferation was less marked on CD8(+) cells compared to the CD4(+) cells after treatment with T3q(Ala/Ala). These properties make T3q(Ala/Ala) an attractive clinical alternative as an immunoregulatory agent endowed with reduced toxicity.
authors.affiliation: Process Development Department, Center of Molecular Immunology, Havana, Cuba.
authors.forename: Luis E
authors.initials: LE
authors.lastname: Hinojosa
authors.forename: Tays
authors.initials: T
authors.lastname: Hernández
authors.forename: Cristina Mateo
authors.initials: CM
authors.lastname: de Acosta
authors.forename: Enrique
authors.initials: E
authors.lastname: Montero
authors.forename: Rolando
authors.initials: R
authors.lastname: Pérez
authors.forename: Alejandro
authors.initials: A
authors.lastname: López-Requena
mesh_terms: D000818:Animals; D000911:Antibodies, Monoclonal / Q000096:biosynthesis* / Q000276:immunology*; D000918:Antibody Specificity / Q000276:immunology; D017252:CD3 Complex / Q000276:immunology*; D049109:Cell Proliferation; D066246:ErbB Receptors / Q000276:immunology; D005822:Genetic Vectors / Q000276:immunology; D006801:Humans; D006825:Hybridomas / Q000276:immunology*; D051379:Mice; D013601:T-Lymphocytes / Q000276:immunology
chemical_list: D000911:Antibodies, Monoclonal; D017252:CD3 Complex; C512478:EGFR protein, human; D066246:ErbB Receptors