title: The chimeric mouse-human anti-CD4 Fab 13B8.2 expressed in baculovirus inhibits both antigen presentation and HIV-1 promoter activation.
abstract: The anti-CD4 mAb 13B8.2, directed against the CDR3-like loop of the D1 domain of CD4, inhibits signal transduction pathways leading to both T cell activation and HIV replication. VH9/DSP2/JH2 and Vkappa12-13/Jkappa2 rearrangements, corresponding to genes encoding the heavy and light chain variable regions of the 13B8.2 mAb, were inserted into baculovirus cassettes upstream from pre-installed human Fdgamma1 and Ckappa genes, respectively. After expression in insect cells, a complete correctly-processed Fab was secreted into the culture medium; it was protein-G immunopurified with a yield of 5 mg/L. The chimeric Fab 13B8.2 showed anti-CD4 binding activity with an affinity value of 3.3 nM and recognized the same region on the CDR3-like loop as the parental mAb. The mouse-human Fab inhibited IL2 secretion following antigen presentation and displayed a strong capacity to prevent HIV-1 promoter activation. Taken together, these results indicate that the chimeric Fab retained a major part of the parental 13B8.2 mAb properties and suggest that it might be a valuable therapeutic tool.
authors.affiliation: CNRS UMR 5094, Faculté de Pharmacie, 15 Avenue Charles Flahault, 34060 Montpellier, France.
authors.forename: C
authors.initials: C
authors.lastname: Bès
authors.forename: M
authors.initials: M
authors.lastname: Cerutti
authors.forename: L
authors.initials: L
authors.lastname: Briant-Longuet
authors.forename: D
authors.initials: D
authors.lastname: Bresson
authors.forename: S
authors.initials: S
authors.lastname: Peraldi-Roux
authors.forename: M
authors.initials: M
authors.lastname: Pugnière
authors.forename: J C
authors.initials: JC
authors.lastname: Mani
authors.forename: B
authors.initials: B
authors.lastname: Pau
authors.forename: C
authors.initials: C
authors.lastname: Devaux
authors.forename: C
authors.initials: C
authors.lastname: Granier
authors.forename: G
authors.initials: G
authors.lastname: Devauchelle
authors.forename: T
authors.initials: T
authors.lastname: Chardès
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D000911:Antibodies, Monoclonal / Q000235:genetics / Q000276:immunology*; D016367:Baculoviridae / Q000235:genetics; D015704:CD4 Antigens / Q000276:immunology*; D004797:Enzyme-Linked Immunosorbent Assay; D000939:Epitopes / Q000737:chemistry; D015488:HIV Antigens / Q000276:immunology*; D015497:HIV-1 / Q000235:genetics* / Q000276:immunology*; D006801:Humans; D007140:Immunoglobulin Fab Fragments / Q000235:genetics / Q000276:immunology*; D051379:Mice; D008969:Molecular Sequence Data; D011401:Promoter Regions, Genetic; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000276:immunology*; D014775:Virus Activation / Q000276:immunology*
chemical_list: D000911:Antibodies, Monoclonal; D015704:CD4 Antigens; D000939:Epitopes; D015488:HIV Antigens; D007140:Immunoglobulin Fab Fragments; D011993:Recombinant Fusion Proteins