title: A monoclonal antibody to an abrin chimera recognizing a unique epitope on abrin A chain confers protection from abrin-induced lethality.
abstract: Abrin, obtained from the seeds of Abrus precatorius plant, is a potent toxin belonging to the family of type II ribosome-inactivating proteins. Recently, a recombinant vaccine consisting of the A subunits of abrin and its homolog Abrus precatorius agglutinin (APA) was demonstrated to protect mice from abrin lethality. Toward identifying neutralizing epitopes recognized during this response, we generated monoclonal antibodies against the proposed vaccine candidate. One antibody, namely A7C4, the corresponding epitope of which was found to be distal to the active site of the enzymatic A chain, prevented abrin-mediated toxicity on cells and abrin-induced lethality in mice but did not inhibit the catalytic activity of the A chain. The in vivo protection conferred by monoclonal antibody A7C4 highlights the potential use of this antibody as a promising immunotherapeutic.
authors.affiliation: a Undergraduate Studies and Department of Biochemistry ; Indian Institute of Science ; Bangalore , Karnataka , India.
authors.forename: Meenakshi Sundaram
authors.initials: MS
authors.lastname: Kumar
authors.affiliation: b Department of Biochemistry ; Indian Institute of Science ; Bangalore , Karnataka , India.
authors.forename: Anjali A
authors.initials: AA
authors.lastname: Karande
mesh_terms: D000036:Abrin / Q000276:immunology* / Q000633:toxicity*; D000818:Animals; D000911:Antibodies, Monoclonal / Q000008:administration & dosage / Q000276:immunology*; D000992:Antitoxins / Q000008:administration & dosage / Q000276:immunology*; D000939:Epitopes / Q000276:immunology*; D008807:Mice, Inbred BALB C; D011041:Poisoning / Q000517:prevention & control*; D016019:Survival Analysis
chemical_list: D000911:Antibodies, Monoclonal; D000992:Antitoxins; D000939:Epitopes; D000036:Abrin
keywords: Abrus precatorius agglutinin; abrin; chimera; epitope; monoclonal antibody; neutralizing