A protective immune response against lethal, dermonecrotic and hemorrhagic effects of Loxosceles intermedia venom elicited by a 27-residue peptide

• Published in: Toxicon (Oxford) Vol. 55; no. 2; pp. 481 - 487
• Main Authors: Dias-Lopes, C., Guimarães, G., Felicori, L., Fernandes, P., Emery, L., Kalapothakis, E., Nguyen, C., Molina, F., Granier, C., Chávez-Olórtegui, C.
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier Ltd 01.02.2010; Elsevier
• Subjects: Amino Acid Sequence; Animal poisons toxicology. Antivenoms; Animals; Antigens - chemistry; Antigens - immunology; Antivenins - biosynthesis; Antivenins - pharmacology; Biological and medical sciences; Edema - chemically induced; Edema - pathology; Enzyme-Linked Immunosorbent Assay; Epitope; Epitopes; Female; Hemorrhage - blood; Hemorrhage - chemically induced; Immunization Schedule; In vivo protection; Lethal Dose 50; Loxosceles intermedia spider; Medical sciences; Mice; Mice, Inbred BALB C; Molecular Sequence Data; Necrosis - chemically induced; Necrosis - pathology; Neutralization Tests; Peptide Fragments - immunology; Rabbits; Recombinant Proteins; Skin Diseases - chemically induced; Skin Diseases - pathology; Spider Venoms - antagonists & inhibitors; Spider Venoms - immunology; Spider Venoms - toxicity; Synthetic peptide; Toxicology; In vivo protection; Synthetic peptide; Epitope; Loxosceles intermedia spider; Skin disease; Immune response; Antigenic determinant; Peptides; Toxicity; Animal origin; Araneida; Hemorrhage; Necrosis; Prevention; In vivo; Arachnida; Residue; Arthropoda; Venom; Invertebrata
• ISSN: 0041-0101; 1879-3150
• DOI: 10.1016/j.toxicon.2009.09.019

Antibodies raised against recombinant Loxosceles intermedia dermonecrotic protein isoform 1 (rLiD1) display neutralizing capacity for the L. intermedia whole venom. We previously found that an immunodominant continuous B-cell epitope, recognized by these antibodies corresponds to a region of the protein known to be involved in the active site. In this study, we extend previous work by preparing a 27-residue synthetic replica of this epitope ( 25NLGANSIETDVSFDDNANPEYTYHGIP 51) and using it as an immunogen in mice and rabbits. The immunization process induced antibodies that protected mice from a lethal dose of L. intermedia crude venom and rabbits against the dermonecrotic effects of rLiD1. An Ala scan of the epitope indicated that 4 residues, E44, Y45, T46 and Y47, are essential (over 70% decrease in binding upon replacement with alanine) for antibody recognition. The possible mechanisms of neutralization are discussed in light of these findings.