A protective immune response against lethal, dermonecrotic and hemorrhagic effects of Loxosceles intermedia venom elicited by a 27-residue peptide.
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 ((25)NLGANSIETDVSFDDNANPEYTYHGIP(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.
Dias-Lopes
C
C
Departamento de Bioquímica-Imunologia, ICB, Universidade Federal de Minas Gerais, CP: 486; CEP: 31270901 Belo Horizonte-MG, Brazil.
Guimarães
G
G
Felicori
L
L
Fernandes
P
P
Emery
L
L
Kalapothakis
E
E
Nguyen
C
C
Molina
F
F
Granier
C
C
Chávez-Olórtegui
C
C
D000595:Amino Acid Sequence; D000818:Animals; D000941:Antigens / Q000737:chemistry* / Q000276:immunology*; D000997:Antivenins / Q000096:biosynthesis / Q000494:pharmacology*; D004487:Edema / Q000139:chemically induced / Q000473:pathology; D004797:Enzyme-Linked Immunosorbent Assay; D000939:Epitopes; D005260:Female; D006470:Hemorrhage / Q000097:blood / Q000139:chemically induced*; D007115:Immunization Schedule; D007928:Lethal Dose 50; D051379:Mice; D008807:Mice, Inbred BALB C; D008969:Molecular Sequence Data; D009336:Necrosis / Q000139:chemically induced / Q000473:pathology; D009500:Neutralization Tests; D010446:Peptide Fragments / Q000276:immunology*; D011817:Rabbits; D011994:Recombinant Proteins; D012871:Skin Diseases / Q000139:chemically induced / Q000473:pathology; D013111:Spider Venoms / Q000037:antagonists & inhibitors / Q000276:immunology* / Q000633:toxicity*
D000941:Antigens; D000997:Antivenins; D000939:Epitopes; D010446:Peptide Fragments; D011994:Recombinant Proteins; D013111:Spider Venoms