Antigenic cross-reactivity of venoms from medically important North American Loxosceles spider species

• Published in: Toxicon (Oxford) 2001-06, Vol.39 (6), p.817-824
• Main Authors: Gomez, H.F, Miller, M.J, Waggener, M.W, Lankford, H.A, Warren, J.S
• Format: Article
• Language: English
• Subjects: Amino Acid Sequence; Animal poisons toxicology. Antivenoms; Animals; Antigens - immunology; Biological and medical sciences; Blotting, Western; Cross Reactions; Dermonecrotic arachnidism; Immunoenzyme Techniques; Loxosceles deserta; Loxosceles reclusa; Loxosceles spider species; Medical sciences; Molecular Sequence Data; North America; Rabbits; Sequence Homology, Amino Acid; Species Specificity; Spider Venoms - chemistry; Spider Venoms - immunology; Spiders; Toxicology; USA, South
• ISSN: 0041-0101; 1879-3150
• DOI: 10.1016/S0041-0101(00)00212-9

We characterized the antigenic cross-reactivity of two medically important North American Loxoxceles species: L. reclusa (native to southeastern US) and L. deserta (native to southwestern US). Dermonecrosis resulting from bites from these two North American spider species are indistinguishable clinically. Polyclonal IgG antivenins directed against L. reclusa and L. deserta were raised in rabbits and used to develop specific enzyme immunoassays (EIAs). Antigenic differences in the two venoms were evaluated as follows: (1) Comparison of the sensitivities and correlation coefficient ( R 2) of anti- L. reclusa (αLoxR) and anti- L. deserta antibodies (αLoxD) in the detection of varying concentrations of the two venoms; (2) separation and western blot comparison of venom components; (3) protein sequence analysis of L. desertavenom and comparison to the L. reclusa protein sequence analysis present in a US national database; and (4) in vivo evaluation of αLoxR and αLoxD antivenins in attenuating dermal lesions (rabbit model). Correlation coefficients for αLoxR ( R 2=0.99) and αLoxD ( R 2=0.99) polyclonal antibodies in the measurements of standard concentrations of venoms were virtually identical. Western blot analysis revealed multiple common bands between the two venoms. Amino acid data (amino acids 1–35, N-terminal) of the active venom components of the two venoms revealed only three non-identical amino acids. αLoxR and αLoxD antivenins were similarly effective in blocking the development of rabbit skin lesions (ANOVA p