Mouse Anti-EIAV Core Antigen (p26) Monoclonal antibody, clone 23F9

Equine Infectious Anemia (EIA) is a persistent lentivirus infection of horses which causes a chronic clinical condition with worldwide importance in veterinary medicine. The p26 protein is usually prepared for use as an antigen in serological tests for EIA diagnosis since it is a well-conserved gene sequence and very immunogenic. In view of the ability of yeast to make post-translational modifications of proteins, this study was carried out to allow Pichia pastoris to be used for the expression of a synthetic codon-optimized EIAV p26 gene. The gene was cloned into pPICZ alpha A vector after appropriate enzymatic digestion. P. pastoris clones transformed with the pPICZ alpha Ap26 construction were induced to produce the recombinant p26 protein (rp26) under the regulation of alcohol oxidase 1 promoter by adding methanol to the culture medium. The p26 gene expression was detected by RT-PCR and the production of rp26 was confirmed by dot blotting, Western blotting, ELISA and AGID. The P. pastoris expression system was capable of producing a functional EIAV p26 protein that can be used directly in the functionality tests without requiring laborious purification or recovery steps. This is the first reported study of EIAV p26 protein production in yeast cells. (C) 2013 Elsevier B.V. All rights reserved.

Today, control of equine infectious anemia (EIA) depends on the accuracy and use, in officially regulated laboratories, of the agar gel immunodiffusion (AGID) test that detects antibody against the major EIAV core protein p26, EIAV surface unit and transmembrane glycoproteins, gp90 and gp45 respectively, also stimulate antibodies that recognize highly conserved group-specific determinants. In most new infections, antibodies against gp90 are detected first, followed by those against p26 and then gp45, Generally, the first positive test in each of the official testing formats is seen within 45 days of exposure, In immunoblot tests, antibodies against gp90 are the most abundant. The immunoblot test detects antibody against multiple antigens and is the most sensitive serologic indicator of infection with EIAV, Experience with official ACID and ELISA-based test kits in a variety of situations has allowed the design of optimal paradigms for the serologic diagnosis of EIA. The strengths of the available ELISA-based test kits (sensitivity, accuracy of interpretation, and multiple antigens) and the specificity of the ACID test are both capitalized upon. An additional advantage of the ELISA kits is potential for adaptation to field use. Our success in reaching reservoirs of EIAV may depend on wider acceptance of horse-side testing, in practical and affordable formats, especially for use in remote rural areas.