Equine infectious anaemia virus proteins with epitopes most frequently recognized by cytotoxic T lymphocytes from infected horses

Abstract

Efficacious lentiviral vaccines designed to induce cytotoxic T lymphocytes (CTL) in outbred populations with a diverse repertoire of MHC class I molecules should contain or express multiple viral proteins. To determine the equine infectious anaemia virus (EIAV) proteins with epitopes most frequently recognized by CTL from seven horses infected for 0n5 to 7 years, retroviral vectortransduced target cells expressing viral proteins were used in CTL assays. Gag p15 was recognized by CTL from 100 % of these infected horses. p26 was recognized by CTL from 86 %, SU and the middle third of Pol protein were each recognized by 43 %, TM by 29 %, and S2 by 14 %. Based on these results, it is likely that a construct expressing the 359 amino acids constituting p15 and p26 would contain epitopes capable of stimulating CTL in most horses.

Presentation and Binding Affinity of Equine Infectious Anemia Virus CTL Envelope and Matrix Protein Epitopes by an Expressed Equine Classical MHC Class I Molecule

“…These studies detected only MHC class I-restricted CD8 ϩ CTL, because equine kidney (EK) cells, which do not express MHC class II, were used as targets (15). These MHC class I-restricted CTL recognized epitopes in Gag, Pol, Env, Rev, and S2 proteins, with Gag p15 and p26 being the most frequently recognized proteins (18). Peptide epitopes have been defined from several of these proteins, including Gag (19), Env (6), and Rev (6).…”

Immune Reconstitution Prevents Continuous Equine Infectious Anemia Virus Replication in an Arabian Foal with Severe Combined Immunodeficiency: Lessons for Control of Lentiviruses

“…Fraser, unpublished observation), the ELA-A haplotypes for SCID1 and SCID2 were inferred from their determined DRA and DQA haplotypes, using known inheritance patterns for these loci for each dam and sire. The ELA-A haplotypes of SCID1 and SCID2 were later confirmed with CTL assays, using EIAV-infected equine kidney (EK) cell targets (3,14) from these foals, and EIAV-stimulated CTL (14) from the lymphocyte donors (A2140 and A2141, respectively).…”

“…Recombinant human IL-2 and additional irradiated EIAV WSU5 -infected autologous PBMC were added in the second week as described (14,15) with modifications. PBMC were suspended at 5 × 10 6 /ml RPMI 1640 medium with 10% fetal bovine serum (FBS), 20 mM HEPES, 10 μg/ml gentamicin, and 10 μM 2-mercaptoethanol.…”

Cloning and large-scale expansion of epitope-specific equine cytotoxic T lymphocytes using an anti-equine CD3 monoclonal antibody and human recombinant IL-2

“…In addition, this clone would be valuable for investigating the differential recognition efficiencies of Rev-QW11 when presented by the 7-6 and 141 class I molecules (25). The cloning procedure utilized an anti-equine CD3 mAb (38,39) and human recombinant IL-2 (rhuIL-2), which stimulates equine lymphocytes (15,19,22,40), such that autologous APC and specific antigen were not required during expansion in culture. Our results demonstrated that large numbers of CD3+/CD8+ Rev-QW11-specific CTL clones could be generated, and that they retained their phenotype and function following cryopreservation.…”

“…In horses infected with equine infectious anemia virus (EIAV), a lentivirus with a world-wide distribution, CTL are critical in the control of viral replication and clinical disease (11)(12)(13)(14)(15)(16)(17)(18)(19)(20)(21)(22). Several factors contribute to the protective effects of CTL against EIAV, including epitope specificity and functional avidity (15,20,21,23,24). Importantly, individual EIAV-specific CTL epitopes can be presented by more than one MHC class I molecule, but subtle changes in class I molecules can enhance, diminish, or abolish recognition of these epitopes by CTL (25).…”