We have investigated virulence determinants of equine infectious anemia virus (EIAV), a macrophage-tropic lentivirus, and have shown that both the surface glycoprotein (SU) and the auxiliary protein, S2, significantly influence disease expression. Based on preliminary studies we hypothesize that (1) A virulent EIAV strain, through the activities of its SU and S2 proteins, modulates host cell gene expression;(2) Modified gene expression alters host cell physiology, generating an environment optimally suited to high titer virus replication and disease expression.
Specific Aims of the proposal are:
AIM 1. Characterize changes in gene expression induced by acutely virulent EIAV and its SU protein. We will: (i) Measure induction of cytokine and chemokine gene expression by virulent EIAV and purified SU in relevant equine cells, (ii) Map the regions of SU responsible for modulation of cytokine/chemokine gene expression using chimeric viruses and recombinant SU proteins, (iii) Test sub-regions of SU for their contribution to the development of acute disease in a Shetland pony model.
AIM 2. We will characterize the properties of the EIAV S2 protein using both in vivo and in vitro assays by site-directed mutagenesis of predicted functional domains. The results obtained from our in vivo acute pathogenesis assay with site-specific virus mutants will serve to guide our in vitro studies that are directed at (i) identifying cellular proteins that interact with the S2 protein and (ii) the characterization of in vitro biologic activities attributable to the S2 protein. Animal studies related to Aims 1 and 2 will include determination of platelet counts, plasma virus loads, provirus levels in circulating PBMC and in tissues, cytokine/chemokine gene expression in circulating PBMC and tissues, and viral gene expression in PBMC and tissues. As EIAV replication and persistence are centered on monocytes/macrophages, and disease expression is rapid (2-3 weeks), this model is ideal for specifically probing the interactions of virus and macrophages that contribute to lentiviral-induced disease.

Agency
National Institute of Health (NIH)
Institute
National Cancer Institute (NCI)
Type
Research Project (R01)
Project #
5R01CA059278-14
Application #
7899941
Study Section
AIDS Immunology and Pathogenesis Study Section (AIP)
Program Officer
Read-Connole, Elizabeth Lee
Project Start
1993-03-01
Project End
2012-07-31
Budget Start
2010-08-01
Budget End
2012-07-31
Support Year
14
Fiscal Year
2010
Total Cost
$347,867
Indirect Cost
Name
Texas A&M University
Department
Veterinary Sciences
Type
Schools of Veterinary Medicine
DUNS #
078592789
City
College Station
State
TX
Country
United States
Zip Code
77845
Covaleda, Lina; Fuller, Frederick J; Payne, Susan L (2010) EIAV S2 enhances pro-inflammatory cytokine and chemokine response in infected macrophages. Virology 397:217-23
Covaleda, Lina; Gno, Bich-Ty; Fuller, Fredrick J et al. (2010) Identification of cellular proteins interacting with equine infectious anemia virus S2 protein. Virus Res 151:235-9
Allen, Charlotte A; Payne, Susan L; Harville, Melissa et al. (2007) Validation of quantitative polymerase chain reaction assays for measuring cytokine expression in equine macrophages. J Immunol Methods 328:59-69
Fagerness, Angela J; Flaherty, Maureen T; Perry, Stephanie T et al. (2006) The S2 accessory gene of equine infectious anemia virus is essential for expression of disease in ponies. Virology 349:22-30
Lim, W-S; Payne, S L; Edwards, J F et al. (2005) Differential effects of virulent and avirulent equine infectious anemia virus on macrophage cytokine expression. Virology 332:295-306
Ball, J M; Swaggerty, C L; Pei, X et al. (2005) SU proteins from virulent and avirulent EIAV demonstrate distinct biological properties. Virology 333:132-44
Payne, Susan L; Pei, Xiao-fang; Jia, Bin et al. (2004) Influence of long terminal repeat and env on the virulence phenotype of equine infectious anemia virus. J Virol 78:2478-85
Lim, W-S; Edwards, J F; Boyd, N K et al. (2003) Simultaneous quantitation of equine cytokine mRNAs using a multi-probe ribonuclease protection assay. Vet Immunol Immunopathol 91:45-51
Shao, H; Robek, M D; Threadgill, D S et al. (1997) Characterization and mutational studies of equine infectious anemia virus dUTPase. Biochim Biophys Acta 1339:181-91
Sellon, D C; Walker, K M; Russell, K E et al. (1996) Equine infectious anemia virus replication is upregulated during differentiation of blood monocytes from acutely infected horses. J Virol 70:590-4

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