Feline Immunodeficiency Virus (FIV) as A Model for Study of Lentivirus Infections: Parallels with HIV

Abstract

FIV is a significant pathogen in the cat and is, in addition, the smallest available natural model for the study of lentivirus infections. Although divergent at the amino acid level, the cat lentivirus has an abundance of structural and pathophysiological commonalities with HIV and thus serves well as a model for development of intervention strategies relevant to infection in both cats and man. The following review highlights both the strengths and shortcomings of the FIV/cat model, particular as regards development of antiviral drugs.

Novel fused tetrathiocines as antivirals that target the nucleocapsid zinc finger containing protein of the feline immunodeficiency virus (FIV) as a model of HIV infection

“…10 The prevalence of FIV is around 11% worldwide, although there are significant regional variations and there is no known cure. 11 FIV and HIV are closely related to other lentiviruses including the simian 12 (SIV) and equine 13 (EIAV) variants, each of which is a species-specific virus using analogous protein in the viral life cycle.…”

Feline Immunodeficiency

“…Factors that influence the length of the asymptomatic stage include the pathogenicity of the infecting strain (also depending on the FIV subtype), exposure to secondary pathogens, and the age of the cat at the time of infection. In the last, symptomatic stage (FAIDS phase) of infection, clinical signs are a reflection of opportunistic infections, skin infections such as demodicosis and pediculosis, neoplasia such as B cell lymphosarcoma and squamous cell carcinoma, myelosuppression, and neurologic disease, similar to those observed in people infected with human immunodeficiency virus (HIV) (Hartmann, 1998;Sellon e Hartmann, 2006;Elder et al, 2010;Gunn-Moore & Reed, 2011;Hartamann, 2011;Korman et al, 2012;Sobrinho et al, 2012). The chronic gingivostomatitis is the most common clinical sign in infected cats and significantly degrade the quality of life of animals Pathologic abnormalities described in FIV positive cats with alterations in the morphology of lymph node: hyperplastic during acute phase, follicular involution in the terminal phase of infection; thymus: cortical involution, atrophy, lymphoid follicular hyperplasia and germinal center formation; intestinal tract: villous blunting, pyogranulomatous colitis, lymphoplasmacytic stomatitis; liver: periportal hepatitis; bone marrow: dysplastic changes, granulocytic hyperplasia and the formation of marrow lymphoid aggregates; kidney: tubulointerstitial infiltrates, glomerulosclerosis; central nervous system: Perivascular cuffing, gliosis, myelitis, loss and reorganization of neurons, axonal sprouting, vacuolar myelinopathy; lung: interstitial pneumonitis, alveolitis; skeletal muscle: lymphocytic myositis, myofiber necrosis, perivascular cuffing; reproductive failure occurs in FIV infected cats (Sellon e Hartmann, 2006;Gunn-Moore & Reed, 2011;Hartmann, 2011).…”

“…1) (Sellon and Hartmann, 2006;Hosie et al, 2009;Simões et al, 2012) . FIV does not use CD4 as a primary binding receptor, its gp120 glycoprotein binds to the CD134 (OX40) a member of the tumor necrosis factor receptor (TNFR)/nerve growth factor receptor family of molecules as the binding receptor in conjunction with the chemokine receptor CXCR4 as a cofactor for infection (Yuan et al, 2003;de Parseval et al, 2005;Willett et al, 2006b;Elder et al, 2010). The CD134 co-stimulatory pathway has been shown to be critical for T, B and antigenpresenting cell (APC) cell activation.…”

“…1) (Hartmann, 1998;Sellon e Hartmann, 2006;Gunn-Moore & Reed, 2011;Hartamann, 2011). The most infected cats exhibit an increase in CD8+ T cells along with a strong humoral antibody response which allows them to control this initial phase of the infection (Elder et al, 2010). After 2-4 weeks after infection, antibodies are detectable in plasma for FIV.…”

The year of the veterinarian: a call to celebrate, and to collaborate

“…For instance, the long-held assumption that infection with the Feline Immuodeficiency Virus would lead to an immunodeficiency state that was synonomous with HIV-AIDS has not served our understanding of the disease in cats. That is despite the value that FIV research has brought to the understanding of human retroviral infections (Elder et al 2010). Similarly, the assumption that the immunopathogenesis of lymphoplasmacytic enteritis is the same as Crohn's disease or ulcerative colitis has not been supported by recent studies (Cerquetella et al 2010).…”