FIV as a Model for AIDS Vaccine Studies

Role of Env in Resistance of Feline Immunodeficiency Virus (FIV)-Infected Cats to Superinfection by a Second FIV Strain as Determined by Using a Chimeric Virus

“…Of note, no cat in the latter group allowed FIV infection despite the fact that challenge was carried out twice, first systemically and then intravaginally. This might indicate that resistance to superinfection was particularly robust in this preinfection-challenge combination, although the fact that FIV was molecularly cloned and grown in vitro, two circumstances known to weaken FIV challenge (14,23,25), may have contributed significantly.…”

“…First, all or a large fraction of the FIV -preinfected cats became superinfected with FIV PET or with FIV M2 , respectively, possibly due to the circumstances that these viruses, being ex vivo derived, had a more complex quasispesies than the FIV used as a challenge in the experiment described above (14,23) and that the time elapsed after preinfection was shorter than in the first part of the study. That the duration of this interval can influence the outcomes of superinfections has been observed in numerous studies with live attenuated SIV vaccines (reviewed in reference 32), as well as in an experiment with HIV-2 in which no macaques became superinfected when challenged 8 weeks after initial infection versus four of four and one of four challenged at weeks 4 and 2, respectively (41).…”

“…FIV is both a significant pathogen of domestic cats (42) and a widely used model to investigate HIV pathogenesis and approaches to AIDS vaccination (14,16,51,54). In the present study, we developed a chimeric FIV, designated FIV , having most of the env gene of a clade B virus and the rest of the genome of a clade A virus and used it in an attempt to gain insight into the variables that may affect the resistance to superinfection by a second strain of virus in this system, including the neutralization specificity of the viral envelope (Env).…”

A novel method for producing target cells and assessing cytotoxic T lymphocyte activity in outbred hosts

“…Here, we describe a novel method for producing target cells that has provided satisfactory results in an F-CTL assay we have set up to assess envelope (Env)-specific CTL activity in domestic specific pathogen-free (SPF) cats infected with feline immunodeficiency virus (FIV), the feline equivalent of HIV. Since no inbred cats are available, testing CTL activity in this species is dependent on the use of autologous target cells, a factor that has hitherto limited routine measurements of CTL activity [ 13 , 14 ]. The method relies on a bicistronic vector derived from FIV but having very little left of the original virus which is used to transduce immortalized feline skin fibroblasts.…”

Human immunodeficiency virus integrase inhibitors efficiently suppress feline immunodeficiency virus replication in vitro and provide a rationale to redesign antiretroviral treatment for feline AIDS

“…FIV is phylogenetically (though not antigenically) related to HIV-1 [ 3 ]. Although vaccines designed for FIV cannot directly be transferred to HIV-1, the feline model may find an application in preliminarily testing the general validity of an approach to vaccination [ 6 ], or to test the feasibility of lentiviral eradication strategies.…”