Effect of type I interferons on the expression of feline leukaemia virus

Abstract

(132 words)The efficacy of interferons (IFNs), used empirically to treat retrovirus-infected cats has been shown in vivo, but the direct effect on infected cells is largely unknown.

Effect of Type-I Interferon on Retroviruses

“…When IFN-I is administered to HIV-, simian immunodeficiency virus (SIV)-, or feline immunodeficiency virus (FIV)-infected individuals clinical signs are seen to improve [30, 33, 60, 106, 117], supporting the hypothesis that type I IFNs play important roles in the response to these retroviruses, as well as to other retroviruses, such as HTLV-I [46, 79, 117], BLV [78], feline leukemia virus (FeLV) [28, 149], or MuLV [2, 52]. …”

“…It is produced in excess by infected cells, and it may be secreted into the extracellular environment not bound to infectious particles [70]. Infectivity is generally estimated through RT activity in the supernatant of treated infected cells [101], as infective viral particles must carry RT [28]. Infectivity can be also evaluated through syncytia formation [71, 102].…”

“…The infectivity of viral particles in IFN-treated cell supernatants was shown to be slightly [51, 131] to drastically [28, 57, 36, 89, 102] reduced. Most studies have shown that protein synthesis is not affected by IFN-I.…”

Naturally occurring feline leukemia virus subgroup A and B infections in urban domestic cats

“…By comparison of the envelope (env) sequence variation it has been possible to identify four FeLV subgroups: FeLV-A, -B, -C and -T, each of which uses distinct cellular receptors to initiate infection of the host cell (Boomer et al, 1997;Tailor et al, 1999; Anderson et al, 2001;Mendoza et al, 2006;Cheng et al, 2007). FeLV has been associated with fatal neoplasia, degenerative diseases of the haematopoietic system and immunodeficiency (Chandhasin et al, 2004;Hofmann-Lehmann et al, 2006;Collado et al, 2007).Traditionally, FeLV infections are diagnosed by virus isolation (VI), immunofluorescent antibody tests (IFA) or ELISA for the detection of soluble antigens (usually the p27 core protein) in whole blood, serum or plasma (Levy et al, 2008). However, FeLV infections in cats with a weakened immune response are not reliably detected by serological methods .…”

“…By comparison of the envelope (env) sequence variation it has been possible to identify four FeLV subgroups: FeLV-A, -B, -C and -T, each of which uses distinct cellular receptors to initiate infection of the host cell (Boomer et al, 1997;Tailor et al, 1999; Anderson et al, 2001;Mendoza et al, 2006;Cheng et al, 2007). FeLV has been associated with fatal neoplasia, degenerative diseases of the haematopoietic system and immunodeficiency (Chandhasin et al, 2004;Hofmann-Lehmann et al, 2006;Collado et al, 2007).…”