Reactivation of latent feline leukaemia virus infection

Abstract

In most cats exposed to the contagious feline leukemia virus (FeLV), viral replication is contained in target haematopoietic tissues and elicits humoral immunity to FeLV and to the feline oncornavirus-associated cell membrane antigen (FOCMA). Recently, we and others have considered that these ostensibly self-limiting infections might be persistent nonproductive (latent) infections in certain haematopoietic cells. This hypothesis could account for the relapsing viraemias, protracted incubation periods, persistently high titres of antiviral and anti-FOCMA antibodies, appearance of FeLV p27 antigen in serum of otherwise non-viraemic animals and occurrence of FeLV-negative but FOCMA-positive leukaemias in naturally infected pet cats. Here we describe the reactivation of latent FeLV from myelomonocytic and lymphoid cells of cats immune to FeLV, cats bearing FeLV-negative tumours, and kittens congenitally exposed to FeLV. Furthermore, the reappearance of FeLV infection is suppressed by the Host's immune system but his can be altered by adrenal corticosteroid hormones in vivo and in vitro.

Modes of transmission and evidence for viral latency from studies of human T-cell lymphotrophic virus type I in Japanese migrant populations in Hawaii.

“…In this case, antibody would only be expressed when an infected T cell was recruited to sustained proliferation and antigen expression. In support of this hypothesis are reports of virus-positive antibody-negative persons with HTLV-I and HTLV-III infection (26,27) and animal models were latent retroviruses are linked to leukemia in the absence of viral antibodies depending on in vivo cell regulation (28).…”

Feline Leukemia Virus Detection by ELISA and PCR in Peripheral Blood from 68 Cats with High, Moderate, or Low Suspicion of having FeLV-Related Disease

“…2,7 However, there is evidence that incorporation of FeLV within the DNA of host cells without accompanying viral replication causes disease in some cats. 11,15,25,34,41 Also, high levels of unintegrated FeLV DNA have been associated with disease progression of the acquired immunodeficiency strain of FeLV. 28 Traditionally, FeLV infection has been diagnosed using the immunofluorescent antibody From the Departments of Veterinary Miciobiology (Jackson, Haines, Misra) and Veterinary Internal Medicine (Taylor), Western College of Veterinary Medicine, University of Saskatchewan, Saskatoon, SK S7N 5B4, Canada.…”

Feline leukemia virus: current status of the feline induced immune depression and immunoprevention

“…However, these cats are often found to have latent bone marrow infection [23][24][25][26]. Cultured bone marrow cells isolated from FeLV-infected and FeLV-exposed cats express FeLV-associatcd membrane antigen for protracted periods in the absence of detectable infectious virus [27].…”