BACKGROUND Cats infected with exogenous feline leukemia virus (exFeLV) have a higher chance of lymphoma development than uninfected cats. Furthermore, an increased exFeLV transcription has been detected in lymphomas compared to non-malignant tissues. The possible mechanisms of lymphoma development by exFeLV are insertional mutagenesis or persistent stimulation of host immune cells by viral anti...

Understanding the basis of virulence of leukemia viruses is a major unsolved problem. Under natural and experimental conditions, retroviruses may replicate freely in the host with no profound consequence. Such is typically the case for vertically transmitted viruses that express early in life, e.g., the endogeneous baboon and murine Akv Grus [I]. We call such viruses avirulent. Horizontally tra...

In cats, horizontally transmitted viruses cause leukemia and lymphoma under natural conditions. As with other retroviruses, feline leukemia virus (FeLV) contains products of 3 major genes; the virus core gag gene products, the polymerase, and the virus envelope glycoprotein. When cells are transformed in vitro by the related feline sarcoma virus (FeSV), an additional protein, FOCMA is expressed...

Neuropathogenic processes that affect the pathfinding properties of neuronal growth cones could account for many of the dysfunctions unique to retroviral infection of developing nervous systems. Pediatric HIV-1 infection, for example, is associated with a distinctive neuropathogenesis that includes marked cortical atrophy, cognitive disorders, and pyramidal dysfunction. The ability of HIV's env...

The entire nucleotide sequence of the long terminal repeat (LTR) of baboon endogenous virus (BaEV) M7 was determined, which consisted of 554 base pairs (bp). At both ends of the LTR, 13 bp sequences, AAATGAAAAGTAA and TGATTCTAACATC, were detected to be inverted repeats. The structure with these inverted repeats resembles those of other retroviruses and transposable elements. a Hogness box, TATA...

Foamy viruses (FVs) are distinct retroviruses classified as Spumaretrovirinae in contrast to the other retroviruses, the Orthoretrovirinae. As a unique feature of FVs, Gag is not sufficient for sub-viral particle (SVP) release. In primate and feline FVs (PFV and FFV), particle budding completely depends on the cognate FV Env glycoproteins. It was recently shown that an artificially added N-term...

Endogenous retroviruses (ERVs) are remnants of ancient retroviral infections of host germ-line cells. While most ERVs are defective, some are active and express viral proteins. The RD-114 virus is a replication-competent feline ERV, and several feline cell lines produce infectious RD-114 viral particles. All domestic cats are considered to have an ERV locus encoding a replication-competent RD-1...

INTRODUCTION As a species, cats are frequently afflicted with immunosuppressive states that put them at risk for serious infections. The retroviruses feline leukemia virus (FeLV) and feline immunodeficiency virus (FIV) are the most common causes of immunosuppression in the cat.21,22 Neutropenia, a specific deficiency of the immune system, can result from a variety of causes. These include prima...

Within the large body of research on retroviruses, the distribution and evolution of endemic retroviruses in natural host populations have so far received little attention. In this study, the epidemiology, genetic diversity, and molecular evolution of feline immunodeficiency virus specific to cougars (FIVpco) was examined using blood samples collected over several years from a free-ranging coug...

BACKGROUND Feline leukaemia virus (FeLV) and feline immunodeficiency virus (FIV) are major causes of morbidity and mortality in domestic and wild felids. Despite the clinical importance of feline retroviruses and the growing interest in cats as pets, information about FeLV and FIV in Malaysia is presently insufficient to properly advise veterinarians and pet owners. A cross-sectional study was ...