We studied a patient with a Philadelphia chromosome-positive chronic myeloid leukemia, who died in relapse after multiple transfusions and grafting with bone marrow from his monozygotic twin brother (referred to as "donor" in this paper). We present data indicating that this patient may have had a retro-virus infection that this virus is related to the group of exogenous primate type C retrovir...

To develop improved vaccination strategies against feline leukemia virus (FeLV), rats were immunized with the transmembrane envelope protein p15E of FeLV alone or in combination with the commercial vaccine Leucogen® comprising the nonglycosylated FeLV surface envelope protein. Binding and neutralizing antibodies were induced in both groups and in the group immunized with Leucogen alone. Higher ...

Human CD7 is one of the earliest molecules to appear in T cell development. In this study, putative feline CD7 cDNA was identified based on its similarities with human and mouse CD7 genes. The feline CD7 cDNA contained an open reading frame consisting of 630 nucleotides. The amino acid sequence of feline CD7 had 47.7% identity with that of human CD7, and 52.9% with that of mouse CD7. In additio...

To the Editor: Feline coronaviruses (FCoVs) occur as 2 pathotypes, feline infectious peritonitis virus (FIPV) and feline enteric coronavirus (FECV). FECV is common in cats, causing mild transient enteritis in kittens, but is asymptomatic in adult cats. In contrast, FIPV occurs sporadically but is lethal. It replicates in monocytes and macrophages and rapidly disseminates throughout the body cau...

Feline leukemia-sarcoma group-specific antigens were located in human embryo cells infected with feline leukemia and feline sarcoma viruses. This was done by using the fluorescent-antibody and enzyme-labeled antibody techniques at both light and electron microscopic levels. The antigens were found to be exclusively intracytoplasmic, diffuse, and located in discrete punctate foci.

Feline herpesvirus-1 and feline calicivirus are common causes of feline upper respiratory tract disease and can cause clinically indistinguishable syndromes. However, they differ in their physical properties, epidemiology, and spectrum of clinical signs; and the differences can affect the diagnosis, prognosis, and management of these infections. The availability and sensitivity of diagnostic te...

Antibody-dependent enhancement of virus infection is a process whereby virus-antibody complexes initiate infection of cells via Fc receptor-mediated endocytosis. We sought to investigate antibody-dependent enhancement of feline infectious peritonitis virus infection of primary feline peritoneal macrophages in vitro. Enhancement of infection was assessed, after indirect immunofluorescent-antibod...