tailieunhanh - Báo cáo y học: "Dominance of highly divergent feline leukemia virus A progeny variants in a cat with recurrent viremia and fatal lymphoma"

Tuyển tập các báo cáo nghiên cứu về y học được đăng trên tạp chí y học Retrovirology cung cấp cho các bạn kiến thức về ngành y đề tài: Dominance of highly divergent feline leukemia virus A progeny variants in a cat with recurrent viremia and fatal lymphoma. | Helfer-Hungerbuehler et al. Retrovirology 2010 7 14 http content 7 1 14 RETR0VIR0L0GY RESEARCH Open Access Dominance of highly divergent feline leukemia virus A progeny variants in a cat with recurrent viremia and fatal lymphoma A Katrin Helfer-Hungerbuehler 1 Valentino Cattori1 Felicitas S Boretti2 Pete Ossent3 Paula Grest3 V4 4 I M 1 1 V5 1 ih- 1 Manfred Reinacher Manfred Henrich Eva Bauer Kim Bauer-Pham Eva Niederer Edgar Holznagel Hans Lutz Regina Hofmann-Lehmann1 Abstract Background In a cat that had ostensibly recovered from feline leukemia virus FeLV infection we observed the reappearance of the virus and the development of fatal lymphoma years after the initial experimental exposure to FeLV-A Glasgow-1. The goals of the present study were to investigate this FeLV reoccurrence and molecularly characterize the progeny viruses. Results The FeLV reoccurrence was detected by the presence of FeLV antigen and RNA in the blood and saliva. The cat was feline immunodeficiency virus positive and showed CD4 T-cell depletion severe leukopenia anemia and a multicentric monoclonal B-cell lymphoma. FeLV-A but not -B or -C was detectable. Sequencing of the envelope gene revealed three FeLV variants that were highly divergent from the virus that was originally inoculated 89-91 identity to FeLV-A Glasgow-1 . In the long terminal repeat 31 point mutations some previously described in cats with lymphomas were detected. The FeLV variant tissue provirus and viral RNA loads were significantly higher than the FeLV-A Glasgow-1 loads. Moreover the variant loads were significantly higher in lymphoma positive compared to lymphoma negative tissues. An increase in the variant provirus blood load was observed at the time of FeLV reoccurrence. Conclusions Our results demonstrate that ostensibly recovered FeLV provirus-positive cats may act as a source of infection following FeLV reactivation. The virus variants that had largely replaced the inoculation strain had