PERV is integrated into the genome of all pigs. PERV-A and PERV-B are polytropic and can productively infect human cell lines, whereas PERV-C is ecotropic. Recombinant PERV-A/C can infect human cells Show more
PERV is integrated into the genome of all pigs. PERV-A and PERV-B are polytropic and can productively infect human cell lines, whereas PERV-C is ecotropic. Recombinant PERV-A/C can infect human cells and exhibits high titer replication. Therefore, use of pigs for human xenotransplantation raises concerns about the risks of transfer of this infectious agent from donors to xenotransplantation recipients. To establish strategies to inhibit PERV production from cells, in the present study, we investigated the mechanism of PERV budding and anti-PERV activity of Tetherin/BST-2. The results showed that DN mutants of WWP-2, Tsg101, and Vps4A/B markedly reduced PERV production in human and porcine cell lines, suggesting that PERV budding uses these cellular factors and the cellular MVB sorting pathway as well as many other retroviruses. Moreover, PERV production was also reduced by human and porcine Tetherin/BST-2. These data are useful for developing strategies to inhibit PERV production and may reduce the risk of PERV infection in xenotransplantation. Show less
RD-114 virus is a feline endogenous retrovirus and produced as infectious viruses in some feline cell lines. Recently, we reported the contamination of an infectious RD-114 virus in a proportion of li Show more
RD-114 virus is a feline endogenous retrovirus and produced as infectious viruses in some feline cell lines. Recently, we reported the contamination of an infectious RD-114 virus in a proportion of live attenuated vaccines for dogs and cats. It is very difficult to completely knock out the RD-114 proviruses from cells, as endogenous retroviruses are usually integrated multiply into the host genome. However, it may be possible to reduce the risk of contamination of RD-114 virus by regulating the viral release from cells. In this study, to understand the molecular mechanism of RD-114 virus budding, we attempted to identify the viral and cellular requirements for RD-114 virus budding. Analyses of RD-114 L-domain mutants showed that the PPPY sequence in the pp15 region of Gag plays a critical role in RD-114 virus release as viral L-domain. Furthermore, we investigated the cellular factors required for RD-114 virus budding. We demonstrated that RD-114 virus release was inhibited by overexpression of dominant negative mutants of Vps4A, Vps4B, and WWP2. These results strongly suggest that RD-114 budding utilizes the cellular multivesicular body sorting pathway similar to many other retroviruses. Show less