The two murine retroviral restriction genes, Fv-4 and Akvr-1, are very similar in their effects, distributions, ranges of action, and phenotypes. Akvr-1 has been shown to segregate independently in backcrosses with a variety of retroviral restriction loci, including Fv-1, Fv-2, Ril-1, and Ril-2. An allelism test cross of FRG (Fv-4R) X LCRR (Akvr-1R) hybrids mated to AKR mice failed to produce a...

Activated protein C (APC) inhibits coagulation by cleaving and inactivating procoagulant factor Va (FVa) and factor VIIIa (FVIIIa). FV, in addition to being the precursor of FVa, has anticoagulant properties; functioning in synergy with protein S as a cofactor of APC in the inhibition of the FVIIIa-factor IXa (FIXa) complex. FV:Q506 isolated from an individual homozygous for APC-resistance is l...

Multiple host genes have been shown to influence the course of erythroleukemia induced by Friend virus (FV) 1 (1). Two H-2-associated genes and a non-H-2-1inked gene are required for recovery from FV leukemia (2, 3). The non-H-2-1inked gene, Rfv-3, appears to influence the production of anti-FV antibody independent of the H-2 genotype (3). Although mice of the Rfv-3 r/~ genotype produce high le...

Activated protein C (APC) inhibits coagulation by cleaving and inactivating procoagulant factor Va (FVa) and factor VIIIa (FVIIIa). FV, in addition to being the precursor of FVa, has anticoagulant properties; functioning in synergy with protein S as a cofactor of APC in the inhibition of the FVIIIafactor IXa (FIXa) complex. FV:Q506 isolated from an individual homozygous for APC-resistance is le...

Fv-4 is a mouse gene that dominantly confers resistance to infection with Friend murine leukemia virus (F-MuLV) (S. Suzuki, Jpn. J. Exp. Med. 45:473-478, 1975). However, the resistance caused by Fv-4 is recessive in nude mice, which suggests that immunological effects play important roles in this resistance in vivo (K. Higo, Y. Kubo, Y. Iwatani, T. Ono, M. Maeda, H. Hiai, T. Masuda, K. Kuribaya...

Foamy virus (FV) vectors are promising tools for gene therapy, but low titer is a major challenge for large-scale clinical trials. Here, we increased FV vector titer 50-fold by constructing novel vector plasmids and using polyethylenimine-mediated transfection. FV and lentiviral (LV) vectors were used separately to transduce human CD34(+) cells at multiplicities of infection of 25, and those ce...

generation at the activated platelet surface. What remains uncertain, however, is whether residual platelet FV levels correlate with the severity of bleeding in severe FV-deficient patients. Although there has been speculation on this correlation,8 no systematic study has been done. Furthermore, mechanistic studies are needed to investigate some remaining questions. The first relates to the ori...

Spumaviruses, commonly called foamy viruses, are complex retroviruses that establish life-long persistent infections in the absence of accompanying pathology. Depending upon cell type, infection of cells in tissue culture cells can result in either lytic replication, persistence, or latency. The cellular factors that mediate foamy virus (FV) latency are poorly understood. In this study we show ...

Coagulation factor V (FV) promotes inactivation of activated factor VIII (FVIIIa) by activated protein C (APC) and protein S. Loss of this APC cofactor activity is proposed to be partially responsible for the APC resistance phenotype of FV(Leiden). However, FVIIIa loses activity rapidly due to dissociation of the A2 domain, and this may be the primary mechanism of FVIIIa inactivation. APC/prote...

Despite substantial evidence suggesting that a diet high in fruit and vegetables (FV) is associated with reduced risk of cancer, only 21% of children in the UK consume the recommended 5 portions of fruit or vegetables a day. This review examines the role of parenting style, feeding style and feeding practices in FV consumption in early childhood. Whilst inconsistencies in concepts and terminolo...