Bovine Leukemia virus 11901 Bovine leukemia virus (BLV) is a bovine virus closely related to HTLV-I, a human tumour virus. BLV is a retrovirus which integrates a DNA intermediate as a provirus into the DNA of B-lymphocytes of blood and milk. It contains an oncogene coding for a protein called Tax. Nevertheless in its natural host the cattle leukemia is rare. Because the oncogenic properties of the virus were discovered early, a search for evidence of pathogenicity humans started soon after discovery. Mostly farm workers drinking raw milk were tested for disease, especially for leukemia. But neither leukemia nor other signs of infection could be detected. So many in many states it was not tried to get rid of this infection. Testing strategies have recently changed since the virus was first detected in Cows. Many potential routes of BLV transmission exist. Transmission through procedures that transmit blood between animals such as gouge dehorning, vaccination and ear tagging with instruments or needles that are not changed or disinfected between animals is a significant means of BLV spread. Rectal palpation with common sleeves poses a risk that is increased by inexperience and increased frequency of palpation. Transmission via colostrum, milk, and in utero exposure is generally considered to account for a relatively small proportion of infections. Embryo transfer and artificial insemination also account for a small number of new infections as long as common equipment and/or palpation sleeves are not used. While transmission has been documented via blood feeding insects, the significance of this risk is unclear. The bottom line appears to be that transmission relies primarily on the transfer of infected lymphocytes from one animal to the next and that BLV positive animals with lymphocytosis are more likely to provide a source for infection. In general BLV causes only a benign mononucleosis-like disease in cattle. Only some animals later develop a B-cell leukemia called enzootic bovine leukosis. Under natural conditions the disease is transmitted mainly by milk to the calf. Infected lymphocytes transmit the disease too. So for artificial infection infected cells are used or the more stable and even heat resistant DNA. Virus particles are difficult to detect and not used for transmission of infection. It is possible that a natural virus reservoir exists in the water buffalo (Wiki: Bovine leukemia virus). Cattle Bos taurus 9913 Chicken Gallus gallus 9031 chinchillas Chinchillidae 10150 Copper Pheasant Syrmaticus soemmerringii 9067 Deer mouse Peromyscus maniculatus 10042 Ducks Anas 8835 Ferret Mustela putorius furo 9669 Goat Capra hircus 9925 Guinea pig Cavia porcellus 10141 Hamster Mesocricetus auratus 10036 Horse Equus caballus 9796 Human Homo sapiens 9606 Monkey Platyrrhini 9479 Mouse Mus musculus 10090 Pig Sus scrofa 9823 Rabbit Oryctolagus cuniculus 9986 Rat Rattus 10114 Raven Corvus corax 56781 Sheep Ovis aries 9940 Vole Microtus ochrogaster 79684 Bovine leukemia virus DNA vaccine encoding Env VO_0011378 Research Intramuscular injection (i.m.) Intramuscular injection (i.m.) DNA vaccine construction The bovine leukemia virus (BLV) envelope gene encoding extracellular glycoprotein gp51 (encoded by env gene) and transmembrane glycoprotein gp30 was cloned into a vehicle expression vector under the human cytomegalovirus (CMV) intermediate early promoter (Brillowska et al., 1999). The intramuscular injection of this plasmid vector generated a cellular immune response. Seven out of ten cows vaccinated with the DNA construct resisted a drastic challenge (Brillowska et al., 1999). Bovine leukemia virus DNA vaccine encoding Tax VO_0011379 Research Intramuscular injection (i.m.) Intramuscular injection (i.m.) DNA vaccine construction The full length tax gene was introduced into the downstream of the SRa promoter in mammalian cell expression plasmid pME18Neo. Plasmid construction (10 ug) was transfected into 3x 10^6 of CC81 cells (feline cell line transformed with mouse sarcoma virus) by electroportion using the Electroporator II (Invitrogen) operated at 1000 uF and 300 V. The expression of the 34 kDa Tax protein in cell lysate was confirmed by Western blot using specific antibody (Usui et al., 2003) Three sheep were injected 3 times at weekly intervals and once at 12 weeks after the first immunization with the Tax DNA vaccine (500 ug) entrapped by cationic liposomes. Three control sheep were injected with liposome-entrapped pME18Neo. At 13 weeks after the first immunization, Tax-vaccinated sheep were injected with the recombinant Tax protein (500 ug/5 ml) mixed with an equal volume of incomplete Freund's Adjuvant (Usui et al., 2003). Results showed higher levels of virus titers in control sheep than those in Tax-vaccinated sheep. Higher levels of IFN-gamma mRNA expression have been demonstrated in vaccinated sheep after the challenge. These results suggested that Th1 type immune response induced by Tax DNA vaccine inhibited BLV propagation in vaccinated sheep at the early phase of infection (Usui et al., 2003). At 1 week after the booster, all sheep were challenged with 7 x 10^6 PBMC contained from BLV-infected sheep. This inoculation dose of PBMC produced 500 synctia in the indicator CC81 cells. All injections were done intramuscularly into each quadricep muscle (Usui et al., 2003). Env/Rex/Tax Bovine leukemia virus VO_0011051 2760849 9626230 BLVgp05 AF033818 NP_056898 11901 4614 7460 + p18 10.96 16183.28 156 >gi|9626225:4614-7460 Bovine leukemia virus, complete genome AATGCCCAAAGAACGACGGTCCCGAAGACGCCCACAACCGATCATCAGATGGGTAAGTCTCACTCTTACT CTCCTCGCTCTCTGTCAGCCCATCCAGACTTGGAGATGCTCCCTGTCCCTAGGAAATCAACAATGGATGA CAACATATAACCAAGAGGCAAAATTTTCCATCTCCATTGACCAAATATTAGAGGCTCACAATCAATCACC TTTCTGTCCCAGGTCTCCCAGATACACCTTGGACTTCGTAAATGGTTATCCTAAGATCTATTGGCCCCCC CCACAAGGGCGGCGCCGGTTTGGAGCCAGGGCCATGGTCACATATGATTGCGAGCCCCGATGCCCTTATG TGGGGGCAGATCACTTCGACTGCCCCCACTGGGACAATGCCTCCCAGGCCGATCAAGGGTCCTTTTATGT CAATCATCAGATTTTATTCCTGCATCTCAAACAATGTCATGGAATTTTCACTCTAACCTGGGAAATATGG GGATATGATCCCCTGATCACCTTTTCTTTACATAAAATTCCTGATCCCCCTCAACCCGACTTCCCTCAGC TGAACAGTGACTGGGTTCCCTCTGTCAGATCATGGGCCCTGCTTTTAAATCAAACGGCACGGGCCTTCCC AGACTGTGCTATATGTTGGGAACCTTCCCCTCCCTGGGCTCCCGAAATATTAGTATATAACAAAACCATC TCCGGCTCTGGACCCGGTCTCGCCCTCCCGGACGCCCAAATCTTCTGGGTCAACACGTCCTTGTTTAACA CCACCCAAGGATGGCACCACCCTTCCCAGAGGTTGTTGTTCAATGTTTCTCAAGGCAACGCCTTATTATT ACCCCCTATCTCCCTGGTTAATCTCTCTACGGTTTCCTCCGCCCCTCCTACCCGGGTCAGACGCAGTCCC GTCGCAGCCCTGACCTTAGGCCTAGCCCTGTCAGTGGGGCTCACTGGAATTAATGTAGCCGTGTCTGCCC TTAGCCATCAGAGACTCACCTCCCTGATCCACGTTCTGGAGCAAGATCAGCAACGCTTGATCACAGCAAT TAACCAGACCCATTATAATTTGCTTAATGTGGCCTCTGTGGTCGCCCAGAACCGACGGGGGCTTGATTGG TTGTACATCCGGCTGGGTTTTCAAAGCCTATGTCCCACAATCAATGAACCTTGCTGTTTCCTACGCATTC AAAATGACTCCATTATCCGCCTCGGTGATCTCCAGCCTCTCTCGCAAAGAGTCTCTACAGACTGGCAGTG GCCCTGGAATTGGGATCTGGGGCTCACCGCCTGGGTGCGAGAAACCATTCATTCTGTTCTAAGCCTATTC CTATTAGCCCTTTTTTTGCTCTTCTTGGCCCCCTGCCTGATAAAATGCTTGACCTCTCGCCTTTTAAAAC TCCTCCGGCAGGCTCCCCACTTCCCTGAAATCTCCTTCCCCCCTAAACCCGATTCTGATTATCAGGCCTT GCTACCGTCAGCACCAGAGATCTACTCTCACCTCTCCCCCACCAAACCCGATTACATCAACCTTCGACCC TGCCCTTGACACCCCCGTGTTTCACGCACCCTCAGGCTGTGGTGGGGCACTGGCTTAGTGGAATAGTCAG TGTACCATCACAAGCCTCTTCTTGCTGCCAGCACCGAGTTCGAACACAGCCCTACCCTGAGCCTCTCTGA GTACATGACTGAGTGTAGCGCAGAGAGGTTGTCGCTTCTGCGTGTCACTCAGTCATTTTTTATAGCCGAT TGGGGTTCGCGCCCTCCCATTGCCTGTGACACGGTTAAGACCTCTCTCACTTCTGCTTCACCATCCCCCT GCCAGCGTTGGTCTAGTGGAAAGAACTAACGCTGACGGGGGCGATTTCTTGCAGCTGTGCTAAGCGAGAG GCTCTGGTGCTGGGGATAAGATGCGGCCCCTAGCACCACAGTCTCTGCGCCTTTTGGGTTCGAATCTTCC CCATGCAGCTTCCGCTTTTTACGCCCTGTTGCACACCCTTTCTAGAGATACCTGAAAATCTCAGCTCGCA CCCCAAGGAAGGTTGTGGCTCAGAGGTTAAAATAGCTCGGACCGCAACCTCCCTTTCTTTTTATTCCACC CTCGCAAGGCCCCGGGTTCTGGGCCCCCTAACGGAGGTTCAGAATTTCCTCTACTAGGGGATGCTCAGGT CCAAGTGTGCACAATATCTCTTCCAAAAGGTCCTGATGAACATCTTCCCATGTAACAAGCCCCAGCAGAG ACATTCCAGCCACATCCAGCAGCATTTGGGCCGCCTTCTCTAACAGTGCCCATAAAGTCCCTTCCGTTTC CACAACGGCTGCCTCTGCATCTTCTATTTCCACCTCGGCACCGACTCCCCCGCCGAGCCCTTCAAGCTCT TCGGGATCCATTACCTGATAACGACAAAATTATTTCTTGTCTTTTAAGCAAGTGTTGTTGGTTGGGGGCC CCACTCTCTACATGCCTGCCCGGCCCTGGTTTTGTCCAATGATGTCACCATCGATGCCTGGTGCCCCCTC TGCGGGCCCCATGAACGACTCCAATTCGAAAGGATCGACACCACGCTCACCTGCGAGACCCACCGTATCA CCTGGACCGCCGATGGACGACCTTTTGGCCTCAATGGAACATTGTTCCCTCGACTGCATGTCTCCGAGAC CCGCCCCCAAGGGCCCCGACGACTCTGGATCAACTGCCCCCTTCCGGCCGTTCGCGCTCAGCCCGGCCCG GTTTCACTTTCCCCCTTCGAGCAGTCCCCCTTCCAGCCCTACCAATGCCAATTGCCCTCGGCCTCTAGCG ACGGTTGCCCCATCATCGGGCACGGCCTTCTTCCCTGGAACAACTTA >gi|9626230|ref|NP_056898.1| p18 [Bovine leukemia virus] MPKERRSRRRPQPIIRWQVLLVGGPTLYMPARPWFCPMMSPSMPGAPSAGPMNDSNSKGSTPRSPARPTV SPGPPMDDLLASMEHCSLDCMSPRPAPKGPDDSGSTAPFRPFALSPARFHFPPSSSPPSSPTNANCPRPL ATVAPSSGTAFFPGTT Protective antigen The bovine leukemia virus (BLV) envelope gene encoding extracellular glycoprotein gp51 (encoded by env gene) and transmembrane glycoprotein gp30 was cloned into a vehicle expression vector under the human cytomegalovirus (CMV) intermediate early promoter. The intramuscular injection of this plasmid vector generated a cellular immune response. Seven out of ten cows vaccinated with the DNA construct resisted a drastic challenge [Ref1047:Brillowska et al., 1999]. Tax Bovine leukemia virus VO_0011050 2760848 9626228 BLVgp01 AF033818 NP_056895 11901 0 8418 + mRNA 9.09 150525.79 1417 >gi|9626225:1-8418 Bovine leukemia virus, complete genome GAAGCGTTCTCCTCCTGAGACCCTAGTGCTCAGCTCTCGGTCCTGAGCTCTCTTGCTCCCGAGACCTTCT GGTCGGCTATCCGGCAGCGGTCAGGTAAGGCAAACCACGGTTTGGAGGGTGGTTCTCGGCTGAGACCGCC GCGAGCTCTATCTCCGGTCCTCTGACCGTCTCCACGTGGACTCTCTCTCTTGCCTCCTGACCCCGCGCTC CAAGGGCGTCTGGCTTGCACCCGCGTTTGTTTCCTGTCTTACTTTCTGTTTCTCGCGGCCCGCGCTCTCT CCCTCGGCGCCCTCTAGCGGCCAGGAGAGACCGGCAAACAATTGGGGGCTCGTCCGGGATTGATCACCCC GGAACCCTAACGATCCTCTGGACCCACCCCCTCGGCGGCGTTTTGGGTCTTTCCTTTAAATTATATCATG GGAAATTCCCCCTCCTATAACCCCCCCGCTGGTATCTCCCCCTCAGACTGGCTCAACCTTCGTCAAAGCG CGCAAAGGCTCAATCCGCGACCCTCTCCTAGCGATTTTACCGATTTAAAAAATTACATCCATTGGTTTCA TAAGACCCAGAAAAAACCATGGACTTTCACTTCTGGTGGCCCCGCCTCATGCCCACCCGGGAAATTCGGT CGGGTTCCCCTCGTCTTGGCCACCCTAAACGAAGTACTCTCAAACGATGAGGGCGCCCCAGGTGCATCAG CCCCAGAAGAACAACCCCCCCCTTATGACCCCCCCGCCATTTTGCCAATTATATCTGAAGGAAATCGCAA CCGCCATCGCGCTTGGGCACTCCGAGAATTACAAGATATTAAAAAAGAAATTGAAAATAAGGCACCGGGT TCGCAAGTATGGATACAAACACTACGACTTGCAATCTTACAGGCCGACCCTACTCCTGCTGACCTAGAAC AACTTTGCCAATATATTGCTTCCCCGGTCGATCAAACGGCCCACATGACCAGCCTAACGGCAGCAATAGC CGCCGCTGAAGCGGCCAATACCCTCCAGGGTTTTAATCCCCAAAATGGGACCCTGACCCAACAATCAGCT CAGCCCAACGCCGGGGACCTTAGAAGTCAATATCAAAACCTTTGGCTTCAGGCCTGGAAAAATCTCCCTA CTCGTCCTTCAGTACAACCCTGGTCCACCATCGTCCAAGGCCCCGCCGAGAGCTATGTAGAGTTTGTCAA CCGGTTACAAATTTCATTAGCTGACAACCTTCCCGACGGAGTCCCTAAAGAACCCATTATTGACTCCCTT AGCTATGCTAATGCTAACAAAGAATGCCAACAAATTTTGCAAGGGCGGGGCCTAGTGGCCGCCCCGGTGG GACAAAAACTGCAGGCTTGTGCACATTGGGCCCCCAAGGTTAAACAGCCTGCAATCCTCGTCCACACCCC AGGGCCCAAGATGCCCGGGCCTCGGCAACCGGCCCCCAAAAGGCCCCCCCCGGGACCATGCTATCGATGC CTCAAAGAAGGCCATTGGGCCCGGGACTGTCCCACCAAGACCACCGGCCCCCCTCCGGGACCTTGTCCCA TATGTAAAGATCCTTCCCATTGGAAACGAGACTGTCCAACCCTCAAATCAAAAAACTAATAGAGGGGGGA CTTAGCGCCCCCCAAACCGTAACCCCTATAACAGATCCTCTTAGTGAGGCCGAATTAGAATGCCTACTTT CTATTCCTCTGGCTCGCAGCCGTCCCTCCGTGGCTGTATACCTGTCTGGCCCCTGGCTGCAGCCCTCTCA GAATCAAGCCCTTATGCTCGTGGACACCGGGGCTGAAAATACGGTCCTCCCACAAAATTGGCTGGTTCGA GATTACCCACGGATCCCCGCCGCGGTGCTCGGAGCAGGGGGAGTCTCCCGGAACAGATACAATTGGCTAC AAGGCCCTCTGACCCTGGCTCTAAAACCAGAGGGTCCCTTTATCACCATCCCAAAAATTTTAGTTGACAC TTTCGATAAATGGCAAATTTTAGGACGGGACGTCCTCTCCCGCCTACAGGCCTCTATCTCCATACCTGAG GAGGTACGCCCCCCCATGGTAGGCGTCCTAGATGCCCCCCCGAGCCACATTGGATTAGAACATTTGCCCG TCCCACCTGAGGTACCTCAATTCCCTTTAAACTAGAACGCCTCCAGGCCCTTCAAGACCTGGTCCATCGC TCTCTGGAGGCAGGCTATATCTCCCCCTGGGACGGGCCAGGCAATAATCCAGTATTCCCGGTACGGAAAC CAAATGGCACCTGGAGGTTTGTGCATGATCTACGAGCTACAAATGCTCTTACAAAGCCCATCCCGGCGCT CTCCCCCGGACCGCCAGACCTTACCGCTATCCCTACACACCTTCCACATATCATTTGCCTAGATCTCAAA GATGCCTTCTTCCAGATTCCAGTCGAAGACCGCTTCCGCTCCTATTTTGCTTTTACCCTCCCTACCCCCG GGGGACTCCAACCTCACAGACGCTTTGCCTGGCGGGTCCTACCTCAAGGCTTCATTAACAGCCCAGCTCT TTTCGAACGGGCACTACAGGAACCCCTTCGCCAAGTTTCCGCCGCCTTCTCCCAGTCTCTTCTGGTGTCC TATATGGACGATATCCTTATCGCTTCGCCTACAGAAGAACAACGGTCACAATGTTATCAAGCCCTGGCTG CCCGCCTCCGGGACCTAGGGTTTCAGGTGGCGTCTGAAAAGACTCGCCAGACGCCTTCGCCCGTCCCCTT CTTGGGACAAATGGTCCATAACCAGATTGTCACCTATCAGTCCCTACCTACCTTGCAGATCTCATCCCCA ATTTCTCTTCACCAATTACAGGCGGTCTTGGGAGACCTCCAGTGGGTCTCTAGGGGCACACCCACTACCC GCCGGCCCCTGCAACTTCTCTACTCTTCCCTTAAAGGCATCGATGACCCTAGGGCCATCATCCAGCTTTC CCCGGAACAGCTACAAGGCATTGCAGAGCTTCGACAAGCCCTGTCCCATAACGCAAGATCTAGATATAAC GAGCAAGAACCCCTGCTGGCCTACGTACACCTAACCCGGGCAGGGTCCACCCTGGTACTCTTCCAAAAGG GCGCTCAATTTCCCCTGGCCTACTTTCAGACCCCCTTGACTGACAACCAAGCCTCACCTTGGGGCCTCCT TCTCCTGCTGGGATGCCAATACCTGCAGACTCAGGCCTTAAGCTCTTATGCCAAGCCCATACTCAAATAC TATCACAATCTTCCTAAAACCTCTCTCGACAATTGGATTCAATCATCTGAGGACCCTCGAGTTCAGGAGT TGTTGCAATTGTGGCCCCAGATTTCCTCTCAGGGAATACAGCCCCCGGGCCCCTGGAAAACCTTGATCAC CAGGGCAGAGGTTTTTTTGACGCCCCAGTTCTCTCCTGAACCGATTCCTGCGGCCCTTTGCCTCTTTAGT GACGGGGCTACAGGACGAGGAGCATATTGCCTGTGGAAAGACCACCTTTTGGACTTTCAGGCCGTTCCGG CTCCAGAGTCCGCCCAAAAGGGAGAACTAGCAGGTCTCTTGGCGGGCTTAGCAGCCGCCCCGCCTGAACC TTTAAATATATGGGTAGATTCCAAATACCTATACTCCTTGCTCAGAACCCTAGTTCTGGGAGCTTGGCTT CAACCTGACCCCGTACCCTCCTATGCCCTCCTATATAAAAGCCTCCTCCGACATCCAGCAATCTTTGTTG GTCATGTCCGGAGCCACTCCTCAGCATCCCACCCTATTGCTTCCCTGAACAATTATGTAGATCAACTGCT CCCCTTAGAAACTCCAGAGCAATGGCATAAGCTCACCCACTGCAACTCTCGGGCCTTGTCTCGATGGCCG AACCCACGTATTTCGGCCTGGGATCCCCGTTCCCCCGCTACGCTGTGTGAAACCTGTCAAAGGCTCAATC CAACTGGAGGTGGGAAGATGCGAACTATTCAGAGAGGGTGGGCCCCGAATCATATTTGGCAGGCCGATAT AACCCATTATAAATACAAACAGTTCACCTACGCTTTGCACGTGTTTGTAGATACTTACTCTGGAGCTACT CATGCCTCAGCAAAGCGAGGGCTCACCACTCAAATGACCATTGAGGGCCTTCTAGAGGCCATAGTGCATC TGGGTCGTCCAAAAAAGCTAAACACTGACCAAGGCGCAAACTACACCTCCAAAACCTTTGTCAGGTTTTG CCAGCAGTTCGGAATTTCCCTTTCTCATCACGTTCCCTACAACCCCACAAGTTCAGGGTTGGTAGAGCGG ACAAATGGACTGCTCAAACTTCTTTTGTCTAAATATCACCTAGACGAACCCCACCTTCCCATGACTCAGG CCCTTTCTCGAGCCCTCTGGACTCACAATCAGATTAACCTCCTACCAATTCTAAAGACCAGATGGGAGTT ACACCATTCACCCCCACTTGCTGTCATTTCAGAGGGCGGAGAAACACCCAAGGGCTCTGATAAACTCTTT TTGTACAAGCTCCCCGGGCAAAACAATCGTCGGTGGCTAGGACCTCTCCCGGCCCTAGTCGAAGCCTCGG GAGGCGCCCTCCTGGCTACTAACCCCCCCGTGTGGGTTCCCTGGCGTTTGCTAAAAGCCTTCAAATGCCC AAAGAACGACGGTCCCGAAGACGCCCACAACCGATCATCAGATGGGTAAGTCTCACTCTTACTCTCCTCG CTCTCTGTCAGCCCATCCAGACTTGGAGATGCTCCCTGTCCCTAGGAAATCAACAATGGATGACAACATA TAACCAAGAGGCAAAATTTTCCATCTCCATTGACCAAATATTAGAGGCTCACAATCAATCACCTTTCTGT CCCAGGTCTCCCAGATACACCTTGGACTTCGTAAATGGTTATCCTAAGATCTATTGGCCCCCCCCACAAG GGCGGCGCCGGTTTGGAGCCAGGGCCATGGTCACATATGATTGCGAGCCCCGATGCCCTTATGTGGGGGC AGATCACTTCGACTGCCCCCACTGGGACAATGCCTCCCAGGCCGATCAAGGGTCCTTTTATGTCAATCAT CAGATTTTATTCCTGCATCTCAAACAATGTCATGGAATTTTCACTCTAACCTGGGAAATATGGGGATATG ATCCCCTGATCACCTTTTCTTTACATAAAATTCCTGATCCCCCTCAACCCGACTTCCCTCAGCTGAACAG TGACTGGGTTCCCTCTGTCAGATCATGGGCCCTGCTTTTAAATCAAACGGCACGGGCCTTCCCAGACTGT GCTATATGTTGGGAACCTTCCCCTCCCTGGGCTCCCGAAATATTAGTATATAACAAAACCATCTCCGGCT CTGGACCCGGTCTCGCCCTCCCGGACGCCCAAATCTTCTGGGTCAACACGTCCTTGTTTAACACCACCCA AGGATGGCACCACCCTTCCCAGAGGTTGTTGTTCAATGTTTCTCAAGGCAACGCCTTATTATTACCCCCT ATCTCCCTGGTTAATCTCTCTACGGTTTCCTCCGCCCCTCCTACCCGGGTCAGACGCAGTCCCGTCGCAG CCCTGACCTTAGGCCTAGCCCTGTCAGTGGGGCTCACTGGAATTAATGTAGCCGTGTCTGCCCTTAGCCA TCAGAGACTCACCTCCCTGATCCACGTTCTGGAGCAAGATCAGCAACGCTTGATCACAGCAATTAACCAG ACCCATTATAATTTGCTTAATGTGGCCTCTGTGGTCGCCCAGAACCGACGGGGGCTTGATTGGTTGTACA TCCGGCTGGGTTTTCAAAGCCTATGTCCCACAATCAATGAACCTTGCTGTTTCCTACGCATTCAAAATGA CTCCATTATCCGCCTCGGTGATCTCCAGCCTCTCTCGCAAAGAGTCTCTACAGACTGGCAGTGGCCCTGG AATTGGGATCTGGGGCTCACCGCCTGGGTGCGAGAAACCATTCATTCTGTTCTAAGCCTATTCCTATTAG CCCTTTTTTTGCTCTTCTTGGCCCCCTGCCTGATAAAATGCTTGACCTCTCGCCTTTTAAAACTCCTCCG GCAGGCTCCCCACTTCCCTGAAATCTCCTTCCCCCCTAAACCCGATTCTGATTATCAGGCCTTGCTACCG TCAGCACCAGAGATCTACTCTCACCTCTCCCCCACCAAACCCGATTACATCAACCTTCGACCCTGCCCTT GACACCCCCGTGTTTCACGCACCCTCAGGCTGTGGTGGGGCACTGGCTTAGTGGAATAGTCAGTGTACCA TCACAAGCCTCTTCTTGCTGCCAGCACCGAGTTCGAACACAGCCCTACCCTGAGCCTCTCTGAGTACATG ACTGAGTGTAGCGCAGAGAGGTTGTCGCTTCTGCGTGTCACTCAGTCATTTTTTATAGCCGATTGGGGTT CGCGCCCTCCCATTGCCTGTGACACGGTTAAGACCTCTCTCACTTCTGCTTCACCATCCCCCTGCCAGCG TTGGTCTAGTGGAAAGAACTAACGCTGACGGGGGCGATTTCTTGCAGCTGTGCTAAGCGAGAGGCTCTGG TGCTGGGGATAAGATGCGGCCCCTAGCACCACAGTCTCTGCGCCTTTTGGGTTCGAATCTTCCCCATGCA GCTTCCGCTTTTTACGCCCTGTTGCACACCCTTTCTAGAGATACCTGAAAATCTCAGCTCGCACCCCAAG GAAGGTTGTGGCTCAGAGGTTAAAATAGCTCGGACCGCAACCTCCCTTTCTTTTTATTCCACCCTCGCAA GGCCCCGGGTTCTGGGCCCCCTAACGGAGGTTCAGAATTTCCTCTACTAGGGGATGCTCAGGTCCAAGTG TGCACAATATCTCTTCCAAAAGGTCCTGATGAACATCTTCCCATGTAACAAGCCCCAGCAGAGACATTCC AGCCACATCCAGCAGCATTTGGGCCGCCTTCTCTAACAGTGCCCATAAAGTCCCTTCCGTTTCCACAACG GCTGCCTCTGCATCTTCTATTTCCACCTCGGCACCGACTCCCCCGCCGAGCCCTTCAAGCTCTTCGGGAT CCATTACCTGATAACGACAAAATTATTTCTTGTCTTTTAAGCAAGTGTTGTTGGTTGGGGGCCCCACTCT CTACATGCCTGCCCGGCCCTGGTTTTGTCCAATGATGTCACCATCGATGCCTGGTGCCCCCTCTGCGGGC CCCATGAACGACTCCAATTCGAAAGGATCGACACCACGCTCACCTGCGAGACCCACCGTATCACCTGGAC CGCCGATGGACGACCTTTTGGCCTCAATGGAACATTGTTCCCTCGACTGCATGTCTCCGAGACCCGCCCC CAAGGGCCCCGACGACTCTGGATCAACTGCCCCCTTCCGGCCGTTCGCGCTCAGCCCGGCCCGGTTTCAC TTTCCCCCTTCGAGCAGTCCCCCTTCCAGCCCTACCAATGCCAATTGCCCTCGGCCTCTAGCGACGGTTG CCCCATCATCGGGCACGGCCTTCTTCCCTGGAACAACTTAGTAACGCATCCTGTCCTCGGAAAAGTCCTT ATATTAAATCAAATGGCCAATTTTTCCTTACTCCCCCCCTTCGATACCCTCCTTGTAGACCCCCTCCGGC TGTCCGTCTTTGCCCCGGACACTAGGGGAGCCATACGTTATCTCTCCACCCTTTTGACGCTATGCCCAGT TACTTGTATTCTACCCCTAGGCGAGCCCTTCTCTCCTAATGTCCCCATATGCCGCTTTCCCCGAGACACC AGTGAACCTCCCCTTTCAGAATTCGAGCTGCCCCTTATCCAAACGCCCGGCCTGTCTTGGTCTGTCCCCG CGATCGACCTATTCCTAACCGGTCCCCCTTCCCCATACGACCGGTTACACGTGTGGTCCAGTCCTCAGGC CTTACAACGCTTCCTCCATGACCCTACGCTCACCTGGTCAGAATTGGTTGCTAGCGGGAAACTAAGACTT GATTCACCCTTAAAATTACAGCTGTTAGAAAATGAATGGCTCTCCCGCCTTTTTTGAGGGGGAGTCATTT GTATGAAAGATCATGCAGGCCTAGGCGCCGCCACCGCCCCGTAAACCAGACAGAGACGTCAGCTGCCAGA GAAGCTGCTGACGGCAGCTGGTGGCTAGAATCCCCGTACCTCCCCAACTTCCCCTTTCCCGAAAAATCCA CACCCTGAGCTGCTGACCTCACCTGCTGATAAATTAATAAAATGCCGGCCCTGTCGAGTTAGCGGCACCA GAAGCGTTCTCCTCCTGAGACCCTAGTGCTCAGCTCTCGGTCCTGAGCTCTCTTGCTCCCGAGACCTTCT GGTCGGCTATCCGGCAGCGGTCAGGTAAGGCAAACCACGGTTTGGAGGGTGGTTCTCGGCTGAGACCGCC GCGAGCTCTATCTCCGGTCCTCTGACCGTCTCCACGTGGACTCTCTCTCTTGCCTCCTGACCCCGCGCTC CAAGGGCGTCTGGCTTGC >gi|9626228|ref|NP_056895.1| RT-IN [Bovine leukemia virus] MGNSPSYNPPAGISPSDWLNLRQSAQRLNPRPSPSDFTDLKNYIHWFHKTQKKPWTFTSGGPASCPPGKF GRVPLVLATLNEVLSNDEGAPGASAPEEQPPPYDPPAILPIISEGNRNRHRAWALRELQDIKKEIENKAP GSQVWIQTLRLAILQADPTPADLEQLCQYIASPVDQTAHMTSLTAAIAAAEAANTLQGFNPQNGTLTQQS AQPNAGDLRSQYQNLWLQAWKNLPTRPSVQPWSTIVQGPAESYVEFVNRLQISLADNLPDGVPKEPIIDS LSYANANKECQQILQGRGLVAAPVGQKLQACAHWAPKVKQPAILVHTPGPKMPGPRQPAPKRPPPGPCYR CLKEGHWARDCPTKTTGPPPGPCPICKRSFPLETRLSNPQIKKLIEGGLSAPQTVTPITDPLSEAELECL LSIPLARSRPSVAVYLSGPWLQPSQNQALMLVDTGAENTVLPQNWLVRDYPRIPAAVLGAGGVSRNRYNW LQGPLTLALKPEGPFITIPKILVDTFDKWQILGRDVLSRLQASISIPEEVRPPMVGVLDAPPSHIGLEHL PVPPEVPQFPLNLERLQALQDLVHRSLEAGYISPWDGPGNNPVFPVRKPNGTWRFVHDLRATNALTKPIP ALSPGPPDLTAIPTHLPHIICLDLKDAFFQIPVEDRFRSYFAFTLPTPGGLQPHRRFAWRVLPQGFINSP ALFERALQEPLRQVSAAFSQSLLVSYMDDILIASPTEEQRSQCYQALAARLRDLGFQVASEKTRQTPSPV PFLGQMVHNQIVTYQSLPTLQISSPISLHQLQAVLGDLQWVSRGTPTTRRPLQLLYSSLKGIDDPRAIIQ LSPEQLQGIAELRQALSHNARSRYNEQEPLLAYVHLTRAGSTLVLFQKGAQFPLAYFQTPLTDNQASPWG LLLLLGCQYLQTQALSSYAKPILKYYHNLPKTSLDNWIQSSEDPRVQELLQLWPQISSQGIQPPGPWKTL ITRAEVFLTPQFSPEPIPAALCLFSDGATGRGAYCLWKDHLLDFQAVPAPESAQKGELAGLLAGLAAAPP EPLNIWVDSKYLYSLLRTLVLGAWLQPDPVPSYALLYKSLLRHPAIFVGHVRSHSSASHPIASLNNYVDQ LLPLETPEQWHKLTHCNSRALSRWPNPRISAWDPRSPATLCETCQRLNPTGGGKMRTIQRGWAPNHIWQA DITHYKYKQFTYALHVFVDTYSGATHASAKRGLTTQMTIEGLLEAIVHLGRPKKLNTDQGANYTSKTFVR FCQQFGISLSHHVPYNPTSSGLVERTNGLLKLLLSKYHLDEPHLPMTQALSRALWTHNQINLLPILKTRW ELHHSPPLAVISEGGETPKGSDKLFLYKLPGQNNRRWLGPLPALVEASGGALLATNPPVWVPWRLLKAFK CPKNDGPEDAHNRSSDG Protective antigen A DNA vaccination trial was performed on sheep to determine whether vaccination with bovine leukemia virus (BLV) transactivator Tax DNA is effective against BLV infection. Results showed higher levels of virus titers in control sheep than those in Tax-vaccinated sheep. Higher levels of IFN-gamma mRNA expression have been demonstrated in vaccinated sheep after the challenge. These results suggested that Th1 type immune response induced by Tax DNA vaccine inhibited BLV propagation in vaccinated sheep at the early phase of infection [Ref1046:Usui et al., 2003]. Brillowska et al., 1999 journal Brillowska A, Dabrowski S, Rułka J, Kubiś P, Buzała E, Kur J 1999 46 4 971-976 Acta biochimica Polonica Usui et al., 2003 journal Usui T, Konnai S, Tajima S, Watarai S, Aida Y, Ohashi K, Onuma M 2003 65 11 1201-1205 The Journal of veterinary medical science / the Japanese Society of Veterinary Science Wiki: Bovine leukemia virus website http://en.wikipedia.org/wiki/Bovine_leukemia_virus