• 대한바이러스학회지
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• 제27권2호
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• pp.217-225
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• 1997

PCR amplication using the primers for gag, pol and env genes in BLV (bovine leukemia virus) proviral DNA and syncytium assay were carried out for the Korean native goats experimentally infected with bovine leukemia virus to investigate pathogenesis of BLV in the goats, and to establish a model animal for BLV infection. The oligonucleotide primers used in PCR revealed very high specificity. The minimal amount of FLK-BLV cellular chromosomal DNA to detect the integrated BLV proviral DNA was 10 ng. The peripheral blood lymphocytes from the goat infected with BLV were examined at regular intervals by PCR amplification and syncytium assay. Pol or gag genes were detected in none of three infected goats at the 1st week post-infection (p.i.). At the 4th week p.i., one of three goats showed the amplified gag gene. Thereafter detection rates for the genes were increased, indicating that the BLV proviral genes were integrated in all of the lymphocytes from three goats, at the 16th weeks p.i., when it was evident in syncytium assay that the lymphocytes from all of three goats were infested with infective BLV. Investigating the tissues from the necropsied goats at the 8th month p.i., the amplified BLV proviral genes and infective BLV were detected in all of the peripheral lymphocytes from three infected-goats. Among various tissues examined, the amplified BLV proviral genes were observed in spleen and superficial cervical, mandibular and retropharyngeal lymph nodes, and the infective BLV, in superficial cervical and mandibular lymph nodes. It was assumed that the Korean native goat was quite susceptible to BLV infection, indicating that the goat could be a good model animal for BLV.

• 대한의생명과학회지
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• 제5권1호
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• pp.101-107
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• 1999

젖소 면역결핍 바이러스 (BIV)는 젖소에게 여러 가지 면역결핍증후군을 야기하는 렌티 바이러스 (역전사효소 바이러스의 아군)로서 국내에서는 이에 대한 연구나 보고가 진행된 바 없다. 본 연구에서는 BIV가 다른 젖소의 역전사효소 바이러스인 젖소 백혈병바이러스 (BLV)와 동시 감염되고 (50%정도)있는 점을 착안해 우선 대구.경북지역의 소의 BLV감염실태를 조사해 BLV가 감염된 젖소를 대상으로 BIV 감염상태를 알아보았다. 먼저 10회에 걸쳐 젖소와 황소 248마리의 혈액을 채취 해 BLV와 BIV의 숙주세포가 되는 말초혈액 단핵구 (peripheral blood monocytes, PBMC)를 분리하고, 이를 이용해 DNA중합효소 연쇄반응 (PCR)과 Southern blot분석법을 통해 BLV와 BIV의 존재여부를 조사하였다. 그 결과 조사대상 젖소의 66.9% (81/121) 이상이 BLV에 감염되어 있음을 PCR 검사를 통해 알 수 있었으며, 이는 Southern blot법으로 재차 확인되었다. 이 결과는 종래에 보고된 대구경북지역에서의 BLV 감염율인 27~30%보다 2배 이상 높은 수치로서, (1) 우리가 사용한 방법들 (PCR & Southern blot법)이 분자생물학적 연구방법인 관계로 고도의 특이성 (specificity)을 지녔기 때문이며 (2) 지난 10년간 조사 대상지역인 대구 경북지역 내에서 젖소들에게 지속적으로 BLV감염이 증가하였기 때문으로 본다. 한편 이들 BLV positive PBMC의 chromosomal DNA를 사용해 BIV의 검출을 시도한 바, lot 3C샘플은 BLV에 100%감염되어 있음과 동시에 그 일부가 BIV에 감염되어 있음을 PCR 방법을 통하여 확인할 수 있었다.

• 대한의생명과학회지
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• 제10권1호
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• pp.55-63
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• 2004

Bovine leukemia virus (BLV) is a causative agent for lymphoma disease in cattle including cows worldwide. BLV shares similar virion structure and characteristics with other retroviruses. The pol gene of the BLV genome produced reverse transcriptase (RT) and integrase (IN) for important roles for BLV genome integration into host cell chromosomes that is known to be coded in the 3' side of the BLV pol gene (one third portion). In this study, we have sequenced 978 bp in the 3' side of the BLV pol gene from BLV 10C3 in order to determine the BLV IN region of it. And we compared it to the nucleotide sequences of an Australian BLV isolate. As a result, nucleotide sequences of the IN region of the Korean-type BLV pol gene were mutated at a rate of 3.7%. We can confirm that the typical mutations are such as Arg (AGG) $\rightarrow$ Lys (AAG), Thr (ACG) $\rightarrow$ Met (ATG), Ile (ATT) $\rightarrow$ Val (GTT), Asn (ACC) $\rightarrow$ His (CAC), Phe (TTT) $\rightarrow$ Leu (TTG) and Asn (ACC) $\rightarrow$ Asp (GAC). From the analysis of the sequencing data, we were able to determine the zinc-finger-like "HHCC" motif in the amino terminus of BLV IN, that was H-$X_3$-H-$X_{25}-C-X_2$-C. It was also found the DD35E motif in the IN catalytic domain as D-$X_{56}$-D-$X_{35}$-E. It fits very well to the consensus sequences of retroviral IN as well as HHCC motif.

• Applied Microscopy
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• 제35권1호
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• pp.23-30
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• 2005

국내 젖소의 54.2%가 BLV에 감염되어 있지만 현재까지 국내에서는 소백혈병 바이러스 (BLV) 입자를 확인한 연구 보고가 없기 때문에 BLV 항체 양성 소의 말초혈액 림프구를 배양, BLV를 발현시켜 전자현미경으로 바이러스 입자를 검출하였고 배양조건에 따른 바이러스 발현율 및 발현 시간을 비교하였다. 검사 결과 전형적인 C-형 바이러스를 확인할 수 있었으며 BLV 단크론 항체를 이용한 면역염색결과 BLV 항원 양성으로 확인되었다. BLV는 대부분 세포 외부에 분포하고 있었으며 세포질 막에서 생성, 발아되어 나오는 것도 관찰되었다. 전체 바이러스의 크기는 $90{\sim}100$ nm였으며 nucleocapsid는 $40{\sim}60$nm였다. 소태아혈청 (FBS)과 T- 및 B-림프구 분열촉진물질(mitogen)을 각각 첨가하여 배양한 결과 두 군 모두에서 BLV 발현이 확인되었다. Lipopolysaccharide 첨가군은 배양 12시간, Conconavalin A 첨가군은 배양 24시간에 각각 림프구의 10%에서 바이러스가 관찰되었다. 또한 FBS만 첨가한 군과 FBS와 mitogen을 모두 첨가하지 않은 군에서도 관찰되었으나 바이러스의 수는 적었다. 본 연구에서 확립된 BLV 배양 기법을 활용하면 BLV에 감염된 소 중 바이러스를 발현하는 소, 즉 전파능이 있는 개체를 찾아내어 우선적으로 도태할 수 있기 때문에 BLV 감염으로 인한 피해를 막는데 효과적으로 이용될 수 있을 것으로 사료된다.

• Asian-Australasian Journal of Animal Sciences
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• 제18권6호
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• pp.879-883
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• 2005

The integral relationship between the occurrence of lymphocyte nuclear pockets (LNPs) and BLV-infection was examined in Holstein-Friesian dairy cattle in Korea. Transmission electron microscope (TEM) was used to detect LNP in peripheral blood lymphocytes. Morphologically, the membranes of LNP were composed of two layers of double nuclear membrane. The full thickness of LNP membranes including inner and outer nuclear membrane was 60 to 70 nm. LNP prevalence was different according to the bovine leukemia virus (BLV) infection status; in BLV-seropositive cattle, LNP prevalence was 48.4% and in BLV-seronegative cattle prevalence was 5.9%. Moreover, even in seropositive animals, leukemic group was the highest at 70% positive among the groups, followed by suspect group (42.4%) and aleukemic group (23.1%). Consequently, the numbers of LNP were increased in proportion to increase of the numbers of leukocytes among BLV-seropositive cattle. The numbers of LNP per lymphocyte were increased in BLVseropositive cattle compared with seronegative cattle. The mean numbers of LNP per 100-lymphocytes were 0.35, 0.77, 1.64 and 4.7 in BLV-seronegative, BLV-seropositive aleukemic, suspect and leukemic groups, respectively. Thus, it is reasonable that LNP test can be used as the one of the diagnostic criteria of BLV infection.

• 대한바이러스학회지
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• 제30권2호
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• pp.131-139
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• 2000

Bovine leukemia virus (BLV) is an etiological agent of chronic diseases in cows worldwide. The BLV is one of retroviruses that contain a multi-functional enzyme, reverse transcriptase produced from the pol gene in its genome. We have sequenced some regions in the pol gene of BLV proviruses found in the Southern province of Korea from samples that turned out to be BL V positives by a PCR analysis. On the 5' side of the BLV pol gene (polymerase region), it was found that there were four leucines located at every 7 amino acids. They can form a leucine zipper motif that was not same as the pol gene of Japanese BLV isolate. The sequencing result of the proviral pol gene in Korean-type BLV also revealed some mutations leading to amino acid changes such as $CCT(Pro){\to}CTC(Leu)$, $AAT(Asn){\to}AAA(Lys)$, and non-sensible variations i.e., $TCT(Ser){\to}TCC(Ser)$, $ATT(Ile){\to}ATC(I1e)$ and $ACG(Thr){\to}ACA(Thr)$. On the 3' side of the pol gene (integrase region), some nucleotide sequences were mutated and led to amino acid changes. Among them, a mutation, $GAA(Glu){\to}GAC(Asp)$ occurred in many Korean-type BLV proviruses was very interesting because the amino acid was regarded as one of the most conserved amino acids in the retroviral integrase. It was also notable that the mutation on any leucine residue did not occur, in spite of its frequent appearance.

• 농업과학연구
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• 제38권2호
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• pp.249-255
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• 2011

This study was performed to investigate the characterization of infectious BLV env gene isolated form Korean Holstein Cattle and to determine its incoming origin. Gp51 region of BLV env gene known as having important role in immunological function was characterized using PCR-RFLP sequencing and phylogenetic analysis. BLV env gene was grouped into PCR-RFLP patterns with three restriction endonucleases including Pvu II, BamHI and Hae III, and we identified two new RFLP patterns from nucleotide sequences of each group. Phylogenetic analysis showed that 80% of the Korean Holstein was included in the USA and Japanese group. These results here can provide a valuable information about the character of the BLV env gene and research on infection route of BLV.

• 대한수의학회지
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• 제26권1호
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• pp.61-68
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• 1986

This paper described the distribution and transmissibility of BLV(bovine leukemia virus), the relationship between antibodies against BLV and lymphocyte count in 313 dairy cattle from 36 herds, the clinical signs and hematological findings of 2 lymphosarcomatous cattle in the northern area of Kyungpook. Eighty three (26.5%) of 313 cattle from 36 herds were positive for BLV antibodies and 19 (52.8%) of 36 herds were infected with BLV by the immunodiffusion test with BLV-gp antigen. The rate of BLV infection in cattle varied from 9.5 to 87.5% in 19 positive herds, it was higher in herds pastured during summer and included lymphosarcomatous onset than the other and also higher with the age. Eight (88.9%) out of 9 cattle which showed persistent lymphocytosis by the hematological test were positive for BLV antibodies. After 5 to 14 months, 13 (31.0%) of 42 cattle being negative for BLV antibodies in the positive herds converted into positive. Two lymphosarcomatous cattle were identified to be EBL (enzootic bovine leukemia) by the clinical sign, hematological examination and serological test.

• 농업과학연구
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• 제38권1호
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• pp.45-50
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• 2011

This study was conducted to investigate the farm situation about bovine leukemia virus(BLV) infection that greatly influence productivity in dairy cattle and compare the accuracy of diagnosis for BLV infection between PCR and ELISA techniques. Blood samples of 193 heads from 5 herds in Chungnam and Chungbuk area were used to analyze BLV gene and serum, and the results were obtained as follows. The amplified BLV gene in dairy cattle by PCR technique resulted in 226 bp, 596 bp and 434 bp, respectively, for gag, pol and env, which were well amplified. The infection rates of BLV virus diagnosed by PCR and ELISA techniques ranged from 80.55 to 100% and from 22.22 to 86.95%, respectively, and the infection rates among 5 herds were significantly different in both methods (P<0.05). Further, the average infection rates of 5 herds were 87.05 and 63.21%, respectively, for PCR and ELISA techniques. Kappa statistics for examining consistency of diagnosis by PCR and ELISA techniques showed 0.246, which represents low consistency. Consequently, PCR based BLV technique was considered as a corrective measure for diagnosis of BLV infection in Holstein dairy cattle.

• 농업과학연구
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• 제27권2호
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• pp.101-106
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• 2000

홀스타인종 181두와 한우 73를 이용하여 Bovine Leukemia Virus (BLV)에 대한 저항성과 경제형질간의 연관성을 분석하고자 실시하였다. 91bp 단편의 증폭산물을 가진 BLV 저항성 계통의 분포는 홀스타인종은 60.0%이고 한우는 39.7%이었다. 홀스타인종에서 BLV 감수성 및 저항성계통의 유전자형과 305 일령 유량 및 305일령 유지량간의 연관성분석에서는 유의성이 인정되지 않았으며 (P>0.05), 생시, 6 및 127개월령 체중에서도 유의성이 인정되지 않았다. 한우에 있어서도 BLV 저항성 및 감수성 계통과 생시, 6, 12 및 18개월령 체중과의 유의성이 인정되지 않았다. 따라서 홀스타인종과 한우에서 BLV 저항성 및 감수성 계통과 경제형질간에는 아무런 연관성이 없는 것으로 판단되었다.