Lack of association between amino acid sequences of the bovine leukemia virus envelope and varying stages of infection in dairy cattle

Cerón-Téllez, Fernando; Méndez, Ana Silvia González; Pérez, Jorge Luis Tórtora; Loza-Rubio, Elizabeth; Álvarez, Hernández

doi:10.1016/j.virusres.2020.197866

Cited by 4 publications

(6 citation statements)

References 40 publications

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“…The current research identified one sample of OP328418 (by the env gene) and OP345019 (by the tax gene) from Belmira as genotype 3. This genotype has previously only been reported in Korea [ 17 ], the United States, and Japan [ 42 ] and was recently identified in Mexico [ 7 ]. The Belmira strain is the first genotype 3 reported in South America, and its entry into the country may also be related to the import of live animals, semen, and embryos, especially from the United States.…”

Section: Discussionmentioning

confidence: 88%

Phylogenetic analysis of the partial sequences of the env and tax BLV genes reveals the presence of genotypes 1 and 3 in dairy herds of Antioquia, Colombia

Úsuga-Monroy,

Díaz,

González-Herrera

et al. 2023

VirusDis.

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Bovine leukemia virus (BLV) is a retrovirus that primarily infects dairy cows. Although few studies have also used the tax gene, phylogenetic studies of BLV use mostly the env gene. The aim of this work was to establish the circulating genotypes of BLV in specialized dairy cattle from Antioquia, Colombia. Twenty blood samples from Holstein Friesian cows were collected, and their DNA was isolated. A PCR was performed for a partial region of the env and tax genes. A phylogenetic analysis was carried out using the maximum likelihood and Bayesian methods for both genes. Nineteen sequences were identified as genotype 1 by env and tax genes. Only one sequence was clustered with genotype 3 and had the highest proportion of different nucleotide sites compared to other strains. Four amino acid substitutions in the 134 amino acid residue fragment of the Env protein were identified in the Colombian sequences, and three new amino acid substitutions were reported in the 296 amino acid residue fragment of the Tax protein. R43K (Z finger), A185T (Activation domain), and L105F changes were identified in the genotype 3 sample. This genotype has been reported in the United States, Japan, Korea, and Mexico, but so far, not in Colombia. The country has a high rate of imported live animals, semen, and embryos, especially from the United States. Although it is necessary to evaluate samples from other regions of the country, the current results indicate the presence of two BLV genotypes in specialized dairy herds.

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Section: Discussionmentioning

confidence: 88%

Phylogenetic analysis of the partial sequences of the env and tax BLV genes reveals the presence of genotypes 1 and 3 in dairy herds of Antioquia, Colombia

Úsuga-Monroy,

Díaz,

González-Herrera

et al. 2023

VirusDis.

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“…We obtained 30 sequences measuring 1156 nt in length that corresponded to the BLV pX region. Phylogenetic analysis showed that all of these sequences were associated with BLV genotype 1, which is widely distributed throughout Mexico [19,20]. Furthermore, the sequences were grouped heterogeneously throughout the genotype 1 reference sequence clade, not displaying any relationship to infection phase (with and without lymphocytosis or lymphoma) nor geographic origin of the samples.…”

Section: Discussionmentioning

confidence: 96%

“…This may be related to the number of infected cells in animals with lymphocytosis, as observed in tumor cells, which did not allow us to identify differences between the study groups. The lack of difference in proviral load could also be related to the number of samples analyzed in each group [19]. Previous studies have also been unable to correlate proviral load with different infection phases [45,46].…”

Section: Discussionmentioning

confidence: 99%

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Genetic Analysis of the pX Region in Bovine Leukemia Virus genotype 1 in Holstein Friesian Cattle with Different Stages of Infection

Machuca

Pérez

Méndez

et al. 2021

Preprint

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The pX genetic region of the Bovine Leukemia Virus (BLV) includes four genes with overlapping reading frames that code for the Tax, Rex, R3 and G4 proteins. These proteins are involved in the regulation of transcriptional and post-transcriptional viral expression, as well as having oncogenic potential. Our goal was to determine the pathogenic role associated with BLV genotype 1 pX region genetics in terms of lymphocytosis, lymphomas and proviral load. We screened 724 serological samples from mixed-age Holstein Friesian cattle from six states in Mexico. Once peripheral blood leukocytes were isolated from whole blood with anticoagulant, we extracted genomic DNA using a commercial kit. Then, we designed in silico primers that hybridize in conserved regions of the BLV pX region, which allowed for PCR standardization to detect proviral DNA in infected cells. Positive amplicons were sequenced using the Sanger method, obtaining 1156 nucleotide-long final sequences that included the four pX region genes. The 30 heads of cattle that formed the genetic study population included 12 with lymphocytosis, 12 without lymphocytosis and six with lymphoma. Lymphoma presence was determined in six bovine tumor tissues using histopathology, and we identified BLV presence with in situ hybridization.Phylogenetic analysis determined that the 30 sequences were associated with genotype 1, and genetic distance between the sequences ranged from 0.2% - 2.09%. We identified two sequences in the G4 gene, one with a three-nucleotide deletion (AGU_7488L, in a cow with lymphocytosis), and one with a nine nucleotide deletion (AGU_18A, in a cow without lymphocytosis). PX region analysis identified positive selection in the G4, rex and R3 genes, and we found no difference in proviral load between the studied groups. It was not possible to establish an association between pX region variability and the development of lymphocytosis, lymphoma, asymptomatic status and proviral load in BLV-infected cattle.

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“…Samples were centrifuged at 350 g for 15 min for phase separation, plasma, and peripheral blood leukocytes (PBLs). Plasma was collected in microtubes, and we then processed the white layer using lysis solutions [18,19] to obtain PBLs. Samples were stored at −70 • C until use.…”

Section: Obtaining Pbls and Plasmamentioning

confidence: 99%

Study of the Genetic Expression of Antiretroviral Restriction Factors and Acute Phase Proteins in Cattle Infected with Bovine Leukemia Virus

et al. 2023

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The goal of this study was to analyze the genetic expression of antiretroviral restriction factors (ARF) and acute phase proteins (APP), as well as their correlation with proviral and viral loads in cattle with aleukemic (AL) and persistent lymphocytosis (PL). Complete blood samples were collected from a herd of dairy cows, and we extracted genetic material from peripheral blood leukocytes. Absolute quantification of the expression of ARF (APOBEC-Z1, Z2, and Z3; HEXIM-1, HEXIM-2, and BST2) and APP (haptoglobin (HP), and serum amyloid A (SAA)) was performed by qPCR. Statistical significance was observed in the expression of APOBEC-Z3 in BLV-infected animals. We only found positive correlations with a strong expression of the ARF genes in the AL group. The participation of APOBEC (Z1 and Z3), HEXIM-1, and HEXIM-2 was more frequently identified in BLV-infected animals. HEXIM-2 showed active gene expression in the AL group. Although the expression of ARF in early stages of infection (AL) maintains an important participation, in late stages (PL) it seems to have little relevance.

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Lack of association between amino acid sequences of the bovine leukemia virus envelope and varying stages of infection in dairy cattle

Cited by 4 publications

References 40 publications

Phylogenetic analysis of the partial sequences of the env and tax BLV genes reveals the presence of genotypes 1 and 3 in dairy herds of Antioquia, Colombia

Phylogenetic analysis of the partial sequences of the env and tax BLV genes reveals the presence of genotypes 1 and 3 in dairy herds of Antioquia, Colombia

Genetic Analysis of the pX Region in Bovine Leukemia Virus genotype 1 in Holstein Friesian Cattle with Different Stages of Infection

Study of the Genetic Expression of Antiretroviral Restriction Factors and Acute Phase Proteins in Cattle Infected with Bovine Leukemia Virus

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