Abstract. This study covered a population of 91 cows aged 3–6 years. Enzootic bovine leukaemia (EBL) was diagnosed with ELISA and PCR tests. The assays were performed in the 1st, 2nd, and 3rd month after calving. Use was made of anti-bovine monoclonal antibodies (Mab), (VMDR Inc. Pullman-USA) and conjugates of FITC and R-PE (Medac – Germany) with an indirect immunofluorescence reaction (IMF). A differentiation observed between the population numbers of CD19 + B lymphocytes and CD2 + T lymphocytes as well as the CD8 + T lymphocyte sub-population was found to be significant between cows with different genotypes of AcP. Moreover, a correlation was found between the polymorphism of AcP and EBL incidence in cows with reference to the number and percentage of CD19 + B lymphocytes (AcP polymorphism x EBL interaction). A significant differentiation in the profile of peripheral blood lymphocytes was observed between EBL-positive and EBL-negative cows as well as over the first three months after calving. The results reported in this study seem to indicate the potential contribution of a genetic predisposition connected with the expression of biological functions of the blood leukocyte acid phosphatase system in the activation and proliferation of these cells.

The aim of this study was to determine whether SNP at position -824 (promoter region) of the TNFα gene significantly differentiates the size of IgM+, CD5+ and CD11b+ cell subpopulations and affects the expression of membrane-bound TNFα protein (mTNFα) on these cells and their susceptibility to BLV infections.In this study, significant differences were determined for the first time between TNFα genotypes and the percentage of cells with the CD11b+TNFα+p24+ immunophenotype. Furthermore, greater expansion of lymphocytes with the IgM+TNFα+p24+ immunophenotype was reported in cows with the G/G genotype than in A/A homozygotes. Cells with the above immunophenotype were more frequently observed in cows with persistent leukocytosis than in aleukemic cattle.Our results suggest that polymorphism of the TNFα -824 A>G gene and mTNFα protein expression play an important role in the pathogenesis of enzootic bovine leukosis.

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The objective of this study was to describe and compare the genetic structure (TNF-α -position 824) of dairy cattle herds infected and not infected with the bovine leukemia virus (BLV). The results of the present study indicate that BLV-positive herds were characterized by similar genetic structure (TNF-α -824A/G). The genetic equilibrium in these herds was preserved, but a tendency to increased frequency of G/G homozygotes was found. The genetic structure of the healthy herd differed considerably from that of leukemic herds.

ABSTRACT. Tumor necrosis factor receptor type II (TNF-RII) is a surface glycoprotein that can form a complex with TNF-α and participate in the body's immune response. Functions of TNF-RII are impaired in the pathogenesis of viral diseases. We analyzed sequences in the regulatory region of the TNF-RII gene in cattle. An attempt was also made to identify mutations that would have the greatest effect on the expression of the TNF-RII gene. Selected fragments of the regulatory region of the TNF-RII gene (5'-flanking region, fragments of intron 1 and 3ꞌ-UTR) were sequenced and analyzed. Seven of the 37 analyzed mutations listed in the dbSNP base (NCBI, Gene ID 338033) were confirmed. Three previously unidentified mutations were also discovered: G/A at position -1085 (5'-flanking region), C/T at position 6338 and CA dinucleotide STR [alleles (CA) 2 , (CA) 5 , (CA) 7 ] at position 16512 (intron 1). Two single nucleotide polymorphisms with potentially the greatest effect on TNF-RII gene expression were identified, at position 16534 in intron 1 (rs42686850) and at position 33102 in the 3ꞌ-UTR (rs136228480). Further study is needed to determine whether these mutations found in the regulatory region influence TNF-RII gene expression, modulate the body's immune response and susceptibility to infections.

A single T>C nucleotide polymorphism (rs42686850) of bovine tumor necrosis factor receptor type II gene (TNF-RII) is located within a sequence with allele-specific affinity to bind E2F transcription factors, considered pivotal in the regulation of cell cycle and cell proliferation. The objective of the study was to determine the effect of this SNP and BLV infection on the TNF-RII gene expression at the mRNA and protein levels in peripheral blood mononuclear cells (PBMC). We noted that analyzed TNF-RII gene polymorphism influenced the expression of the TNF-RII gene at the mRNA level but only in BLV-positive cows. Concurrently, no statistically significant association was found between gene polymorphism and TNF-RII expression at the protein level. However, we found a significant effect of BLV infection status on the amount of TNF-RII mRNA and the percentage of PBMC expressing TNF-RII. These results show an unclear effect of considered T>C polymorphism on TNF-RII gene expression in bovine leukocytes and they suggest the involvement of BLV in modifying the TNF-RII expression in BLV-infected cows potentially implying the EBL (Enzootic Bovine Leukosis) associated pathogenesis.

Effectiveness of the methods applied to control mastitis is low. Therefore, indices are sought which could improve cow immunity to udder pathogens. The aim of the study was to determine the relationship between the polymorphism of blood leukocyte acid phosphatase (AcP), BLV infection, the somatic cell counts and the milk composition in the first trimester of lactation. Studies were performed on a population of 65 Black-and-White cows, aged 3-6 years, from a leukemia-dominated herd. Enzootic bovine leukemia was diagnosed with ELISA and PCR tests. The following analyses were performed: the contents of total protein, lactose, dry matter, somatic cell count in milk as well as microbiological analyses. The obtained results indicate the occurrence of an association between a natural BLV-infection and mammary gland secretion disturbances in cows, whereas the relationship with the acid phosphatase polymorphism is not explicit. The obtained results encourage the continuation of studies into the role of blood leukocytes AcP in the pathogenesis of mastitis.Key Words: cattle, virus BLV, udder pathogens, interactions Zusammenfassung Titel der Arbeit: Anzahl somatischer Zellen und chemische Zusammensetzung der Milch bei Kühen mit unterschiedlichen Phänotypen der sauren Phosphatase der weiβen Blutkörperchen, die auf natürliche Weise mit dem Virus der bovinen Leukämie infiziert wurden Die Wirksamkeit der eingesetzten Methoden bei der Bekämpfung von mastitis ist nicht groß. Es wird also nach Koeffizienten gesucht, die hilfreich sein könnten, um die Verbesserung der Widerstandsfähigkeit der Euter gegen die Pathogene zu erreichen. Das Ziel der Untersuchungen lag in der Bestimmung der Abhängigkeiten zwischen dem Polymorphismus der sauren Phosphatase der weißen Blutkörperchen, der BLV Infektion und der Anzahl somatischer Zellen und der Milchzusammensetzung bei Kühen, die sich im ersten Trimester der Laktation befanden. Es wurden 65 Kühe der schwarz-weißen Rasse in einem Alter von 3 bis 6 Jahren der Untersuchung unterzogen, die in einer durch Leukose befallenen Herde standen. Die enzootische Leukose der Tiere wurde anhand der Tests ELISA und PCR diagnostiziert. Es wurden Bestimmungen des Gesamteiweißes, der Laktose, der Trockenmasse, der Anzahl somatischer Zellen in der Milch und mikrobiologische Untersuchungen durchgeführt. Die erzielten Ergebnisse lassen darauf schließen, dass eine Verbindung zwischen der natürlichen Infektion BLV und den Absonderungsstörungen der Milchdrüse bei den Kühen besteht, während die Abhängigkeit vom Polymorphismus der sauren Phosphatase nicht so eindeutig erscheint. Die erzielten Ergebnisse ermutigen, die Untersuchungen über die Rolle von AcP der weißen Blutkörperchen bei der Pathogenese mastitis fortzusetzen.

ABSTRACT:The bovine leukaemia virus (BLV) is the aetiological agent of enzootic bovine leukosis. The aim of this study was to determine whether polymorphism in the TNFα gene at positions -824 AG and -793 CT in the 5' flanking region, and g.1787 in exon 4 influences leukocyte counts, the percentages of monocytes and apoptotic cells and the sizes of CD14