The present review aims to integrate the anatomical characteristics of the mammary gland and the ... more The present review aims to integrate the anatomical characteristics of the mammary gland and the neurophysiology of milk ejection to understand the milking capacity of the water buffalo. Since one of the main uses of this species is milk production, this article will analyze the controversies on the use of oxytocin as a stimulant during milking as well as the existing alternatives that farmers apply to promote correct stimulation during milk letdown. According to the available literature, the efficiency of the milking process, the quality of the milk, and the health of the animals are elements that require the consideration of species-specific characteristics to enhance the performance of buffaloes. The incorporation of technological innovations and competitive strategies could contribute to a better understanding of water buffalo in the milk industry.
Brazilian Journal of Animal and Environmental Research, 2022
El virus de la leucosis bovina (BLV) es el agente etiológico de la leucosis enzoótica bovina (LEB... more El virus de la leucosis bovina (BLV) es el agente etiológico de la leucosis enzoótica bovina (LEB), la enfermedad neoplásica más común del ganado bovino, caracterizada por presentar una expansión policlonal benigna de linfocitos B circulantes en sangre periférica durante los primeros años post-infección que puede progresar a un estado tumoral causando la muerte del animal, o mantenerse este estado pre-leucémico durante toda la vida del animal, generando una función inmunológica anormal. BLV infecta al ganado en todo el mundo, generando un impacto económico importante en la industria del ganado lechero. Desde principios de los `90, haciendo uso de técnicas hematológicas, se han clasificado los animales infectados con BLV en linfocitóticos (LP) o asintomáticos. Sin embargo, a partir de técnicas moleculares como la PCR, en las últimas décadas se han clasificado los animales infectados según su carga proviral, permitiendo distinguir dos grupos bien definidos donde todos los animales LP ...
El estrés por calor constituye un desafío importante para la industria láctea. Los bovinos de raz... more El estrés por calor constituye un desafío importante para la industria láctea. Los bovinos de raza europea (Bos taurus) están adaptados al clima frío, presentando características morfo-fisiológicas que los vuelven vulnerables al estrés por calor. El aumento de la temperatura global, del número de vacas lecheras de alta producción (VLAP) y la intensificación de los sistemas productivos puede afectar su potencial productivo, reproductivo y su sistema inmune. Por primera vez se evalúa el patrón de expresión de ARNm de TNF-α y sus receptores en animales expuestos a estrés por calor. La expresión de ARNm de esta citoquina proinflamatoria y sus receptores se realizó mediante la técnica de PCR en tiempo real (qPCR), en bovinos Holando Argentino, en Tandil, Argentina. Los animales se evaluaron durante un año, en tres períodos: primavera (n = 15), verano (n = 14) y otoño (n = 11). Se utilizaron los registros del Sistema Meteorológico Nacional de Argentina para estimar el índice de temperatur...
This review presents and analyzes recent scientific findings on the structure, physiology, and ne... more This review presents and analyzes recent scientific findings on the structure, physiology, and neurotransmission mechanisms of transient receptor potential (TRP) and their function in the thermoregulation of mammals. The aim is to better understand the functionality of these receptors and their role in maintaining the temperature of animals, or those susceptible to thermal stress. The majority of peripheral receptors are TRP cation channels formed from transmembrane proteins that function as transductors through changes in the membrane potential. TRP are classified into seven families and two groups. The data gathered for this review include controversial aspects because we do not fully know the mechanisms that operate the opening and closing of the TRP gates. Deductions, however, suggest the intervention of mechanisms related to G protein-coupled receptors, dephosphorylation, and ligands. Several questions emerge from the review as well. For example, the future uses of these data f...
Heat stress is one of the environmental factors that most severely affects milk industry, as it h... more Heat stress is one of the environmental factors that most severely affects milk industry, as it has impact on production, immune responses and reproductive performance. The present study was conducted with high-performance Holando-Argentino cows. Our objective was to study TNF-α and its receptors pattern expression in cows from a region characterized by extreme climatic seasonality. Animals were evaluated in three periods: spring (n = 15), summer (n = 14) and autumn (n = 11). Meteorological records from a local station were used to estimate the temperature and humidity index (THI) by means of an equation previously defined. A THI higher than 68 is indicative of stressing conditions. During the summer period, the animals were exposed to 8.5 ± 1.09 h of heat stress, or THI > 68. In spring, stress hours were reduced to 1.4 ± 0.5 every day, while during the autumn, there were no recorded heat stress events. Expression of TNF-α, and its receptors was determined by qPCR. During the summer, TNF-α and its receptors expression diminished drastically compared to the rest of the year, when stressful conditions were infrequent. We conclude that animals that are not physiologically prepared to resist high temperatures might have a less efficient immune response, reinforcing the need to develop new strategies to improve animal welfare.
Brazilian Journal of Veterinary Research and Animal Science, 2017
O vírus da leucemia bovina (BLV) está associado à doença neoplásica mais comum do gado bovino. O ... more O vírus da leucemia bovina (BLV) está associado à doença neoplásica mais comum do gado bovino. O BLV tem uma disseminação silenciosa no rebanho devido à troca de células infectadas, assim, a concentração de células BLV infectadas no sangue deve desempenhar um papel importante no sucesso da transmissão viral. Os genes do antígeno leucocitário bovino (BoLA), sistema MHC do gado bovino, estão associados à resistência genética e à susceptibilidade a uma ampla gama de doenças, bem como às características da produção. Alguns polimorfismos de alelos de BoLA DRB3.2 em bovinos Holstein têm sido associados à resistência ou susceptibilidade ao desenvolvimento da doença BLV, ou com carga proviral (PVL). Esta investigação avaliou 107 vacas leiteiras da raça Holstein argentina infectadas com BLV e pertencentes a um único rebanho. A PVL foi analisada por qPCR, os animais foram classificados em alta carga proviral (HPVL, N = 88) e baixa carga proviral (LPVL, N = 19), e os alelos BoLA DRB3.2 foram g...
Infrared thermography (IRT) is a non-ionizing, non-invasive technique that permits evaluating the... more Infrared thermography (IRT) is a non-ionizing, non-invasive technique that permits evaluating the comfort levels of animals, a topic of concern due to the growing interest in determining the state of health and welfare of production animals. The operating principle of IRT is detecting the heat irradiated in anatomical regions characterized by a high density of near-surface blood vessels that can regulate temperature gain or loss from/to the environment by modifying blood flow. This is essential for understanding the various vascular thermoregulation mechanisms of different species, such as rodents and ruminants’ tails. The usefulness of ocular, nasal, and vulvar thermal windows in the orbital (regio orbitalis), nasal (regio nasalis), and urogenital (regio urogenitalis) regions, respectively, has been demonstrated in cattle. However, recent evidence for the river buffalo has detected discrepancies in the data gathered from distinct thermal regions in these large ruminants, suggesting...
Bovine leukemia virus (BLV) is a retrovirus that infects cattle and is associated with an increas... more Bovine leukemia virus (BLV) is a retrovirus that infects cattle and is associated with an increase in secondary infections. The objective of this study was to analyze the effect of BLV infection on cell viability, apoptosis and morphology of a bovine mammary epithelial cell line (MAC-T), as well as Toll like receptors (TLR) and cytokine mRNA expression. Our findings show that BLV infection causes late syncytium formation, a decrease in cell viability, downregulation of the anti-apoptotic gene Bcl-2, and an increase in TLR9 mRNA expression. Moreover, we analyzed how this stably infected cell line respond to the exposure to Staphylococcus aureus (S. aureus), a pathogen known to cause chronic mastitis. In the presence of S. aureus, MAC-T BLV cells had decreased viability and decreased Bcl-2 and TLR2 mRNA expression. The results suggest that mammary epithelial cells infected with BLV have altered the apoptotic and immune pathways, probably affecting their response to bacteria and favoring the development of mastitis.
Production of antimicrobial peptides cathelicidins, interferons and cytokines is an important fea... more Production of antimicrobial peptides cathelicidins, interferons and cytokines is an important feature in airway epithelial host defense. The innate immune response to alpha-herpesvirus infection at the sites of primary replication has not been fully studied. Thus, the aim of this study was to determine the expression of innate immune components, cathelicidins, IFNβ, TNFα and TNF receptors (TNFRI and TNFRII) during acute infection and reactivation of bovine herpesvirus type 1 (BoHV-1) and 5 (BoHV-5) in the respiratory tract and lymphoid tissue of their natural host. We found that BoHV infection modulates mainly the expression of BMAP28, a key cathelicidin in cattle. It was downregulated by both viruses in retropharyngeal lymph nodes of acutely infectedcalves, and it was accompanied by a lower expression of IFNβ, TNFα and TNFRI. BoHV-5 showed a pronounced role in the downregulation of BMAP28, even in nasal mucosa and lung. However, during reactivation, BoHV-5 upregulated both BMAP28 and IFNβ in retropharyngeal lymph nodes. Acute replication induced also TNFα mRNA and protein synthesis, and expression of TNFRI and II was positively regulated during both acute infection and reactivation, particularly in the trachea. Moreover, BMAP27 was detected during BoHV-1 reactivation suggesting a potential role at this stage. Thus, cathelicidins are implicated in alpha-herpesvirus infections of the bovine respiratory system and the response is distinct during BoHV-1 and BoHV-5 acute infection and reactivation. This demonstrates that these viruses modulate differentially the components of innate immune response, possibly influencing their pathogenesis. This study provides an initial pilot analysis of factors that might be implicated in alpha-herpesvirus infection of the bovine respiratory system.
Journal of Mammary Gland Biology and Neoplasia, 2018
The incidence of breast cancer is continuously increasing worldwide, as influenced by many factor... more The incidence of breast cancer is continuously increasing worldwide, as influenced by many factors that act synergistically. In the last decade there was an increasing interest in the possible viral etiology of human breast cancer. Since then, many viruses have been associated with this disease (murine mammary tumor virus, MMTV; Epstein-Barr virus, EBV; and human papillomavirus, HPV). Recently, BLV has been identified in human breast cancers giving rise to the hypothesis that it could be one of the causative agents of this condition. BLV is a retrovirus distributed worldwide that affects cattle, causing lymphosarcoma in a small proportion of infected animals. Because of its similarity with human retroviruses like HTLV and HIV, BLV was assumed to also be involved in tumor emergence. Based on this assumption, studies were focused on the possible role of BLV in human breast cancer development.
Bovine leukemia virus (BLV) is one of the most important virus in dairy cattle. The infection beh... more Bovine leukemia virus (BLV) is one of the most important virus in dairy cattle. The infection behavior follows what we call the iceberg phenomenon: 60% of infected animals do not show clinical signs; 30% develop persistent lymphocytosis (PL); and the remaining 10%, die due to lymphosarcoma. BLV transmission depends on infected cell exchange and thus, proviral load is determinant. Understanding the mechanisms by which cattle governs the control of viral dissemination will be desirable for designing effective therapeutic or preventive strategies for BLV. The development of high proviral load (HPL) or low proviral load (LPL) might be associated to genetic factors and humoral immune responses, however cellular responses are not fully described. It is known that BLV affects cellular homeostasis: proliferation and apoptosis. It is also known that the BLV tropism is directed towards B lymphocytes, and that lymphocytotic animals have elevated amounts of these cells. Usually, when an animal is infected by BLV, the B markers that increase are CD21, CD5 and CD11b. This increase could be related to the modulation of apoptosis in these cells. This is the first work in which animals infected with BLV are classified according to their proviral load and the subpopulations of B and T lymphocytes are evaluated in terms of their percentage in peripheral blood and its stage of apoptosis and viability. PBMCs from HPL animals proliferated more than LPL and non-infected animals. CD11b + /CD5 + lymphocytes in LPL animals presented greater early and late apoptosis than HPL animals and cells of HPL animals had increased viability than LPL animals. Our results confirm that BLV alters the mechanism of apoptosis and proliferation of infected cells.
Bovine leukemia virus (BLV) is a retrovirus that affects cattle causing a lymphoproliferative dis... more Bovine leukemia virus (BLV) is a retrovirus that affects cattle causing a lymphoproliferative disease. BLV infection has been associated with misbalance of the immune response causing a higher incidence of other infections. Mastitis is one of the most important conditions that affect milk production in cattle. The aim of this study was to stably infect a bovine mammary epithelial cell line (MAC-T). MAC-T cell line was successfully infected with BLV and the infection was confirmed by nested PCR, qPCR, immunocytochemistry, western blot and transmission electron microscopy. This is the first report of a bovine mammary epithelial cell line stably infected with BLV. This new cell line could be used as an in vitro model to study the effect of BLV on the immune response in the mammary gland and the relationship with other agents causing mastitis.
Bovine leukemia virus (BLV) infection is widespread mainly in dairy cattle and 5-10% of infected ... more Bovine leukemia virus (BLV) infection is widespread mainly in dairy cattle and 5-10% of infected animals will die due to lymphosarcoma; most cattle remain asymptomatic but 30% develop persistent lymphocytosis (PL). BLV transmission depends on infected cell exchange and thus, proviral load is determinant. Understanding the mechanisms which govern the control of viral dissemination will be desirable for the design of effective therapeutic or preventive strategies for BLV. The development of high proviral load (HPL) or low proviral load (LPL) might be associated to genetic factors and humoral immune responses, however cellular responses are not fully described. We aimed to characterize cytokines and toll-like receptors (TLR) expression related to the proviral load profiles. IFN-γ and IL-12 mRNA expression level was significantly higher in PBMC from infected cattle (LPL n = 6 and HPL n = 7) compared to uninfected animals (n = 5). While no significant differences were observed in IL-12 expression between LPL and HPL group, IFN-γ expression was significantly higher in LPL animals. Infected cattle exhibited higher expression levels of TLR3, 7-9. Animals with HPL had significantly higher expression of TLR7/8 than uninfected cattle. TLR8 and TLR9 were up-regulated in HPL group, and TLR3 was up-regulated in LPL group. This is the first report related to TLR gene expression in BLV infected cattle and represents evidence of the involvement of these receptors in BLV recognition. Further studies on different subpopulations of immune cells may help clarify their role in response to BLV and its consequences on viral dissemination.
Tumor necrosis factor alpha (TNF-a) is a pleiotropic cytokine involved in the immune response aga... more Tumor necrosis factor alpha (TNF-a) is a pleiotropic cytokine involved in the immune response against viral and other infections. Its expression levels are affected by a polymorphism in the promoter region of the gene. Bovine leukemia virus is a retrovirus that infects cattle and develops two different infection profiles in the host. One profile is characterized by a high number of proviral copies integrated into the host genome and a strong immune response against the virus, while the most relevant property of the other profile is that the number of copies integrated into the host genome is almost undetectable and the immune response is very weak. We selected a population of cattle sufficiently large for statistical analysis and classified them according to whether they had a high or low proviral load (HPL or LPL). Polymorphisms in the promoter region were identified by PCR-RFLP. The results indicated that, in the HPL group, the three possible genotypes were normally distributed and that, in the LPL group, there was a significant association between the proviral load and a low frequency of the G/G genotype at position-824.
Bovine leukemia virus (BLV)-infected cattle were classified by their proviral load into low and h... more Bovine leukemia virus (BLV)-infected cattle were classified by their proviral load into low and high proviral load profiles (LPL and HPL, respectively). Blood from these animals was used to infect sheep to obtain multiple identical copies of integrated provirus. An env fragment of BLV was amplified from all infected sheep and sequenced. The sequences that were obtained were compared to already published BLV genome sequence, resulting in three clusters. Mutations could not be attributed to the passage of provirus from cattle to sheep and subsequent amplification and sequencing. The description of two different proviral load profiles, the association of the BoLA-DRB3.2*0902 allele with the LPL profile, the availability of complete BLV sequences, and the comparison of a variable region of the env gene from carefully characterized cattle are still not enough to explain the presence of animals in every herd that are resistant to BLV dissemination. M. A. Juliarena and P. A. Lendez contributed equally to the development of this work.
Purpose: To compare recent data sets on frequency of bovine leukemia virus (BLV) detection in bre... more Purpose: To compare recent data sets on frequency of bovine leukemia virus (BLV) detection in breast tissue in different human populations, and association of BLV with a confirmed diagnosis of breast cancer and expression of common clinical biomarkers. Many risk factors are associated with breast cancer, but what causes initial molecular/cellular changes from normal to malignant is not well understood. Six types of human cancer are caused by viruses, and several viruses have been studied for a role in breast cancer. BLV is a common virus of US cattle (38% of beef herds, 89% of dairy herds, 90-100% of large dairy operations). BLV DNA and protein were previously identified in human tissues. Methods: Breast tissue specimens were archived formalin-fixed, paraffin-embedded tissue sections from sources mentioned below. In situ PCR (IS-PCR) was performed on intact deparaffinized sections on glass slides, using primers from the tax region (transforming gene), highly conserved and rarely del...
The present review aims to integrate the anatomical characteristics of the mammary gland and the ... more The present review aims to integrate the anatomical characteristics of the mammary gland and the neurophysiology of milk ejection to understand the milking capacity of the water buffalo. Since one of the main uses of this species is milk production, this article will analyze the controversies on the use of oxytocin as a stimulant during milking as well as the existing alternatives that farmers apply to promote correct stimulation during milk letdown. According to the available literature, the efficiency of the milking process, the quality of the milk, and the health of the animals are elements that require the consideration of species-specific characteristics to enhance the performance of buffaloes. The incorporation of technological innovations and competitive strategies could contribute to a better understanding of water buffalo in the milk industry.
Brazilian Journal of Animal and Environmental Research, 2022
El virus de la leucosis bovina (BLV) es el agente etiológico de la leucosis enzoótica bovina (LEB... more El virus de la leucosis bovina (BLV) es el agente etiológico de la leucosis enzoótica bovina (LEB), la enfermedad neoplásica más común del ganado bovino, caracterizada por presentar una expansión policlonal benigna de linfocitos B circulantes en sangre periférica durante los primeros años post-infección que puede progresar a un estado tumoral causando la muerte del animal, o mantenerse este estado pre-leucémico durante toda la vida del animal, generando una función inmunológica anormal. BLV infecta al ganado en todo el mundo, generando un impacto económico importante en la industria del ganado lechero. Desde principios de los `90, haciendo uso de técnicas hematológicas, se han clasificado los animales infectados con BLV en linfocitóticos (LP) o asintomáticos. Sin embargo, a partir de técnicas moleculares como la PCR, en las últimas décadas se han clasificado los animales infectados según su carga proviral, permitiendo distinguir dos grupos bien definidos donde todos los animales LP ...
El estrés por calor constituye un desafío importante para la industria láctea. Los bovinos de raz... more El estrés por calor constituye un desafío importante para la industria láctea. Los bovinos de raza europea (Bos taurus) están adaptados al clima frío, presentando características morfo-fisiológicas que los vuelven vulnerables al estrés por calor. El aumento de la temperatura global, del número de vacas lecheras de alta producción (VLAP) y la intensificación de los sistemas productivos puede afectar su potencial productivo, reproductivo y su sistema inmune. Por primera vez se evalúa el patrón de expresión de ARNm de TNF-α y sus receptores en animales expuestos a estrés por calor. La expresión de ARNm de esta citoquina proinflamatoria y sus receptores se realizó mediante la técnica de PCR en tiempo real (qPCR), en bovinos Holando Argentino, en Tandil, Argentina. Los animales se evaluaron durante un año, en tres períodos: primavera (n = 15), verano (n = 14) y otoño (n = 11). Se utilizaron los registros del Sistema Meteorológico Nacional de Argentina para estimar el índice de temperatur...
This review presents and analyzes recent scientific findings on the structure, physiology, and ne... more This review presents and analyzes recent scientific findings on the structure, physiology, and neurotransmission mechanisms of transient receptor potential (TRP) and their function in the thermoregulation of mammals. The aim is to better understand the functionality of these receptors and their role in maintaining the temperature of animals, or those susceptible to thermal stress. The majority of peripheral receptors are TRP cation channels formed from transmembrane proteins that function as transductors through changes in the membrane potential. TRP are classified into seven families and two groups. The data gathered for this review include controversial aspects because we do not fully know the mechanisms that operate the opening and closing of the TRP gates. Deductions, however, suggest the intervention of mechanisms related to G protein-coupled receptors, dephosphorylation, and ligands. Several questions emerge from the review as well. For example, the future uses of these data f...
Heat stress is one of the environmental factors that most severely affects milk industry, as it h... more Heat stress is one of the environmental factors that most severely affects milk industry, as it has impact on production, immune responses and reproductive performance. The present study was conducted with high-performance Holando-Argentino cows. Our objective was to study TNF-α and its receptors pattern expression in cows from a region characterized by extreme climatic seasonality. Animals were evaluated in three periods: spring (n = 15), summer (n = 14) and autumn (n = 11). Meteorological records from a local station were used to estimate the temperature and humidity index (THI) by means of an equation previously defined. A THI higher than 68 is indicative of stressing conditions. During the summer period, the animals were exposed to 8.5 ± 1.09 h of heat stress, or THI > 68. In spring, stress hours were reduced to 1.4 ± 0.5 every day, while during the autumn, there were no recorded heat stress events. Expression of TNF-α, and its receptors was determined by qPCR. During the summer, TNF-α and its receptors expression diminished drastically compared to the rest of the year, when stressful conditions were infrequent. We conclude that animals that are not physiologically prepared to resist high temperatures might have a less efficient immune response, reinforcing the need to develop new strategies to improve animal welfare.
Brazilian Journal of Veterinary Research and Animal Science, 2017
O vírus da leucemia bovina (BLV) está associado à doença neoplásica mais comum do gado bovino. O ... more O vírus da leucemia bovina (BLV) está associado à doença neoplásica mais comum do gado bovino. O BLV tem uma disseminação silenciosa no rebanho devido à troca de células infectadas, assim, a concentração de células BLV infectadas no sangue deve desempenhar um papel importante no sucesso da transmissão viral. Os genes do antígeno leucocitário bovino (BoLA), sistema MHC do gado bovino, estão associados à resistência genética e à susceptibilidade a uma ampla gama de doenças, bem como às características da produção. Alguns polimorfismos de alelos de BoLA DRB3.2 em bovinos Holstein têm sido associados à resistência ou susceptibilidade ao desenvolvimento da doença BLV, ou com carga proviral (PVL). Esta investigação avaliou 107 vacas leiteiras da raça Holstein argentina infectadas com BLV e pertencentes a um único rebanho. A PVL foi analisada por qPCR, os animais foram classificados em alta carga proviral (HPVL, N = 88) e baixa carga proviral (LPVL, N = 19), e os alelos BoLA DRB3.2 foram g...
Infrared thermography (IRT) is a non-ionizing, non-invasive technique that permits evaluating the... more Infrared thermography (IRT) is a non-ionizing, non-invasive technique that permits evaluating the comfort levels of animals, a topic of concern due to the growing interest in determining the state of health and welfare of production animals. The operating principle of IRT is detecting the heat irradiated in anatomical regions characterized by a high density of near-surface blood vessels that can regulate temperature gain or loss from/to the environment by modifying blood flow. This is essential for understanding the various vascular thermoregulation mechanisms of different species, such as rodents and ruminants’ tails. The usefulness of ocular, nasal, and vulvar thermal windows in the orbital (regio orbitalis), nasal (regio nasalis), and urogenital (regio urogenitalis) regions, respectively, has been demonstrated in cattle. However, recent evidence for the river buffalo has detected discrepancies in the data gathered from distinct thermal regions in these large ruminants, suggesting...
Bovine leukemia virus (BLV) is a retrovirus that infects cattle and is associated with an increas... more Bovine leukemia virus (BLV) is a retrovirus that infects cattle and is associated with an increase in secondary infections. The objective of this study was to analyze the effect of BLV infection on cell viability, apoptosis and morphology of a bovine mammary epithelial cell line (MAC-T), as well as Toll like receptors (TLR) and cytokine mRNA expression. Our findings show that BLV infection causes late syncytium formation, a decrease in cell viability, downregulation of the anti-apoptotic gene Bcl-2, and an increase in TLR9 mRNA expression. Moreover, we analyzed how this stably infected cell line respond to the exposure to Staphylococcus aureus (S. aureus), a pathogen known to cause chronic mastitis. In the presence of S. aureus, MAC-T BLV cells had decreased viability and decreased Bcl-2 and TLR2 mRNA expression. The results suggest that mammary epithelial cells infected with BLV have altered the apoptotic and immune pathways, probably affecting their response to bacteria and favoring the development of mastitis.
Production of antimicrobial peptides cathelicidins, interferons and cytokines is an important fea... more Production of antimicrobial peptides cathelicidins, interferons and cytokines is an important feature in airway epithelial host defense. The innate immune response to alpha-herpesvirus infection at the sites of primary replication has not been fully studied. Thus, the aim of this study was to determine the expression of innate immune components, cathelicidins, IFNβ, TNFα and TNF receptors (TNFRI and TNFRII) during acute infection and reactivation of bovine herpesvirus type 1 (BoHV-1) and 5 (BoHV-5) in the respiratory tract and lymphoid tissue of their natural host. We found that BoHV infection modulates mainly the expression of BMAP28, a key cathelicidin in cattle. It was downregulated by both viruses in retropharyngeal lymph nodes of acutely infectedcalves, and it was accompanied by a lower expression of IFNβ, TNFα and TNFRI. BoHV-5 showed a pronounced role in the downregulation of BMAP28, even in nasal mucosa and lung. However, during reactivation, BoHV-5 upregulated both BMAP28 and IFNβ in retropharyngeal lymph nodes. Acute replication induced also TNFα mRNA and protein synthesis, and expression of TNFRI and II was positively regulated during both acute infection and reactivation, particularly in the trachea. Moreover, BMAP27 was detected during BoHV-1 reactivation suggesting a potential role at this stage. Thus, cathelicidins are implicated in alpha-herpesvirus infections of the bovine respiratory system and the response is distinct during BoHV-1 and BoHV-5 acute infection and reactivation. This demonstrates that these viruses modulate differentially the components of innate immune response, possibly influencing their pathogenesis. This study provides an initial pilot analysis of factors that might be implicated in alpha-herpesvirus infection of the bovine respiratory system.
Journal of Mammary Gland Biology and Neoplasia, 2018
The incidence of breast cancer is continuously increasing worldwide, as influenced by many factor... more The incidence of breast cancer is continuously increasing worldwide, as influenced by many factors that act synergistically. In the last decade there was an increasing interest in the possible viral etiology of human breast cancer. Since then, many viruses have been associated with this disease (murine mammary tumor virus, MMTV; Epstein-Barr virus, EBV; and human papillomavirus, HPV). Recently, BLV has been identified in human breast cancers giving rise to the hypothesis that it could be one of the causative agents of this condition. BLV is a retrovirus distributed worldwide that affects cattle, causing lymphosarcoma in a small proportion of infected animals. Because of its similarity with human retroviruses like HTLV and HIV, BLV was assumed to also be involved in tumor emergence. Based on this assumption, studies were focused on the possible role of BLV in human breast cancer development.
Bovine leukemia virus (BLV) is one of the most important virus in dairy cattle. The infection beh... more Bovine leukemia virus (BLV) is one of the most important virus in dairy cattle. The infection behavior follows what we call the iceberg phenomenon: 60% of infected animals do not show clinical signs; 30% develop persistent lymphocytosis (PL); and the remaining 10%, die due to lymphosarcoma. BLV transmission depends on infected cell exchange and thus, proviral load is determinant. Understanding the mechanisms by which cattle governs the control of viral dissemination will be desirable for designing effective therapeutic or preventive strategies for BLV. The development of high proviral load (HPL) or low proviral load (LPL) might be associated to genetic factors and humoral immune responses, however cellular responses are not fully described. It is known that BLV affects cellular homeostasis: proliferation and apoptosis. It is also known that the BLV tropism is directed towards B lymphocytes, and that lymphocytotic animals have elevated amounts of these cells. Usually, when an animal is infected by BLV, the B markers that increase are CD21, CD5 and CD11b. This increase could be related to the modulation of apoptosis in these cells. This is the first work in which animals infected with BLV are classified according to their proviral load and the subpopulations of B and T lymphocytes are evaluated in terms of their percentage in peripheral blood and its stage of apoptosis and viability. PBMCs from HPL animals proliferated more than LPL and non-infected animals. CD11b + /CD5 + lymphocytes in LPL animals presented greater early and late apoptosis than HPL animals and cells of HPL animals had increased viability than LPL animals. Our results confirm that BLV alters the mechanism of apoptosis and proliferation of infected cells.
Bovine leukemia virus (BLV) is a retrovirus that affects cattle causing a lymphoproliferative dis... more Bovine leukemia virus (BLV) is a retrovirus that affects cattle causing a lymphoproliferative disease. BLV infection has been associated with misbalance of the immune response causing a higher incidence of other infections. Mastitis is one of the most important conditions that affect milk production in cattle. The aim of this study was to stably infect a bovine mammary epithelial cell line (MAC-T). MAC-T cell line was successfully infected with BLV and the infection was confirmed by nested PCR, qPCR, immunocytochemistry, western blot and transmission electron microscopy. This is the first report of a bovine mammary epithelial cell line stably infected with BLV. This new cell line could be used as an in vitro model to study the effect of BLV on the immune response in the mammary gland and the relationship with other agents causing mastitis.
Bovine leukemia virus (BLV) infection is widespread mainly in dairy cattle and 5-10% of infected ... more Bovine leukemia virus (BLV) infection is widespread mainly in dairy cattle and 5-10% of infected animals will die due to lymphosarcoma; most cattle remain asymptomatic but 30% develop persistent lymphocytosis (PL). BLV transmission depends on infected cell exchange and thus, proviral load is determinant. Understanding the mechanisms which govern the control of viral dissemination will be desirable for the design of effective therapeutic or preventive strategies for BLV. The development of high proviral load (HPL) or low proviral load (LPL) might be associated to genetic factors and humoral immune responses, however cellular responses are not fully described. We aimed to characterize cytokines and toll-like receptors (TLR) expression related to the proviral load profiles. IFN-γ and IL-12 mRNA expression level was significantly higher in PBMC from infected cattle (LPL n = 6 and HPL n = 7) compared to uninfected animals (n = 5). While no significant differences were observed in IL-12 expression between LPL and HPL group, IFN-γ expression was significantly higher in LPL animals. Infected cattle exhibited higher expression levels of TLR3, 7-9. Animals with HPL had significantly higher expression of TLR7/8 than uninfected cattle. TLR8 and TLR9 were up-regulated in HPL group, and TLR3 was up-regulated in LPL group. This is the first report related to TLR gene expression in BLV infected cattle and represents evidence of the involvement of these receptors in BLV recognition. Further studies on different subpopulations of immune cells may help clarify their role in response to BLV and its consequences on viral dissemination.
Tumor necrosis factor alpha (TNF-a) is a pleiotropic cytokine involved in the immune response aga... more Tumor necrosis factor alpha (TNF-a) is a pleiotropic cytokine involved in the immune response against viral and other infections. Its expression levels are affected by a polymorphism in the promoter region of the gene. Bovine leukemia virus is a retrovirus that infects cattle and develops two different infection profiles in the host. One profile is characterized by a high number of proviral copies integrated into the host genome and a strong immune response against the virus, while the most relevant property of the other profile is that the number of copies integrated into the host genome is almost undetectable and the immune response is very weak. We selected a population of cattle sufficiently large for statistical analysis and classified them according to whether they had a high or low proviral load (HPL or LPL). Polymorphisms in the promoter region were identified by PCR-RFLP. The results indicated that, in the HPL group, the three possible genotypes were normally distributed and that, in the LPL group, there was a significant association between the proviral load and a low frequency of the G/G genotype at position-824.
Bovine leukemia virus (BLV)-infected cattle were classified by their proviral load into low and h... more Bovine leukemia virus (BLV)-infected cattle were classified by their proviral load into low and high proviral load profiles (LPL and HPL, respectively). Blood from these animals was used to infect sheep to obtain multiple identical copies of integrated provirus. An env fragment of BLV was amplified from all infected sheep and sequenced. The sequences that were obtained were compared to already published BLV genome sequence, resulting in three clusters. Mutations could not be attributed to the passage of provirus from cattle to sheep and subsequent amplification and sequencing. The description of two different proviral load profiles, the association of the BoLA-DRB3.2*0902 allele with the LPL profile, the availability of complete BLV sequences, and the comparison of a variable region of the env gene from carefully characterized cattle are still not enough to explain the presence of animals in every herd that are resistant to BLV dissemination. M. A. Juliarena and P. A. Lendez contributed equally to the development of this work.
Purpose: To compare recent data sets on frequency of bovine leukemia virus (BLV) detection in bre... more Purpose: To compare recent data sets on frequency of bovine leukemia virus (BLV) detection in breast tissue in different human populations, and association of BLV with a confirmed diagnosis of breast cancer and expression of common clinical biomarkers. Many risk factors are associated with breast cancer, but what causes initial molecular/cellular changes from normal to malignant is not well understood. Six types of human cancer are caused by viruses, and several viruses have been studied for a role in breast cancer. BLV is a common virus of US cattle (38% of beef herds, 89% of dairy herds, 90-100% of large dairy operations). BLV DNA and protein were previously identified in human tissues. Methods: Breast tissue specimens were archived formalin-fixed, paraffin-embedded tissue sections from sources mentioned below. In situ PCR (IS-PCR) was performed on intact deparaffinized sections on glass slides, using primers from the tax region (transforming gene), highly conserved and rarely del...
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Papers by Pamela Lendez