Bovine Herpesvirus Type 1 Infection Research Articles

Bovine cyclic GMP-AMP synthase recognizes exogenous double-stranded DNA and activates the STING-depended interferon β production pathway

The cytosolic DNA sensor cyclic GMP-AMP synthase (cGAS) recognizes exogenous double-stranded DNA and produces 2′3′-cyclic GMP-AMP (2′3′-cGAMP), activating the stimulator of interferon genes (STING) and innate immunity. Bovine cGAS functions remain poorly understood. Herein, the coding sequence of the bo-cGAS gene was obtained and its recognition function was investigated. Bo-cGAS consists of 1542 nucleotides and the encoding acid sequence contained high sequence homology to that of other livestock. Bo-cGAS was localized in the endoplasmic reticulum and was abundant in the lung. Bo-cGAS and bo-STING coexistence significantly activated the IFN-β promotor. Synthesized 2′3′-cGAMP activated the STING-dependent pathway. Upon bo-cGAS recognition of poly(dA:dT) and bovine herpesvirus type 1 (BHV-1), Viperin transcription displayed the opposite time-dependent trend. Significant restriction of IFN-β transcription but augmentation of myxovirus resistance protein 1 (Mx1) and Viperin occurred during BHV-1 infection. Thus, bo-cGAS recognized exogenous double-stranded DNA and triggered the STING-dependent IFN-β production pathway.

Diagnostic techniques for infectious bovine rhinotracheitis: a review

Infectious bovine rhinotracheitis (IBR) is a group of the bovine respiratory disease multifaceted pathogens and a key disease of cattle, leading to significant economic losses to the dairy industry globally. The causative agent of IBR is Bovine herpesvirus type-1 (BoHV-1), which is a member of the genus Varicellovirus in the Alphaherpesvirinae subfamily, which belongs to the family Herpesviridae, order Herpesvirales. BoHV-1 can be categorized into three subtypes (BoHV-1.1, BoHV-1.2a, and BoHV-1.2b) that belong to one single viral species, which is a serologically indistinguishable strain. Therefore, a more optimal method for the rapid diagnosis of BoHV-1 infection is highly needed. Hence, the objective of this paper is to review the appropriate diagnostic techniques for the IBR virus in infected cattle. In this review, various rapid and confirmatory diagnostic methods used for the diagnosis of BoHV-1 infection were briefly described. BoHV-1 can be routinely detected by virus neutralization tests and enzyme-linked immunosorbent assays (indirect or blocking ELISA). IBRgE-ELISA is the most specific serological test for BoHV-1 and is recommended for marker vaccine to differentiate wild infection from vaccination schemes. Furthermore, virus isolation from tissue or swab samples by cell culture and DNA detection with LAMP, PCR, and real-time PCR techniques are all used to detect infected cattle. Direct sequencing of the entire genome using the Sanger sequencing method recently allowed for the differentiation of BoHV-1 subspecies and the distinction of the BoHV-1 field strain from vaccine strains based on single nucleotide polymorphisms. As the gold standard diagnosis for IBR is virus isolation in cell culture, commonly followed by BoHV-1 gene sequencing, it is also recommended.

Diagnostic Techniques for Infectious Bovine Rhinotracheitis: A Review

Infectious Bovine Rhinotracheitis (IBR) is a group of the bovine respiratory disease multifaceted pathogens and a key disease of cattle, leading to significant economic losses to the dairy industry globally. The causative agent of IBR is Bovine herpesvirus type-1 (BoHV-1), which is a member of the genus Varicellovirus in the Alphaherpesvirinae subfamily, which belongs to the family Herpesviridae, order Herpesvirales. BoHV-1 can be categorized into three subtypes (BoHV-1.1, BoHV-1.2a, and BoHV-1.2b) that belong to one single viral species, which is a serologically indistinguishable strain. Therefore, a more optimal method for the rapid diagnosis of BoHV-1 infection is highly needed. Hence, the objective of this paper is to review the appropriate diagnostic techniques for the IBR virus in infected cattle. In this review, various rapid and confirmatory diagnostic methods used for the diagnosis of BoHV-1 infection were briefly described. BoHV-1 can be routinely detected by virus neutralization tests and enzyme-linked immunosorbent assays (indirect or blocking ELISA). IBRgEELISA is the most specific serological test for BoHV-1 and is recommended for marker vaccine to differentiate wild infection from vaccination schemes. Furthermore, virus isolation from tissue or swab samples by cell culture and DNA detection with LAMP, PCR, and real-time PCR techniques are all used to detect infected cattle. Direct sequencing of the entire genome using the Sanger sequencing method recently allowed for the differentiation of BoHV-1 subspecies and the distinction of the BoHV-1 field strain from vaccine strains based on single nucleotide polymorphisms. As the gold standard diagnosis for IBR is virus isolation in cell culture, commonly followed by BoHV-1 gene sequencing, it is also recommended.

1 Cellular protein TTC4 and its cofactor HSP90 are pro-viral for bovine herpesvirus 1

Bovine Herpesvirus Type 1 (BoHV-1) infection causes infectious bovine rhinotracheitis and genital disease in cattle, with significant economic and welfare impacts. However, the role of cellular host factors during viral replication remains poorly characterised. A previously performed genome-wide CRISPR knockout screen identified pro- and antiviral host factors acting during BoHV-1 replication. Herein we validate a pro-viral role for a candidate from this screen: the cellular protein tetracopeptide repeat protein 4 (TTC4). We show that TTC4 transcript production is upregulated during BoHV-1 infection. Depletion of TTC4 protein impairs BoHV-1 protein production but does not reduce production of infectious virions, whereas overexpression of exogenous TTC4 results in a significant increase in production of infectious BoHV-1 virions. TTC4 itself is poorly characterized (especially in the context of virus infection), but is a known co-chaperone of heat shock protein 90 (HSP90). HSP90 has a well-characterized pro-viral role during the replication of diverse herpesviruses, and we therefore hypothesized that HSP90 is also pro-viral for BoHV-1. Drug-mediated inhibition of HSP90 using geldanamycin at sub-cytotoxic concentrations inhibited both BoHV-1 protein production and viral genome replication, indicating a pro-viral role for HSP90 during BoHV-1 infection. Our data demonstrates pro-viral roles for both TTC4 and HSP90 during BoHV-1 replication; possibly, interactions between these two proteins are required for optimal BoHV-1 replication, or the two proteins may have independent pro-viral roles.

β-Catenin-Specific Inhibitor, iCRT14, Promotes BoHV-1 Infection-Induced DNA Damage in Human A549 Lung Adenocarcinoma Cells by Enhancing Viral Protein Expression.

Oncolytic bovine herpesvirus type 1 (BoHV-1) infection induces DNA damage in human lung adenocarcinoma cell line A549. However, the underlying mechanisms are not fully understood. We found that BoHV-1 infection decreased the steady-state protein levels of p53-binding protein 1 (53BP1), which plays a central role in dictating DNA damage repair and maintaining genomic stability. Furthermore, BoHV-1 impaired the formation of 53BP1 foci, suggesting that BoHV-1 inhibits 53BP1-mediated DNA damage repair. Interestingly, BoHV-1 infection redistributed intracellular β-catenin, and iCRT14 (5-[[2,5-Dimethyl-1-(3-pyridinyl)-1H-pyrrol-3-yl]methylene]-3-phenyl-2,4-thiazolidinedione), a β-catenin-specific inhibitor, enhanced certain viral protein expression, such as the envelope glycoproteins gC and gD, and enhanced virus infection-induced DNA damage. Therefore, for the first time, we provide evidence showing that BoHV-1 infection disrupts 53BP1-mediated DNA damage repair and suggest β-catenin as a potential host factor restricting both virus replication and DNA damage in A549 cells.

Antiviral Property of the Fungal Metabolite 3-O-Methylfunicone in Bovine Herpesvirus 1 Infection.

Bovine herpesvirus type-1 (BoHV-1) is a widespread pathogen that provokes infectious rhinotracheitis and polymicrobial infections in cattle, resulting in serious economic losses to the farm animal industry and trade restrictions. To date, non-toxic active drugs against BoHV-1 are not available. The exploitation of bioactive properties of microbial products is of great pharmaceutical interest. In fact, fungi are a promising source of novel drugs with a broad spectrum of activities and functions, including antiviral properties. Hence, the potential antiviral properties of 3-O-methylfunicone (OMF), a secondary metabolite produced by Talaromyces pinophilus, were evaluated on BoHV-1. In this study, during BoHV-1 infection in bovine cells (MDBK), the non-toxic concentration of 5 µM OMF considerably reduced signs of cell death and increased cell proliferation. Furthermore, OMF significantly decreased the virus titer as well as the cytopathic effect and strongly inhibited the expression of bICP0, the major regulatory protein in the BoHV-1 lytic cycle. These findings were accompanied by a considerable up-regulation in the expression of the aryl hydrocarbon receptor (AhR), a multifunctional transcription factor also linked to the host’s response to a herpesvirus infection. Overall, our results suggest that by involving AhR, OMF shows potential against a BoHV-1 infection.

High mortality rate of shipping fever cases in cattle caused by bovine herpesvirus type 1 (BoHV-1)

This study reports the high prevalence and molecular characterization of BoHV-1 infection in imported cattle with respiratory system disease after international transport. A high mortality rate of 14.16% (51/360) was reported in a group of animals imported from Hungary to Turkey in 2019. A total of 17 samples were evaluated (3 lung tissue and 14 nasal swab samples) from 15 cattle aged 6 to 9 months not vaccinated against BoHV-1. Virus isolation, polymerase chain reaction (PCR) and restriction endonuclease analysis (REA) procedures were performed within the scope of this study. By virus isolation in MDBK cells, cytopathologic effects was detected in 8 samples (3 lung tissue and 5 nasal swabs samples). The same eight samples were also found positive by BoHV-1 PCR targeting gC (UL44) gene region. According to the sequencing result, the sample (ID: 10054) dropped into a cluster of BoHV-1.1. The REA was applied to the samples to confirm the results of phylogenetic analysis. All of the isolates were identified in the subgroup BoHV-1.1 by REA. These results showed a high mortality risk for imported animals and the possibility for BoHV-1 entering the receiving country via imported animals after transport. This event is a serious problem both for the control of BoHV-1 as well as for animal health and welfare.

Risk assessment and seroprevalence of bovine herpesvirus type 1 infection in dairy herds in the inner Aegean Region of Turkey

This cross-sectional study was performed to investigate the seroprevalence and associated risk factors of bovine herpesvirus type 1 (BoHV-1) infection in dairy cattle herds in Afyonkarahisar province in the Aegean Region of Turkey. Blood samples were collected from 602 cattle from 56 unvaccinated dairy herds between May 2018 and June 2019. Animal and herd-level epidemiological information was collected with a questionnaire during blood collection. Specific antibodies against BoHV-1 and bovine viral diarrhea virus (BVDV) were detected by using a virus neutralization test and a commercial indirect ELISA kit, respectively. Univariable and multivariable logistic regression analyses were used to determine any association between categorical variables and BoHV-1 seropositivity. The animal-level and herd-level seroprevalences of BoHV-1 infection were determined to be 39.53% (95% confidence interval, CI: 35.71–43.50) and 73.21% (95% CI: 60.41–83.04), respectively. Within-herd prevalence was more than 50% in 34.14% of infected herds. Cattle age (odds ratio, OR= 2.34, 95% CI: 1.58–3.44), BVDV infection (OR= 7.74, 95% CI: 5.08–11.76), and the presence of goats in the herd (OR= 2.84, 95% CI: 1.91–4.19) were identified as risk factors for BoHV-1 seropositivity by the multivariable logistic regression model. This is the first study conducted in Turkey using two-layer sampling and logistic regression analyses to determine the herd-level and animal-level seroprevalence and associated risk factors of BoHV-1 infection.

Development of a reliable bovine neuronal cell culture system and labeled recombinant bovine herpesvirus type-1 for studying virus-host cell interactions

Bovine herpesvirus type 1 (BoHV-1) is the viral causative agent of infectious bovine rhinotracheitis and a component of the bovine respiratory complex commonly referred to as shipping fever in calves. BoHV-1 is also responsible for losses of aborted calves and reductions in dairy productivity. BoHV-1 belongs to the neurotropic alphaherpesviruses which have a predilection to infect and establish latency in sensory neurons. Neuronal cell cultures provide a useful platform for experiments investigating neuronal entry, retrograde and anterograde transport, and the establishment of latency. Rodent neuronal cell lines and primary rabbit neuronal cells have been utilized for BoHV-1, though a reliable host-specific neuronal cell culture system has not been developed. In this study, BoHV-1 readily infected bovine-derived immortalized neuronal progenitor cells (FBBC-1) differentiated in cell culture producing neurite-like projections and exhibiting neuronal cell markers NeuN and L1CAM. FBBC-1 cells expressed both nectin-1 and nectin-2 alphaherpesvirus receptors on their cell surfaces, however, nectin-2 was detected in much greater abundance than nectin-1. To facilitate investigations of BoHV-1 infection, a recombinant BoHV-1 virus expressing the green fluorescent protein (GFP) cloned into a bacterial artificial chromosome (BAC) was used to generate an mCherry-VP26 fusion protein. The BoHV-1 GFP expressing VP26mCherry labeled virus infected differentiated FBBC-1 cells as evidenced by the production of infectious virions and the expression of both GFP and mCherry fluorophores. Time-lapse live cell microscopy revealed the presence of mCherry fluorescent capsids in neuronal projections immediately after virus entry moving retrograde in a saltatory manner. Proximity ligation assays (PLA) using MDBK cells demonstrated that BoHV-1 glycoprotein D (gD) interacted more efficiently with nectin-1 than nectin-2. However, the gD interaction with nectin-2 predominated in differentiated FBBC-1 cells in comparison to the gD nectin-1 interaction. The efficiently differentiated FBBC-1 neuronal cell line and fluorescently labeled BoHV-1 virions will assist experimentation aiming to elucidate specific mechanisms of virus entry and transport in a homologous bovine neuronal cell culture system.

Epidemiology of age-dependent prevalence of Bovine Herpes Virus Type 1 (BoHV-1) in dairy herds with and without vaccination

Many studies report age as a risk factor for BoHV-1 infection or seropositivity. However, it is unclear whether this pattern reflects true epidemiological causation or is a consequence of study design and other issues. Here, we seek to understand the age-related dynamics of BoHV-1 seroprevalence in seasonal calving Irish dairy herds and provide decision support for the design and implementation of effective BoHV-1 testing strategies. We analysed seroprevalence data from dairy herds taken during two Irish seroprevalence surveys conducted between 2010 and 2017. Age-dependent seroprevalence profiles were constructed for herds that were seropositive and unvaccinated. Some of these profiles revealed a sudden increase in seroprevalence between adjacent age-cohorts, from absent or low to close to 100% of seropositive animals. By coupling the outcome of our data analysis with simulation output of an individual-based model at the herd scale, we have shown that these sudden increases are related to extensive virus circulation within a herd for a limited time, which may then subsequently remain latent over the following years. BoHV-1 outbreaks in dairy cattle herds affect animals independent of age and lead to almost 100% seroconversion in all age groups, or at least in all animals within a single epidemiological unit. In the absence of circulating infection, there is a year-on-year increase in the age-cohort at which seroprevalence changes from low to high. The findings of this study inform recommendations regarding testing regimes in the context of contingency planning or an eradication programme in seasonal calving dairy herds.

Efficacy of a modified-live IBR-BVD-PI3-BRSV-Mannheimia haemolytica toxoid vaccine against challenge with virulent BHV-1 and PI3 viruses in calves 60 days of age

Efficacy of attenuated (att) bovine herpesvirus type 1 (BHV-1) and bovine parainfluenza type-3 (PI3) viruses as antigen fractions in a modified-live virus (MLV) multivalent vaccine was evaluated following single, subcutaneous (SC) administration and intranasal (IN) challenge 28 days after vaccination, with either virulent BHV-1 or PI3 viruses in young calves. A total of 80 seronegative calves, 50 to 63 days of age at the time of vaccination, were used in 2 separate studies with 40 animals per study. Calves were allocated to 2 treatment groups with 20 animals per group which received either a single dose of a MLV IBR-BVD-PI3-BRSV vaccine, Mannheimia haemolytica toxoid, or corresponding placebo formulation without targeted test antigen fractions attBHV-1 (Study 1) or attPI3 (Study 2). Incidence and duration of clinical signs associated with respiratory disease, rectal temperatures, virus shedding, and serologic responses were compared between treatment groups in each study to assess vaccine efficacy. The 5-way vaccine induced significantly higher (p<0.0001) virus neutralizing antibody responses and reduction in fever (p<0.0001), mean rectal temperatures, and lower incidence or shorter duration of clinical disease related to BHV-1 and PI3 infection than placebo-treated calves. Infectious bovine rhinotracheitis (IBR) disease, hallmark of BHV-1 infection, was observed in 95% of control calves and in only 10% of vaccinates. Vaccinated animals in Study 1 and Study 2 demonstrated a 98.8 and 98.9% reduction in virus shedding, respectively, and significantly (p<0.0001) shorter duration of virus shedding compared to control calves, demonstrating protective vaccine efficacy.

Seroprevalence and risk factors assessment of the three main infectious agents associated with abortion in dairy cattle in Isfahan province, Iran.

This study aimed to determine the seroprevalence and identify the risk factors associated with Neospora caninum, Bovine herpesvirus type 1 (BHV-1), and Bovine viral diarrhea virus (BVDV) infection on industrial Holstein dairy cattle farms in Isfahan province, Central Iran. Blood samples were taken from 216 apparently healthy cattle from 16 randomly selected Holstein dairy farms in the North, South, East, and West of Isfahan in the summer of 2017. The antibodies to N. caninum, BHV-1, and BVDV were detected using a commercially available ELISA kit. The overall seroprevalence for N. caninum, BHV-1, and BVDV was 19%, 72.2%, and 52.8%, respectively. The significant major risk factors of BHV-1 in cattle were identified as farm direction, age groups, parity, and milk yield by the univariate analysis (p < 0.05). The significant major risk factors of BVDV in cattle were identified as age groups, parity, milk yield, and stage of pregnancy (p < 0.05). The only significant major risk factor of N. caninum was farm direction (p < 0.05). A significant association of concurrent infection with BVDV and BHV-1 has shown in the current study (p < 0.05). This study is the first to report the risk factors for N. caninum, BHV-1, and BVDV infection in the central part of Iran and allows us to conclude that these agents are widely distributed in this region.

Mapping a highly conserved linear neutralizing epitope at the N-terminus of the gD glycoprotein of bovine herpesvirus type I using a monoclonal antibody

Bovine herpesvirus type 1 (BoHV-1), a member of the Alphaherpesvirinae subfamily, causes significant economic losses to the cattle industry worldwide. Envelope glycoprotein D (gD) of BoHV-1 plays an essential role in the viral entry into permissive cells and possibly cooperates with other envelope glycoproteins. The herpesvirus gD induces a protective immune response against diseases in cattle or animal models. Mapping epitopes on gD will facilitate the understanding of the BoHV-1 pathogenesis and development of alternative vaccines against various diseases associated with the virus. In this study, a monoclonal antibody (MAb), designated as 3C1, was generated using naive BoHV-1 in vaccination of mice, demonstrating that 3C1 was specific to gD and represents a neutralizing activity against BoHV-1 infection in Madin–Darby bovine kidney cells. Panels of overlapping gD recombinant proteins with glutathione S-transferase tag were prepared to define the epitope recognized by 3C1. The data demonstrated that the N-terminus of gD 23APRVTVYVD31 was recognized by 3C1. Furthermore, the 26VTVYVD31 motif was the minimal amino acid sequence for the recognition. The epitope identified in this study is highly conserved among the typical strains of BoHV-1 and BoHV-5, suggesting that this epitope may be useful in the diagnosis of diseases. In addition, the defined region on gD of BoHV-1 might be essential in viral entry upon comparison with the prototype virus in herpes simplex virus (Alphaherpesvirinae). The data will elucidate the roles of gD of BoHV-1 in viral entry and pathogenesis and its potential application for the development of vaccine candidates and diagnostic techniques based on the conserved epitopes on gD or in combination with those of other herpesvirus glycoproteins.

Bovine Herpesvirus 1 Productive Infection Led to Inactivation of Nrf2 Signaling through Diverse Approaches.

Bovine herpesvirus type 1 (BoHV-1) is a significant cofactor for bovine respiratory disease complex (BRDC), the most important inflammatory disease in cattle. BoHV-1 infection in cell cultures induces overproduction of pathogenic reactive oxygen species (ROS) and the depletion of nuclear factor erythroid 2 p45-related factor 2 (Nrf2), a master transcriptional factor regulating a panel of antioxidant and cellular defense genes in response to oxidative stress. In this study, we reported that the virus productive infection in MDBK cells at the later stage significantly decreased the expression levels of heme oxygenase-1 (HO-1) and NAD(P)H quinone oxidoreductase-1 (NQO1) proteins, the canonical downstream targets regulated by Nrf2, inhibited Nrf2 acetylation, reduced the accumulation of Nrf2 proteins in the nucleus, and relocalized nuclear Nrf2 proteins to form dot-like staining patterns in confocal microscope assay. The differential expression of Kelch-like ECH associated protein 1 (KEAP1) and DJ-1 proteins as well as the decreased association between KEAP1 and DJ-1 promoted Nrf2 degradation through the ubiquitin proteasome pathway. These data indicated that the BoHV-1 infection may significantly suppress the Nrf2 signaling pathway. Moreover, we found that there was an association between Nrf2 and LaminA/C, H3K9ac, and H3K18ac, and the binding ratios were altered following the virus infection. Taken together, for the first time, we provided evidence showing that BoHV-1 infection inhibited the Nrf2 signaling pathway by complicated mechanisms including promoting Nrf2 degradation, relocalization of nuclear Nrf2, and inhibition of Nrf2 acetylation.

Seroprevalence and risk factor associated with respiratory viral pathogens in dual-purpose cattle of Aguachica, Rio de Oro, and La Gloria municipalities in Cesar department, Colombia.

Aim:The research was conducted to determine the seroprevalence and risk factor associated with respiratory viral pathogens in dual-purpose cattle of Aguachica, Rio de Oro and La Gloria municipalities in Cesar department, Colombia.Materials and Methods:The seroprevalence study was done from the random sampling (n=1000) of blood collected from 29 dual-purpose herds, located in three municipalities (Aguachica, Rio de Oro, and La Gloria) of Cesar department. The presence of antibodies against bovine herpesvirus type 1 (BHV-1), bovine respiratory syncytial virus (BRSV), bovine viral diarrhea virus (BVDV), and bovine parainfluenza-3 virus (BPI-3V) in the samples was detected by indirect enzyme-linked immunosorbent assay. Epidemiological data were obtained using a questionnaire administered to the owner or manager of each herd.Results:The overall highest seroprevalence was observed for BHV-1 (94.7%), followed by BRSV (98.6%), BVDV (35.2%), and BPI-3V (47.1%). Regarding the seroprevalence by municipalities, there was a statistical association (p<0.05) for BVDV; however, for BRSV, BHV-1, and BPI-3V, no statistical association was found (p>0.05) between seropositive values and the municipalities, indicating that animal was seropositive in similar proportions in the three municipalities. Female sex and older animals (>24 months) were a significant risk factor for BHV-1 and BPI-3V infection. Regarding the clinical signs, there was a statistical association (p<0.05) between the seropositive values of BVDV and most of clinical signs observed, except for abortion.Conclusion:This research confirms the high seroprevalence of the respiratory viral pathogens in nonvaccinated cattle within the study areas. Therefore, appropriate sanitary management practices and routine vaccination programs should be adopted to reduce the seroprevalence of these infectious agents.

Modulation of cathelicidins, IFNβ and TNFα by bovine alpha-herpesviruses is dependent on the stage of the infectious cycle

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 infected-calves, 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.

Mapping a highly conserved linear neutralizing epitope on gD glycoprotein of bovine herpesvirus type I using a monoclonal antibody.

Bovine herpesvirus type 1 (BoHV-1), a member of the Alphaherpesvirinae, causes a variety of diseases, which result in significant economic losses worldwide. Envelope glycoprotein D (gD) of BoHV-1 plays an important role in viral entry into the permissive cells, and protective immune response. The fine mapping epitope on the gD will contribute to the understanding of viral pathogenesis and development of alternative vaccines against various diseases associated with BoHV-1. We previously reported the preparation of a monoclonal antibody (MAb) 2B6, which was raised by a truncated recombinant gD protein, demonstrating a neutralizing activity against BoHV-1 infection in Madin–Darby bovine kidney cells. This study described the identification of a linear B-cell epitope on gD using MAb 2B6. A series of partially overlapping gD proteins with glutathione S-transferase tag were generated to define the epitope recognized by MAb 2B6. The amino acid (aa) sequence 323GEPKPGPSPDADRPE337 was recognized by MAb 2B6 using Western blot with the variedly truncated recombinant proteins. Importantly, this epitope was highly conserved among the typical members of BoHV-1, indicating that the epitope may be utilized in diagnosis of diseases due to BoHV-1 infection. Furthermore, the minimal linear epitope sequence 323GEPKPGP329 on gD recognized by MAb 2B6 was confirmed using single-aa residue deletion mutation in carboxyl terminal. This finding not only contributes to our understanding of gD of BoHV-1 virion but also shows a potential for the development of vaccine candidates and diagnostic techniques.

Photodynamic inactivation of Bovine herpesvirus type 1 (BoHV-1) by porphyrins

In this work, the photodynamic efficiency of anionic meso-tetrakis sulfonophenyl (TPPS4), cationic meso-tetrakis methylpyridiniumyl (TMPyP) and their zinc complexes (ZnTPPS4 and ZnTMPyP) in the inactivation of Bovine herpesvirus type 1 (BoHV-1) was evaluated. At a non-cytotoxic concentration, all porphyrins showed significant antiviral activity after irradiation using a halogen lamp. The efficiency of the cationic porphyrins was higher than that of the anionic ones. Porphyrin complexation with zinc increases its lipophilicity and the number of absorbed photons, dramatically reducing the time for complete virus inactivation. The high superposition of the compound optical absorption and light source emission spectra played a key role in the virus inactivation efficiency. The results demonstrated the high effectivity of the photodynamic inactivation of BoHV-1. This method can be used as an auxiliary in the treatment of disorders attributed to BoHV-1 infection, and the porphyrins are promising photosensitizers for this application.

Occurrence of Bovine Viral Diarrhea (BVDV) and Bovine Infectious Rhinotracheitis (IBR) Virus Infections in Buffaloes in Pernambuco state - Brazil

Background: Buffaloes are susceptible to viral infections, often associated with pathologies of importance in cattle breeding. Among the numerous infectious diseases, Bovine Viral Diarrhea (BVDV) and Bovine Infectious Rhinotracheitis (IBR) have a negative impact on buffalo creations. This study aimed to detect the occurrence of bovine viral diarrhea virus (BVDV) and infectious bovine rhinotracheitis (IBR) virus infections in buffaloes in Pernambuco state, Brazil.Materials, Methods &amp; Results: For this purpose, serum samples were obtained from 244 buffaloes on eight properties distributed in six municipalities. The search for anti-BVDV and -bovine herpesvirus type-1 (BoHV-1) antibodies was performed using the virus neutralization technique. To analyze the association between the serological status of BoHV-1 infection and aspects of hygienic-sanitary and reproductive management, an investigative questionnaire with objective questions was used. In total, 97.9% (239/244) of buffaloes had anti-BVDV antibodies and 56.1% (137/244) had anti-BoHV-1 antibodies. Co-infection was observed in 55.3% (135/244) of buffaloes. The distribution of antibody occurrence in buffaloes by properties ranged from 90.5% to 100.0% for BVDV and from 4.8% to 100% for BoHV-1. It was not possible to perform an association analysis for BVDV infection; however, in that for BoHV-1 infection, the following variables exhibited a significant association: an extensive breeding system (P &lt; 0.001), open herd (P = 0.029), lack of reproductive rest (P = 0.029), natural mating in females with reproductive disorders (P &lt; 0.001), exploration type (P = 0.0014), presence of wild animals (P &lt; 0.001), and lack of cleaning facilities (P = 0.008).Discussion: The occurrence of anti-BVDV antibodies in this study was 97.9% this was higher than those reported in other country’s regions. The results of the present study demonstrate a high occurrence of anti-BVDV antibodies in each of the properties in Pernambuco state, demonstrating that the animals have contact with infection sources, due to the large number of positive animals. Indeed, it is likely that there is at least one PI animal in every herd. It was observed that 100% of the properties possessed at least one positive animal. The high number of positive animal properties may be related to the absence of biosecurity measures; a subclinical BVDV infection can occur which the owners cannot identify it, as it is not common the adoption of a reproductive program in the region. The occurrence of the anti-BoHV-1 antibody in this study was 56.1%. In other states, both lower and higher prevalences were reported compared to this study. The high number of properties with positive animals may be related to several factors, including the ability of the virus to remain latent, thus introducing a single animal infected with BoHV-1 sufficient for infection spread and perpetuation in buffaloes. It is believed that the introduction of infected animals and the lack of disease knowledge by the producers may have been responsible for the agent’s introduction and maintenance in the herds. In conclusion, BVDV and IBR virus infections occur in buffaloes in Pernambuco state. Thus, it is suggested that prophylactic measures, including routine diagnosis, reproductive animal control, and strict health care, such as employing cleaning facilities, avoiding contact with neighboring herds, acquiring animals with a negative diagnosis and using an artificial insemination program should be implemented at each property to reduce the reproductive losses caused by these infections.

Molecular study for bovine herpes virus type 1 detection in Iranian cattle

Bovine herpes virus type 1 (BHV-1), the causative agent of infectious bovine rhinotracheitis, is a DNA virus. This pathogen is represents the most common viral pathogen found in cattle semen. The aim of the present study was to set up a of BHV-1 detection assay in bovine blood in Lorestan province using PCR assay. The blood samples of 285 cattle in Khoramabad, Azna, Aligoodarz, Borujerd and Poldokhtar were collected, total DNA was extracted and the region encoded the gI glycoprotein was amplified by PCR using specific primers. Out of 285 blood samples, 56 (19.64%) were positive for BHV-1 (468 bp). The highest and lowest frequencies of the bacterial infection were observed in Khoramabad and Borujerd cities with 21 and 12%, respectively. The results of this study demonstrated that PCR assay represent an excellent (suitable) alternative or additional tool for BHV-1 isolates detection. Finally the study revealed a high incidence of BHV-1 in the blood of Iranian cattle. Thus all cattle must be tested periodically for BHV-1 infection and antimicrobial drugs, to prevent BHV-1 occurrence in cattle must be used. The cattle must be free BHV-1 infection prior to use.