Search Results (77)

Background/Objectives: This study aimed to determine the changes in BVDV (bovine viral diarrhea virus), BoHV-1 (bovine herpesvirus-1), and BRSV (bovine respiratory syncytial virus) antibody levels until weaning in calves who ingested colostrum from vaccinated dairy cattle. Additionally, it aimed to measure the antibody levels induced by the vaccine administered before and after socialization after weaning. Methods: Exposure to respiratory viral and bacterial agents was monitored by PCR analysis using nasal swabs at regular intervals from birth to weaning (pre-colostral and after the 2nd, 7th, 15th, 25th, 35th, 45th, 55th, and 65th days). The levels of colostral BVDV, BoHV-1, and BRSV antibodies were monitored using an enzyme-linked immunosorbent assay (ELISA) at the same intervals from birth to weaning (pre-colostral and after the 2nd, 7th, 15th, 25th, 35th, 45th, 55th, and 65th days). Results: The highest level of maternal antibodies in the blood was detected on day 7. BoHV-1, BVDV, and BRSV antibody levels decreased steadily until weaning by 69.14%, 38%, and 53%, respectively. Conclusions: Vaccination strategies should be planned by considering the presence of maternally derived antibodies and minimizing stress that may negatively affect vaccine titers, thus maximizing vaccine efficacy in calves. Full article

Background: Infectious Bovine Rhinotracheitis (IBR), Infectious Pustular Balanoposthitis (IPB), Infectious Pustular Vulvovaginitis (IPV), late-term abortions, and neurological and systemic disease are common manifestations of Bovine Herpesvirus-1 (BoHV-1) infections. IBR is enzootic to India and several other countries across the world. Globally, both live attenuated and inactivated vaccines are available commercially for the control of the disease. This communication reports the results of an open-label, randomized field trial of an inactivated IBR marker vaccine in cattle. Methods: An indigenously developed, inactivated, glycoprotein-E (gE)-deleted marker vaccine was subjected to a field trial involving 90 healthy cattle of more than three months of age, evaluating its safety and immunogenicity. Results: Vaccination was safe without any adverse and serious adverse events, except a self-limiting and self-subsiding induration at the site of injection in a few cases. The vaccine caused elevation of body temperature but within normal physiological range; no derangements in feed intake or milk yield were recorded. A total of 90% of the subjects developed protective titers of SNT₅₀ ≥ 8 after receiving both doses of initial vaccination and maintained protective titers until 180 days thereafter. Conclusions: Altogether, our findings uphold that the indigenously developed, inactivated gE-deleted marker vaccine against IBR is safe and results in protective levels of immunity for at least six months in cattle of more than three months of age. Full article

Orthoherpesviridae is a large family of enveloped DNA virus. Among the most significant animal-infecting viruses are bovine alphaherpesvirus 1 (BoAHV1), caprine alphaherpesvirus 1 (CpAHV1) and equid alphaherpesvirus 1 (EqAHV1). Research into new methods to combat herpesvirus infections is ongoing. The aim of this study was to evaluate the antiviral activity of three extracts of the Helleborus bocconei roots against BoAHV1, CpAHV1 and EqAHV1. The roots were air-dried, extracted with methanol (MeOH) and then partitioned between n-butanol (n-BuOH) and water. All three extracts were tested for cytotoxicity on MDBK and RK-13 cells, and for antiviral activity. Two non-cytotoxic concentrations were assessed for their anti-BoAHV1, anti-CpAHV1 and anti-EqAHV1effects. Cells were incubated with the extracts for 72 h under three experimental conditions: pretreatment before viral infection, treatment post virus infection and simultaneous viral infection and treatment with extracts. The n-BuOH extract (BE) at 0.62 µg/mL inhibited the cytopathic effects of all three viruses in the simultaneous assay. Additionally, no cytopathic effect was observed in MDBK cells infected with CpAHV1and treated with 0.31 µg/mL BE post virus infection. Therefore, the BE contains molecules or groups of molecules potentially useful for developing an alternative therapy against herpesvirus (HV) infection. Full article

Rift Valley fever (RVF) is a vector-borne zoonotic viral disease that causes abortion storms, fetal malformations, and neonatal mortality in livestock ruminants. In humans, RVF can lead to hemorrhagic fever, encephalitis, retinitis, or blindness, and about 1% of patients die. Since there are no registered vaccines for human use, developing RVF vaccines for use in animals is crucial to protect animals and prevent the spread of the virus from infecting humans. We recently developed a live bovine herpesvirus type 1 quadruple gene-mutant vector (BoHV-1qmv) that lacks virulence and immunosuppressive properties. Further, we engineered a BoHV-1qmv-vectored subunit Rift Valley fever virus (RVFV) vaccine (BoHV-1qmv Sub-RVFV) for cattle, in which a chimeric polyprotein coding for the RVFV Gc, Gn, and bovine granulocyte–macrophage colony-stimulating factor (GMCSF) proteins is fused but cleaved proteolytically in infected cells into individual membrane-anchored Gc and secreted Gn-GMCSF proteins. Calves vaccinated with the BoHV-1qmv Sub-RVFV vaccine generated moderate levels of RVFV-specific serum-neutralizing (SN) antibodies and cellular immune responses. In the current study, we repurposed the BoHV-1qmv Sub-RVFV for sheep by replacing the RVFV Gc and Gn ORF sequences codon-optimized for bovines with the corresponding ovine-codon-optimized sequences and by fusing the sheep GM-CSF ORF sequences with the Gn ORF sequence. A combined primary intranasal-plus-subcutaneous primary immunization induced a moderate level of BoHV-1 (vector)- and vaccine strain MP12-specific SN antibodies and MP-12-specific cellular immune responses. Notably, an intranasal booster vaccination after 29 days triggered a rapid (within 7 days) rise in MP-12-specific SN antibody titers. Therefore, the BoHV-1qmv-vectored subunit RVFV vaccine is safe and highly immunogenic in sheep and can potentially be an efficient subunit vaccine for sheep against RVFV. Full article

Bovine alphaherpesvirus 1 (BoHV-1) acute infection leads to latently infected sensory neurons in trigeminal ganglia. During lytic infection, the immediate early expression of infected cell protein 0 (bICP0) and bICP4 is regulated by an immediate early transcription unit 1 (IEtu1) promoter. A separate bICP0 early (E) promoter drives bICP0 as an early viral gene, presumably to sustain high levels during productive infection. Notably, bICP0 protein expression is detected before bICP4 during reactivation from latency, suggesting the bICP0 E promoter drives bICP0 protein expression during the early phases of reactivation from latency. The glucocorticoid receptor (GR) and Krüppel-like factor 4 (KLF4) cooperatively transactivate the bICP0 E promoter despite this promoter lacks a consensus GR response element (GRE). KLF and specificity protein (Sp) family members comprise a “super-family” of transcription factors. Consequently, we hypothesized Sp1 and Sp3 transactivated the bICP0 E promoter. These studies revealed GR and Sp3 or Sp1 cooperatively transactivated bICP0 E promoter activity. KLF4 and Sp3, but not Sp1, had an additive effect on bICP0 E promoter activity. Mutating the consensus Sp1 and CACCC binding sites proximal to the TATA box impaired promoter activity more than the Sp1 sites further upstream from the TATA box. Full article

Bovine herpesvirus 1 (BoHV-1) productive infection induces the generation of DNA double-strand breaks (DSBs), which may consequently lead to cell apoptosis. In response to DSBs, the DNA damage repair-related protein 53BP1 is recruited to the sites of DSBs, leading to the formation of 53BP1foci, which are crucial for the repair of damaged DNA and maintaining genomic integrity by repairing DSBs. In this study, we discovered that HMGA1 may play a significant role in counteracting virus infection-induced DNA damage, as the siRNA-mediated knockdown of HMGA1 protein expression or inhibition of HMGA1 activity by the chemical inhibitor Netropsin uniformly exacerbates the DNA damage induced by BoHV-1 productive infection. Interestingly, HMGA1 may positively regulate 53BP1 expression, and treatment with Netropsin reduced the accumulation of 53BP1 protein in the nucleus, suggesting that HMGA1 may potentially influence 53BP1’s nuclear localization. However, this effect was reversed in the context of virus infection. Furthermore, Netropsin treatment restored the disruption of 53BP1 foci caused by virus infection, which is consistent with our findings that Netropsin enhances the nuclear accumulation of 53BP1. Collectively, these results indicate that HMGA1 is involved in countering DNA damage induced by virus infection. HMGA1 does indeed modulate the nuclear accumulation of 53BP1 protein, but this effect is counteracted by virus infection. Therefore, the biological function of HMGA1 in countering virus infection-induced DNA damage may be independent of its regulation of 53BP1 signaling. This is the first report suggesting that HMGA1 may be implicated in virus infection-induced DNA damage, although the precise mechanism remains to be elucidated. Furthermore, we report for the first time an interaction between HMGA1 and 53BP1, which is disrupted following virus infection. Full article

Approximately 30 distinct Mycoplasma species have been isolated from cattle, but only a few are pathogenic and can cause serious respiratory diseases. Consequently, this study aimed to identify Mycoplasma spp. infections in cattle with bovine respiratory disease (BRD), considering factors such as animal demographics, concurrent infections with other pathogens, post-mortem clinical findings and histological examinations, and seasonality. A total of 326 samples were collected from 322 cattle that had died from BRD in Northwestern Italy. A total of 54 animals (16.8%) tested positive for Mycoplasma spp., and Mycoplasma bovis (n = 22, 40.7%) and Mycoplasma dispar (n = 13, 24.1%) were the most frequently detected species among the examined cattle. Among positive cattle, those aged five months or younger were approximately five times more likely to be infected by Mycoplasma dispar than by Mycoplasma bovis compared to those older than five months (proportional incidence ratio: 5.1, 95% CI 1.2–21.2). The main bacterial pathogens identified in cattle exhibiting co-infection was Pasteurella multocida, whereas the main viral pathogens were BRSV and BoHV-1. Histopathological investigations predominantly revealed catarrhal bronchopneumonia or purulent catarrhal bronchopneumonia among the examined cattle. Finally, Mycoplasma hyopharyngis, a species isolated from the pharyngeal and nasal cavities of pigs so far, was detected for the first time in the pneumonic lung of a bovine infected with BRD. Further investigations are necessary to thoroughly characterize its host range and pathogenic potential. Full article

Bovine gammaherpesvirus 6 (BoHV-6) is endemic in cattle in Europe, with a high prevalence. There is evidence that the virus is a commensal and not associated with disease processes. For other gammaherpesviruses, it is known that they have a rather specific target cell spectrum, generally including B cells and, at least in the early phase of infection, the epithelium of the respiratory tract. In a previous study we detected BoHV-6 by quantitative PCR for the gB gene sequence of BoHV-6 in lung, bronchial lymph nodes, spleen and tongue with variable loads, suggesting cells in these tissues as target cells. In the present study, formalin-fixed, paraffin embedded samples of the same tissues from 10 cattle, with high overall BoHV-6 copy numbers, were examined by RNA in situ hybridization for BoHV-6 ORF73. This revealed extremely limited viral ORF73 transcription. A signal was only detected in individual lymphocytes within lymphatic follicles in bronchial lymph nodes, and within very rare alveolar epithelial cells and interstitial cells in the lungs, without any evidence of pathological changes in the tissues. No signal was detected in the spleen or in the oral mucosa of the tongue. The results are consistent with previous findings with other gammaherpesviruses, murine herpesvirus-68, ovine herpesvirus-2 and/or Epstein–Barr virus. They provide further evidence that BoHV-6 is without any consequence to the host and can indeed represent a commensal in cattle. Full article

A new multivalent vaccine (DIVENCE^®), containing live gE/tk double-gene-deleted BoHV-1, live-attenuated BRSV, inactivated PI3, and BVDV-1, and BVDV-2 recombinant proteins, has been designed to protect cattle against the main viral pathogens associated with bovine respiratory disease (BRD). The aim of this study was to demonstrate the efficacy of DIVENCE^® against BRD in field conditions. A total of 360 animals from three different farms were included in this study. Calves were randomly distributed to the vaccinated (n = 183; DIVENCE^®) or control (n = 177; phosphate-buffered saline solution) group. All animals received two intramuscular doses (2 mL/dose) three weeks apart of the corresponding product. The entire fattening period (approximately 9 months) was monitored to assess the incidence, severity, and morbidity of BRD as well as administered treatments and growth performance. During this study, a BRSV outbreak was reported in one farm, where vaccinated animals had significantly (p < 0.02) lower morbidity (20.4%) and severity (score of 1.70) compared to the control group (53.70% and score of 2.11). Overall, vaccinated animals had a significantly lower number of cases (p < 0.001; 0.36 vs. 0.64 cases/calf), lower morbidity (p < 0.004; 26.78% vs. 41.24%), and lower antimicrobial treatments (p = 0.01; 33.3% vs. 57.4%) than control animals. Vaccinated animals presented significantly (p = 0.01) higher carcass weight than controls (6.58 kg). Vaccination with DIVENCE^® at the beginning of the fattening period decreased the incidence and morbidity of BRD following a BRSV outbreak. Additionally, the overall incidence and morbidity of BRD throughout the entire fattening period were reduced across farms. Thus, DIVENCE^® can improve economic outcomes in fattening units by reducing antibiotic treatments and enhancing performance. Full article

Bovine alpha-herpesvirus 1 (BoHV-1) is a significant problem for the cattle industry, in part because the virus establishes latency, and stressful stimuli increase the incidence of reactivation from latency. Sensory neurons in trigeminal ganglia and unknown cells in pharyngeal tonsils are important
sites for latency. Reactivation from latency can lead to reproductive problems in pregnant cows, virus transmission to young calves, suppression of immune responses, and bacterial pneumonia. BoHV-1 is also a significant cofactor in bovine respiratory disease (BRD). Stress, as mimicked by the synthetic corticosteroid dexamethasone, reproducibly initiates reactivation from latency. Stress-mediated activation of the glucocorticoid receptor (GR) stimulates viral replication and transactivation of viral promoters that drive the expression of infected cell protein 0 (bICP0) and bICP4. Notably, GR and Krüppel-like factor 15 (KLF15) form a feed-forward transcription loop that cooperatively transactivates immediate early transcription unit 1 (IEtu1 promoter). Two  pioneer transcription factors, GR and KLF4, cooperatively transactivate the bICP0 early promoter. Pioneer transcription factors bind silent viral  heterochromatin, remodel chromatin, and activate gene expression. Thus, we
predict that these novel transcription factors mediate early stages of BoHV-1 reactivation from latency. Full article

The high variability observed in the clinical symptoms of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infections has been attributed to the presence, in a proportion of infection-naive subjects, of pre-existing cross-reactive immune responses. Here, we demonstrate that the bovine coronavirus spike protein (BoS) may represent a source of protective immunity to SARS-CoV-2. Indeed, vaccination of BALB/c mice with a Bovine herpesvirus 4 (BoHV-4)-based vector expressing BoS induced both cell-mediated and humoral immune responses that cross-react with SARS-CoV-2 spike protein. Although the spike-specific antibodies induced by BoS did not neutralize SARS-CoV-2, the T lymphocytes activated by BoS were able to induce cytotoxicity of cells expressing spike proteins derived from several SARS-CoV-2 variants. These results demonstrate that immunization with BoS may represent a source of cross-reactive immunity to SARS-CoV-2, and that these cross-reactive immune responses may exert protective functions. These results contribute to deciphering the mechanisms responsible for lack or mildness of symptoms observed in many individuals upon SARS-CoV-2 infection and may open new ways for the development of new vaccines for coronaviruses. Full article

Bovine herpesvirus type 1 (BoHV-1) causes severe diseases in bovine species and great economic burden to the cattle industry worldwide. Due to its complex life cycle, many host factors that affect BoHV-1 replication remain to be explored. To understand the possible roles that the Oct1 cellular protein could play in this process, we first created Oct1-deficient MDBK cells using CRISPR/Cas9-mediated genome editing. Upon infection, the absence of Oct1 in MDBK cells significantly impacted BoHV-1 replication, a phenotype rescued by over-expressing the wild-type Oct1 protein in the deficient cells. We further found that the expression of all three classes of temporal genes, including essential and non-essential viral genes, were significantly reduced in Oct1 knockout MDBK cells, following both high and low multiplicity of infection. In summary, our findings confirm that the bovine Oct1 protein acts as a pro-viral factor for BoHV-1 replication by promoting its viral gene transcription in MDBK cells. Full article

Bovine herpesvirus type 1 (BoHV-1) establishes lifelong latency in trigeminal ganglionic (TG) neurons following intranasal and ocular infection in cattle. Periodically, the latent virus reactivates in the TG due to stress and is transported anterogradely to nerve endings in the nasal epithelium, where the virus replicates and sheds. Consequently, BoHV-1 is transmitted to susceptible animals and maintained in the cattle population. Modified live BoHV-1 vaccine strains (BoHV-1 MLV) also have a similar latency reactivation. Therefore, they circulate and are maintained in cattle herds. Additionally, they can regain virulence and cause vaccine outbreaks because they mutate and recombine with other circulating field wild-type (wt) strains. Recently, we constructed a BoHV-1 quadruple mutant virus (BoHV-1qmv) that lacks immune evasive properties due to UL49.5 and glycoprotein G (gG) deletions. In addition, it also lacks the gE cytoplasmic tail (gE CT) and Us9 gene sequences designed to make it safe, increase its vaccine efficacy against BoHV-1, and restrict its anterograde neuronal transport noted above. Further, we engineered the BoHV-1qmv-vector to serve as a subunit vaccine against the Rift Valley fever virus (BoHV-1qmv Sub-RVFV) (doi: 10.3390/v15112183). In this study, we determined the latency reactivation and nasal virus shedding properties of BoHV-1qmv (vector) and BoHV-1qmv-vectored subunit RVFV (BoHV-1qmv sub-RVFV) vaccine virus in calves in comparison to the BoHV-1 wild-type (wt) following intranasal inoculation. The real-time PCR results showed that BoHV-1 wt- but not the BoHV-1qmv vector- and BoHV-1qmv Sub-RVFV-inoculated calves shed virus in the nose following dexamethasone-induced latency reactivation; however, like the BoHV-1 wt, both the BoHV-1qmv vector and BoHV-1qmv Sub-RVFV viruses established latency, were reactivated, and replicated in the TG neurons. These results are consistent with the anterograde neurotransport function of the gE CT and Us9 sequences, which are deleted in the BoHV-1qmv and BoHV-1qmv Sub-RVFV. Full article

Ovine herpesvirus 2 (OvHV-2) and bovine herpesvirus 4 (BoHV-4) are gamma herpesviruses that belong to the genera Macavirus and Rhadinovirus, respectively. As with all herpesviruses, both OvHV-2 and BoHV-4 express glycoprotein B (gB), which plays an essential role in the infection of host cells. In that context, it has been demonstrated that a BoHV-4 gB-null mutant is unable to infect host cells. In this study, we used homologous recombination to insert OvHV-2 ORF 8, encoding gB, into the BoHV-4 gB-null mutant genome, creating a chimeric BoHV-4 virus carrying and expressing OvHV-2 gB (BoHV-4∆gB/OvHV-2-gB) that was infectious and able to replicate in vitro. We then evaluated BoHV-4∆gB/OvHV-2-gB as a potential vaccine candidate for sheep-associated malignant catarrhal fever (SA-MCF), a fatal disease of ungulates caused by OvHV-2. Using rabbits as a laboratory model for MCF, we assessed the safety, immunogenicity, and efficacy of BoHV-4∆gB/OvHV-2-gB in an immunization/challenge trial. The results showed that while BoHV-4∆gB/OvHV-2-gB was safe and induced OvHV-2 gB-specific humoral immune responses, immunization conferred only 28.5% protection upon challenge with OvHV-2. Therefore, future studies should focus on alternative strategies to express OvHV-2 proteins to develop an effective vaccine against SA-MCF. Full article

Bovine respiratory disease (BRD) is one of the most common diseases in the cattle industry; it is a globally prevalent multifactorial infection primarily caused by viral and bacterial coinfections. In China, Mycoplasma bovis (M. bovis) and bovine herpesvirus type 1 (BoHV-1) are the most notable pathogens associated with BRD. Our previous study attempted to combine the two vaccines and conducted a preliminary investigation of their optimal antigenic ratios. Based on this premise, the research extended its investigation by administering varying vaccine doses in a rabbit model to identify the most effective immunization dosage. After immunization, all rabbits in other immunization dose groups had a normal rectal temperature without obvious clinical symptoms. Furthermore, assays performed on the samples collected from immunized rabbits indicated that there were increased humoral and cellular immunological reactions. Moreover, the histological analysis of the lungs showed that immunized rabbits had more intact lung tissue than their unimmunized counterparts after the challenge. Additionally, there appears to be a positive correlation between the protective efficacy and the immunization dose. In conclusion, the different immunization doses of the attenuated and marker M. bovis HB150 and BoHV-1 gG-/tk- combined vaccine were clinically safe in rabbits; the mix of 2.0 × 10⁸ CFU of M. bovis HB150 and 2.0 × 10⁶ TCID₅₀ BoHV-1 gG-/tk- strain was most promising due to its highest humoral and cellular immune responses and a more complete morphology of the lung tissue compared with others. These findings determined the optimal immunization dose of the attenuated and marker M. bovis HB150 and BoHV-1 gG-/tk- combined vaccine, laying a foundation for its clinical application. Full article