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1.
The onset of protection offered by intranasal vaccination with attenuated bovine herpesvirus-1 (BHV-1) was studied in 18 calves given a virulent BHV-1 aerosol challenge inoculum and an aerosol challenge exposure to Pasteurella haemolytica. Calves challenge exposed with virus 3, 7, 11, 15, or 19 days after vaccination and challenge exposed 4 days later with Pasteurella haemolytica did not develop viral-bacterial pneumonia, whereas 2 of 3 control calves died of fibrinous bronchopneumonia 40 and 60 hours after the bacterial aerosol and the 3rd control calf had similar lesions. All vaccinated and control calves had detectable amounts of interferon at the time of viral challenge exposure. Protection was observed before detection of neutralizing antibodies to BHV-1 in nasal secretions or in serum. Protection was therefore present from day 3 through day 19 after vaccination, but the mechanism could not be explained completely by neutralizing antibody or interferon.  相似文献   

2.
OBJECTIVE: To determine whether a combination viral vaccine containing modified-live bovine herpesvirus-1 (BHV-1) would protect calves from infection with a recent field isolate of BHV-1. DESIGN: Randomized controlled trial. ANIMALS: Sixty 4- to 6-month-old beef calves. PROCEDURE: Calves were inoculated with a placebo 42 and 20 days prior to challenge (group 1; n = 10) or with the combination vaccine 42 and 20 days prior to challenge (group 2; 10), 146 and 126 days prior to challenge (group 3; 10), 117 and 96 days prior to challenge (group 4; 10), 86 and 65 days prior to challenge (group 5; 10), or 126 days prior to challenge (group 6; 10). All calves were challenged with BHV-1 via aerosol. Clinical signs, immune responses, and nasal shedding of virus were monitored for 14 days after challenge. RESULTS: Vaccination elicited increases in BHV-1-specific IgG antibody titers. Challenge with BHV-1 resulted in mild respiratory tract disease in all groups, but vaccinated calves had less severe signs of clinical disease. Extent and duration of nasal BHV-1 shedding following challenge was significantly lower in vaccinated calves than in control calves. In calves that received 2 doses of the vaccine, the degree of protection varied with the interval between the last vaccination and challenge, as evidenced by increases in risk of clinical signs and extent and duration of viral shedding. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that this combination vaccine provided protection from infection with virulent BHV-1 and significantly reduced nasal shedding of the virus for at least 126 days after vaccination.  相似文献   

3.
Eight calves (2 calves in each of 4 groups) were exposed to an aerosol of bovine herpesvirus-1 (BHV-1) and 4 days later to an aerosol of Pasteurella haemolytica. Samples of tracheal and exhaled air were taken simultaneously beginning 1 day before viral exposure and once a day up to 3 to 4 days after the bacterial exposure. Samples were also taken during the period of aerosol exposure. Only 0.04% to 0.42% of P haemolytica-carrying droplets of the bacterial aerosol passed beyond the cranial part of the respiratory tract to the trachea. Nevertheless, numbers of bacteria as few as 1 bacterium/L of tracheal air were sufficient to produce fatal disease in the lungs of BHV-1-infected calves. In 1 of 4 groups, BHV-1 was isolated from most daily samples of exhaled and tracheal air. Pasteurella haemolytica was isolated 7 times more frequently from air when calves were kept at 1 C than when calves were kept at 23 C. The number of P haemolytica-carrying droplets in exhaled air was low (less than 1/L of air); however, samples obtained during the time that calves were coughing contained up to 10 P haemolytica-carrying droplets/L of air. It was learned that the cranial part of the respiratory tract serves as an efficient filter on inhalation and exhalation, but this filter is deficient in the animal when coughing occurs. This process expels infective droplets of size suitable for inhalation by other cattle in close proximity.  相似文献   

4.
The in vivo administration of bovine recombinant interleukin-2 (rIL-2) was evaluated in calves vaccinated and then challenged with bovine herpesvirus-1 (BHV-1). In Experiment 1, 24 calves were allotted to four groups: control; bovine rIL-2; BHV-1 vaccine (modified-live); and bovine rIL-2 + BHV-1 vaccine. Serum neutralizing antibody titers to BHV-1 were increased sixfold, and virus shedding was fourfold less in calves vaccinated and treated with rIL-2 (25 micrograms/kg, intramuscularly) when compared to calves that received vaccine only. Treatment with rIL-2 induced lymphokine-activated killer activity that was eliminated by pretreating effector cells with complement and a monoclonal antibody (B26A) specific for the sheep red blood cell receptor. The rIL-2 treatment in BHV-1-vaccinated calves increased the calves' ability to withstand a BHV-1 challenge. However, during treatment with rIL-2, calves developed diarrhea and mild fever that abated after IL-2 treatment was stopped. A second experiment was then conducted to determine a dose of rIL-2 that would enhance immunity to BHV-1 without causing adverse side effects. Twenty-five calves were allotted to five groups that received injections of rIL-2 at 0.0, 25.0, 2.5, 0.25, or 0.025 micrograms kg-1 day-1 for 5 days. All calves received a modified-live BHV-1 vaccine. Calves treated with 25.0 micrograms kg-1 day-1 showed similar adverse side effects as in the first experiment but all other calves were normal. Compared to control calves, those treated with 25.0, 2.5, and 0.25 micrograms kg-1 day-1 of rIL-2 had higher (P less than 0.05) serum antibody titers to BHV-1 and following challenge lower (P less than 0.05) BHV-1 titers in nasal secretions; additionally, clinical disease as evidenced by nasal and ocular discharge was less severe (P less than 0.05). In vitro cytotoxic responses against BHV-1-infected bovine kidney cells were increased (P less than 0.05) in calves treated with rIL-2 in a dose dependent manner. These data suggest that bovine rIL-2 at 2.5 to 0.25 micrograms/kg may be an effective adjuvant to immunization.  相似文献   

5.
Pulmonary lavage samples were collected from 90- to 130-day-old calves before and 6 days after aerosol inoculation with bovine herpesvirus-1 (BHV-1) or parainfluenza-3 (PI3) virus. Alveolar lining material was separated from lavage fluids by high-speed centrifugation and phospholipids were extracted from alveolar lining material and analyzed by high-performance liquid chromatography. Phosphatidylcholine and phosphatidylethanolamine were 74.2 +/- 6.5% and 13.3 +/- 2.8%, respectively, of the total phospholipid content in the surfactant obtained from calves before virus inoculation. Other phospholipids were represented by substantially lower percentages. Infection with either of the 2 viruses caused a significant (P less than or equal to 0.05) decrease in the percentage of phosphatidylcholine to 66.0 +/- 8.0% and 65.1 +/- 10.8% in the calves inoculated with BHV-1 and PI3 virus, respectively. A significant (P less than or equal to 0.05) increase in the percentage of phosphatidylethanolamine to 18.1 +/- 2.2% and 17.8 +/- 4.5% developed in calves inoculated with BHV-1 and PI3 virus, respectively. Infection with BHV-1 also induced an increase (not significant) in the percentage of phosphatidylinositol from 5.5 +/- 2.8% to 7.8 +/- 2.2%. A similar, but not significant, increase in the percentage of phosphatidylinositol was also seen in the calves inoculated with PI3 virus. Less substantial changes in the percentage of other phospholipids were detected after virus infection.  相似文献   

6.
A DNA vaccine expressing glycoprotein C (gC) of bovine herpesvirus-1 (BHV-1) was evaluated for inducing immunity in bovines. The plasmid encoding gC of BHV-1 was injected six times intramuscularly or intradermally into calves at monthly intervals. After immunization by both routes neutralizing antibody and lymphoproliferative responses developed. The responses in the intradermally immunized calves were better than those in calves immunized intramuscularly. However, the intradermal (i.d.) route was found to be less efficacious when protection against BHV-1 challenge was compared. Following intranasal BHV-1 challenge, all immunized calves demonstrated a rise in IgG antibody titre on day 3, indicating an anamnestic response. The control non-immunized calf developed a neutralizing antibody response on day 7 post-challenge. The immunized calves showed a slight rise in temperature and mild clinical symptoms after challenge. The intramuscularly immunized calves showed earlier clearance of challenge virus compared with intradermally immunized calves. These results indicate that DNA immunization with gC could induce neutralizing antibody and lymphoproliferative responses with BHV-1 responsive memory B cells in bovines. However, the immunity developed was not sufficient to protect calves completely from BHV-1 challenge.  相似文献   

7.
A bovine herpesvirus-1 (BHV-1) vaccine expressing glycoprotein D, the form with the transmembrane anchor removed, was evaluated for inducing immunity in calves. The plasmid encoding gD of BHV-1 was injected three times to nine calves, using three animals for each of the following routes: intramuscularly (i.m.), intradermally (i.d.), or intranasally (i.n.). Three additional calves were given the plasmid vector only and served as unvaccinated controls. When calves were subjected to challenge infection with BHV-1, all vaccinated calves as well as the controls developed a typical severe form of infectious bovine rhinotracheitis. However, compared to the controls, the vaccinated calves showed earlier clearance of challenge virus. Moreover, the calves given the vaccine i.m. developed neutralizing antibody to BHV-1 between 21 and 42 days following the first injection of vaccine, whereas in calves vaccinated either i.d. or i.n., as well as the controls, antibody first appeared in their sera 14 days post-challenge infection.  相似文献   

8.
Outbreaks of infectious bovine rhinotracheitis (IBR) have recently been observed in vaccinated feedlot calves in Alberta a few months post-arrival. To investigate the cause of these outbreaks, lung and tracheal tissues were collected from calves that died of IBR during a post-arrival outbreak of disease. Bovine herpesvirus-1 (BHV-1), the causative agent of IBR, was isolated from 6 out of 15 tissues. Of these 6 isolates, 5 failed to react with a monoclonal antibody specific for one of the epitopes on glycoprotein D, one of the most important antigens of BHV-1. The ability of one of these mutant BHV-1 isolates to cause disease in calves vaccinated with a modified-live IBR vaccine was assessed in an experimental challenge study. After one vaccination, the majority of the calves developed humoral and cellular immune responses. Secondary vaccination resulted in a substantially enhanced level of immunity in all animals. Three months after the second vaccination, calves were either challenged with one of the mutant isolates or with a conventional challenge strain of BHV-1. Regardless of the type of virus used for challenge, vaccinated calves experienced significantly (P < 0.05) less weight loss and temperature rises, had lower nasal scores, and shed less virus than non-vaccinated animals. The only statistically significant (P < 0.05) difference between the 2 challenge viruses was the amount of virus shed, which was higher in non-vaccinated calves challenged with the mutant virus than in those challenged with the conventional virus. These data show that calves vaccinated with a modified-live IBR vaccine are protected from challenge with either the mutant or the conventional virus.  相似文献   

9.
Four bovine herpesvirus-1 (BHV-1) commercial vaccines, three of which (vaccines B, D, E) were modified live vaccines (MLV) and one (vaccine A) identified as a live strain of BHV-1 gE negative, were used for vaccination of calves, using three calves for each vaccine. Three months after vaccination calves were subjected to dexamethasone (DMS) treatment following which virus was recovered from calves inoculated with vaccine B and from those given vaccine D. No virus reactivation was obtained in calves, which received vaccines A or E. The DNA extracted from the two reactivated viruses was subjected to restriction endonuclease analysis. The restriction pattern of the isolate obtained from calves vaccinated with vaccine D differs significantly from that of the original vaccine, whereas the reactivated virus from calves given vaccine B conserved the general pattern of the original vaccine strain. For each reactivated virus in this experiment (B and D) as well as for the isolate obtained from calves vaccinated with a further MLV (vaccine C) in a previous trial, three calves were inoculated. No clinical signs of disease were detected in any of the inoculated calves during the observation period. When the nine calves were exposed 40 days later to challenge infection with virulent BHV-1, they remained healthy and no virus was isolated from their nasal swabbings. These results indicate that some BHV-1 vaccines considered in the project can establish latency in the vaccinated calves, however, the latency does not appear to interfere with the original properties of the vaccines in terms of safety and efficacy.  相似文献   

10.
Influence of isoprinosine on bovine herpesvirus type-1 infection in cattle   总被引：1，自引：0，他引：1  
A study was conducted to determine the in vivo efficacy of isoprinosine (ISO) in calves infected with bovine herpesvirus type-1 (BHV-1). Calves were infected with BHV-1 on day 0 and received ISO daily for 14 days. Clinical signs of disease, shedding of BHV-1, lymphocyte proliferative responses to mitogens, interleukin-2 production, and alveolar macrophage bactericidal activity were monitored during the study. Rectal temperatures were increased (P less than 0.05) in BHV-1 and ISO-BHV-1 calves at days 3 to 7 postinfection (PI). Isoprinosine did not influence BHV-1 shedding in calves. Lymphocyte proliferative responses to phytohemagglutinin (PHA) were lower (P less than 0.01) in BHV-1 calves when compared to control or ISO calves at day 4 PI, but ISO did not ameliorate this effect. Interleukin-2 activity was greater (P less than 0.05) in ISO-BHV-1 calves on days 4 and 8 PI in PHA-stimulated lymphocytes and on day 8 PI in concanavalin A-stimulated lymphocytes when compared to control, ISO or BHV-1 calves. Isoprinosine treatment of BHV-1-infected calves tended to decrease alveolar macrophage bactericidal activity. These data suggest that ISO does not reverse BHV-1 suppression of lymphocyte proliferation, but may enhance IL-2 production in BHV-1 infected calves.  相似文献   

11.
Susceptible calves were administered modified live virus (MLV) vaccines containing bovine herpesvirus-1 (BHV1) and bovine viral diarrhoea type 1 (BVDV1a) strains intramuscularly, with one vaccine containing both MLV and inactivated BHV-1 and inactivated BVDV1a. There was no evidence of transmission of vaccine (BHV-1 and BVDV1a) strains to susceptible non-vaccinated controls commingled with vaccinates. No vaccinates had detectable BHV-1 in peripheral blood leucocytes (PBL) after vaccination. Each of three vaccines containing an MLV BVDV1a strain caused a transient BVDV vaccine induced viremia in PBL after vaccination, which was cleared as the calves developed serum BVDV1 antibodies. The vaccine containing both MLV and inactivated BHV-1 induced serum BHV-1 antibodies more rapid than MLV BHV-1 vaccine. Two doses of MLV BHV-1 (days 0 and 28) in some cases induced serum BHV-1 antibodies to higher levels and greater duration than one dose.  相似文献   

12.
Peripheral blood mononuclear cells (PBMCs) from 5 calves (3 controls and 2 vaccinates) used in a bovine herpesvirus 1 (BHV-1) vaccine study with a BHV-1 Cooper strain challenge were collected 6 months after challenge. The PBMCs from the control animals were positive by immunofluorescence for the BHV-1 glycoprotein D (gD) while the vaccinates were negative. The PBMC samples from 4 of the 5 animals were examined for BHV-1 DNA by polymerase chain reaction (PCR) and for gD immunofluorescence at 8 months after challenge. The BHV-1 DNA and viral antigen were detected in PBMC samples at 8 months postinfection, but no virus was isolated.  相似文献   

13.
Calves, 90 to 130 days old, were inoculated with bovine herpesvirus-1 (BHV-1) or parainfluenza-3 (PI-3) virus. Pulmonary lavage specimens obtained from calves before virus inoculation contained 98% alveolar macrophages (AM) and 1% neutrophils. Six days after inoculation, the mean percentage of neutrophils in lavage specimens had significantly increased to 7.9 +/- 6.0% in BHV-1-inoculated calves and to 18.3 +/- 9.9% in PI-3 virus-inoculated calves, reflecting viral-induced pulmonary inflammation that was confirmed histologically. Approximately 75% of AM obtained before virus inoculation had Fc surface receptors, and 60% had C3b receptors. Six days after inoculation, the percentage of AM with Fc and C3b receptors was significantly reduced to 69.7 +/- 8.6% and 27.1 +/- 19.8%, respectively, in BHV-1-inoculated calves and to 67.8 +/- 15.4% and 38.8 +/- 23.2%, respectively, in PI-3 virus-inoculated calves. Alveolar macrophages obtained after virus inoculation were significantly impaired in their ability to phagocytize opsonized Staphylococcus epidermidis, but were able to kill ingested bacteria. Alveolar macrophage dysfunctions caused by BHV-1 or PI-3 respiratory infection did not differ appreciably.  相似文献   

14.
Latent bovine herpesvirus-1 (BHV-1) infection was established in 6 calves and was demonstrated by reinduction of virus shedding after administration of corticosteroids. Latently infected calves failed to transmit BHV-1 during 4 weeks' contact with sentinel calves. Infected calves were killed and necropsied during latency or induced recrudescence. The BHV-1 DNA was demonstrated intranuclearly in trigeminal ganglion neurons by in situ hybridization. The BHV-1 antigen was demonstrated by immunofluorescence in trigeminal ganglion neurons during recrudescence. By electron microscopy, changes in the appearance of the Nissl bodies and a high frequency of nuclear bodies were observed in trigeminal ganglion neurons.  相似文献   

15.
Recrudescence of bovine herpesvirus-5 in experimentally infected calves   总被引：2，自引：0，他引：2  
A latent infection of bovine herpesvirus-5 (BHV-5) was established in 4 calves. These calves, plus 2 controls, were given dexamethasone (DM) to reactivate the latent virus. The 4 principal calves developed antibodies to BHV-5 by postinoculation day (PID) 21. Antibody titers increased until PID 42 before decreasing to low levels of PID 75. After the first DM treatment (started on PID 76), an anamnestic antibody response was demonstrated in the 4 principal calves. Calves, 2, 3, and 4 were euthanatized and necropsied at PID 121, and their antibody titers were again decreasing. The virus BHV-5 was not isolated from the tissues by conventional techniques of viral isolation but was isolated from the trigeminal ganglion and spinal cord of calf 3 by explantation techniques. The BHV-5 was isolated, using conventional viral isolation techniques, from a nasal swab sample of calf 1 on PID 91 (15 days after the first DM treatment) and from the thoracic lymph node 6 days after the start of a 2nd DM treatment. Seemingly, BHV-5 may be latently harbored in the nerve tissues or calves and this virus may be reactivated from the upper respiratory tract following subsequent DM treatment.  相似文献   

16.
The immune receptor-mediated functions of bovine alveolar macrophages (AM) inoculated in vitro with bovine herpesvirus-1 (BHV-1) or parainfluenza-3 (PI-3) virus were tested in the presence or absence of virus-specific antiserum or pulmonary lavage fluids collected from calves 6 days after inoculation with BHV-1 or PI-3 virus. The Fc and C3b phagocytic indices of noninoculated AM, collected from 6- to 16-week-old calves, ranged from 75 to 87 and 59 to 64, respectively, and the binding indices ranged from 5 to 8 and 22 to 28, respectively. Infection of AM with either BHV-1 or PI-3 virus had no significant effect on receptor-mediated phagocytosis or binding, with the exception of a significant (P less than 0.05) decrease, from 64 to 46, of the C3b phagocytic index of PI-3 virus-infected AM. The addition of lavage fluids, collected after BHV-1 or PI-3 virus infection, to AM infected with the respective virus caused a significant (P less than 0.05) decrease in phagocytic indices with values for the Fc and C3b indices in BHV-1-infected AM decreasing from 81 to 49 and from 47 to 8, respectively, and those for the PI-3 virus-infected AM from 79 to 51 and from 46 to 15, respectively. The binding indices of virus-infected AM increased with the addition of viral lavage fluids, but the only significant (P less than 0.05) increase was for C3b binding in PI-3 virus-infected cells, which increased from 33 to 56.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   

17.
Four immunisation protocols based on inactivated and attenuated commercially available marker vaccines for bovine herpesvirus type 1 (BHV-1) were compared. The first group of calves were vaccinated with an attenuated vaccine administered intranasally and an inactivated vaccine injected subcutaneously, four weeks apart; the second group were vaccinated twice with the attenuated vaccine, first intranasally and then intramuscularly; the third group were vaccinated twice subcutaneously with the inactivated vaccine; and the fourth group were vaccinated twice intramuscularly with the attenuated vaccine. A control group of calves were not vaccinated. The cellular and humoral immune responses were highest in the two groups which received at least one injection of the inactivated vaccine. Virological protection was observed in all the vaccinated groups after a challenge infection and reactivation by treatment with dexamethasone, but the calves which received one dose of the inactivated vaccine as a booster or two doses of the inactivated vaccine excreted significantly less of the challenge virus than the calves which were vaccinated only with the attenuated preparation.  相似文献   

18.
The aim of this work was to investigate the susceptibility of calves infected with bovine viral diarrhea virus (BVDV) against secondary infections. For this purpose, the profile of cytokines implicated in the immune response of calves experimentally infected with a non-cytopathic strain of BVDV type-1 and challenged with bovine herpesvirus 1.1 (BHV-1.1) was evaluated in comparison with healthy animals challenged only with BHV-1.1. The immune response was measured by serum concentrations of cytokines (IL-1β, TNFα, IFNγ, IL-12, IL-4 and IL-10), acute phase proteins (haptoglobin, serum amyloid A and fibrinogen) and BVDV and BHV-1.1 specific antibodies. BVDV-infected calves displayed a great secretion of TNFα and reduced production of IL-10 following BHV-1 infection, leading to an exacerbation of the inflammatory response and to the development of more intense clinical symptoms and lesions than those observed in healthy animals BHV-1-inoculated. A Th1 immune response, based on IFNγ production and on the absence of significant changes in IL-4 production, was observed in both groups of BHV-1-infected calves. However, whereas the animals inoculated only with BHV-1 presented an IFNγ response from the start of the study and high expression of IL-12, the BVDV-infected calves showed a delay in the IFNγ production and low levels of IL-12. This alteration in the kinetic and magnitude of these cytokines, involved in cytotoxic mechanisms responsible for limiting the spread of secondary pathogens, facilitated the dissemination of BHV-1.1 in BVDV-infected calves.  相似文献   

19.
Generalized bovine herpesvirus 1 (BHV-1) infection was diagnosed in six Salers calves from the same herd. The calves had received an intramuscular injection of modified-live infectious bovine rhinotracheitis parainfluenza-3 vaccine between birth and three days of age. The purpose of this study was to determine if the outbreak was associated with the vaccine strain of BHV-1. Analysis of epidemiological data and BHV-1 DNA for restriction fragment length polymorphism was undertaken. Multifocal necrosis in multiple organs was observed on pathological examination, and the presence of BHV-1 in tissues was confirmed by immunohistochemistry. Forty-three calves (aged birth to thirty days) were vaccinated over an 11-day interval. The 10 deaths recorded for vaccinated calves were clustered over a subsequent 14-day interval. Mortality in calves vaccinated between birth and three days of age was significantly higher than in nonvaccinated calves (chi-square test; p < or = 0.025), and this mortality was characterized by a greater age at death and duration of illness for vaccinated calves (t test; p < or = 0.001). The patterns of the restriction fragments, generated by six restriction endonucleases, of BHV-1 isolated from a necropsied calf and from the vaccine were identical, and different from that of a laboratory strain of BHV-1 (P8-2). These findings support the conclusion that newborn calves were susceptible to an intramuscularly injected vaccine strain of BHV-1, and that administration of an intramuscular modified-live infectious bovine rhinotracheitis parainfluenza-3 vaccine to neonatal calves may not be an innocuous procedure.  相似文献   

20.
Four DNA vaccines against BoHV-1 were evaluated for their efficacy in calves. Twelve animals were divided into four groups which were injected with four different DNA vaccines: pVAX-tgD (Vaccine A); pVAX-tgD co-immunised with pVAX-48CpG (Vaccine B); pVAX-UbiLacI-tgD-L (Vaccine C); pVAX-UbiLacI-tgD-L co-immunised with pVAX-48CpG (Vaccine D). Three additional calves were given the plasmid vector and served as controls. Ninety days after the first vaccination all calves were challenge infected with BoHV-1.All animals developed a severe form of infections bovine rhinotracheitis. Only the calves given the pVAX-tgD co-immunised with pVAX-48CpG (Vaccine B) developed humoral antibodies against BoHV-1 between 56 and 90 days after the first vaccination, whereas in calves of other groups and in the controls, antibodies appeared only after the infection. In the calves vaccinated with either pVAX-tgD (Vaccine A) or pVAX-tgD combined with pVAX-48CpG (Vaccine B), BoHV-1-specific IFN-γ secreting cells were detected in PBMCs 90 days after the first vaccination and their number increased after challenge exposure. In the other groups the IFN-γ secreting cells were detected after virus infection and at low values.  相似文献   

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