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1.
The cytotoxic effect of bovine neutrophils, alveolar macrophages, monocytes and lymphocytes for parainfluenza type-3 (PI-3) virus-infected cells in 51chromium-release assays is described. Specific lysis of virus-infected target cells with PI-3 virus antibody and complement was first observed 8 h after infection coincident with the appearance of haemadsorption-positive cells. Specific lysis increased rapidly reaching a peak 18-24 h after infection. This increase was paralleled by the increase in the percentage of cells with surface haemagglutinin. Target cells were subsequently used in 51chromium-release assays between 18 and 20 h after virus infection. Antibody-independent killing of PI-3 virus-infected cells was observed with neutrophils, alveolar macrophages and lymphocytes. Levels of specific lysis up to 30% for neutrophils and 68% for alveolar macrophages were observed, although there was considerable variation in activity from animal to animal. Lymphocyte preparations showed levels of cytotoxicity up to 20% in some cases while monocytes had low killing ability. Addition of PI-3 virus-specific antibodies enhanced killing by neutrophils, monocytes and lymphocytes but inhibited killing by alveolar macrophages. Complement, particularly guinea pig complement, was cytotoxic for virus-infected but not for uninfected cells, and also considerably enhanced the cytotoxic effect of neutrophils and lymphocytes.  相似文献   

2.
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   

3.
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   

4.
Conventionally raised male Holstein calves, 1 month of age, were infected by intranasal and intratracheal inoculation with bovine respiratory syncytial virus. Viral antigen was identified by fluorescence microscopy most commonly in the cytoplasm of tracheal and bronchial epithelial cells 3 to 5 days after inoculation. Cytoplasmic viral antigen was identified also in nasal, nasopharyngeal, bronchiolar, and alveolar epithelial cells and in alveolar macrophages. Bronchitis and tracheitis, characterized in part by epithelial necrosis, formation of syncytial epithelial cells and epithelial hyperplasia, were the most common lesions observed histologically. Rhinitis, bronchiolitis, and interstitial pneumonia were observed less frequently. Alterations were not detected in the numbers of cells recovered by bronchoalveolar lavage after inoculation. An increase in the phagocytic rate of latex beads occurred in macrophages 5 days after inoculation. Viral-induced lesions were resolved by 30 days after inoculation. The results indicated that bovine respiratory syncytial virus inoculation of calves results in reversible alterations in airway epithelial structure and in the phagocytic function of alveolar macrophages.  相似文献   

5.
Peripheral blood mononuclear cells (PBMC) from calves infected with and hyperimmunized to infectious bovine rhinotracheitis virus (IBRV) were stimulated in vitro with viral antigens to evaluate their cytotoxicity for a variety of cells. The 51-Cr release assay was used to measure cytotoxicity. Cytotoxicity was not present in fresh nonstimulated cells, but was detected in cultured, IBRV-stimulated cells at day 3, was maximal at day 7, and declined thereafter. PBMC stimulated in vitro with IBRV expressed a preference for killing IBRV-infected cells compared to pseudorabies virus (PRV)-infected cells. IBRV-infected, but not PRV-infected, cold target cells inhibited lysis of IBRV-labeled target cells. High concentrations of IBRV hyperimmune serum partially blocked cytotoxicity. Cells expressing a viral preference for cytotoxicity showed no preference for lysis of autologous compared to heterologous bovine cells. PBMC from calves that were either IBRV-immune or not immune were cultured without IBRV stimulation and had similar levels of cytotoxicity for IBRV-infected cells as cells from IBRV-infected cattle.  相似文献   

6.
Bovine parainfluenza-3 virus (PI-3V) replicated in cultured bovine alveolar macrophages (BAM) in vitro. Cytopathic changes included spindle cell and giant cell formation, diffuse cell lysis, and cellular detachment progressing to total destruction of the monolayer. Direct immunofluorescent microscopy revealed viral antigen in greater than 90% of BAM on post-inoculation day (PID) 3. Virus titers in culture supernatants increased by a factor of 1.6 X 10(6) TCID50 by PID 6. Candida glabrata was phagocytized by a similar proportion of glass-adherent PI-3V-infected and sham-inoculated control BAM. However, when the number of glass-adherent cells available for assay was taken into account (normalization), the percentage of phagocytic PI-3V-infected BAM was significantly lower than that of the control cells at PID 5 and 7 (P less than 0.01). Phagosome-lysosome fusion assays had a marked reduction of fusion activity in PI-3V-infected BAM as compared with that of control BAM. Proportions of infected cells that showed fusion were approximately 50% of that of the control cells at PID 4 and 6 (P less than 0.05). Normalization of these values reduced the fusion rate of PI-3V-infected BAM to 34% of that of control BAM (P less than 0.01).  相似文献   

7.
The effect of bovine respiratory syncytial virus (BRSV) upon alveolar macrophage (AM) function was investigated using an in vivo calf inoculation model. Alveolar macrophages were collected sequentially from live calves at multiple time points during the 14 day period following viral inoculation. Alveolar macrophages from bronchoalveolar lavage fluids were purified by density gradient centrifugation (> 95% AM) prior to in vitro evaluation of cell functions. There were significant but variable and inconsistent differences in the functions of AM from the BRSV inoculated calves compared to the control calves. Fc-receptor mediated phagocytosis was either increased or unchanged by BRSV inoculation. Nonopsonized phagocytosis was decreased during the early postinoculation period and later increased. There was a variable effect on AM phagosome lysosome fusion with increased fusion activity on postinoculation days 2 through 5, 7 and 12 but reduced activity on days 6 and 10. The AM respiratory burst, as measured by nitroblue tetrazolium dye reduction, was essentially unaffected with a reduction in activity on day 10 only. In this model, BRSV inoculation of calves primarily resulted in an alteration of the membrane associated phagocytic functions of the alveolar macrophages (p < 0.05).  相似文献   

8.
Bovine alveolar macrophages (BAM) were harvested from nonsedated cattle, adhered to glass or plastic surfaces, and infected with parainfluenza-3 (PI-3) virus at a multiplicity of infection of 10. Control and PI-3 virus-infected BAM were compared at 24-hour intervals up to 168 hours for their ability to phagocytize antibody-coated sheep erythrocytes (EAC) and latex particles, to kill Staphylococcus epidermidis, and to alter intracellular acid phosphatase concentrations. The effect of antiviral serum on phagocytic functions of virus-infected cells was also evaluated. Compared with noninfected controls, alveolar macrophages infected with PI-3 virus were 15.3% less adherent to the glass or plastic surfaces at postinoculation hour (PIH) 72 and were 64.0% less adherent at PIH 168. Significant differences (P less than 0.05) between the numbers of control and infected BAM phagocytizing EAC were observed at PIH 24 through 72, with final values differing by approximately 50%. Similar changes were observed in the phagocytic efficiencies of individual cells. The PI-3 virus-infected BAM that were exposed to antiserum or to immunoglobulins against PI-3 virus had approximately a 2-fold greater inhibition in EAC phagocytosis than did infected BAM exposed to serum without PI-3 activity. Significant differences in latex particle phagocytosis were not observed between infected and control BAM. Compared with control BAM, the PI-3 virus-infected BAM contained significantly lower concentrations of acid phosphatase from PIH 48 through 96; at PIH 96, acid phosphatase concentrations were 4-fold less in infected than in control BAM.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   

9.
Cultures of bovine alveolar macrophages were inoculated with type-1 and type-8 adenoviruses, initially isolated from calves with respiratory tract disease, and functional properties of the cells were observed over a period of 10 to 11 days. Both viruses replicated in macrophages; viral titers were low (less than 3.75 log10 TCID50/0.1 ml), and intranuclear inclusions were detected by indirect immunofluorescence in 5 to 10% of the cells from 3 days after inoculation. Highest titers were induced by type-1 adenovirus, which also induced the greatest functional changes. Expression of Fc and complement receptors was reduced by both viruses, although the greatest effects were seen with type 1. Phagocytosis of Candida krusei cells was reduced following type 1 infection, whereas phagocytosis in type-8-infected cells was not different from that of noninfected macrophages. Ability to kill ingested Candida cells also was reduced following type-1 infection, whereas type-8-infected macrophages had lower killing ability only at 2 to 4 days after inoculation. Neither virus had substantial effects on the production of neutrophil chemotactic factors by the macrophages.  相似文献   

10.
An antibody-complement-mediated cytotoxicity assay was employed to determine whether susceptible host cells infected with bovine parainfluenza-3 virus could be destroyed by the humoral immune mechanism. The cytotoxicity assay yielded 21.5% to 76.9% specific release of 51Cr with sera collected from calves 28 days after inoculation with the virus. A multiplicity of infection of 5, a postinfection period of 2 days, an antibody dilution of 1:10, and an incubation period of 12 hours with antibody and complement were found to be optimal for this assay.  相似文献   

11.
A vaccine strain of respiratory syncytial (RS) virus and an isolate from pneumonic calves (AC2) were inoculated onto cultures of bovine alveolar macrophages recovered by lung lavage, and the functional properties of the cells observed over a period of 10 days. In most cultures no infectious virus was produced although immunofluorescence indicated the presence of virus antigens in some cells. No significant difference was noted between infected and control macrophage cultures in their capacity to phagocytose latex particles (neutral phagocytosis), although the ability to phagocytose complement-coated Candida krusei cells was affected, particularly with the AC2 strain after 6 days. Killing of C. krusei cells was slightly affected by infection of macrophages with the vaccine strain and was dramatically affected by infection with strain AC2. C3b and Fc receptor expression was adversely affected by both virus strains. Production of neutrophil chemotactic factors was increased in cultures infected with both strains, but was greater with AC2, suggesting that some properties of the cells were activated.  相似文献   

12.
A group of four conventional, colostrum-fed calves was vaccinated with live parainfluenza type 3 (PI-3) virus vaccine at 1 and 5 weeks of age. A group of four control calves was treated with cell culture medium at the same time. Two weeks after the second vaccination, both groups of calves were challenged with PI-3 virus by a combined respiratory route. Blood and nasal mucus samples were collected at intervals, and alveolar macrophages were recovered before and after challenge by bronchoalveolar lavage. The results demonstrated that clearance of virus, as indicated by presence of virus antigen was more rapid in previously vaccinated calves. Several alveolar macrophage functions were markedly reduced in all calves 5 to 7 days following virus challenge, although microbicidal activity was unaffected, compared to the controls. The production of neutrophil chemotactic factors by alveolar macrophages occurred more rapidly after virus challenge in the previously vaccinated calves and this correlated with a more rapid neutrophil influx into the lungs in these animals.  相似文献   

13.
The objective of this study was to verify whether a mixed infection in calves with bovine viral diarrhea virus (BVDV) and other bovine viruses, such as bovid herpesvirus-4 (BHV-4), parainfluenza-3 (PI-3) and infectious bovine rhinotracheitis (IBR) virus, would influence the pathogenesis of the BVDV infection sufficiently to result in the typical form of mucosal disease being produced.

Accordingly, two experiments were undertaken. In one experiment calves were first infected with BVDV and subsequently with BHV-4 and IBR virus, respectively. The second experiment consisted in a simultaneous infection of calves with BVDV and PI-3 virus or BVDV and IBR virus.

From the first experiment it seems that BVDV infection can be reactivated in calves by BHV-4 and IBR virus. Evidence of this is that BVDV, at least the cytopathic (CP) strain, was recovered from calves following superinfection. Moreover, following such superinfection the calves showed signs which could most likely be ascribed to the pathogenetic activity of BVDV. Superinfection, especially by IBR virus, created a more severe clinical response in calves that were initially infected with CP BVDV, than in those previously given the non-cytopathic (NCP) biotype of the virus. Simultaneous infection with PI-3 virus did not seem to modify to any significant extent the pathogenesis of the experimentally induced BVDV infection whereas a severe clinical response was observed in calves when simultaneous infection was made with BVDV and IBR virus.  相似文献   


14.
Our objectives were to describe the ultrastructural morphogenesis of pulmonary lesions induced by 3-methylindole in 30- to 45-day-old Holstein calves and to determine whether toxic exposure to 3-methylindole exacerbates pulmonary lesions induced by bovine respiratory syncytial virus. Administration of 3-methylindole (0.25 g/kg) to calves resulted in interstitial edema and ultrastructural swelling of type-I alveolar epithelial cells and nonciliated bronchiolar epithelial cells as early as 4 to 6 hours after intraruminal administration. More severe alveolar edema containing protein was associated with swelling of capillary endothelial cells at 2 days after administration. Proliferation of type-II alveolar epithelial cells was first observed at 2 days after 3-methylindole administration, and marked hyperplasia of type-II epithelial cells and nonciliated bronchiolar epithelial cells was evident by 4 days after administration. Pulmonary cytochrome P-450 monooxygenase concentrations decreased significantly (P less than 0.001) by 12 hours after administration and did not increase significantly again by 8 days after administration. Calves were inoculated with bovine respiratory syncytial virus 3 days after administration of 3-methylindole, and pulmonary lesions were assessed 5 days after viral inoculation. Viral replication was demonstrated by fluorescence microscopy for viral antigen or by transmission electron microscopy in ciliated and nonciliated airway epithelial cells. Viral antigen was identified infrequently in alveolar macrophages and in type-II alveolar epithelial cells. 3-Methylindole exposure in calves did not result in more widespread distribution of viral antigen in alveolar tissue of respiratory syncytial virus-inoculated calves or in significant enhancement of viral pneumonia.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   

15.
Three, 5, or 7 days after inoculation with bovine viral diarrhea (BVD) virus (n = 12) or Mycoplasma bovis (n = 12), groups of calves were exposed to aerosols of Pasteurella haemolytica and were euthanatized 4 hours later. Histologic lesions in the lungs and the ratios of neutrophils to alveolar macrophages, collected by bronchoalveolar lavage, were compared with those of clinically healthy calves (n = 8) and calves inoculated with BVD virus only (n = 4), M bovis only (n = 4), or P haemolytica only (n = 2). Inoculation with BVD virus or M bovis did not have a significant (P greater than 0.05) effect on the neutrophil/macrophage ratio in the bronchoalveolar lavage. Aerosol exposure to P haemolytica induced a marked and significant (P less than 0.01) change in the neutrophil/macrophage ratio (from less than 1:9 to greater than 9:1). The reversed neutrophil/macrophage ratio in calves exposed to P haemolytica correlated well with the histologic changes in which small bronchi and bronchioles were plugged with purulent exudate. Inoculation with BVD virus did not induce gross or microscopic lesions in the lungs. Inoculation with M bovis resulted in a severe peribronchial lymphoid hyperplasia with mild exudation of neutrophils and macrophages into the cranioventral parts of the lungs.  相似文献   

16.
Bovine blood lymphocytes, depleted of macrophages by absorption on plasma-gelatin coated plastic flasks, followed by passage through Sephadex G-10 columns, failed to respond to pokeweed mitogen stimulation. Adherent monocytes or alveolar macrophages added to purified lymphocyte preparations at 10% or less were able to restore the transformation response. Exposure of alveolar macrophages or purified lymphocytes to 2 bovine respiratory syncytial virus strains for 24 hours substantially reduced the transformation response when mixed with uninfected lymphocytes or macrophages. Exposure of alveolar macrophages or purified lymphocytes to 2 bovine parainfluenza type 3 virus strains produced a similar reduction in activity after 48 hours. Heat inactivation of the viruses removed their inhibitory ability. Immunofluorescence studies revealed that both alveolar macrophages and lymphocytes were permissive for parainfluenza type 3 virus, whereas only a small number of alveolar macrophages and lymphocytes were infected with respiratory syncytial virus. The results suggest that both viruses are capable of adversely affecting the interaction between macrophages and lymphocytes, although the mechanisms by which this is achieved may be different.  相似文献   

17.
The morphogenesis and repair of airway and alveolar injury induced by bovine respiratory syncytial virus (BRSV) was studied ultrastructurally in conventional calves to characterize pulmonary cell types susceptible to viral infection and cytopathologic changes associated with infection. Viral nucleocapsids and budding virions were present in tracheal and bronchial ciliated and nonciliated epithelial cells and mucous cells 3, 5, and 7 days after inoculation and in bronchiolar ciliated and nonciliated epithelial cells 5 days after inoculation. Mild interstitial pneumonia was observed 5 days after inoculation and was characterized by swelling of type 1 and type 2 alveolar epithelial cells, interstitial edema, and infiltration by lymphocytes and macrophages. Viral assembly and release in tracheal and bronchial epithelial cells was associated with loss of cilia from ciliated cells, formation of syncytial epithelial cells, swelling of mitochondria and endoplasmic reticulum, and cell necrosis. Neutrophils, lymphocytes, and macrophages were present in close association with the viral-infected and damaged epithelial cells. There was intercurrent hyperplasia of basal epithelial cells that, in association with other epithelial lesions, resulted in the loss of normal ciliated epithelium in these airways 5 and 7 days after inoculation. Regeneration of airway epithelium was largely completed by 10 days after inoculation, except in 1 of 4 calves that had failure of epithelial repair and that developed secondary bacterial pneumonia. Pulmonary ultrastructure in BRSV-inoculated calves 30 days after inoculation was indistinguishable from that in controls. The results demonstrated that BRSV can induce reversible alterations in airway epithelium, which may cause depression of mucociliary clearance and thereby enhance susceptibility to bacterial infection.  相似文献   

18.
Natural transmission of bovine leukaemia virus (BLV) infection in south-eastern Queensland dairy herds was slow in 2 herds with a low to moderate (13 to 22%) prevalence of infection. Infection spread much more rapidly in a herd that had a higher prevalence (42%) when first tested. In a 13 month study of this herd, the cumulative incidence of infection was 24%. In one herd new infections were confined almost entirely to calves of uninfected dams. Following the end of feeding bulk milk to calves, a common practice in dairy herds, no more calves in this herd became infected. In laboratory experiments, neither prolonged housing of susceptible calves with infected cattle, consumption of drinking water contaminated with infected blood, nor inoculation of sheep with saliva from infected cattle resulted in transmission of BLV infection. Sheep were infected by subcutaneous inoculation of a suspension of purified lymphocytes from an infected heifer. The minimum infective dose was 10(3) lymphocytes, equivalent to the number of lymphocytes in approximately 0.1 microliter blood. Thus, procedures involving the transfer of a very small volume of blood from animal-to-animal have the potential to transmit infection.  相似文献   

19.
Previous research has demonstrated that 4-ipomeanol toxicosis can enhance the severity of para-influenza virus-induced pneumonia in mice. The objectives of this study were to determine whether calves are susceptible to 4-ipomeanol-induced enhancement of parainfluenza type 3 viral pneumonia and to determine whether 4-ipomeanol alters pulmonary replication of parainfluenza virus. Male Holstein calves were injected with either 4-ipomeanol (3 mg/kg) or vehicle (polyethylene glycol) 3 days prior to intratracheal inoculation with either parainfluenza virus or sham inoculum of culture medium. Calves in the four treatment groups (ipomeanol-parainfluenza, ipomeanol-medium, vehicle-parainfluenza, and vehicle-medium) were necropsied at 5 days after inoculation with parainfluenza virus or medium. The lungs were studied by correlated methods of light and electron microscopy, digitizing morphometry and pulmonary lavage to quantitate the severity of pneumonia. Pulmonary viral titers were determined, and viral antigen was identified in the lung by immunoperoxidase technique. The calves in the ipomeanol-virus treatment group had over a 9-fold higher (P less than 0.05) volume density of virus-induced interstitial pneumonia than did the calves in the other three treatment groups. This 4-ipomeanol-enhanced viral pneumonia was associated with significantly greater (P less than 0.05) numbers of pulmonary macrophages and neutrophils in the lavage fluid and higher (P less than 0.05) pulmonary titers of pulmonary infectious parainfluenza virus. Four-ipomeanol-enhanced viral pneumonia was characterized in part by extensive hyperplasia of type II alveolar epithelial cells and by dense aggregates of macrophages and neutrophils in alveolar spaces and interalveolar septa. The results indicate that 4-ipomeanol exacerbates interstitial pneumonia in calves induced by bovine parainfluenza type 3 virus.  相似文献   

20.
Serum samples were collected from early weaned fall calves shortly after the onset of respiratory tract disease. Antibody titers to infectious bovine rhinotracheitis (IBR) virus, parainfluenza type 3 (PI-3) virus, bovine viral diarrhea (BVD) virus, bovine adenovirus type 3 (BAV-3), and bovine respiratory syncytial virus (BRSV) were determined on paired (acute and convalescent) serums. Seroconversion rate (a fourfold or greater rise in antibody titer) for IBR virus was 4.3%, PI-3 virus--16.3%, BVD virus--9.6%, and BAV-3--2.2%. Seroconversion for BRSV was 45.4%. An increased rate of seroconversion for IBR, PI-3, and BVD viruses and BAV-3 was observed in the presence of BRSV seroconversion. These results suggest that BRSV may facilitate infection by other viruses. Results of virus isolation procedures from these calves were negative.  相似文献   

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