Cargando…
Chronic pneumonia in calves after experimental infection with Mycoplasma bovis strain 1067: Characterization of lung pathology, persistence of variable surface protein antigens and local immune response
BACKGROUND: Mycoplasma bovis is associated with pneumonia in calves characterized by the development of chronic caseonecrotic lesions with the agent persisting within the lesion. The purposes of this study were to characterize the morphology of lung lesions, examine the presence of M. bovis variable...
Autores principales: | , , , , , , |
---|---|
Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
BioMed Central
2012
|
Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3287114/ https://www.ncbi.nlm.nih.gov/pubmed/22305416 http://dx.doi.org/10.1186/1751-0147-54-9 |
_version_ | 1782224616347926528 |
---|---|
author | Hermeyer, Kathrin Buchenau, Inka Thomasmeyer, Anne Baum, Berit Spergser, Joachim Rosengarten, Renate Hewicker-Trautwein, Marion |
author_facet | Hermeyer, Kathrin Buchenau, Inka Thomasmeyer, Anne Baum, Berit Spergser, Joachim Rosengarten, Renate Hewicker-Trautwein, Marion |
author_sort | Hermeyer, Kathrin |
collection | PubMed |
description | BACKGROUND: Mycoplasma bovis is associated with pneumonia in calves characterized by the development of chronic caseonecrotic lesions with the agent persisting within the lesion. The purposes of this study were to characterize the morphology of lung lesions, examine the presence of M. bovis variable surface protein (Vsp) antigens and study the local immune responses in calves after infection with M. bovis strain 1067. METHODS: Lung tissue samples from eight calves euthanased three weeks after experimental infection with M. bovis were examined by bacteriology and pathology. Lung lesions were evaluated by immunohistochemical (IHC) staining for wide spectrum cytokeratin and for M. bovis Vsp antigens and pMB67 antigen. IHC identification and quantitative evaluation of CD4(+ )and CD8(+ )T lymphocytes and immunoglobulin (IgG1, IgG2, IgM, IgA)-containing plasma cells was performed. Additionally, expression of major histocompatibility complex class II (MHC class II) was studied by IHC. RESULTS: Suppurative pneumonic lesions were found in all calves. In two calves with caseonecrotic pneumonia, necrotic foci were surrounded by epithelial cells resembling bronchial or bronchiolar epithelium. In all calves, M. bovis Vsp antigens were constantly present in the cytoplasm of macrophages and were also present extracellularly at the periphery of necrotic foci. There was a considerable increase in numbers of IgG1- and IgG2-positive plasma cells among which IgG1-containing plasma cells clearly predominated. Statistical evaluation of the numbers of CD4(+ )and CD8(+ )T cells, however, did not reveal statistically significant differences between inoculated and control calves. In M. bovis infected calves, hyperplasia of bronchus-associated lymphoid tissue (BALT) was characterized by strong MHC class II expression of lymphoid cells, but only few of the macrophages demarcating the caseonecrotic foci were positive for MHC class II. CONCLUSIONS: The results from this study show that infection of calves with M. bovis results in various lung lesions including caseonecrotic pneumonia originating from bronchioli and bronchi. There is long-term persistence of M. bovis as demonstrated by bacteriology and immunohistochemistry for M. bovis antigens, i.e. Vsp antigens and pMB67. The persistence of the pathogen and its ability to evade the specific immune response may in part result from local downregulation of antigen presenting mechanisms and an ineffective humoral immune response with prevalence of IgG1 antibodies that, compared to IgG2 antibodies, are poor opsonins. |
format | Online Article Text |
id | pubmed-3287114 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2012 |
publisher | BioMed Central |
record_format | MEDLINE/PubMed |
spelling | pubmed-32871142012-02-28 Chronic pneumonia in calves after experimental infection with Mycoplasma bovis strain 1067: Characterization of lung pathology, persistence of variable surface protein antigens and local immune response Hermeyer, Kathrin Buchenau, Inka Thomasmeyer, Anne Baum, Berit Spergser, Joachim Rosengarten, Renate Hewicker-Trautwein, Marion Acta Vet Scand Research BACKGROUND: Mycoplasma bovis is associated with pneumonia in calves characterized by the development of chronic caseonecrotic lesions with the agent persisting within the lesion. The purposes of this study were to characterize the morphology of lung lesions, examine the presence of M. bovis variable surface protein (Vsp) antigens and study the local immune responses in calves after infection with M. bovis strain 1067. METHODS: Lung tissue samples from eight calves euthanased three weeks after experimental infection with M. bovis were examined by bacteriology and pathology. Lung lesions were evaluated by immunohistochemical (IHC) staining for wide spectrum cytokeratin and for M. bovis Vsp antigens and pMB67 antigen. IHC identification and quantitative evaluation of CD4(+ )and CD8(+ )T lymphocytes and immunoglobulin (IgG1, IgG2, IgM, IgA)-containing plasma cells was performed. Additionally, expression of major histocompatibility complex class II (MHC class II) was studied by IHC. RESULTS: Suppurative pneumonic lesions were found in all calves. In two calves with caseonecrotic pneumonia, necrotic foci were surrounded by epithelial cells resembling bronchial or bronchiolar epithelium. In all calves, M. bovis Vsp antigens were constantly present in the cytoplasm of macrophages and were also present extracellularly at the periphery of necrotic foci. There was a considerable increase in numbers of IgG1- and IgG2-positive plasma cells among which IgG1-containing plasma cells clearly predominated. Statistical evaluation of the numbers of CD4(+ )and CD8(+ )T cells, however, did not reveal statistically significant differences between inoculated and control calves. In M. bovis infected calves, hyperplasia of bronchus-associated lymphoid tissue (BALT) was characterized by strong MHC class II expression of lymphoid cells, but only few of the macrophages demarcating the caseonecrotic foci were positive for MHC class II. CONCLUSIONS: The results from this study show that infection of calves with M. bovis results in various lung lesions including caseonecrotic pneumonia originating from bronchioli and bronchi. There is long-term persistence of M. bovis as demonstrated by bacteriology and immunohistochemistry for M. bovis antigens, i.e. Vsp antigens and pMB67. The persistence of the pathogen and its ability to evade the specific immune response may in part result from local downregulation of antigen presenting mechanisms and an ineffective humoral immune response with prevalence of IgG1 antibodies that, compared to IgG2 antibodies, are poor opsonins. BioMed Central 2012-02-04 /pmc/articles/PMC3287114/ /pubmed/22305416 http://dx.doi.org/10.1186/1751-0147-54-9 Text en Copyright ©2012 Hermeyer et al; licensee BioMed Central Ltd. http://creativecommons.org/licenses/by/2.0 This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. |
spellingShingle | Research Hermeyer, Kathrin Buchenau, Inka Thomasmeyer, Anne Baum, Berit Spergser, Joachim Rosengarten, Renate Hewicker-Trautwein, Marion Chronic pneumonia in calves after experimental infection with Mycoplasma bovis strain 1067: Characterization of lung pathology, persistence of variable surface protein antigens and local immune response |
title | Chronic pneumonia in calves after experimental infection with Mycoplasma bovis strain 1067: Characterization of lung pathology, persistence of variable surface protein antigens and local immune response |
title_full | Chronic pneumonia in calves after experimental infection with Mycoplasma bovis strain 1067: Characterization of lung pathology, persistence of variable surface protein antigens and local immune response |
title_fullStr | Chronic pneumonia in calves after experimental infection with Mycoplasma bovis strain 1067: Characterization of lung pathology, persistence of variable surface protein antigens and local immune response |
title_full_unstemmed | Chronic pneumonia in calves after experimental infection with Mycoplasma bovis strain 1067: Characterization of lung pathology, persistence of variable surface protein antigens and local immune response |
title_short | Chronic pneumonia in calves after experimental infection with Mycoplasma bovis strain 1067: Characterization of lung pathology, persistence of variable surface protein antigens and local immune response |
title_sort | chronic pneumonia in calves after experimental infection with mycoplasma bovis strain 1067: characterization of lung pathology, persistence of variable surface protein antigens and local immune response |
topic | Research |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3287114/ https://www.ncbi.nlm.nih.gov/pubmed/22305416 http://dx.doi.org/10.1186/1751-0147-54-9 |
work_keys_str_mv | AT hermeyerkathrin chronicpneumoniaincalvesafterexperimentalinfectionwithmycoplasmabovisstrain1067characterizationoflungpathologypersistenceofvariablesurfaceproteinantigensandlocalimmuneresponse AT buchenauinka chronicpneumoniaincalvesafterexperimentalinfectionwithmycoplasmabovisstrain1067characterizationoflungpathologypersistenceofvariablesurfaceproteinantigensandlocalimmuneresponse AT thomasmeyeranne chronicpneumoniaincalvesafterexperimentalinfectionwithmycoplasmabovisstrain1067characterizationoflungpathologypersistenceofvariablesurfaceproteinantigensandlocalimmuneresponse AT baumberit chronicpneumoniaincalvesafterexperimentalinfectionwithmycoplasmabovisstrain1067characterizationoflungpathologypersistenceofvariablesurfaceproteinantigensandlocalimmuneresponse AT spergserjoachim chronicpneumoniaincalvesafterexperimentalinfectionwithmycoplasmabovisstrain1067characterizationoflungpathologypersistenceofvariablesurfaceproteinantigensandlocalimmuneresponse AT rosengartenrenate chronicpneumoniaincalvesafterexperimentalinfectionwithmycoplasmabovisstrain1067characterizationoflungpathologypersistenceofvariablesurfaceproteinantigensandlocalimmuneresponse AT hewickertrautweinmarion chronicpneumoniaincalvesafterexperimentalinfectionwithmycoplasmabovisstrain1067characterizationoflungpathologypersistenceofvariablesurfaceproteinantigensandlocalimmuneresponse |