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Mahdy MAA, Mohamed SA, Abdalla KEH. Morphology of the soft palate and palatine tonsil of the goat (Capra hyricus). Microsc Res Tech 2023; 86:1091-1098. [PMID: 37191111 DOI: 10.1002/jemt.24346] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2023] [Revised: 04/04/2023] [Accepted: 05/06/2023] [Indexed: 05/17/2023]
Abstract
The present study was carried out to study the morphology of the goat's soft palate and palatine tonsil by gross anatomy, morphometry, light and scanning electron microscopy (SEM). Twelve heads of normal adult (18-24 months) apparently healthy goats of both sexes were collected from local commercial slaughterhouses in Qena Governorate, Egypt. The oral cavity was dissected, and samples were collected for both light and SEM. The soft palate of the goat formed the caudal continuation of the hard palate. It was relatively short, it extended from the level of the caudal border of the last upper molar tooth to terminate caudally against the base of the epiglottis. The oral mucous membrane of the soft palate was covered by non-keratinized stratified squamous epithelium. The lamina propria and submucosa contained connective tissue fibers, diffuse and nodular lymphatic tissue, striated muscle fibers, and a large number of mucous and serous palatine glands. By SEM, the ventral surface had several rounded openings occupied by flower-like structures. These openings represented the entrances to the palatine glands. The palatine tonsil was large and protruded from a fossa in the lateral wall of the oropharynx. It had 2-3 elongated irregular openings that lead to the underlying crypts. These crypts were well-developed and lined by non-keratinized stratified squamous epithelium. The epithelium of the tonsillar crypts directly covered lymphoid tissue and was infiltrated by lymphocytes. Tonsillar glands of pure mucous type were demonstrated. In conclusion, the study provides the basic morphological features of soft palate, as well as the palatine tonsil of the goat by gross observation, light and SEM. The palatine tonsils of goat were well-developed with extensive crypt system, suggesting their essential role in the immunological response against antigens that enter through the oral cavity. The current findings may be useful to understand the role of the palatine tonsil in immunity and disease pathogenesis. RESEARCH HIGHLIGHTS: The study reported the basic morphological features of soft palate and palatine tonsil of goat. The ventral surface of the soft palate had several rounded openings occupied by flower-like structures. The palatine tonsils of goat were well-developed with extensive crypt system. The findings might help to understand the role of the palatine tonsil in immunity and disease pathogenesis.
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Affiliation(s)
- Mohamed A A Mahdy
- Department of Anatomy and Embryology, Faculty of Veterinary Medicine, South Valley University, Qena, Egypt
- Department of Anatomy and Histology, Faculty of Veterinary Medicine, King Salman International University, Ras Sudr, Egypt
| | - Salma A Mohamed
- Department of Anatomy and Embryology, Faculty of Veterinary Medicine, South Valley University, Qena, Egypt
| | - Kamal E H Abdalla
- Department of Anatomy and Histology, Faculty of Veterinary Medicine, Assiut University, Assiut, Egypt
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Ez Elarab SM, El-Gendy SAA, El-Bakary NER, Alsafy MAM. Ultrastructure of the palatine tonsils of the donkey (Equus asinus): New insights by light, scanning, and transmission electron microscopy. Microsc Res Tech 2022; 85:3793-3803. [PMID: 36260813 DOI: 10.1002/jemt.24245] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2022] [Revised: 09/14/2022] [Accepted: 10/04/2022] [Indexed: 11/12/2022]
Abstract
The study aimed to explore the ultrastructure of the donkeys' palatine tonsils. Palatine tonsils of five male donkeys (5 years old) were investigated macroscopically and microscopically. The tonsils appeared as a dome shape with slight elevation and a circular opening on the surface of the oropharynx. The central tonsillar crypt appeared on the medial side of the palate-pharyngeal folds and the floor of the oropharynx. The external surface of the palatine tonsil had different sizes of mucosal folds, some grooves directed to drainage at the tonsillar opening, and the tonsil crypt opening was a crescentic or irregular oval shape. The outer surface was covered by stratified squamous epithelium and modified to be reticular epithelium invaded by lymphocytes in the crypt called lympho-epithelium. The tonsil crypt had aggregated lymphoid nodules, and the cryptal epithelium has surrounded by diffused lymphocytes and hassles corpuscles-like structures. The lymphocytes infiltrated into different layers of the cryptal epithelium and transformed into reticular or lympho-epithelium. The organized lymphoid nodules were primary and secondary, and the secondary ones had a light germinal center. The interfollicular area had many high endothelial venules and blood capillaries. The endothelial venules were lined by simple cuboidal epithelium and had lymphocytes. The blood capillaries had red blood cells and neutrophils. The tonsil was surrounded incompletely by a connective tissue capsule with mucous glands under that capsule. In conclusion, the epithelial lymphocyte infiltration, crypt epithelium, lymphoid nodules, and intra-follicular area of the donkey's palatine tonsils indicate the humoral and cell-mediated immunological process.
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Affiliation(s)
- Samar M Ez Elarab
- Histology and Cytology Department, Faculty of Veterinary Medicine, Alexandria University, Alexandria, Egypt
| | - Samir A A El-Gendy
- Anatomy and Embryology Department, Faculty of Veterinary Medicine, Alexandria University, Alexandria, Egypt
| | | | - Mohamed A M Alsafy
- Anatomy and Embryology Department, Faculty of Veterinary Medicine, Alexandria University, Alexandria, Egypt
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Meek HC, Stenfeldt C, Arzt J. Morphological and Phenotypic Characteristics of the Bovine Nasopharyngeal Mucosa and Associated Lymphoid Tissue. J Comp Pathol 2022; 198:62-79. [PMID: 36116893 DOI: 10.1016/j.jcpa.2022.07.011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2022] [Revised: 06/01/2022] [Accepted: 07/21/2022] [Indexed: 12/01/2022]
Abstract
The mammalian nasopharynx is an anatomically complex region of the upper respiratory tract that directly communicates with the nasal cavity, laryngopharynx, oesophagus and trachea. The nasopharyngeal mucosa contains moderate quantities of mucosa-associated lymphoid tissue (MALT) that is appropriately located for immunological sampling but also creates vulnerability to pathogens. In recent years, the nasopharynx has been inculpated in the pathogenesis of important diseases of cattle (foot-and-mouth disease) and humans (COVID-19), yet the tissue has never been described in detail in any species. In order to characterize the morphology and cellular composition of the bovine nasopharynx, samples of mucosa were collected from the nasopharynx of five 8-13-month-old steers and examined using light microscopy, immunohistochemistry and multichannel immunofluorescence. Morphologically, the nasopharyngeal epithelium was highly heterogeneous, with a continuum ranging from stratified squamous epithelium to highly attenuated, follicle-associated epithelium (FAE). Distribution of MALT was similarly regionally variable ranging from absent to clusters of multiple lymphoid follicles. Phenotypic characterization demonstrated dense distributions of dendritic cells and T lymphocytes surrounding lymphoid follicles, which comprised mostly B lymphocytes. The FAE overlaying the lymphoid follicles also contained higher numbers of dendritic cells and lymphocytes compared with the adjacent non-lymphoid epithelium, although cytotoxic T cells were notably scarce in the FAE. The bovine nasopharyngeal lymphoid tissue had comparable elements to other MALTs with specific differences that may help to elucidate the pathogenesis of infectious agents that have specific tropism for this tissue.
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Affiliation(s)
- Haillie C Meek
- Foreign Animal Disease Research Unit, Agricultural Research Service, United States Department of Agriculture, Plum Island Animal Disease Center, Greenport, New York, USA; Research Participation Program, Oak Ridge Institute for Science and Education, Oak Ridge, Tennessee, USA
| | - Carolina Stenfeldt
- Foreign Animal Disease Research Unit, Agricultural Research Service, United States Department of Agriculture, Plum Island Animal Disease Center, Greenport, New York, USA; Department of Diagnostic Medicine/Pathobiology, College of Veterinary Medicine, Kansas State University, Manhattan, Kansas, USA
| | - Jonathan Arzt
- Foreign Animal Disease Research Unit, Agricultural Research Service, United States Department of Agriculture, Plum Island Animal Disease Center, Greenport, New York, USA.
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Stenfeldt C, Arzt J. The Carrier Conundrum; A Review of Recent Advances and Persistent Gaps Regarding the Carrier State of Foot-and-Mouth Disease Virus. Pathogens 2020; 9:E167. [PMID: 32121072 PMCID: PMC7157498 DOI: 10.3390/pathogens9030167] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2020] [Revised: 02/25/2020] [Accepted: 02/25/2020] [Indexed: 12/12/2022] Open
Abstract
The existence of a prolonged, subclinical phase of foot-and-mouth disease virus (FMDV) infection in cattle was first recognized in the 1950s. Since then, the FMDV carrier state has been a subject of controversy amongst scientists and policymakers. A fundamental conundrum remains in the discordance between the detection of infectious FMDV in carriers and the apparent lack of contagiousness to in-contact animals. Although substantial progress has been made in elucidating the causal mechanisms of persistent FMDV infection, there are still critical knowledge gaps that need to be addressed in order to elucidate, predict, prevent, and model the risks associated with the carrier state. This is further complicated by the occurrence of a distinct form of neoteric subclinical infection, which is indistinguishable from the carrier state in field scenarios, but may have substantially different epidemiological properties. This review summarizes the current state of knowledge of the FMDV carrier state and identifies specific areas of research in need of further attention. Findings from experimental investigations of FMDV pathogenesis are discussed in relation to experience gained from field studies of foot-and-mouth disease.
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Affiliation(s)
- Carolina Stenfeldt
- Foreign Animal Disease Research Unit, Agricultural Research Service, US Department of Agriculture, Plum Island animal Disease Center, Orient, NY 11957, USA
- Department of Diagnostic Medicine/Pathobiology, Kansas State University, Manhattan, KS 66506, USA
| | - Jonathan Arzt
- Foreign Animal Disease Research Unit, Agricultural Research Service, US Department of Agriculture, Plum Island animal Disease Center, Orient, NY 11957, USA
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Sun J, Cui Y, Yu S, Xu Y, He J, Liu P, Huang Y, Li Q. Yak (Bos grunniens) Tonsils: Morphological Description and Expression of IgA and IgG. Anat Rec (Hoboken) 2018; 302:999-1009. [DOI: 10.1002/ar.24001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2017] [Revised: 08/01/2018] [Accepted: 08/22/2018] [Indexed: 12/19/2022]
Affiliation(s)
- Juan Sun
- Laboratory of Animal Anatomy and Tissue Embryology, Department of Basic Veterinary Medicine, Faculty of Veterinary MedicineGansu Agricultural University Lanzhou Gansu China
| | - Yan Cui
- Laboratory of Animal Anatomy and Tissue Embryology, Department of Basic Veterinary Medicine, Faculty of Veterinary MedicineGansu Agricultural University Lanzhou Gansu China
- Gansu Province Livestock Embryo Engineering Research Center, Department of Clinical Veterinary MedicineFaculty of Veterinary Medicine, Gansu Agricultural University Lanzhou Gansu China
| | - Si‐Jiu Yu
- Gansu Province Livestock Embryo Engineering Research Center, Department of Clinical Veterinary MedicineFaculty of Veterinary Medicine, Gansu Agricultural University Lanzhou Gansu China
| | - Yuan‐Fang Xu
- Laboratory of Animal Anatomy and Tissue Embryology, Department of Basic Veterinary Medicine, Faculty of Veterinary MedicineGansu Agricultural University Lanzhou Gansu China
| | - Jun‐Feng He
- Laboratory of Animal Anatomy and Tissue Embryology, Department of Basic Veterinary Medicine, Faculty of Veterinary MedicineGansu Agricultural University Lanzhou Gansu China
| | - Peng‐Gang Liu
- Laboratory of Animal Anatomy and Tissue Embryology, Department of Basic Veterinary Medicine, Faculty of Veterinary MedicineGansu Agricultural University Lanzhou Gansu China
| | - Yu‐Feng Huang
- Laboratory of Animal Anatomy and Tissue Embryology, Department of Basic Veterinary Medicine, Faculty of Veterinary MedicineGansu Agricultural University Lanzhou Gansu China
| | - Qin Li
- Gansu Province Livestock Embryo Engineering Research Center, Department of Clinical Veterinary MedicineFaculty of Veterinary Medicine, Gansu Agricultural University Lanzhou Gansu China
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Contreras G, Kabara E, Brester J, Neuder L, Kiupel M. Macrophage infiltration in the omental and subcutaneous adipose tissues of dairy cows with displaced abomasum. J Dairy Sci 2015; 98:6176-87. [DOI: 10.3168/jds.2015-9370] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2015] [Accepted: 05/11/2015] [Indexed: 01/14/2023]
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Changes observed in the thymus and lymph nodes 14 days after exposure to BVDV field strains of enhanced or typical virulence in neonatal calves. Vet Immunol Immunopathol 2014; 160:70-80. [PMID: 24809640 DOI: 10.1016/j.vetimm.2014.03.018] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2013] [Revised: 03/11/2014] [Accepted: 03/29/2014] [Indexed: 11/23/2022]
Abstract
Clinical presentation following uncomplicated acute infection with bovine viral diarrhea viruses (BVDV) ranges from clinically unapparent to severe (including hemorrhagic disease and death) depending on the strain virulence. Regardless of clinical presentation, BVDV infection of cattle results in a generalized immunosuppression. BVDV immunosuppression is characterized by a reduction of circulating white blood cells (WBC) that is typically evident by day 3 post infection (PI). In infections with typical BVDV field strains WBC counts decrease until days 6-9 PI and then return to baseline values. In infections with enhanced virulence BVDV, WBC counts may continue to decline through day 14. In this study, the lymph nodes and thymus of non-infected neonatal calves and neonatal calves infected 14 days previously with either a BVDV of typical virulence or one of enhanced virulence were compared. It was found that while calves, infected with the typical virulence BVDV, had cleared BVDV, and WBC counts had returned to near baseline, the number of B-B7(+) cells in lymph nodes were reduced whereas numbers of CD4(+) cells were increased as compared to control calves. In contrast, calves infected with the high virulence strain, had not cleared the virus by day 14 and WBC counts had not returned to pre-exposure levels. Furthermore, these calves had more substantial deficits of B-B7(+) and CD4(+) cell subpopulations, compared to calves infected with a typical virulence strain. There were also an increased number of macrophages observed in both lymphoid tissues examined. The thymuses from both groups of BVDV-infected calves were significantly smaller than non-infected age matched calves. The reduction in size was accompanied by a significant depletion of the thymic cortex. These results indicate that regardless of the virulence of the infecting BVDV, infection leaves neonatal calves with deficits in specific lymphocyte subsets and lymphoid tissues that could have long-term immunosuppressive implications.
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Bovine mammary dendritic cells: A heterogeneous population, distinct from macrophages and similar in phenotype to afferent lymph veiled cells. Comp Immunol Microbiol Infect Dis 2012; 35:31-8. [DOI: 10.1016/j.cimid.2011.09.009] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2011] [Revised: 09/12/2011] [Accepted: 09/28/2011] [Indexed: 11/22/2022]
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Liu Z, Yu Q, Li P, Yang Q. Histological and ultrastructural examinations of porcine tonsils. Anat Rec (Hoboken) 2011; 295:686-90. [PMID: 22190355 DOI: 10.1002/ar.21534] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2011] [Accepted: 10/17/2011] [Indexed: 11/09/2022]
Abstract
The histology and ultrastructure of porcine tonsils were studied. The porcine tonsils were lymphoepithelial organs situated at the opening of both the digestive and respiratory tracts. The tonsil of the soft palate in the oropharyngeal tract and the paraepiglottic tonsil in the laryngopharynx were mainly consisted of secondary lymphoid follicles encapsulated by connective tissue. The stratified squamous epithelia covering the tonsils and their crypts were frequently heavily infiltrated by lymphoid cells. The pharyngeal and tubal tonsils (TT) were situated in the nasopharyngeal tract. The cells of the pseudostratified columnar epithelia of the pharyngeal and TT were loosely connected, with large intercellular space. They consisted of scattered lymphoid follicles, aggregations of lymphoid cells and diffuse lymphoid tissues. Many high endothelial venules, specialized for the diapedesis of lymphoid cells into the tonsillar tissue, were detected in the four porcine tonsils. Therefore, the overall structures of the tonsils (the tonsil of the soft palate, the paraepiglottic tonsil, the pharyngeal and the TT) reflect their immune functionality in the oral and intranasal immunity.
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Affiliation(s)
- Zhixue Liu
- Key Laboratory of Animal Physiology and Biochemistry, Ministry of Agriculture, Nanjing Agricultural University, Weigang 1, Nanjing, Jiangsu, People's Republic of China
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Yamada T, Jiang X, Kubo S, Sakashita M, Narita N, Yamamoto H, Sunaga H, Fujieda S. B type CpG-DNA suppresses poly(I:C)-induced BLyS expression and production in human tonsillar fibroblasts. Clin Immunol 2011; 141:365-71. [PMID: 22015147 DOI: 10.1016/j.clim.2011.09.012] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2011] [Revised: 09/13/2011] [Accepted: 09/21/2011] [Indexed: 12/18/2022]
Abstract
Although B lymphocyte stimulator (BLyS) has potent costimulatory effects on B cells, the details of BLyS-expression in tonsillar fibroblasts remain unexplored. We examined the effect of the Toll-like receptor (TLR) ligands on BLyS-expression in human tonsillar fibroblasts as well as the crosstalk that occurs among different TLR ligands. The expression of BLyS mRNA by tonsillar fibroblasts was strongly induced in the presence of polyinosinic-polycytidylic acid (poly(I:C)) that is a ligand, of TLR3. We also revealed that DNA containing CpG motifs (CpG-DNA), coding for a TLR9 ligand, markedly suppressed the poly(I:C)-induced mRNA expression and protein production of BLyS. B type CpG-DNA decreased the poly(I:C)-induced phosphorylation of inhibitor kappa B alpha (IκBα) and its degradation. Pre-incubation with nuclear factor kappa B (NF-κB) signaling inhibitors reduced the poly(I:C)-induced BLyS-expression. These results indicate that human tonsillar fibroblasts strongly induce BLyS-expression and production that can be inhibited by CpG-DNA and regulated through NF-κB signaling.
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Affiliation(s)
- Takechiyo Yamada
- Department of Otorhinolaryngology, University of Fukui, Fukui, 910-1193, Japan.
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Palmer MV, Stasko J, Waters WR, Thacker TC. Examination of the Reticular Epithelium of the Bovine Pharyngeal Tonsil. Anat Rec (Hoboken) 2011; 294:1939-50. [DOI: 10.1002/ar.21448] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2011] [Accepted: 06/14/2011] [Indexed: 11/05/2022]
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12
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Zidan M, Pabst R. The microanatomy of the palatine tonsils of the buffalo (Bos bubalus). Vet Immunol Immunopathol 2011; 139:83-9. [DOI: 10.1016/j.vetimm.2010.08.006] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2009] [Revised: 08/11/2010] [Accepted: 08/14/2010] [Indexed: 11/24/2022]
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Casteleyn C, Cornelissen M, Simoens P, Van den Broeck W. Ultramicroscopic examination of the ovine tonsillar epithelia. Anat Rec (Hoboken) 2010; 293:879-89. [PMID: 20225209 DOI: 10.1002/ar.21098] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
As solid morphological knowledge of ovine tonsillar epithelia might contribute to a better understanding of the pathogenesis of several diseases including prion diseases, the epithelia of all tonsils of 7 one-year-old Texel sheep were examined using scanning and transmission electron microscopy. Major parts of the pharyngeal and tubal tonsils were covered by pseudostratified columnar ciliated epithelia that were interrupted by patches of epithelium containing cells with densely packed microfolds or microvilli, and cells with both microvilli and cilia. Smaller parts were covered by either flattened polygonal cells with densely packed microvilli or microfolds, squamous epithelial cells, or patches of reticular epithelium. The palatine and paraepiglottic tonsils were mainly lined by squamous epithelial cells with apical microplicae or short knobs. Additionally, regions of reticular epithelium containing epithelial cells with apical microvilli were seen. The lingual tonsil was uniformly covered by a keratinized squamous epithelium and devoid of microvillous cells and patches of reticular epithelium. The rostral half of the tonsil of the soft palate was lined by a pseudostratified columnar ciliated epithelium with characteristics of the pharyngeal and tubal tonsils. The epithelium of the caudal part resembled the epithelia of the palatine and paraepiglottic tonsils. Putative M cells, mainly characterized by apical microvilli or microfolds and a close association with lymphoid cells, seem manifestly present on the nasopharyngeal tonsils. The reticular epithelium of the palatine and paraepiglottic tonsils also harbor cells with small apical microvilli. The exact nature of these presumptive M cells should, however, be elucidated in functional studies.
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Affiliation(s)
- Christophe Casteleyn
- Department of Morphology, Faculty of Veterinary Medicine, Ghent University, Merelbeke, Belgium.
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Arzt J, Pacheco JM, Rodriguez LL. The early pathogenesis of foot-and-mouth disease in cattle after aerosol inoculation. Identification of the nasopharynx as the primary site of infection. Vet Pathol 2010; 47:1048-63. [PMID: 20587691 DOI: 10.1177/0300985810372509] [Citation(s) in RCA: 114] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
To characterize the early events of foot-and-mouth disease virus (FMDV) infection in cattle subsequent to simulated natural exposure, 16 steers were aerosol inoculated with FMDV and euthanized at various times. Samples were collected from each steer antemortem (serum, nasal swabs, and oral swabs) and postmortem (up to 40 tissues per animal) and screened for FMDV by virus isolation and for FMDV RNA by real-time reverse transcription polymerase chain reaction. Tissues that tested positive for FMDV or viral RNA were examined by immunohistochemistry and multichannel immunofluorescence microscopy. In previremic steers, FMDV was most consistently localized to nasopharyngeal tissues, thereby indicating this region as the most important site of primary viral replication. The earliest site of microscopic localization of FMDV antigens was the lymphoid follicle-associated epithelium of the pharyngeal mucosa-associated lymphoid tissue of the nasopharynx at 6 hours postaerosolization. At early time points after aerosol inoculation, viral antigens colocalized with cytokeratin-positive pharyngeal epithelial cells; intraepithelial FMDV-negative, MHCII/CD11c-double-positive dendritic cells were present in close proximity to FMDV-positive cells. Onset of viremia coincided with marked increase of viral loads in pulmonary tissues and with substantial decrease of viral detection in nasopharyngeal tissues. These data indicate that subsequent to aerogenous exposure to FMDV, the temporally defined critical pathogenesis events involve (1) primary replication in epithelial cells of the pharyngeal mucosa-associated lymphoid tissue crypts and (2) subsequent widespread replication in pneumocytes in the lungs, which coincides with (3) the establishment of sustained viremia.
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Affiliation(s)
- J Arzt
- Foreign Animal Disease Research Unit, USDA/ARS Plum Island Animal Disease Center, PO Box 848, Greenport, NY 11944, USA.
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Characterization of sheep (Ovis aries) palatine tonsil innervation. Neuroscience 2009; 161:813-26. [DOI: 10.1016/j.neuroscience.2009.04.015] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2009] [Revised: 04/02/2009] [Accepted: 04/07/2009] [Indexed: 11/20/2022]
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