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Comparative Immunopathology of Cetacean morbillivirus Infection in Free-Ranging Dolphins From Western Mediterranean, Northeast-Central, and Southwestern Atlantic.
- Source :
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Frontiers in immunology [Front Immunol] 2019 Mar 18; Vol. 10, pp. 485. Date of Electronic Publication: 2019 Mar 18 (Print Publication: 2019). - Publication Year :
- 2019
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Abstract
- Cetacean morbillivirus (CeMV; Paramyxoviridae ) causes epizootic and interepizootic fatalities in odontocetes and mysticetes worldwide. Studies suggest there is different species-specific susceptibility to CeMV infection, with striped dolphins ( Stenella coeruleoalba ), bottlenose dolphins ( Tursiops truncatus ), and Guiana dolphins ( Sotalia guianensis ) ranking among the most susceptible cetacean hosts. The pathogenesis of CeMV infection is not fully resolved. Since no previous studies have evaluated the organ-specific immunopathogenetic features of CeMV infection in tissues from infected dolphins, this study was aimed at characterizing and comparing immunophenotypic profiles of local immune responses in lymphoid organs (lymph nodes, spleen), lung and CNS in CeMV-molecularly (RT-PCR)-positive cetaceans from Western Mediterranean, Northeast-Central, and Southwestern Atlantic. Immunohistochemical (IHC) analyses targeted molecules of immunologic interest: caspase 3, CD3, CD20, CD57, CD68, FoxP3, MHCII, Iba1, IFNγ, IgG, IL4, IL10, lysozyme, TGFβ, and PAX5. We detected consistent CeMV-associated inflammatory response patterns. Within CNS, inflammation was dominated by CD3 <superscript>+</superscript> (T cells), and CD20 <superscript>+</superscript> and PAX5 <superscript>+</superscript> (B cells) lymphocytes, accompanied by fewer Iba1 <superscript>+</superscript> , CD68 <superscript>+</superscript> , and lysozyme <superscript>+</superscript> histiocytes, mainly in striped dolphins and bottlenose dolphins. Multicentric lymphoid depletion was characterized by reduced numbers of T cells and B cells, more pronounced in Guiana dolphins. Striped dolphins and bottlenose dolphins often had hyperplastic (regenerative) phenomena involving the aforementioned cell populations, particularly chronically infected animals. In the lung, there was mild to moderate increase in T cells, B cells, and histiocytes. Additionally, there was a generalized increased expression of caspase 3 in lymphoid, lung, and CNS tissues. Apoptosis, therefore, is believed to play a major role in generalized lymphoid depletion and likely overt immunosuppression during CeMV infection. No differences were detected regarding cytokine immunoreactivity in lymph nodes, spleen, and lung from infected and non-infected dolphins by semiquantitative analysis; however, there was striking immunoreactivity for IFNγ in the CNS of infected dolphins. These novel results set the basis for tissue-specific immunophenotypic responses during CeMV infection in three highly susceptible delphinid species. They also suggest a complex interplay between viral and host's immune factors, thereby contributing to gain valuable insights into similarities, and differences of CeMV infection's immunopathogenesis in relation to body tissues, CeMV strains, and cetacean hosts.
- Subjects :
- Animals
Atlantic Ocean
Central Nervous System immunology
Central Nervous System pathology
Cytokines biosynthesis
Cytokines genetics
Female
Immunohistochemistry
Lung immunology
Lung pathology
Lymphoid Tissue immunology
Lymphoid Tissue pathology
Male
Mediterranean Sea
Morbillivirus Infections immunology
Morbillivirus Infections pathology
Paraffin Embedding
Species Specificity
Tissue Fixation
Dolphins immunology
Morbillivirus immunology
Morbillivirus Infections veterinary
Subjects
Details
- Language :
- English
- ISSN :
- 1664-3224
- Volume :
- 10
- Database :
- MEDLINE
- Journal :
- Frontiers in immunology
- Publication Type :
- Academic Journal
- Accession number :
- 30936878
- Full Text :
- https://doi.org/10.3389/fimmu.2019.00485