Comparative immunopathology of cetacean morbillivirus infection: histologic, immunohistochemical, and molecular studies

• Grant number: 17/24335-2
• Support Opportunities: Regular Research Grants
• Duration: March 01, 2018 - February 29, 2020
• Field of knowledge: Agronomical Sciences - Veterinary Medicine - Animal Pathology
• Principal Investigator: Jose Luiz Catao Dias
• Grantee: Jose Luiz Catao Dias
• Host Institution: Faculdade de Medicina Veterinária e Zootecnia (FMVZ). Universidade de São Paulo (USP). São Paulo , SP, Brazil
• Associated researchers: Eliana Faquim de Lima Mauro ; Geraldo Santana Magalhães ; Josué Díaz Delgado ; Kátia Regina Groch

Abstract

Cetacean morbillivirus (CeMV; genus Morbillivirus, family Paramyxoviridae) has caused multiple outbreaks of lethal disease in odontocetes and mysticetes worldwide. CeMV includes three well characterized strains: porpoise morbillivirus, dolphin morbillivirus, and pilot whale morbillivirus (northern hemisphere), and three novel strains, one of them detected in Brazil and considered the first description in South America. Studies suggest there is different species-specific susceptibility to CeMV infection, and bottlenose dolphins (Tursiops truncatus) and striped dolphins (Stenella coeruleoalba) are among the most susceptible ones, with historical fatal epizootics. No previous studies have evaluated the local immunopathogenetic aspects in tissues other than peripheral blood in CeMV-seropositive animals. This study will employ archival, formalin-fixed, paraffin-embedded and frozen tissues from organs with major pathogenetic significance (brain, lung, and lymph nodes) of CeMV-positive bottlenose dolphins and striped dolphins (central eastern Atlantic, Mediterranean Sea), and selected Brazilian species (southwestern Atlantic), as determined by RT-PCR analysis. A suit of lymphocytic, histiocytic and additional immunohistochemical markers will be used to characterize the local immune responses. In this regard, one of our preliminary studies demonstrated satisfactory cross-reactivity for primary antibodies anti- caspase 3, CD3, CD57, CD68, FoxP3, HLA-DR±, IFN³, IgG, IL4, IL10, Lysozyme, TGF² and PAX-5. However, the antibody anti-CD4 failed to cross-react. Therefore, we deem necessary to pursue elaboration of a CD4 antibody specific for cetaceans, increasing the completeness of this project. Additionally, the expression of TH1 and TH2 cytokines will be evaluated via RT-qPCR/PCR. Worth noting, this proposal will fund the post-doctoral project of associated researcher JDD (FAPESP 2017/02223-8). Parallel histopathologic, immunohistochemical, and molecular analysis may provide insight into immunopathogenetic mechanisms of CeMV-AP, a disease with worldwide distribution and major conservation significance. (AU)

Scientific publications

(References retrieved automatically from Web of Science and SciELO through information on FAPESP grants and their corresponding numbers as mentioned in the publications by the authors)

GROCH, KATIA R.; DIAZ-DELGADO, JOSUE; SANTOS-NETO, ELITIERI B.; IKEDA, JOANA M. P.; CARVALHO, RAFAEL R.; OLIVEIRA, RAISSA B.; GUARI, EMI B.; FLACH, LEONARDO; SIERRA, EVA; GODINHO, ANA I.; et al. The Pathology of Cetacean Morbillivirus Infection and Comorbidities in Guiana Dolphins During an Unusual Mortality Event (Brazil, 2017-2018). VETERINARY PATHOLOGY, v. 57, n. 6, p. 845-857, NOV 2020. (17/24335-2, 15/05043-5, 15/00735-6, 14/24932-2, 17/02223-8)

DIAZ-DELGADO, JOSUE; GROCH, KATIA R.; SIERRA, EVA; SACCHINI, SIMONA; ZUCCA, DANIELE; QUESADA-CANALES, OSCAR; ARBELO, MANUEL; FERNANDEZ, ANTONIO; SANTOS, ELITIERI; IKEDA, JOANA; et al. Comparative histopathologic and viral immunohistochemical studies on CeMV infection among Western Mediterranean, Northeast-Central, and Southwestern Atlantic cetaceans. PLoS One, v. 14, n. 3, MAR 20 2019. (15/00735-6, 15/05043-5, 17/02223-8, 17/24335-2, 14/24932-2)