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Pandolfo GW, de Cristo TG, Withoeft JA, da Silva Sá JJ, Fornara MA, Viebrantz A, Casa M, Wisser CS, Casagrande RA. Neoplastic and non-neoplastic diseases associated with feline leukaemia virus (FeLV) in cats in southern Brazil. Comp Immunol Microbiol Infect Dis 2024; 112:102228. [PMID: 39151280 DOI: 10.1016/j.cimid.2024.102228] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2024] [Revised: 07/30/2024] [Accepted: 08/07/2024] [Indexed: 08/19/2024]
Abstract
The objective of this study was to categorise diseases associated with FeLV infection in cats. A total of 154 cats were submitted to necropsy, histopathology exam and anti-FeLV immunohistochemistry (IHC), and 83 (50.9 %) were IHC FeLV-positive. The cats age means of 4.1 years, including 3.6 % kittens, 34.9 % junior, 37.4 % prime, 18.1 % mature, 2.4 % senior, 3.6 % unknown age. Neoplastic diseases were most prevalent with leukaemia and lymphoma being most predominant, followed by viral diseases, bacterial, trauma, degenerative, intoxications, parasitic, malformation and others. FeLV+ cats were 5.73 times more likely to be diagnosed with neoplasms than other diseases. The odds ratio (OR) of FeLV+ cats developing leukaemia (OR = 7.75) and lymphoma (OR = 6.75) was higher than other neoplasms. FeLV infection was more prevalent in the mixed breed, junior to prime, male, with neoplastic diseases, including leukaemia and lymphoma. Therefore, understanding the diseases associated with FeLV is of paramount importance in Brazil due to its high prevalence, and it may encourage the implementation of prophylactic measures to reduce its dissemination.
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Affiliation(s)
- Gustavo Willian Pandolfo
- Laboratório de Patologia Animal (LAPA), Centro de Ciências Agroveterinárias - Universidade do Estado de Santa Catarina (CAV/UDESC), Lages, SC, Brazil.
| | - Thierry Grima de Cristo
- Laboratório de Patologia Animal (LAPA), Centro de Ciências Agroveterinárias - Universidade do Estado de Santa Catarina (CAV/UDESC), Lages, SC, Brazil.
| | - Jéssica Aline Withoeft
- Laboratório de Patologia Animal (LAPA), Centro de Ciências Agroveterinárias - Universidade do Estado de Santa Catarina (CAV/UDESC), Lages, SC, Brazil.
| | - Jennyfer Júlia da Silva Sá
- Laboratório de Patologia Animal (LAPA), Centro de Ciências Agroveterinárias - Universidade do Estado de Santa Catarina (CAV/UDESC), Lages, SC, Brazil.
| | - Maria Augusta Fornara
- Laboratório de Patologia Animal (LAPA), Centro de Ciências Agroveterinárias - Universidade do Estado de Santa Catarina (CAV/UDESC), Lages, SC, Brazil.
| | - Aline Viebrantz
- Laboratório de Patologia Animal (LAPA), Centro de Ciências Agroveterinárias - Universidade do Estado de Santa Catarina (CAV/UDESC), Lages, SC, Brazil.
| | | | - Claudia Salete Wisser
- Laboratório de Patologia Animal (LAPA), Centro de Ciências Agroveterinárias - Universidade do Estado de Santa Catarina (CAV/UDESC), Lages, SC, Brazil.
| | - Renata Assis Casagrande
- Laboratório de Patologia Animal (LAPA), Centro de Ciências Agroveterinárias - Universidade do Estado de Santa Catarina (CAV/UDESC), Lages, SC, Brazil.
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2
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Parisi F, Fonti N, Millanta F, Freer G, Pistello M, Poli A. Exploring the link between viruses and cancer in companion animals: a comprehensive and comparative analysis. Infect Agent Cancer 2023; 18:40. [PMID: 37386451 DOI: 10.1186/s13027-023-00518-7] [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: 05/12/2023] [Accepted: 06/16/2023] [Indexed: 07/01/2023] Open
Abstract
Currently, it is estimated that 15% of human neoplasms globally are caused by infectious agents, with new evidence emerging continuously. Multiple agents have been implicated in various forms of neoplasia, with viruses as the most frequent. In recent years, investigation on viral mechanisms underlying tumoral transformation in cancer development and progression are in the spotlight, both in human and veterinary oncology. Oncogenic viruses in veterinary medicine are of primary importance not only as original pathogens of pets, but also in the view of pets as models of human malignancies. Hence, this work will provide an overview of the main oncogenic viruses of companion animals, with brief notes of comparative medicine.
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Affiliation(s)
- Francesca Parisi
- Dipartimento di Scienze Veterinarie, Università di Pisa, Viale delle Piagge, 2, 56124, Pisa, Italy.
| | - Niccolò Fonti
- Dipartimento di Scienze Veterinarie, Università di Pisa, Viale delle Piagge, 2, 56124, Pisa, Italy
| | - Francesca Millanta
- Dipartimento di Scienze Veterinarie, Università di Pisa, Viale delle Piagge, 2, 56124, Pisa, Italy
| | - Giulia Freer
- Dipartimento di Ricerca Traslazionale e delle Nuove Tecnologie in Medicina e Chirurgia, Università di Pisa, Via Risorgimento, 36, 56126, Pisa, Italy
| | - Mauro Pistello
- Dipartimento di Ricerca Traslazionale e delle Nuove Tecnologie in Medicina e Chirurgia, Università di Pisa, Via Risorgimento, 36, 56126, Pisa, Italy
| | - Alessandro Poli
- Dipartimento di Scienze Veterinarie, Università di Pisa, Viale delle Piagge, 2, 56124, Pisa, Italy
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3
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de Mello LS, Ribeiro PR, de Almeida BA, Bandinelli MB, Sonne L, Driemeier D, Pavarini SP. Diseases associated with feline leukemia virus and feline immunodeficiency virus infection: A retrospective study of 1470 necropsied cats (2010-2020). Comp Immunol Microbiol Infect Dis 2023; 95:101963. [PMID: 36858000 DOI: 10.1016/j.cimid.2023.101963] [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: 09/14/2022] [Revised: 02/07/2023] [Accepted: 02/13/2023] [Indexed: 02/18/2023]
Abstract
Feline leukemia virus (FeLV) and feline immunodeficiency virus (FIV) are retroviruses affecting cats worldwide, and the prevalence of infection varies considerably according to the geographic area. We retrospectively described FIV- and FeLV-associated diseases in a population of 1470 necropsied cats, of which 396 (26.9%) were infected with FeLV, 199 (13.5%) with FIV, and 134 (9.1%) with FeLV and FIV concomitantly. Cats infected with FeLV (OR 3.4) and co-infected with FeLV and FIV (OR 1.9) were more likely to have neoplasms. The diagnosis of lymphoma and leukemia was higher in cats infected with FeLV (OR 3.9 and 19.4, respectively) and coinfected with FeLV and FIV (OR 1.9 and 19.3, respectively). The odds of diagnosing bacterial diseases were higher in cats coinfected with FeLV and FIV (OR: 2.8), whereas the odds of viral diseases were higher in those infected with FeLV (OR: 2.8), with 2.2 times more diagnoses of feline infectious peritonitis. Neoplastic and infectious diseases in FIV-infected cats did not differ significantly from those in uninfected cats. According to our results, a high prevalence of retroviral infections was observed in southern Brazil, mainly in relation to FeLV. Infected cats were significantly younger than uninfected cats. The main causes of death associated with FeLV infection and FeLV and FIV coinfection were neoplastic and infectious diseases. In contrast, FIV infection was not associated with any specific condition.
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Affiliation(s)
- Lauren Santos de Mello
- Department of Veterinary Pathology, College of Veterinary Medicine, Federal University of Rio Grande do Sul (UFRGS), 9090 Av. Bento Gonçalves, Porto Alegre, RS 91540-000, Brazil.
| | - Paula Reis Ribeiro
- Department of Veterinary Pathology, College of Veterinary Medicine, Federal University of Rio Grande do Sul (UFRGS), 9090 Av. Bento Gonçalves, Porto Alegre, RS 91540-000, Brazil.
| | - Bruno Albuquerque de Almeida
- Department of Veterinary Pathology, College of Veterinary Medicine, Federal University of Rio Grande do Sul (UFRGS), 9090 Av. Bento Gonçalves, Porto Alegre, RS 91540-000, Brazil.
| | - Marcele Bettim Bandinelli
- Department of Veterinary Pathology, College of Veterinary Medicine, Federal University of Rio Grande do Sul (UFRGS), 9090 Av. Bento Gonçalves, Porto Alegre, RS 91540-000, Brazil.
| | - Luciana Sonne
- Department of Veterinary Pathology, College of Veterinary Medicine, Federal University of Rio Grande do Sul (UFRGS), 9090 Av. Bento Gonçalves, Porto Alegre, RS 91540-000, Brazil.
| | - David Driemeier
- Department of Veterinary Pathology, College of Veterinary Medicine, Federal University of Rio Grande do Sul (UFRGS), 9090 Av. Bento Gonçalves, Porto Alegre, RS 91540-000, Brazil.
| | - Saulo Petinatti Pavarini
- Department of Veterinary Pathology, College of Veterinary Medicine, Federal University of Rio Grande do Sul (UFRGS), 9090 Av. Bento Gonçalves, Porto Alegre, RS 91540-000, Brazil.
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4
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Molecular epidemiology of type I and II feline coronavirus from cats with suspected feline infectious peritonitis in China between 2019 and 2021. Arch Virol 2021; 167:189-194. [PMID: 34739587 PMCID: PMC8570233 DOI: 10.1007/s00705-021-05291-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2021] [Accepted: 09/20/2021] [Indexed: 11/03/2022]
Abstract
Feline infectious peritonitis (FIP) is one of the deadliest diseases of cats in China. In this study, 120 ascitic fluid samples from FIP-suspected cats were collected from veterinary hospitals in 21 provinces in China between 2019 and 2021. One hundred nine samples were positive for feline coronavirus (FCoV), with no feline immunodeficiency virus infections and one feline leukemia virus infection (1/109, 0.92%). The prevalence of FCoV was significantly associated with age (p < 0.01) and was not highly associated with gender, breed, geographical location, or viral coinfection (p > 0.01). One unique strain, SD/202012/003, contained a six-nucleotide deletion in the spike gene. Sequence analysis showed that 94.68% (89/94) of the isolates had a mutation of methionine to leucine at position 1058 in the spike protein. The epidemiological data obtained of FCoV in this study may be beneficial for clinical monitoring of FCoV in China.
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Cloutier M, Nandi M, Ihsan AU, Chamard HA, Ilangumaran S, Ramanathan S. ADE and hyperinflammation in SARS-CoV2 infection- comparison with dengue hemorrhagic fever and feline infectious peritonitis. Cytokine 2020; 136:155256. [PMID: 32866898 PMCID: PMC7439999 DOI: 10.1016/j.cyto.2020.155256] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2020] [Revised: 08/05/2020] [Accepted: 08/12/2020] [Indexed: 12/13/2022]
Abstract
The COVID-19 pandemic has rapidly spread around the world with significant morbidity and mortality in a subset of patients including the elderly. The poorer outcomes are associated with 'cytokine storm-like' immune responses, otherwise referred to as 'hyperinflammation'. While most of the infected individuals show minimal or no symptoms and recover spontaneously, a small proportion of the patients exhibit severe symptoms characterized by extreme dyspnea and low tissue oxygen levels, with extensive damage to the lungs referred to as acute respiratory distress symptom (ARDS). The consensus is that the hyperinflammatory response of the host is akin to the cytokine storm observed during sepsis and is the major cause of death. Uncertainties remain on the factors that lead to hyperinflammatory response in some but not all individuals. Hyperinflammation is a common feature in different viral infections such as dengue where existing low-titer antibodies to the virus enhances the infection in immune cells through a process called antibody-dependent enhancement or ADE. ADE has been reported following vaccination or secondary infections with other corona, Ebola and dengue virus. Detailed analysis has shown that antibodies to any viral epitope can induce ADE when present in sub-optimal titers or is of low affinity. In this review we will discuss ADE in the context of dengue and coronavirus infections including Covid-19.
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Affiliation(s)
- Maryse Cloutier
- Department of Immunology and Cell Biology, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Sherbrooke, QC, Canada
| | - Madhuparna Nandi
- Department of Immunology and Cell Biology, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Sherbrooke, QC, Canada
| | - Awais Ullah Ihsan
- Department of Immunology and Cell Biology, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Sherbrooke, QC, Canada
| | - Hugues Allard Chamard
- Division of Rheumatology, Department of Medicine, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Sherbrooke, QC, Canada; Centre de Recherche Clinique, Centre Hospitalier d'Université de Sherbrooke, Sherbrooke, QC, Canada
| | - Subburaj Ilangumaran
- Department of Immunology and Cell Biology, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Sherbrooke, QC, Canada; Centre de Recherche Clinique, Centre Hospitalier d'Université de Sherbrooke, Sherbrooke, QC, Canada.
| | - Sheela Ramanathan
- Department of Immunology and Cell Biology, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Sherbrooke, QC, Canada; Centre de Recherche Clinique, Centre Hospitalier d'Université de Sherbrooke, Sherbrooke, QC, Canada.
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6
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Beatty J. Viral causes of feline lymphoma: Retroviruses and beyond. Vet J 2014; 201:174-80. [DOI: 10.1016/j.tvjl.2014.05.026] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2013] [Revised: 05/11/2014] [Accepted: 05/17/2014] [Indexed: 11/30/2022]
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7
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The transmembrane proteins contribute to immunodeficiencies induced by HIV-1 and other retroviruses. AIDS 2014; 28:1081-90. [PMID: 24445366 DOI: 10.1097/qad.0000000000000195] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Many microorganisms including retroviruses suppress the immune system of the infected host in order to maintain infection. Unfortunately, it is still unclear how retroviruses induce immunosuppression. There is increasing evidence of a common mechanism based on their transmembrane envelope proteins. This review therefore summarizes evidence of the involvement of the transmembrane envelope proteins in the immunopathogenesis of different retroviruses including HIV-1. Mutations in the immunosuppressive (isu) domain of the transmembrane envelope protein of several retroviruses abrogate the immunosuppressive activities in vitro and in vivo. Most importantly, virus sequences with such abrogating mutations were never found in HIV-1-infected individuals despite the fact that the mutated viruses are replication-competent. However, there is also evidence for additional, perhaps even divergent, strategies for each retrovirus. For example, in contrast to many other retroviruses, the HIV directly interacts with immune cells and infects them. In addition, HIV uses several accessory proteins to evade the immune response. Furthermore, the possible contribution of the transmembrane envelope proteins of endogenous retroviruses to immunosuppression when expressed on tumor cells or in the placenta is analyzed.
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8
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Drechsler Y, Alcaraz A, Bossong FJ, Collisson EW, Diniz PPVP. Feline coronavirus in multicat environments. Vet Clin North Am Small Anim Pract 2012; 41:1133-69. [PMID: 22041208 PMCID: PMC7111326 DOI: 10.1016/j.cvsm.2011.08.004] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Affiliation(s)
- Yvonne Drechsler
- College of Veterinary Medicine, Western University of Health Sciences, 309 East Second Street, Pomona, CA 91766-1854, USA
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9
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Beatty JA, Tasker S, Jarrett O, Lam A, Gibson S, Noe-Nordberg A, Phillips A, Fawcett A, Barrs VR. Markers of feline leukaemia virus infection or exposure in cats from a region of low seroprevalence. J Feline Med Surg 2011; 13:927-33. [PMID: 21880527 PMCID: PMC10832971 DOI: 10.1016/j.jfms.2011.07.011] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2011] [Revised: 07/11/2011] [Accepted: 07/16/2011] [Indexed: 11/18/2022]
Abstract
Molecular techniques have demonstrated that cats may harbour feline leukaemia virus (FeLV) provirus in the absence of antigenaemia. Using quantitative real-time polymerase chain reaction (qPCR), p27 enzyme-linked immunosorbent assay (ELISA), anti-feline oncornavirus-associated cell-membrane-antigen (FOCMA) antibody testing and virus isolation (VI) we investigated three groups of cats. Among cats with cytopenias or lymphoma, 2/75 were transiently positive for provirus and anti-FOCMA antibodies were the only evidence of exposure in another. In 169 young, healthy cats, all tests were negative. In contrast, 3/4 cats from a closed household where FeLV was confirmed by isolation, had evidence of infection. Our results support a role for factors other than FeLV in the pathogenesis of cytopenias and lymphoma. There was no evidence of exposure in young cats. In regions of low prevalence, where the positive predictive value of antigen testing is low, qPCR may assist with diagnosis.
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Affiliation(s)
- Julia A Beatty
- Valentine Charlton Cat Centre, Faculty of Veterinary Science, The University of Sydney, NSW 2006, Australia.
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Wardini AB, Guimaraes-Costa AB, Nascimento MTC, Nadaes NR, Danelli MGM, Mazur C, Benjamim CF, Saraiva EM, Pinto-da-Silva LH. Characterization of neutrophil extracellular traps in cats naturally infected with feline leukemia virus. J Gen Virol 2009; 91:259-64. [DOI: 10.1099/vir.0.014613-0] [Citation(s) in RCA: 88] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
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11
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Affiliation(s)
- Niels C Pedersen
- Department of Medicine and Epidemiology and Center for Companion Animal Health, School of Veterinary Medicine, University of California, Davis, CA 95616, USA.
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12
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Kipar A, Kremendahl J, Jackson ML, Reinacher M. Comparative examination of cats with feline leukemia virus-associated enteritis and other relevant forms of feline enteritis. Vet Pathol 2001; 38:359-71. [PMID: 11467470 DOI: 10.1354/vp.38-4-359] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Cats with feline leukemia virus (FeLV)-associated enteritis (FAE), enteritis of other known viral etiology (parvovirus [PV], enteric coronavirus [CoV]), and enteritis of unknown etiology with histologic features similar to those of FAE and PV enteritis (EUE) and FeLV-negative and FeLV-positive cats without enterocyte alterations were examined. Amount and types of infiltrating leukocytes in the jejunum and activity and cellular constituents of mesenteric lymph nodes, spleen, and bone marrow were determined. PV and CoV infections were confirmed by immunohistologic demonstration of PV and CoV antigen, ultrastructural demonstration of viral particles in the intestinal content, and in situ hybridization for PV genome. FeLV infection was detected by immunohistology for gp70, p27, and p15E. Latent FeLV infection was excluded by polymerase chain reaction methods for exogenous FeLV DNA. Enterocyte lesions involved the crypts in cats with PV enteritis, FAE, and EUE and the villous tips in cats with CoV enteritis. Inflammatory infiltration was generally dominated by mononuclear cells and was moderate in the unaltered intestine and in cats with PV enteritis and marked in cats with FAE, CoV enteritis, and EUE. In cats with EUE, myeloid/histiocyte antigen-positive macrophages were relatively numerous, suggesting recruitment of peripheral blood monocytes. Lymphoid tissues were depleted in cats with PV enteritis and with EUE but were normal or hyperplastic in cats with FAE. Bone marrow activity was decreased in cats with PV enteritis; in cats with FAE or EUE and in FeLV-positive cats without enterocyte alterations, activity was slightly increased. In cats with FAE and PV enteritis, a T-cell-dominated response prevailed. EUE showed some parallels to human inflammatory bowel disease, indicating a potential harmful effect of infiltrating macrophages on the intestinal epithelium.
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Affiliation(s)
- A Kipar
- Institut für Veterinär-Pathologie, Justus-Liebig-Universität Giessen, Germany.
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Kohn CW, Swardson C, Provost P, Gilbert RO, Couto CG. Myeloid and megakaryocytic hypoplasia in related standardbreds. J Vet Intern Med 1995; 9:315-23. [PMID: 8531176 DOI: 10.1111/j.1939-1676.1995.tb01090.x] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
Myeloid and megakaryocytic bone marrow hypoplasia in association with moderate to profound neutropenia was observed in 8 young Standardbred horses sired by the same stallion; 7 horses were intermittently thrombocytopenic. Evaluation of serial neutrophil counts in 2 horses suggested that a cyclic variation in neutrophil numbers was present, that lymphocyte numbers increased when neutrophil counts decreased, and that platelet counts decreased when neutrophil counts decreased. Preliminary bone marrow cultures indicated that myeloid progenitor cells were present and that these cells were able to respond to exogenous growth factors by differentiating. A bone marrow microenvironment or growth factor defect is suspected. Seven of 8 horses died or were euthanized. One horse with moderate neutropenia and a normal platelet count has been racing for 3 years. Necropsies in 4 horses did not reveal a cause for the myeloid hypoplasia. A familial basis for the disease is suspected.
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Affiliation(s)
- C W Kohn
- Department of Veterinary Clinical Sciences, Ohio State University, Columbus 43210, USA
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Abstract
Three immunopathological mechanisms may determine the pathogenesis of viral diseases in animals. (1) A variety of viruses causes transient or prolonged immunosuppression by infecting lymphoreticular tissues and interacting with components of the immune system. (2) In persistent viral infections effective immune responses may result in tissue damage. The mechanisms involved are T-cell-mediated destruction of infected cells and delayed-type hypersensitivity. (3) In a number of viral diseases pathogenic immune complexes are formed when antibodies are produced and react with viral antigen molecules persisting in the host. The selected examples of immune dysfunction are the focus of this review.
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Affiliation(s)
- G Trautwein
- Department of Pathology, School of Veterinary Medicine, Hannover, Germany
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Brown PJ, Hopper CD, Harbour DA. Pathological features of lymphoid tissues in cats with natural feline immunodeficiency virus infection. J Comp Pathol 1991; 104:345-55. [PMID: 1651959 PMCID: PMC7130401 DOI: 10.1016/s0021-9975(08)80145-4] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
A range of tissues from a total of 17 cats naturally infected with the feline immunodeficiency virus was examined histologically. In 11 cases, chronic inflammatory lesions were present in various tissues including, most commonly, the intestine, brain and lung. Extensive inflammation in the intestinal wall was present in seven of the cats. No particular bacterial organisms were demonstrated in these inflammatory lesions. A range of changes was present in the lymph nodes, including hyperplasia, atrophy or a mixed pattern. Erythrophagocytosis was a consistent feature. The changes resembled those reported in human acquired immunodeficiency syndrome as a result of infection with human immunodeficiency virus.
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Affiliation(s)
- P J Brown
- University of Bristol School of Veterinary Science, Langford, U.K
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16
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Kizaki T, Mitani M, Cianciolo GJ, Ogasawara M, Good RA, Day NK. Specific association of retroviral envelope protein, p15E, with human cell surfaces. Immunol Lett 1991; 28:11-8. [PMID: 1649129 DOI: 10.1016/0165-2478(91)90121-p] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Experiments were carried out to analyze the binding sites on human cells for highly purified retroviral protein p15E isolated from Feline Leukemia Virus, Rickard Strain. Binding of 125I-labeled p15E was tested with surfaces of human peripheral blood lymphocytes and 3 cell lines, Raji, MOLT-4, and U-937. 125I-labeled p15E showed specific binding to human peripheral blood lymphocytes. In addition, all of the cell lines tested showed binding of 125I-labeled p15E. Using U-937 cells, we characterized the interaction between p15E and the surface of these cells, and showed that the binding was specific by the following 3 different sets of evidence: (i) in equilibrium binding experiments, 18,000 binding sites with a dissociation constant of 2 x 10(-9) M were present on U-937 cells; (ii) trypsin or N-glycanase treatment decreased the binding sites of 125I-labeled p15E; and (iii) by affinity chromatography using p15E or BSA Sepharose columns, the isolated membranes of 125I-labeled U-937 cells previously treated with Triton X-100 showed a significantly higher binding to the p15E column than to the BSA column.
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Affiliation(s)
- T Kizaki
- All Children's Hospital, University of South Florida, St. Petersburg 33701
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Lymphocyte subset alterations and viral determinants of immunodeficiency disease induction by the feline leukemia virus FeLV-FAIDS. J Virol 1990; 64:5465-74. [PMID: 1976822 PMCID: PMC248598 DOI: 10.1128/jvi.64.11.5465-5474.1990] [Citation(s) in RCA: 46] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
The FeLV-FAIDS strain of feline leukemia virus consistently induces fatal immunodeficiency. To investigate the immunopathogenesis and viral genetic determinants responsible for the induction of immunodeficiency disease in vivo, we have generated chimeras between the two major viral genomes in the original virus isolate, designated common form clone 61E and major variant clone 61C, which were molecularly cloned directly from DNA of the same animal and tissue. Each of three 61E/C chimeras, containing at minimum a 34-amino-acid segment (including a 6-amino-acid insertion and one amino acid substitution) near the C terminus of the 61C surface glycoprotein (gp70), induced fatal immunodeficiency disease in all (12 of 12) infected animals over a course of 33 +/- 10 weeks. By contrast, animals infected with virus 61E, although persistently antigenemic, remained asymptomatic throughout a 48-week observation period. Beginning 14 weeks after infection, a significant decrease (8 to 10%) in the percent of circulating CD4+ T lymphocytes developed in the 61E/C chimera-infected cats, compared with either 61E-infected or control animals. At this time, no significant changes were seen in CD8 cells, B cells, or mitogen-induced blastogenesis. Prior to this initial decline in CD4 cells, the ability of all antigenemic 61E/C-infected cats to generate a primary antibody response to the T-cell-dependent antigen keyhole limpet hemocyanin was markedly impaired, whereas all 61E-infected cats, one 61E/C-infected but nonviremic cat, and all uninfected control cats produced normal antibody responses. The results reported here demonstrate that a major determinant of in vivo immunodeficiency induction by FeLV-FAIDS is contained within a 34-amino-acid C-terminal segment of its surface glycoprotein and that this gp70 alteration determines the early and persistent deficits in CD4+ T lymphocytes and T-cell-dependent antibody responses. We hypothesize that these early immunologic alterations could result from early deletion of a CD4+ helper T-cell subset.
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18
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Pedersen NC, Torten M, Rideout B, Sparger E, Tonachini T, Luciw PA, Ackley C, Levy N, Yamamoto J. Feline leukemia virus infection as a potentiating cofactor for the primary and secondary stages of experimentally induced feline immunodeficiency virus infection. J Virol 1990; 64:598-606. [PMID: 2153226 PMCID: PMC249149 DOI: 10.1128/jvi.64.2.598-606.1990] [Citation(s) in RCA: 85] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Preexistent feline leukemia virus (FeLV) infection greatly potentiated the severity of the transient primary and chronic secondary stages of feline immunodeficiency virus (FIV) infection. Of 10 FeLV-FIV carrier cats, 5 died of experimentally induced FIV infection, compared with 2 deaths in 10 cats infected only with FeLV and 1 death in 7 cats infected only with FIV. FIV-infected cats with preexistent FeLV infections developed severe depression, anorexia, fever, diarrhea, dehydration, weight loss, and leukopenia 4 to 6 weeks after infection and were moribund within 2 weeks of the onset of signs, whereas cats infected only with FIV developed much milder self-limiting gross and hematologic abnormalities. Pathologic findings in dually infected cats that died were similar to those observed previously in cats dying from uncomplicated primary FIV infection but were much more widespread and severe. Coinfection of asymptomatic FeLV carrier cats with FIV did not increase the levels of FeLV p27 antigen present in their blood over that seen in cats infected with FeLV alone. The amount of proviral FIV DNA was much higher, however, in dually infected cats than in cats infected only with FIV; there was a greater expression of FIV DNA in lymphoid tissues, where the genome was normally detected, and in nonlymphoid tissues, where FIV DNA was not usually found. Dually infedted cats that recovered from the primary stage of FIV infection remained more leukopenic than cats infected with FIV or FeLV alone, and their CD4+/CD8+ T-lymphocyte ratios were inverted. One of these cats developed what was considered to be an opportunistic infection. It was concluded, therefore, that a preexistent FeLV infection in some way enhanced the expression and spread of FIV in the body and increased the severity of both the resulting transient primary and chronic secondary stages of FIV infection. This study also demonstrated the usefulness of the FIV model in studying the role of incidental infectious diseases as cofactors for immunodeficiency-causing lentiviruses.
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Affiliation(s)
- N C Pedersen
- Department of Medicine, School of Veterinary Medicine, University of California, Davis 95616
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19
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Mertins SD, Ortona L, Cauda R. Role of polymorphonuclear leukocytes in infection by retroviruses with emphasis on the human immunodeficiency virus. Viral Immunol 1990; 3:173-94. [PMID: 2175193 DOI: 10.1089/vim.1990.3.173] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Neutrophil function is an integral part of the host defense against multiple pathogens. Through phagocytosis and production of toxic substances, these short lived cells aid in the effective elimination of invading microorganisms such as bacterial and fungal targets. Viral infections, and in particular those of the retroviral type, appear to suppress the immune response through direct cytotoxic destruction of immune cells or alteration of the biochemical interactions that are essential for eradicating the foreign agent. In this report, we describe abnormalities of neutrophil number and function consequent to HIV and other retroviral infections. A myriad of mechanisms, either alone or in concert may explain the underlying aberrations.
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Affiliation(s)
- S D Mertins
- Infectious Disease Section, National Cancer Institute, National Institutes of Health, Bethesda, MD
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20
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Weiss RC, Cox NR. Evaluation of immunity to feline infectious peritonitis in cats with cutaneous viral-induced delayed hypersensitivity. Vet Immunol Immunopathol 1989; 21:293-309. [PMID: 2552650 PMCID: PMC7133611 DOI: 10.1016/0165-2427(89)90038-x] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Delayed-type hypersensitivity (DTH)-like reactions to feline infectious peritonitis (FIP) virus (FIPV) were induced in the skin of nine cats that were asymptomatic after a previous challenge-exposure with FIPV. Four of the nine previously challenge-exposed cats were negative for virus-neutralizing antibodies against FIPV at the time of intradermal (ID) testing for DTH. Two other cats tested for DTH when acutely ill with clinical FIP did not have cutaneous DTH responses to FIPV. Gross skin reactions to FIPV injected ID were observed in six of nine asymptomatic cats (67%) at postintradermal inoculation hours (PIH) 24, 48, and/or 72. The reactions consisted of focal, 1-5-mm to 2.5-cm diameter indurated or semi-firm, nonerythematous, slightly raised nodules. Microscopically, DTH-like reactions were observed in biopsies taken from the FIPV-inoculated skin of asymptomatic cats at PIH 24 to 72. The lesions consisted of perivascular and diffuse dermal infiltrations by macrophages, lymphocytes, and polymorphonuclear leukocytes (PMN). The dermal infiltrates, which were maximal at PIH 48 or 72, were predominantly mixed inflammatory cells (five of nine cats) or PMN (four of nine cats) at PIH 24, but later were predominantly mononuclear cells (six of nine cats) or mixed inflammatory cells (two of nine cats) at PIH 72. Five of nine cats (56%) with positive DTH skin responses had increased survival times after lethal ID challenge-exposure with FIPV compared to mean survival times in FIPV-naive, non-immune control cats that were DTH-negative when ID challenge-exposed. Four of nine DTH-positive cats (44%) resisted an ID challenge-exposure dose of FIPV that was fatal in both control cats, and two of the four remaining DTH-positive cats survived a third challenge-exposure with highly lethal doses of FIPV given intraperitoneally. Four of the six DTH-positive cats (67%) that died after re-challenge and were necropsied had lesions of noneffusive FIP, suggesting that cellular immunity may also be involved in the pathogenesis of noneffusive disease, whereas both control cats and both DTH-negative cats with clinical disease succumbed to effusive FIP. Seemingly, DTH responses to FIPV can be associated with an increased level of resistance to disease; however, this state of immunity is variable and apparently can be lost with time in some cats.
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Affiliation(s)
- R C Weiss
- Scott Ritchey Research Program, Auburn University, AL 36849
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21
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Mullins JI, Hoover EA, Overbaugh J, Quackenbush SL, Donahue PR, Poss ML. FeLV-FAIDS-induced immunodeficiency syndrome in cats. Vet Immunol Immunopathol 1989; 21:25-37. [PMID: 2549691 DOI: 10.1016/0165-2427(89)90127-x] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Findings are reviewed, relevant to elucidation of the pathogenic, genetic and biochemical properties of a single, genetically heterogeneous isolate of feline leukemia virus (FeLV-FAIDS) shown to induce fatal immunodeficiency disease in nearly 100% of inoculated cats. Hypotheses are suggested which pertain to the mechanism of T-cell killing by this virus, and which extrapolate findings in the FeLV-FAIDS animal model to AIDS induced in humans by human immunodeficiency virus (HIV).
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Affiliation(s)
- J I Mullins
- Department of Cancer Biology, Harvard University School of Public Health, Boston, MA 02115
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22
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Abstract
More than 2000 cats sent for necropsy in order to provide a diagnosis were investigated immunohistologically using paraffin sections for the presence of a persistent infection with feline leukemia virus (FeLV). The spectrum of neoplastic and non-neoplastic diseases associated significantly with FeLV infection was determined statistically. Three-quarters of the cats with persistent FeLV infections died of non-neoplastic diseases and about 23% died of tumors, nearly exclusively those of the leukemia/lymphoma disease complex. A strong association with liver degeneration, icterus and a FeLV-associated enteritis was found in addition to the known association with non-neoplastic diseases and conditions such as anemia, bacterial secondary infections and respiratory tract inflammations due to the immunosuppressive effect of FeLV, hemorrhages and feline infectious peritonitis. Surprisingly, diseases and conditions like feline infectious panleukopenia, enteritis (of other types than FeLV-associated enteritis and feline infectious panleukopenia), glomerulonephritis, uremia and hemorrhagic cystitis were not associated with persistent FeLV infection. Another unexpected finding was that most pathogenic infectious agents demonstrated in the cats were not FeLV-associated either. Thus, immunosuppression due to FeLV infection seems to make the animals susceptible to certain pathogenic infectious agents, but not to the majority.
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Affiliation(s)
- M Reinacher
- Department of Veterinary Pathology, Justus-Liebig-Universität Giessen, Federal Republic of Germany
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Zeidner NS, Strobel JD, Perigo NA, Hill DL, Mullins JI, Hoover EA. Treatment of FeLV-induced immunodeficiency syndrome (FeLV-FAIDS) with controlled release capsular implantation of 2',3'-dideoxycytidine. Antiviral Res 1989; 11:147-60. [PMID: 2544137 DOI: 10.1016/0166-3542(89)90026-0] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
2',3'-dideoxycytidine (ddC) inhibits replication of the immunodeficiency inducing strain of feline leukemia virus (FeLV-FAIDS) in vitro at concentrations ranging from 1-10 micrograms/ml. Additive antiviral effect is achieved when ddC is combined with either human recombinant alpha interferon (IFN alpha) or tumor necrosis factor (TNF) plus IFN alpha. Initial in vivo pharmacokinetic studies in cats, utilizing bolus intravenous administration of ddC (20 mg/kg), resulted in peak plasma concentrations of 15 micrograms/ml 1 min after administration and a half-life of approximately 1 h. These values could not be augmented with high levels of the deaminase blocker tetrahydrouridine administered prior to or concurrently with ddC. In vivo trials utilizing multiple, daily intravenous injections of ddC could not prevent the development of persistent viremia in cats infected with FeLV-FAIDS. To enhance ddC pharmacokinetics and antiviral activity, controlled release capsular implants were developed by blending ddC with a copolymer consisting of DL-lactide glycolide and hydroxypropyl cellulose, which was melt-spun into fibers and encapsulated in a sheath of polyethylene glycol for subcutaneous implantation. Pharmacokinetic studies, conducted in cats receiving an average dose of 600 mg of ddC, indicated an average peak plasma concentration of 17 micrograms/ml achieved at 6 h post implantation with 3.5 micrograms/ml noted at 48 h; and an extension of plasma half-life from 1.5 (bolus subcutaneous injection) to 20 h. sustained plasma concentrations of 1.5 to 10 micrograms/ml, equivalent to ddC levels previously shown to have anti-FeLV activity in vitro, were maintained throughout a 72 h period. Implantation devices could be replenished every 48 h and elevated plasma levels were sustained for four weeks without signs of clinical toxicity, sepsis or significant alterations in the hemogram. Initial clinical trials employing controlled release capsular ddC implants in vivo indicate significant retardation of FeLV-FAIDS replication throughout a four week treatment period.
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Affiliation(s)
- N S Zeidner
- Department of Pathology, Colorado State University, Fort Collins 80523
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24
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Amadori A, Faulkner-Valle GP, De Rossi A, Zanovello P, Collavo D, Chieco-Bianchi L. HIV-mediated immunodepression: in vitro inhibition of T-lymphocyte proliferative response by ultraviolet-inactivated virus. CLINICAL IMMUNOLOGY AND IMMUNOPATHOLOGY 1988; 46:37-54. [PMID: 3257177 DOI: 10.1016/0090-1229(88)90004-9] [Citation(s) in RCA: 25] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
In order to assess whether the human retrovirus HIV, like other animal retroviruses, is endowed with intrinsic immunosuppressive activity, we studied the effects of noninfectious, uv-irradiated virus on in vitro lymphocyte function. uvHIV preparations inhibited T-cell proliferation to mitogens and alloantigens, as well as mitogen-driven IL-2 production. The inhibitory effect, which was not exerted by uv-irradiated HTLV-I, was apparently not due to a decrease in cell viability and was likely associated with thermoresistant viral component(s). The suppression proved to be selective for T-cell responses, while sparing other lymphocyte functions, such as the B-cell proliferative response to a selective B-cell mitogen. The inhibitory effect of uvHIV was not counteracted by a substantial reduction in the number of monocytes or by indomethacin. Moreover, IL-1 production by monocytes was not affected upon virus incubation. On the other hand, the proliferative response of both CD4+ and CD8+ T-cell clones was inhibited by uvHIV, suggesting that T cells represent the actual target for the inhibitory effect. Although a sizeable decrease in IL-2 production was observed following uvHIV incubation, exogenous IL-2 was not capable of reversing the virus-induced suppression of the proliferation. The possibility that the immunosuppressive activity of noninfectious HIV contributes to the T-cell defect in infected patients by mechanisms other than the cytopathic effect on CD4+ T lymphocytes is discussed.
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Affiliation(s)
- A Amadori
- Institute of Oncology, University of Padova, Italy
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25
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Rojko J, Essex M, Trainin Z. Feline leukemia/sarcoma viruses and immunodeficiency. ADVANCES IN VETERINARY SCIENCE AND COMPARATIVE MEDICINE 1988; 32:57-96. [PMID: 2847504 PMCID: PMC7271325 DOI: 10.1016/b978-0-12-039232-2.50007-4] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
This chapter discusses the structure feline leukemia virus (FeLV) and pathogenesis of lymphomas and leukemias BY FeLV. FeLV is quite similar to the better-studied murine leukemia viruses in structure and genetic map. The virus particles bud from cytoplasmic membranes into either extracellular spaces or into vacuoles. FeLV has long been considered a typical noncytopathogenic, longlatency leukemia virus based on its behavior in fibroblasts in vitro . Recent evidence suggests that its in vivo behavior in critical target hemolymphatic tissues is as likely to be cytopathic as transforming. The type of FeLV-related disease that occurs and the disease-free interval probably are influenced by viral envelope proteins and glycoproteins and the consequences of proviral integration. FeLV subgroup specificity apparently determines when and what type of disease will occur. The ecotropic FeLV-A is the most frequent subgroup found in pet cats and is transmitted contagiously. Immunosuppression is the most frequent and the most devastating manifestation of FeLV viremia in clinical and experimental studies. It seems that multiple cell types and multiple processes are involved in the development of feline retrovirus-induced immunosuppression. Although no solid evidence is available for the malfunctioning of cat T helper cells because of the paucity of T-cell specific markers, the circumstantial evidence provided thus far indicates an impaired T helper function in FeLV-infected cats similar to that observed in humans infected with HIV. Studies on the pathogenesis of FeLV-induced immunosuppression might provide a valuable mode for a better understanding and means of control of human AIDS.
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Affiliation(s)
- J Rojko
- Veterinary Pathobiology, College of Veterinary Medicine, Ohio State University, Columbus 43210
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26
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Pedersen NC. Virologic and immunologic aspects of feline infectious peritonitis virus infection. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 1987; 218:529-50. [PMID: 2829567 DOI: 10.1007/978-1-4684-1280-2_69] [Citation(s) in RCA: 105] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
A number of feline coronavirus isolates have been characterized over the last few years. These isolates consist of what we have referred to as feline enteric coronaviruses (FECVs) and feline infectious peritonitis viruses (FIPVs). FECVs cause a transient enteritis in kittens but no systemic illness. FIPVs, in contrast, cause a systemic and usually fatal disease syndrome characterized either by an exudative serositis or a disseminated granulomatous disease. Although the diseases they cause are quite different, FECVs and FIPVs are antigenically and morphologically indistinguishable from each other. FECVs have a strict tropism for mature intestinal epithelial cells and do not appear to replicate in macrophages. In contrast, FIPVs, appear to spread rapidly from the intestinal mucosa and replicate in macrophages. Experiments will be presented, and literature cited, that will allow us to make the following assumptions about the pathogenesis of FIPV infection: 1) FIPVs and FECVs represent a spectrum of viruses that differ only in infectivity (ability to evoke seroconversion following oral infection) and virulence (ability to cause FIP), 2) field isolates are generally nearer to FECVs in behavior than laboratory isolates made from animal passaged material, 3) immunity to FIPV appears to be of the premunition type and is maintained for as long as the infection persists in a reactivatable form, 4) strains of feline coronaviruses that do not cause systemic disease, such as FECVs or low virulence FIPVs, can actually sensitize cats to infection with virulent FIPV strains, 5) FeLV infection interferes with established FIP immunity and allows for the reactivation of disease in healthy carriers, 6) FIPV may be passaged from queen to kitten either in utero or during neonatal life, and 7) kittens infected by their mothers with FIPV do not usually develop FIP but become immune carriers of the virus for a period of 5-6 months; recovery from the carrier state is associated with a loss of premunition immunity.
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Affiliation(s)
- N C Pedersen
- Department of Medicine, School of Veterinary Medicine, University of California, Davis 95616
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27
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Mitani M, Cianciolo GJ, Snyderman R, Yasuda M, Good RA, Day NK. Suppressive effect on polyclonal B-cell activation of a synthetic peptide homologous to a transmembrane component of oncogenic retroviruses. Proc Natl Acad Sci U S A 1987; 84:237-40. [PMID: 3025858 PMCID: PMC304178 DOI: 10.1073/pnas.84.1.237] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
Purified feline leukemia virus, UV light-inactivated feline leukemia virus, and a synthetic peptide (CKS-17) homologous to a well-conserved region of the transmembrane components of several human and animal retroviruses were each studied for their effects on IgG production by feline peripheral blood lymphocytes. Using a reverse hemolytic plaque assay, both the viable virus and the UV-inactivated feline leukemia virus, but not the CKS-17, activated B lymphocytes to secrete IgG. When staphylococcal protein A, a polyclonal B-cell activator, was used to stimulate IgG synthesis by feline lymphocytes, the viable virus, the UV-inactivated virus, and the CKS-17 peptide each strongly suppressed IgG secretion without compromising viability of the lymphocytes. These findings suggest that the immunosuppressive influences of feline leukemia virus on immunoglobulin synthesis may reside in a conserved portion of the envelope glycoprotein that includes the region homologous to CKS-17.
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28
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Abstract
The many studies that have addressed the possibility for FeLV infection in human beings are reviewed in this article. Because of the many similarities between FeLV-induced immune system impairment in cats and retrovirus related acquired immune deficiency syndrome in man, these two conditions are discussed as well.
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29
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Cockerell GL, Parodi AL, Levy D. Immunocompetence of sheep experimentally infected with bovine leukemia virus. Vet Immunol Immunopathol 1986; 13:189-202. [PMID: 3026080 DOI: 10.1016/0165-2427(86)90072-3] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
The humoral and cellular immunological reactivity of sheep were studied throughout the first 32 weeks following experimental infection with bovine leukemia virus (BLV). Seroconversion of BLV-inoculated sheep occurred within 4 weeks, but infection was not transmitted to contact control sheep. Despite the persistence of the viral infection, no differences were demonstrated in leukograms, serum IgG concentrations, humoral response to immunization with an irrelevant antigen (rabbit red blood cells), phytomitogen (Concanavalin A and Pokeweek mitogen)-induced lymphocyte blastogenesis, or chemical (1-chloro, 2-4 dinitrobenzene) skin contact hypersensitivity, between BLV-infected and uninfected contact control sheep. These results demonstrate the absence of a nonspecific immunosuppressive effect of BLV and further negate the influence of a generalized immunological deficit on the development of clinical disease in BLV-infected animals.
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30
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Engelman RW, Machida K, Longley RE, Liu WT, Trang LQ, Good RA, Day NK. Characterization of a newly established feline lymphoma-derived cell line (BKD) lacking T and B cell surface markers. IN VITRO CELLULAR & DEVELOPMENTAL BIOLOGY : JOURNAL OF THE TISSUE CULTURE ASSOCIATION 1986; 22:273-9. [PMID: 2423498 DOI: 10.1007/bf02621230] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
A new feline lymphoma-derived cell line, designated BKD, was isolated from an anterior mediastinal tumor. Cells of this line were characterized as lymphoid based on morphology, the lack of intracellular esterase and peroxidase activity, and absence of phagocytic function. In contrast with other established feline lymphoma-derived cell lines, cells of the BKD line lack characteristics of both feline T-cells and B-cells in that they neither form rosettes with guinea pig erythrocytes nor have demonstrable surface or cytoplasmic immunoglobulin. Approximately one third of BKD cells form EAC rosettes, a significant number of rosette forming cells (p = 0.0001) when compared to background sheep E-rosetting activity. In addition, a consistently titratable level of interleukin-2-like activity was produced when BKD cells were coincubated with concanavalin A and phorbol-12-myristate-13-acetate. Chromosome analysis showed that a majority of BKD cells are diploid. This new cell line has been continuously replicating in culture for over one year and produces feline leukemia virus as demonstrated by several analyses.
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31
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Denner J, Wunderlich V, Bierwolf D. Suppression of human lymphocyte mitogen response by proteins of the type-D retrovirus PMFV. Int J Cancer 1986; 37:311-6. [PMID: 3943925 DOI: 10.1002/ijc.2910370221] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
A type-D retrovirus, derived from a human cell line and designated PMFV, which is related to, but distinct from the Mason-Pfizer monkey virus (MPMV) suppressed the in vitro mitogen response of human lymphocytes. PMFV was suppressive either as intact virus or after disruption by ether or detergents. In kinetic studies, the time course of the interaction between suppressive virus components and lymphocytes was characterized. Neither cytotoxicity nor time shifts in optimum 3H-thymidine incorporation of responding lymphocytes were observed. The suppressive activity of the disrupted virus was diminished by heating, freeze-thawing or treatment with pronase or trypsin, indicating temperature-sensitive proteins as suppressive components. By Sephacryl S-200 gel chromatography, molecular weights of approximately 70 and 15 kDa were determined for the suppressive components which were isolated from disrupted virus or virus-producing cells but not from non-infected cells.
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33
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Engelman RW, Gengozian N, Good RA, Day NK. Polyclonal induction of immunoglobulin synthesis by feline leukocytes as identified in a reverse hemolytic plaque assay. J Immunol Methods 1985; 81:65-71. [PMID: 3894522 DOI: 10.1016/0022-1759(85)90122-x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Optimal conditions of culture and assay for identification of feline immunoglobulin-secreting mononuclear cells were determined for the staphylococcal protein A-reverse hemolytic plaque assay (SpA-RHPA). Hemolytic plaques were most distinct and numerous when peripheral blood mononuclear cells were stimulated with 6.9 micrograms/ml pokeweed mitogen for 7 days. Immunoglobulin-secreting cells were identified morphologically within a zone of hemolysis utilizing a 1:5 dilution of rabbit anti-cat IgG and a 1:30 dilution of guinea pig complement as developing reagents. The SpA-RHPA system should contribute to an understanding of normal feline T- and B-lymphocyte interactions and will likely aid in the identification and understanding of immune cell dysfunctions associated with chronic feline leukemia virus infection.
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Engelman RW, Fulton RW, Good RA, Day NK. Suppression of gamma interferon production by inactivated feline leukemia virus. Science 1985; 227:1368-70. [PMID: 2983424 DOI: 10.1126/science.2983424] [Citation(s) in RCA: 28] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Supernatants from cultures of normal feline lymphocytes stimulated with Staphylococcus enterotoxin A showed antiviral activity, characterized as a gamma-like interferon. With the addition of inactivated feline leukemia virus, markedly less interferon was produced. The reduction in interferon production was not attributable to lowered lymphocyte viability or reduced mitogenic properties of Staphylococcus enterotoxin A and appears to be a direct retroviral effect. This finding may reflect clinically relevant events that may contribute to the development of the feline or human states of acquired immunodeficiency.
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Abstract
As veterinarians, our responsibilities do not end with the care of our patients. The welfare of our clients and their families depends on our ability to detect and control potentially zoonotic diseases in their pets. Because some of these zoonoses can have devastating effects on the development of the unborn fetus or on family health in general, discussion about these diseases between veterinarian and client is often emotionally charged. Under such circumstances, the offering of inaccurate and erroneous information by the veterinarian can have drastic consequences. It is likely that other zoonotic diseases of domestic pets will be identified in the future, especially those that can cause opportunistic infections in debilitated and immunodeficient persons. In the meantime, the potential hazards of cat ownership can be significantly reduced through an increased understanding of feline diseases and an improved level of health care for our feline patients.
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