Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3
pubmed:dateCreated
2002-1-22
pubmed:abstractText
Ebola virus (EBOV) infections are characterized by dysregulation of normal host immune responses. Insight into the mechanism came from recent studies in nonhuman primates, which showed that EBOV infects cells of the mononuclear phagocyte system (MPS), resulting in apoptosis of bystander lymphocytes. In this study, we evaluated serum levels of cytokines/chemokines in EBOV-infected nonhuman primates, as possible correlates of this bystander apoptosis. Increased levels of interferon (IFN)-alpha, IFN-beta, interleukin (IL)-6, IL-18, MIP-1alpha, and MIP-1beta were observed in all EBOV-infected monkeys, indicating the occurrence of a strong proinflammatory response. To investigate the mechanism(s) involved in lymphoid apoptosis, soluble Fas (sFas) and nitrate accumulation were measured. sFas was detected in 4/9 animals, while, elevations of nitrate accumulation occurred in 3/3 animals. To further evaluate the potential role of these factors in the observed bystander apoptosis and intact animals, in vitro cultures were prepared of adherent human monocytes/macrophages (PHM), and monocytes differentiated into immature dendritic cells (DC). These cultures were infected with EBOV and analyzed for cytokine/chemokine induction and expression of apoptosis-related genes. In addition, the in vitro EBOV infection of peripheral blood mononuclear cells (PBMC) resulted in strong cytokine/chemokine induction, a marked increase in lactate dehydrogenase (LDH) activity, and an increase in the number of apoptotic lymphocytes examined by electron microscopy. Increased levels of sFAS were detected in PHM cultures, although, <10% of the cells were positive by immunohistochemistry. In contrast, >90% of EBOV-infected PHM were positive for tumor necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL) by immunohistochemistry, RNA analysis, and flow cytometry. Inactivated EBOV also effected increased TRAIL expression in PHM, suggesting that the TNF receptor superfamily may be involved in apoptosis of the host lymphoid cells, and that induction may occur independent of viral replication. In further studies with infected PHM, expression of MHC II was remarkably suppressed after 6 days, an additional correlate of immunological dysregulation. In conclusion, our findings suggest that infection of mononuclear phagocytes is critical, triggering a cascade of events involving cytokines/chemokines and oxygen free radicals. It is the consequence of these events rather than direct viral infection that results in much of the observed pathology. Identification of cytokine/chemokine, nitric oxide, and reactive oxygen species involvement in the observed filoviral pathogenesis may lend insight into the rational design of therapeutic countermeasures of filoviral pathogenesis.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
http://linkedlifedata.com/resource/pubmed/chemical/Antigens, CD95, http://linkedlifedata.com/resource/pubmed/chemical/Apoptosis Regulatory Proteins, http://linkedlifedata.com/resource/pubmed/chemical/Cytokines, http://linkedlifedata.com/resource/pubmed/chemical/Membrane Glycoproteins, http://linkedlifedata.com/resource/pubmed/chemical/Nitrates, http://linkedlifedata.com/resource/pubmed/chemical/RNA, Messenger, http://linkedlifedata.com/resource/pubmed/chemical/Reactive Oxygen Species, http://linkedlifedata.com/resource/pubmed/chemical/Receptors, Tumor Necrosis Factor, http://linkedlifedata.com/resource/pubmed/chemical/TNF-Related Apoptosis-Inducing..., http://linkedlifedata.com/resource/pubmed/chemical/TNFSF10 protein, human, http://linkedlifedata.com/resource/pubmed/chemical/Tumor Necrosis Factor-alpha
pubmed:status
MEDLINE
pubmed:month
Mar
pubmed:issn
0165-2478
pubmed:author
pubmed:issnType
Print
pubmed:day
1
pubmed:volume
80
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
169-79
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed-meshheading:11803049-Animals, pubmed-meshheading:11803049-Antigens, CD95, pubmed-meshheading:11803049-Apoptosis, pubmed-meshheading:11803049-Apoptosis Regulatory Proteins, pubmed-meshheading:11803049-Cells, Cultured, pubmed-meshheading:11803049-Cytokines, pubmed-meshheading:11803049-Disease Models, Animal, pubmed-meshheading:11803049-Flow Cytometry, pubmed-meshheading:11803049-Hemorrhagic Fever, Ebola, pubmed-meshheading:11803049-Humans, pubmed-meshheading:11803049-Inflammation, pubmed-meshheading:11803049-Lymphocytes, pubmed-meshheading:11803049-Macaca, pubmed-meshheading:11803049-Membrane Glycoproteins, pubmed-meshheading:11803049-Microscopy, Electron, pubmed-meshheading:11803049-Nitrates, pubmed-meshheading:11803049-RNA, Messenger, pubmed-meshheading:11803049-Reactive Oxygen Species, pubmed-meshheading:11803049-Receptors, Tumor Necrosis Factor, pubmed-meshheading:11803049-TNF-Related Apoptosis-Inducing Ligand, pubmed-meshheading:11803049-Time Factors, pubmed-meshheading:11803049-Tumor Necrosis Factor-alpha
pubmed:year
2002
pubmed:articleTitle
Proinflammatory response during Ebola virus infection of primate models: possible involvement of the tumor necrosis factor receptor superfamily.
pubmed:affiliation
Pathology Division, US Army Medical Research Institute of Infectious Diseases (USAMRIID), Attn: MCMR-UIP-D, 1425 Porter Street, Fort Detrick, MD 21702-5011, USA. lisa.hensley@amedd.army.mil
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, Non-P.H.S.