Linked Life Data

14734762

Source:http://linkedlifedata.com/resource/pubmed/id/14734762

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3
pubmed:dateCreated
2004-1-21
pubmed:abstractText
Human monocytotropic ehrlichiosis (HME) is an emerging, life-threatening, infectious disease caused by Ehrlichia chaffeensis, an obligate intracellular bacterium that lacks cell wall LPS. We have previously developed an animal model of severe HME using a strain of Ehrlichia isolated from Ixodes ovatus ticks (IOE). To understand the basis of susceptibility to severe monocytotropic ehrlichiosis, we compared low and high doses of the highly virulent IOE strain and the less virulent Ehrlichia muris strain that are closely related to E. chaffeensis in C57BL/6 mice. Lethal infections caused by high or low doses of IOE were accompanied by extensive liver damage, extremely elevated levels of TNF-alpha in the serum, high frequency of Ehrlichia-specific, TNF-alpha-producing CD8(+) T cells in the spleen, decreased Ehrlicha-specific CD4(+) T cell proliferation, low IL-12 levels in the spleen, and a 40-fold decrease in the number of IFN-gamma-producing CD4(+) Th1 cells. All groups contained negligible numbers of IL-4-producing cells in the spleen. Transfer of Ehrlichia-specific polyclonal Abs and IFN-gamma-producing Ehrlichia-specific CD4(+) and CD8(+) type 1 cells protected naive mice against lethal IOE challenge. Interestingly, infection with high dose E. muris provided protection against rechallenge with a lethal dose of IOE. Cross-protection was associated with substantial expansion of IFN-gamma-producing CD4(+) and CD8(+) cells, but not TNF-alpha-producing CD8(+) T cells, a high titer of IgG2a, and a low serum level of TNF-alpha. In conclusion, uncontrolled TNF-alpha production by CD8(+) T cells together with a weak CD4(+) Th1 cell response are associated with immunopathology and failure to clear IOE in the fatal model of HME.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
AIM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Feb
pubmed:issn
0022-1767
pubmed:author
pubmed:issnType
Print
pubmed:day
1
pubmed:volume
172
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1786-800
pubmed:dateRevised
2008-11-21
pubmed:meshHeading
pubmed-meshheading:14734762-Adoptive Transfer, pubmed-meshheading:14734762-Animals, pubmed-meshheading:14734762-Antibodies, Bacterial, pubmed-meshheading:14734762-CD4-Positive T-Lymphocytes, pubmed-meshheading:14734762-CD8-Positive T-Lymphocytes, pubmed-meshheading:14734762-Disease Models, Animal, pubmed-meshheading:14734762-Disease Susceptibility, pubmed-meshheading:14734762-Dose-Response Relationship, Immunologic, pubmed-meshheading:14734762-Down-Regulation, pubmed-meshheading:14734762-Ehrlichia, pubmed-meshheading:14734762-Ehrlichiosis, pubmed-meshheading:14734762-Epitopes, T-Lymphocyte, pubmed-meshheading:14734762-Humans, pubmed-meshheading:14734762-Immunization Schedule, pubmed-meshheading:14734762-Immunoglobulin G, pubmed-meshheading:14734762-Interferon-gamma, pubmed-meshheading:14734762-Ixodes, pubmed-meshheading:14734762-Mice, pubmed-meshheading:14734762-Mice, Inbred C57BL, pubmed-meshheading:14734762-Shock, Septic, pubmed-meshheading:14734762-Species Specificity, pubmed-meshheading:14734762-Th1 Cells, pubmed-meshheading:14734762-Tumor Necrosis Factor-alpha
pubmed:year
2004
pubmed:articleTitle
Overproduction of TNF-alpha by CD8+ type 1 cells and down-regulation of IFN-gamma production by CD4+ Th1 cells contribute to toxic shock-like syndrome in an animal model of fatal monocytotropic ehrlichiosis.
pubmed:affiliation
Departments of Pathology, University of Texas Medical Branch, Galveston, TX 77555, USA.
pubmed:publicationType
Journal Article, Comparative Study, Research Support, U.S. Gov't, P.H.S.