Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
9
pubmed:dateCreated
2005-4-21
pubmed:abstractText
Termination of an immune response requires elimination of activated T lymphocytes by activation-induced cell death (AICD). In AICD, CD95 (Apo-1/Fas) ligand (L) triggers apoptosis of CD95-positive activated T lymphocytes. In AIDS patients, AICD is strongly enhanced and accelerated. We and others have previously shown that HIV-1 trans-activator of transcription (HIV-1 Tat) sensitizes T cells toward CD95-mediated apoptosis and up-regulates CD95L expression by affecting the cellular redox balance. In this study, we show that it is hydrogen peroxide (H(2)O(2)) that functions as an essential second messenger in TCR signaling. The H(2)O(2) signal combined with simultaneous calcium (Ca(2+)) influx into the cytosol constitutes the minimal requirement for induction of CD95L expression. Either signal alone is insufficient. We further show that HIV-1 Tat interferes with TCR signaling and induces a H(2)O(2) signal. H(2)O(2) generated by HIV-1 Tat combines with CD4-dependent calcium influx and causes massive T cell apoptosis. Thus, our data provide an explanation for CD4(+) T lymphocyte depletion during progression of AIDS.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
AIM
pubmed:chemical
http://linkedlifedata.com/resource/pubmed/chemical/Calcium, http://linkedlifedata.com/resource/pubmed/chemical/Chelating Agents, http://linkedlifedata.com/resource/pubmed/chemical/FASLG protein, human, http://linkedlifedata.com/resource/pubmed/chemical/Fas Ligand Protein, http://linkedlifedata.com/resource/pubmed/chemical/Fluoresceins, http://linkedlifedata.com/resource/pubmed/chemical/Gene Products, tat, http://linkedlifedata.com/resource/pubmed/chemical/Hydrogen Peroxide, http://linkedlifedata.com/resource/pubmed/chemical/Membrane Glycoproteins, http://linkedlifedata.com/resource/pubmed/chemical/Reactive Oxygen Species, http://linkedlifedata.com/resource/pubmed/chemical/Receptor-CD3 Complex, Antigen..., http://linkedlifedata.com/resource/pubmed/chemical/Recombinant Proteins, http://linkedlifedata.com/resource/pubmed/chemical/calcein AM, http://linkedlifedata.com/resource/pubmed/chemical/tat Gene Products, Human...
pubmed:status
MEDLINE
pubmed:month
May
pubmed:issn
0022-1767
pubmed:author
pubmed:issnType
Print
pubmed:day
1
pubmed:volume
174
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
5249-60
pubmed:dateRevised
2007-11-15
pubmed:meshHeading
pubmed-meshheading:15843521-Apoptosis, pubmed-meshheading:15843521-CD4-Positive T-Lymphocytes, pubmed-meshheading:15843521-Calcium, pubmed-meshheading:15843521-Calcium Signaling, pubmed-meshheading:15843521-Chelating Agents, pubmed-meshheading:15843521-Fas Ligand Protein, pubmed-meshheading:15843521-Fluoresceins, pubmed-meshheading:15843521-Gene Products, tat, pubmed-meshheading:15843521-HIV-1, pubmed-meshheading:15843521-Humans, pubmed-meshheading:15843521-Hydrogen Peroxide, pubmed-meshheading:15843521-Jurkat Cells, pubmed-meshheading:15843521-Lymphocyte Activation, pubmed-meshheading:15843521-Membrane Glycoproteins, pubmed-meshheading:15843521-Oxidative Stress, pubmed-meshheading:15843521-Reactive Oxygen Species, pubmed-meshheading:15843521-Receptor-CD3 Complex, Antigen, T-Cell, pubmed-meshheading:15843521-Recombinant Proteins, pubmed-meshheading:15843521-tat Gene Products, Human Immunodeficiency Virus
pubmed:year
2005
pubmed:articleTitle
HIV-1 trans-activator of transcription substitutes for oxidative signaling in activation-induced T cell death.
pubmed:affiliation
Tumor Immunology Program, German Cancer Research Center, Heidelberg, Germany.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't