Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
6
pubmed:dateCreated
2007-9-5
pubmed:abstractText
Within the broad problem of host immune surveillance versus tumor immune evasion, a most intriguing question is how the cellular immunity can cope with cancerous cells that have gotten rid of the classical antigen-presenting machinery. One such option stems from (1) the fact that HLA loss is often attended with expression of Hsp70 on the tumor cell surface, and (2) our findings that human lymphocytes express a protein Tag7 (also known as PGRP-S) capable of tight and specific interaction with cognate Hsp70. Here we show that a subpopulation of human CD4(+)CD25(+) lymphocytes, obtained either in culture as lymphokine-activated killers or directly from healthy donors, carry Tag7 and FasL on their surface and can indeed kill the HLA-negative tumor-derived cells K562 and MOLT-4 that expose Hsp70 and Fas. The primary binding of lymphocyte Tag7 to target-cell Hsp70 is very specific (eg, it is blocked by preincubating either cell with minimal peptides from the "partner" protein), and secures cell contact indispensable for subsequent FasL/Fas-triggered apoptosis. Unrelated to natural killer cell action or the putative role of Hsp as an antigen-presenting substitute, this novel mechanism is rather a backup analog of orthodox (CD8(+)) target recognition (Tag7 acting as built-in T-cell receptor and Hsp70 itself as ligand).
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
AIM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Sep
pubmed:issn
0006-4971
pubmed:author
pubmed:issnType
Print
pubmed:day
15
pubmed:volume
110
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1997-2004
pubmed:meshHeading
pubmed:year
2007
pubmed:articleTitle
Cytotoxic T lymphocytes carrying a pattern recognition protein Tag7 can detect evasive, HLA-negative but Hsp70-exposing tumor cells, thereby ensuring FasL/Fas-mediated contact killing.
pubmed:affiliation
Institute of Gene Biology, Russian Academy of Sciences, Moscow, Russia. sashchenko@genebiology.ru
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't