Linked Life Data

3782800

Source:http://linkedlifedata.com/resource/pubmed/id/3782800

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
1987-1-21
pubmed:abstractText
Human leukocyte-derived lipoxin A (LXA; 5S,-6R,15S-trihydroxy-7,9,13-trans-11-cis-eicosatetraenoic acid) inhibits the cytotoxic activity of human natural killer (NK) cells. LXA and three of its isomers were prepared by total organic synthesis and assayed for activity with human NK cells. Dose-response studies showed that biologically derived LXA and synthetic LXA were equally effective in inhibiting NK cell cytotoxicity. 6S-LXA, with its 6S-OH group in an (S) configuration, proved to be approximately half as potent as LXA. In contrast, 6S-11-trans-LXA and 11-trans-LXA displayed virtually no inhibitory activities. The methyl esters of both LXA and 6S-LXA proved to be more potent than their corresponding free acids. Thus, LXA inhibition of NK cells displays clear-cut stereochemistry. In the absence of putative inhibitors, NK cells bind to their targets to form conjugates. This event is followed by polarization of the NK Golgi apparatus, which moves towards the plasma membrane that is in contact with the target cell. However, in the presence of either the methyl ester or free acid of LXA, the Golgi apparati of NK cells bound to their targets were randomly oriented. In contrast, neither 6S-11-trans-LXA nor the potent NK inhibitor prostaglandin E2 affected the polarization. Furthermore, although prostaglandin E2 resulted in a decrease in NK-target cell binding efficiency, LXA and its isomers failed to affect conjugate formation. Together these results indicate that LXA-induced inhibition of NK cytotoxicity does not act on NK cell binding but may block cytotoxicity by disrupting "signals" involved in the specific orientation of the Golgi. Thus, this latter event may appear to be important in cytotoxicity.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
AIM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jan
pubmed:issn
0022-1767
pubmed:author
pubmed:issnType
Print
pubmed:day
1
pubmed:volume
138
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
266-70
pubmed:dateRevised
2008-11-21
pubmed:meshHeading
pubmed:year
1987
pubmed:articleTitle
Lipoxin A-induced inhibition of human natural killer cell cytotoxicity: studies on stereospecificity of inhibition and mode of action.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't