Linked Life Data

207735

Source:http://linkedlifedata.com/resource/pubmed/id/207735

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
5
pubmed:dateCreated
1978-8-14
pubmed:abstractText
The present study demonstrates the existence on human peripheral blood lymphocytes of a saturable cell surface receptor for low density lipoprotein inhibitor (LDL-In), a subset of normal human serum low density lipoprotein (LDL) that has been previously demonstrated to suppress selected lymphocyte functions in vivo and in vitro. The binding of radioiodinated LDL-In of demonstrable biological activity occurs rapidly and is quantitatively augmented by prior cultivation of the lymphocytes in lipoprotein-depleted serum, suggesting regulation of receptor density by lipoproteins in vivo. Binding is temperature dependent, facilitated by calcium ions, saturable at 4 degrees C within 40-60 min, and blocked by prior exposure to unlabeled LDL-In. The lymphocyte receptor is trypsin sensitive and regenerates in vitro with a t1/2 of 3.6 h. LDL-In receptors are calculated to have a maximum density of 4,860 +/- 460 per cell if uniformly distributed on all lymphocyte subsets. These receptors have an estimated average association constant of 1.47 X 10(7) liters/mol. When considered in context of the estimated concentration of LDL-In in blood, the receptors should be partially occupied in vivo by endogenous plasma LDL-In. Prior site occupancy inhibition experiments designed to analyze the specificity of LDL-In binding demonstrate that (a) LDL-In is 13.7-fold more effective than whole LDL in blocking the subsequent binding of 125I-LDL-In to cells; and that (b) LDL is 11-fold more effective than LDL-In in blocking the binding of 125I-LKL. This is consistent with the degree of contamination of each lipoprotein with the other lipoprotein. An independent identity of the LDL-In receptor is also supported by observations that in contrast to the previously described LDL receptor, synthesis and expression of the LDL-In receptor on lymphocytes are not suppressed by cultivation of the cells in the presence of 25-hydroxycholesterol and cholesterol. These findings suggest the existence of a previously undescribed and discrete receptor on lymphocytes for LDL-In, and that the modulation of lymphocyte function by LDL-In may be mediated by a specific cell surface receptor pathway.
pubmed:commentsCorrections
http://linkedlifedata.com/resource/pubmed/commentcorrection/207735-1083396, http://linkedlifedata.com/resource/pubmed/commentcorrection/207735-13252080, http://linkedlifedata.com/resource/pubmed/commentcorrection/207735-13428781, http://linkedlifedata.com/resource/pubmed/commentcorrection/207735-14332483, http://linkedlifedata.com/resource/pubmed/commentcorrection/207735-14907713, http://linkedlifedata.com/resource/pubmed/commentcorrection/207735-172585, http://linkedlifedata.com/resource/pubmed/commentcorrection/207735-174194, http://linkedlifedata.com/resource/pubmed/commentcorrection/207735-178796, http://linkedlifedata.com/resource/pubmed/commentcorrection/207735-180780, http://linkedlifedata.com/resource/pubmed/commentcorrection/207735-182894, http://linkedlifedata.com/resource/pubmed/commentcorrection/207735-186492, http://linkedlifedata.com/resource/pubmed/commentcorrection/207735-190318, http://linkedlifedata.com/resource/pubmed/commentcorrection/207735-191022, http://linkedlifedata.com/resource/pubmed/commentcorrection/207735-193990, http://linkedlifedata.com/resource/pubmed/commentcorrection/207735-212203, http://linkedlifedata.com/resource/pubmed/commentcorrection/207735-300398, http://linkedlifedata.com/resource/pubmed/commentcorrection/207735-4179068, http://linkedlifedata.com/resource/pubmed/commentcorrection/207735-4366526, http://linkedlifedata.com/resource/pubmed/commentcorrection/207735-4368448, http://linkedlifedata.com/resource/pubmed/commentcorrection/207735-4845665
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
AIM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
May
pubmed:issn
0021-9738
pubmed:author
pubmed:issnType
Print
pubmed:volume
61
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1298-308
pubmed:dateRevised
2009-11-18
pubmed:meshHeading
pubmed:year
1978
pubmed:articleTitle
Identification of a lymphocyte surface receptor for low density lipoprotein inhibitor, an immunoregulatory species of normal human serum low density lipoprotein.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S.