Linked Life Data

1693641

Source:http://linkedlifedata.com/resource/pubmed/id/1693641

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
12
pubmed:dateCreated
1990-7-18
pubmed:abstractText
The Entamoeba histolytica galactose-binding lectin is a surface glycoprotein composed of 170- and 35-kDa subunits. Inhibition of this lectin with galactose or anti-170 kDa subunit polyclonal antibody blocks amebic adherence to target cells and colonic mucin glycoproteins. We describe the properties of 10 mAb with specificity for the 170-kDa subunit. Based on competitive binding studies, six nonoverlapping antigenic determinants on the lectin were identified. The effect of the mAb on adherence of amebic trophozoites to both Chinese hamster ovary (CHO) cells and human colonic mucins was measured. Antilectin antibodies directed against epitopes 1 and 2 enhanced adherence, with the number of amebae having at least three adherent CHO cells increasing with the addition of epitope 1 mAb from 26 +/- 9 to 88 +/- 2% and the binding of colonic mucins increasing from 34 +/- 1 to 164 +/- 3 pg/10(5) amebae. Antibody-enhanced adherence remained 90 to 100% galactose inhibitable, occurred at 4 degrees C and was not Fc mediated. Univalent Fab fragments of epitope 1 mAb augmented mucin binding by 238% and CHO cell adherence by 338%. The binding of purified lectin to CHO cells was increased from 1.1 +/- 0.1 to 2.4 +/- 0.3 ng/10(3) CHO cells by mAb directed to epitope 1, demonstrating that enhanced adherence was due to direct activation of the lectin. mAb to epitope 3 bound to the lectin only upon its solubilization from the membrane and had no effect on adherence. Adherence to CHO cells and mucins was inhibited from 50 to 75% by mAb to epitopes 4 and 5; epitope 6 mAb inhibited amebic adherence to CHO cells but not mucins. The pooled sera from 10 patients with amebic liver abscess blocked the binding to the 170-kDa subunit of mAb directed to all six epitopes. Striking individual variations in the effects of immune sera on adherence were observed. Although the sera of all 44 South African patients with amebic liver abscess had high titer anti-lectin antibodies, 16 patients' sera significantly (more than 3 SEM) enhanced adherence whereas 25 patients' sera significantly inhibited adherence. Antilectin antibodies exert profound functional effects on the interaction of E. histolytica with target cells and human colonic mucins. Exploration of the clinical consequences of adherence-enhancing and inhibitory antibody responses may give insight into the role of antilectin antibodies in immunity to invasive amebiasis.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
AIM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jun
pubmed:issn
0022-1767
pubmed:author
pubmed:issnType
Print
pubmed:day
15
pubmed:volume
144
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
4803-9
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1990
pubmed:articleTitle
Monoclonal antibodies directed against the galactose-binding lectin of Entamoeba histolytica enhance adherence.
pubmed:affiliation
Department of Medicine, University of Virginia, Charlottesville 22908.
pubmed:publicationType
Journal Article, In Vitro, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't