Linked Life Data

19726674

Source:http://linkedlifedata.com/resource/pubmed/id/19726674

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
44
pubmed:dateCreated
2009-10-26
pubmed:databankReference
pubmed:abstractText
We describe murine monoclonal antibodies (mAbs) raised by immunization with an electrophilic gp120 analog (E-gp120) expressing the rare ability to neutralize genetically heterologous human immunodeficiency virus (HIV) strains. Unlike gp120, E-gp120 formed covalent oligomers. The reactivity of gp120 and E-gp120 with mAbs to reference neutralizing epitopes was markedly different, indicating their divergent structures. Epitope mapping with synthetic peptides and electrophilic peptide analogs indicated binary recognition of two distinct gp120 regions by anti-E-gp120 mAbs, the 421-433 and 288-306 peptide regions. Univalent Fab and single chain Fv fragments expressed the ability to recognize both peptides. X-ray crystallography of an anti-E-gp120 Fab fragment revealed two neighboring cavities, the typical antigen-binding cavity formed by the complementarity determining regions (CDRs) and another cavity dominated by antibody heavy chain variable (V(H)) domain framework (FR) residues. Substitution of the FR cavity V(H) Lys-19 residue by an Ala residue resulted in attenuated binding of the 421-433 region peptide probe. The CDRs and V(H) FR replacement/silent mutation ratios exceeded the ratio for a random mutation process, suggesting adaptive development of both putative binding sites. All mAbs studied were derived from V(H)1 family genes, suggesting biased recruitment of the V gene germ line repertoire by E-gp120. The conserved 421-433 region of gp120 is essential for HIV binding to host CD4 receptors. This region is recognized weakly by the FR of antibodies produced without exposure to HIV, but it usually fails to induce adaptive synthesis of neutralizing antibodies. We present models accounting for improved CD4-binding site recognition and broad HIV neutralizing activity of the mAbs, long sought goals in HIV vaccine development.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Oct
pubmed:issn
1083-351X
pubmed:author
pubmed:issnType
Electronic
pubmed:day
30
pubmed:volume
284
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
30627-42
pubmed:dateRevised
2010-11-2
pubmed:meshHeading
pubmed:year
2009
pubmed:articleTitle
Toward effective HIV vaccination: induction of binary epitope reactive antibodies with broad HIV neutralizing activity.
pubmed:affiliation
Department of Pathology and Laboratory Medicine, Chemical Immunology Research Center, University of Texas-Houston Medical School, Houston, Texas 77030, USA.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't, Research Support, N.I.H., Extramural