Linked Life Data

3264307

Source:http://linkedlifedata.com/resource/pubmed/id/3264307

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
12
pubmed:dateCreated
1989-1-18
pubmed:abstractText
There is evidence that the initial interaction between HIV-1 and the host that is essential for infection is the specific binding of the viral envelope glycoprotein, gp120, to the CD4 molecule found on certain T cells and monocytes. Most individuals infected with HIV develop antibodies against the gp120 protein. Although in vitro treatment of CD4+ T cells with mAb to a specific epitope of the CD4 molecule (T4a) blocks virus binding, syncytia formation, and infectivity, it is unclear if antibodies to gp120 from an infected individual that can inhibit the binding of gp120 to CD4 is in any way related to the clinical course of disease. Our present study characterizes the binding of 125I-labeled rgp120 to CD4+ cells, and describes an assay system that measures a potentially relevant form of immunity to HIV infection, i.e., the blocking of HIV binding to CD4+ cells. Optimal binding conditions included a 2-h incubation at 22 degrees C, 4 x 10(6) CD4+ cells, and 1 nM gp120. The dissociation constant (KD) for gp120 binding to cell surface CD4 was 5 nM, and was inhibited by soluble CD4 and by mAb to T4a but not to T3 or T4. For the binding inhibition assay, negative controls included healthy seronegatives, seronegatives with connective tissue diseases, patients with HTLV-1 disease, and patients infected with HIV-2. In studying over 100 sera, the assay was highly sensitive (98%) and specific (100%). The majority of HIV+ sera could inhibit binding at dilutions of 1/100 to 1/1000. No correlation was noted between binding inhibition (BI) titer in this assay and clinical stage of HIV infection. In addition, there was no correlation between BI titer and HIV neutralizing activity. The BI titer was correlated with the titer of anti-gp160 (r = 0.63) and the titer of anti-gp120 (r = 0.52) antibodies determined by Western blot dilution. As with neutralizing antibodies and other forms of immune response to HIV, it is unclear what role antibody blocking of HIV binding to CD4+ cells may play in active immunity to HIV in infected individuals. This activity may prove to have some value in protection against initial HIV infection and, thus, the assay may be of use in monitoring vaccine trials.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
AIM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Dec
pubmed:issn
0022-1767
pubmed:author
pubmed:issnType
Print
pubmed:day
15
pubmed:volume
141
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
4181-6
pubmed:dateRevised
2011-11-17
pubmed:meshHeading
pubmed:year
1988
pubmed:articleTitle
Characterization of GP120 binding to CD4 and an assay that measures ability of sera to inhibit this binding.
pubmed:affiliation
Laboratory of Immunoregulation, National Institute of Allergy and Infectious Diseases, Bethesda, MD 20892.
pubmed:publicationType
Journal Article