ABSTRACT
Previous studies have demonstrated that the principal neutralizing determinant of human immunodeficiency virus type 1 (HIV-1) is located in the V3 loop of glycoprotein gp120. Antibodies prepared against this region using gp120 or peptides as immunogens have been predominantly HIV-1-isolate-specific. In the present studies, murine monoclonal antibodies (mAbs) were prepared against the HIV-1MN strain. One mAb, designated NM-01, was selected for its ability to neutralize both the MN and IIIB strains. Neutralization of H9-cell infectivity as determined by reverse transcriptase assay demonstrated an ID50 of less than 1 microgram/ml for both MN and IIIB. mAb NM-01 also blocked MN and IIIB infectivity in the MT-2 assay and inhibited their reactivity in syncytium formation. The results further demonstrate that mAb NM-01 binds to the V3 loop of gp120 at amino acids 312-326. This mAb reacted equally well with loop peptides from the MN, IIIB, RF, and CDC4 isolates. In contrast, there was less affinity with a similar peptide from the NY5 strain and little if any reactivity with loop peptides from the Z2, Z6, and ELI strains. We also demonstrate that peptides corresponding to the V3 loops of MN and IIIB, but not Z6, block neutralization of IIIB virus by mAb NM-01. These findings indicate that mAb NM-01 reacts with diverse HIV-1 isolates through the Gly-Pro-Gly-Arg sequence of the V3 loop.
Subject(s)
Antibodies, Monoclonal , HIV Envelope Protein gp120/immunology , HIV-1/immunology , Amino Acid Sequence , Animals , Antibodies, Monoclonal/immunology , Antigen-Antibody Complex , Cell Line , Immunoblotting , Kinetics , Mice , Mice, Inbred BALB C/immunology , Molecular Sequence Data , Neutralization Tests , Peptides/chemical synthesis , Peptides/immunology , Protein ConformationABSTRACT
The shaking method of harvesting human immunodeficiency virus type 1 (HIV-1) is a powerful method of obtaining high titer, highly infective virus solutions. In this method infected cells are suspended in a small volume of liquid and the mixture is shaken. Viral infectivity, measured by tissue culture infective dose (TCID50) studies, rises faster than virus titer, as measured by reverse transcriptase levels. It is postulated that this disproportionate increase in infectivity results from improved infectivity for the virus particles obtained from shaking the infected cells. Of the five strains of HIV-1 studied (IIIB, AL1212, 906, RJ4029, and MN), one strain, MN, behaved differently than the others. Upon shaking, its virus titer increased 18-fold, as opposed to the 5-10 fold increase demonstrated by the other strains. These results may indicate that MN virions are retained more on the surface of the infected cells, rather than budding off into the surrounding medium, than other HIV-1 strains. In support of this theory it was found that ratios of immunofluorescence assay scores to reverse transcriptase levels were higher for MN than for other strains.
Subject(s)
HIV-1/isolation & purification , Virus Replication , Acquired Immunodeficiency Syndrome/microbiology , Cell Line , HIV-1/enzymology , HIV-1/growth & development , Humans , RNA-Directed DNA Polymerase/metabolism , T-Lymphocytes/microbiology , Virology/methodsABSTRACT
We report a case of parathyroid adenoma correctly localized prior to operation by computed tomography (CT) and thyroid scanning. The use of CT and other noninvasive diagnostic modalities to aid the surgeon prior to initial operation for parathyroid adenoma is discussed.
