Frequent and early HIV-1MN neutralizing capacity in sera from Dutch HIV-1 seroconverters is related to antibody reactivity to peptides from the gp120 V3 domain.

The temporal development of HIV-1 neutralizing activity and antibodies to the gp120-V3 neutralization domain were studied in sera from 20 Dutch HIV-1-infected individuals followed from seroconversion on. Serum neutralizing capacity was assessed with three T cell line-tropic isolates: HIV-1MN, HIV-1HXB2, and the patient isolate HIV-1(320). Neutralizing activity to HIV-1MN developed in 18 individuals (90%) within 0 to 10 months after seroconversion.

Ordered appearance of zidovudine resistance mutations during treatment of 18 human immunodeficiency virus-positive subjects.

The order of appearance in the reverse transcriptase gene of four mutations implicated in the development of resistance to zidovudine was investigated by selective polymerase chain reaction. Serial human immunodeficiency virus isolates were studied from 18 initially asymptomatic individuals who had been treated with zidovudine for 2 years. Most subjects had similar patterns.

Immunodominance and antigenic variation of the principal neutralization domain of HIV-1.

The principal neutralization domain (PND) of HIV-1 is located in the third variable region (V3) of the envelope glycoprotein gp 120. Cross-reactivity of experimental and natural sera with recombinant proteins containing the V3 region of four HIV-1 variants showed that a group of viruses (among which HIV-1 MN) had antigenically similar V3 regions. The V3 regions of HIV-1 IIIB and HIV-1 RF were antigenically distinct.

Association of antibodies blocking HIV-1 gp 160-sCD4 attachment with virus neutralizing activity in human sera.

Sera, from HIV-1 and HIV-2 seropositive individuals, were tested for the presence of antibodies able to inhibit the binding (BI) of HIV-IIIB gp 160 (produced in mammalian cells using a vaccinia expression system) to the extracellular portion of the CD4 receptor. A competition enzyme immunoassay (EIA) with soluble CD4 (sCD4) was used. BI antibodies were highly prevalent among HIV-1 seropositives but not in HIV-2 infected individuals.

Characterization of the African HIV-1 isolate CBL-4 (RUT) by partial sequence analysis and virus neutralization with peptide antibody and antisense phosphate-methylated DNA.

The HIV-1 isolate CBL-4 (RUT), originating from Tanzania, was characterized using a comprehensive virus-typing system. This system included sequence analysis of the region coding for the neutralization domain in the third variable region (V3) of the external envelope and of the tat responsive (TAR) region after polymerase chain reaction (PCR) amplification of these sequences from cellular DNA in the CBL-4 (RUT) producer line. Based on independent cluster analysis of TAR and V3 sequences the CBL-4 (RUT) virus was positioned closest to the Z6 (and ELI) African virus family.