Search

Provides information on a study which evaluated male genital tract shedding to characterize HIV expression in semen during primary infection. Methods; Virologic characterization after simian/HIV infection; Virus-specific antibody responses and lymphocyte fluctuations during primary infection.

Examines the viral and immunologic complications of HIV-positive patients. Determination of whether persistent seronegativity was attributable to immune dysfunction or infection; Results of the in vitro stimulation of peripheral blood mononuclear cells.

Virus load based on levels of functional reverse transcriptase (RT) was measured in plasma from 50 human immunodeficiency virus (HIV) type 1-infected persons, in 87 samples from 10 HIV-1 seroconversion panels, and in 100 uninfected persons by use of Amp-RT, an ultrasensitive RT assay. Of the 50 clinical samples, 38 (76%) were Amp-RT positive, while all uninfected controls were negative. Pearson's correlation coefficient of RNA and RT levels was .73 for all samples, .86 for seroconversion samples, and .49 for clinical samples. Calculated ratios of RT activity to virion RNA varied widely during both early and late stages of infection. Mean RT:RNA ratios in 8 seroconversion panels and in 12 (34.3%) of 35 individual clinical samples were significantly lower than the ratio for a reference virus. However, ratios were stable in individual seroconversions over time. These data demonstrate that RT activity can be used to quantitate plasma virus load and provide evidence of different levels of virion-associated RT among HIV-1-infected persons. [ABSTRACT FROM PUBLISHER]

Human immunodeficiency virus (HIV)-2 differs from HIV-1 in its relative lower transmissibility and pathogenicity. To understand the virologic basis of these differences, the nef gene from HIV-2-seropositive persons was analyzed because of its importance for disease progression in the genetically related simian immunodeficiency virus (SIV[MAC]). Proviral nef sequences from 60 HIV-2-infected persons were amplified from peripheral blood lymphocytes, and nef open-reading frames were screened by a transcription and translation assay for the presence of full-length (32- to 36-kDa) or truncated (<32 kDa) Nef proteins. Overall, 6 (10%) of 60 persons had truncated Nef proteins; of these, 5 were among the 36 asymptomatic subjects (13.9%) and only 1 was among the 24 symptomatic subjects (4.2%) (P =.23). The results of this study document the presence of defective nef genes in HIV-2 infections with a prevalence higher than that previously seen in HIV-1-infected cohorts of long-term nonprogressors or patients with AIDS. [ABSTRACT FROM AUTHOR]

In an ultrasensitive assay for reverse transcriptase (RT), an in vitro-transcribed heteropoly-meric RNA sequence was used as a template and polymerase chain reaction (PCR) amplification with Southern blot hybridization served as a detection system for the cDNA reaction product. The assay, called Amp-RT, detected 9 tested retroviruses in unconcentrated culture supernatants diluted 102- to 105-fold. A comparative analysis using human immunodeficiency virus type 1 (HIV-l) revealed that Amp-RT was 100,000 times more sensitive than the standard RT assay, 10,000 times more sensitive than p24 antigen capture and branched DNA assays, and 100 times more sensitive than RT-PCR or TCID50 assays. Analysis of serum specimens from 42 HIV-l-infected persons by Amp-RT showed that 36 samples (85.7%) were RT-positive. In contrast, 41 serum specimens from persons seronegative for HIV-1 and human T lymphotropic virus types I and II were all Amp-RT-negative. [ABSTRACT FROM PUBLISHER]

Synthetic peptides corresponding with unique regions of the envelope glycoproteins (gp46) of human T cell Iymphotropic viruses (HTLVs)were used in an enzyme immunoassay to determine if HTLV-I and -II infections could bediscriminated. Two synthetic HTLV-Isequence-derived peptides, Env-1 (amino acids 191–215) and Env-5 (amino acids 242–257), reacted with 92% and 100% of the serum specimens (n = 52) from HTLV-I-infected persons, respectively. Although a small percentage (8.6%)of serum specimens from persons infected with HTLV-IIcross-reacted with Env-1, none of these specimens reacted with Env-5. Peptide Env-2 encoded by the envelope region ofHTLY-1I(amino acids 187–210)reacted with serum specimens from both HTLY-I(94%)and HTLV-II (74%)-infected patients, whereas Env-6, another HTLV-II peptide (amino acids 238–254), reacted with <6% of the specimens. Therefore, the Env-5 peptide with amino acid sequence SerProAsnValSerValProSerSerSerSerThrProLeuLeuTyr represents an immunodominant domain of HTLV-I that is recognized by serum antibodies from all HTLV-I-infected persons. Moreover, the Env-5-based ELISA allows a categorical distinction between the closely related HTLV-I and -II infections. [ABSTRACT FROM PUBLISHER]