OBJECTIVES:Human immunodeficiency virus type 2 (HIV-2) progression to disease is significantly slower than that of human immunodeficiency virus type 1 (HIV-1). Genetic determinants for susceptibility to disease progression were hypothesized to play a more significant role in this infection compared with HIV-1. We sought to identify common human lymphocyte antigen (HLA) alleles in the Senegalese population and to compare HLA profiles between HIV-2-infected individuals with low and high risk for disease progression.STUDY DESIGN/METHODS:We conducted a case-control study investigating possible associations between MHC class I genes and the risk of disease progression in HIV-2-infected individuals. The MHC class I genotype was molecularly defined using polymerase chain reaction with sequence specific primers (PCR-SSP) in 62 female sex workers from the Dakar, Senegal cohort. Lack of antibodies to the HIV-2 antigen p26 has been previously shown to predict disease progression and was used in this study as a surrogate marker. Twenty-one cases were identified lacking antibodies to p26, therefore at a higher risk of disease progression, and were compared with 41 p26 antibody-positive, randomly selected controls.RESULTS:Statistical analysis showed that HLA B35 was significantly associated with lack of p26 antibodies, and higher risk of disease progression ( < 0.05). The same association was found for the self-defined class I haplotypes B35-Cw4 and A23-Cw 7 ( < 0.05). The HLA B 53 allele was associated with slower disease progression; however, this association was not statistically significant. We observed a trend whereby heterozygotes were at lower risk for HIV-2 disease progression, as previously reported in HIV-1 disease.CONCLUSIONS:In this West African population, a distinct profile of HLA class I alleles was observed, and many of these appear to influence disease progression in HIV-2 infection.
OBJECTIVES:To determine the role of the hepatitis C virus 3' untranslated region in viral mRNA translation in transfected cells and in cell extracts.STUDY DESIGN/METHODS:Noninfectious hepatitis C virus mini-genome RNAs with various deletions in the viral 3' untranslated region were transfected into cells or translated in vitro, and the translation efficiency was determined.RESULTS:We have found that the presence of the hepatitis C virus 3' untranslated region modestly increases mRNA translation. The positive effect correlated with the binding of a 45-kDa cytoplasmic factor to the hepatitis C virus 3' untranslated region. Furthermore, the U-rich sequence in the hepatitis C virus 3' untranslated region inhibits translation of capped and polyadenylated mRNAs as a result of the hybridization.CONCLUSIONS:The modest effect of the hepatitis C virus 3' untranslated region on translation suggests that it does not play a major role in mRNA translation. The inhibitory effect of the hepatitis C virus 3' untranslated region on translation of polyadenylated mRNAs supports the notion that translation of hepatitis C virus mRNAs occurs independently of a polyA tail.
The antigenic diversity, rapid genetic integration into host cell DNA, and immune evasion tactics of human immunodeficiency virus type 1 (HIV-1) create formidable obstacles to the development of an effective vaccine against it. In spite of this, the advent of conformationally constrained HIV-1 Env and gp120 immunogens has made it feasible to formulate HIV-1 vaccines that induce broadly cross-reactive neutralizing antibodies and afford protection through humoral mechanisms. This paper reviews recent advances made by the authors toward the development of an HIV-1 vaccine that elicits such antibodies in both the mucosal and systemic immune compartments.
OBJECTIVES:To understand the mitochondrial mechanisms underlying the lactic acidosis and hepatic steatosis seen in some HIV-1-infected individuals after long-term stavudine (d4T) exposure, we have explored mitochondrial integrity in adult monkeys (Erythrocebus patas) given a daily human equivalent dose of d4T for 78 days.STUDY DESIGN/METHODS:Three Erythrocebus patas (patas) monkeys were given 3 mg d4T orally twice daily (total 6 mg d4T), or approximately 1.2 mg d4T/kg body weight per day, for 78 days and compared with 3 unexposed animals. Blood taken from controls and from treated monkeys before and after drug exposure was subjected to a complete clinical chemistry profile. Liver and skeletal muscles were examined for oxidative phosphorylation enzyme specific activities, mitochondrial deoxyribonucleic acid (mtDNA) quantity by slot blot, and mtDNA integrity by Southern blot.RESULTS:Clinical chemistry assays demonstrated few significant differences; however, one d4T-exposed monkey had a serum lactate of 8.1 mmol/L after 78 days of oral d4T ingestion. Specific activities of oxidative phosphorylation Complexes I, II, and IV were significantly altered in both livers and skeletal muscles from the d4T-exposed animals, compared with the controls (p < or = 0.05). Significant depletion of mitochondrial DNA was observed in livers of drug-exposed monkeys, but not in skeletal muscle (p < or = 0.05). Further examination of liver DNA by Southern blot confirmed hepatic mtDNA depletion in drug exposed animals.CONCLUSIONS:The data suggest that direct examination of the liver may be required to elucidate clinical d4T-induced hepatotoxicity related to mitochondrial damage.
OBJECTIVES:Lassa fever virus (LAS) is transmitted to man by rodent carriers and is fatal in a third of untreated cases. Our goal is to provide immune protection from Lassa fever by mucosal vaccination. STUDY DESIGN/METHODS:Mice were vaccinated intragastrically with control vectors or with vectors (vaccinia or Salmonella) expressing LAS nucleocapsid protein (NP). Mice were challenged intracranially with a lethal dose of the related arenavirus, lymphocytic choriomeningitis virus (LCMV), as a measure of the vaccine's ability to elicit cross-protection. RESULTS:Salmonella and vaccinia vectors expressing LAS NP each protected a third of the mice from lethal challenge with LCMV. All mice vaccinated with a vector expressing LCMV NP were protected as expected. CONCLUSIONS:The LAS recombinant Salmonella vector is comparable to the LAS recombinant vaccinia vector in its ability to cross-protect mice from lethal challenge. Nucleocapsid protein is an inadequate immunogen on its own, but provides sufficient cross-protection to make it a useful component of a broadly reactive arenavirus vaccine.
Objectives: To characterize human immunodeficiency virus type 1 (HIV-1) subtype E variants in blood and genital fluid of infected Thai couples.Study Design/Methods: Blood and genital fluid were collected from 30 asymptomatic healthy HIV-1 subtype E infected couples from Bangkok, Thailand from 1995 to 1998.Results: All 60 viruses in blood samples were identified as subtype E by heteroduplex mobility assay. The biotype of viruses founded in blood was syncytium.-inducing (SI), whereas M-tropic and non-syncytium-inducing (NSI) isolates were predominantly detected in genital fluid. HIV-1 proviral DNA was detected in 43.33% and 56.67%, and viral RNA was detected in 93.33% and 56.67%, of semen (n = 30) and cervicovaginal secretion (n = 30) samples tested, respectively. A higher intersample genetic distance and more positive charge of the V3 loop were found in blood strains composed of genital fluid strains (22.30 +/- 5.92% and 17.96 +/- 6.3%), which was statistically significant (P = 0.003). The env V1-V4 intraperson variation of the HIV-1 subtype E in the blood and genital fluid of each individual was in the range 3.0%-5.7%. We also determined the intrasample variation of HIV-1 from blood and genital fluid by heteroduplex mobility assay. The mean heteroduplex mobility of the HIV-1, V1-V4 region of env gene, in blood (n = 8) and genital fluid (n = 8) was 0.59 +/- 0.06 and 0.74 +/- 0.11 (t test, p = 0.001), respectively.Conclusions: There was genetic and phenotypic compartmentalization of HIV-1 subtype E in blood and genital fluid with the presence of S1 qnd NSI phenotypic variants as a common property of subtype E isolates from blood and genital fluid, respectively.
OBJECTIVE:To determine whether genotypes from human immunodeficiency virus type 1 (HIV-1) subtypes A, C, or D or intersubtype recombinants have the same probability of being transmitted from mother to child.METHODS:We determined the HIV-1 genetic subtype and maternal risk factors of 51 matched transmitting and nontransmitting mothers from Tanzania. The HIV-1 gag (p24-p7) and env (C2-C5) nucleotide sequences were used for genotype classification, and matched logistic regression analysis was used to assess differences among genotypes.RESULTS:Mothers infected with HIV-1 subtype A (odds ratio, 3.8; 95% CI, 0.8-24.7%), HIV-1 subtype C (odds ratio, 5.1; 95% CI, 1.3-30.8%), or HIV-1 intersubtype recombinant viruses (odds ratio, 5.3; 95% CI, 1.2-33.4%) were more likely to transmit HIV-1 to their infants than mothers infected with HIV-1 subtype D. Lower CD4 cell counts at enrollment were associated with transmission, but CD4 cell counts within each genotype did not explain differences in transmission among HIV-1 genotypes.CONCLUSION:We have shown that HIV-1 genotypes might be associated with differential risk for vertical transmission. These findings provide the first evidence that HIV-1 genetic subtypes may play a role in rates of vertical transmission in an African setting.
OBJECTIVES:Immunity to the human immunodeficiency virus type-1 (HIV-1) G/P-92 fusion protein consisting of highly immunogenic regions of Gag (p17 and p24) and Pol (p51) expressed in recombinant vaccinia virus (vG/P-92) was compared with responses to the entire viral Gag-Pol precursor protein (vVK1).STUDY DESIGN/METHODS:We analyzed the level of Gag and Pol protein expression in vG/P-92-infected cells as well as the ability of the G/P-92 fusion protein to form virus-like particles (VLP) in infected cultures. The efficacy of vG/P-92 and vVK1 vaccines was evaluated in a murine model by measuring T helper (Th), cytotoxic T lymphocyte (CTL), and antibody responses to Gag and Pol antigens.RESULTS:The deletion of a frameshift site resulted in an increased level of Pol in cells expressing the G/P-92 fusion protein. Particles budding from the plasma membrane were detected in both vG/P-92- and vVK1-infected cells, but the release of VLP was less efficient from cells expressing the G/P-92 fusion protein than the entire gag-pol gene product. Immunization with vG/P-92 vector elicited a higher level of cellular and humoral responses to both Gag and Pol antigens than the vVK1 vaccine.CONCLUSIONS:The enhanced immunogenicity of the G/P-92 fusion protein compared with the entire viral gag-pol gene product might be related to a higher intracellular level of Pol and Gag expression due to the deletion of a frameshift site and less efficient transport of VLP from vG/P-92-infected cells, respectively.
OBJECTIVE:TT virus (TTV) is frequently detected in the serum and in other body fluids of humans. Recently TTV-specific deoxyribonucleic acid has been detected in cervical specimens from apparently healthy women and in seminal fluid, suggesting that sexual transmission may be common.STUDY DESIGN/METHODS:TT virus-deoxyribonucleic acid prevalence was assessed in paired samples of blood and cervical smears from 110 human immunodeficiency virus-positive women. Detection and typing of human papillomavirus (HPV) present in cervical smears was also performed.RESULTS:The prevalence of TTV-deoxyribonucleic acid in cervical smears was 16.4%, without significant difference (p = 0.81) between HPV-positive (18.6%) and -negative (14.9%) samples. The distribution of high/middle and low-risk HPV types was similar in TTV-positive and -negative samples. On the contrary, women with multiple HPV infections had a significantly higher TTV-deoxyribonucleic acid prevalence (60.0%) than HPV-negative women (p = 0.04).CONCLUSIONS:TT virus excretion in the female genital tract of human immunodeficiency virus-infected women is common, further supporting sexual transmission of this virus.
Objective: The viral transcriptional activator encoded by Kaposi's sarcoma-associated herpesvirus (KSHV) open reading frame 50 (RTA) is expressed in the immediate-early phase of reactivation. We isolated an RTA-depressed cell line, BLS50-4, by subcloning from the KSHV-infected cell line, BCBL-1.Results: In addition to RTA, induction of some lytic gene expressions was also remarkably reduced in BLS50-4 cells, but that of the K8.1 and ORF65 gene expressions was not. Both the replication of the KSHV genome and the release of KSHV DNA into the medium were greatly reduced. Transfection of RTA into BLS50-4 cells restored the expression of K9 (vIRF) and ORF59, but not K8.1.Conclusions: Thus, we showed that expression of late genes was not directly controlled by RTA, unlike the other groups concluded. We also showed that, by isolating the RTA-depressed cell line, the RTA protein had a critical role in viral DNA replication and the expression of several lytic genes.
OBJECTIVE The major molecular events in the genesis of most breast cancers are unknown. However, human papillomaviruses (HPV) have been reported to be found in a significant portion of breast cancers of women with concomitant cervical intraepithelial neoplasia III. To investigate a potential HPV-breast cancer link, we carried out a small survey to identify HPV in unselected, general breast cancer tissues. STUDY DESIGN/METHODS Deoxyribonucleic acid (DNA) was isolated from 17 breast cancer tissues (and one cervical swab) taken from our local, randomly selected patient population. Two different previously characterized broad-spectrum primer sets (targeting the E6/E7 or L1 regions) were used to amplify HPV DNA, and another primer set was used to amplify the ColE1/pBR322 origin of replication by polymerase chain reaction amplification. The polymerase chain reaction product DNA was analyzed by dot blot hybridization with HPV-16, -18, -31, or pRB322 DNA probes. Total cellular DNA was also analyzed by one- and two-dimensional Southern blot analysis. Finally, the E6/E7 polymerase chain reaction products were cloned, sequenced, and compared to previously cloned HPV types. RESULTS Polymerase chain reaction/dot blot analysis by both the HPV E6-E7 and L1 primer sets identified the same 6 out of 17 (35%) breast cancers as being HPV positive. ColE1/pBR322 origin targeted polymerase chain reaction/dot blot analysis failed to identify plasmid contamination. One- and two-dimensional Southern blot analysis showed that the breast cancers specimens contained significant levels of HPV DNA and that the viral DNA was largely episomal. The sequences of the HPV clones demonstrated that HPV-16, -18, and possibly type 11 were present within the breast cancer specimens. Furthermore, the HPV sequences cloned from the cervical swab and breast cancer of the same patient were found to be identical. CONCLUSIONS These data suggest that HPV may be associated with a significant subset of breast cancers, and further suggest that additional studies are warranted.
Objective: Emergence of human immunodeficiency virus type-1 (HIV-1) genotypic drug resistance is generally attributed to noncompliance, poorly absorbed drugs, or drug-to-drug interaction. Attempts to determine emerging genotypic drug resistance from study subjects on highly active antiretroviral therapy (HAART) relied on insensitive polymerase chain reaction (PCR) techniques, revealing wild type HIV-1 or precursor resistant genotypes from few plasma samples successfully amplified with <50 copies/mL.Study Design/Methods: In this analysis, using Applied Biosystems' ViroSeq HIV-1 Genotyping Systems, Version 2.0 (Applied Biosystems, Foster City, CA, USA) and the supplemental, for research use only, nested PCR primers, genotypic drug resistance was determined in longitudinal plasma samples from 11 study subjects on HAART.Results: In 4 of 11 study subjects, newly emerging genotypic primary resistant mutations were detected in plasma samples with <50 copies/mL. Most of these primary drug-resistant mutations were detected in subsequent longitudinal samples with detectable viral load (viral breakthrough).Conclusions: This analysis suggests sufficient viral replication <50 copies/mL to generate genotypic drug resistance in study subjects on suppressive HAART.
Objectives: To understand the mechanism for the refractoriness of B-chronic lymphocytic leukemia (B-CLL) cells for Epstein-Barr virus (EBV)-induced immortalization.Study Design/Methods: Cultures were initiated with EBV-infected tonsillar B and B-CLL cells. Expression of EBNA-2 and some of the key players regulating G1/S phase transition such as c-myc expression, phosphorylation of Rb protein, expression of G1 cyclins, and the cyclin-dependent kinase inhibitor p27 were followed.Results: In line with earlier studies, EBV infection induced c-myc expression, pRb phosphorylation, D2 and D3 expression, and disappearance of p27 in normal B cells. In contrast, EBV-infected B-CLL cells remained resting and they did not express c-myc cyclin D2, ppRb and cyclin D3 were seen only in occasional cells. Importantly, p27 expression was maintained.Conclusions: In B-CLL cells, the expression of the EBV-encoded nuclear proteins EBNAs is not followed by entrance to the cell cycle. Thus, the difference in the interaction of EBV-normal B cells and EBV-B-CLL cells is already apparent early after infection.
OBJECTIVES To develop an assay for the early detection and quantification of minor human immunodeficiency virus-1 populations bearing multiple drug resistance (MDR) mutations. STUDY DESIGN/METHODS The oligonucleotide ligation assay (OLA) is based on ligation of probe and detector oligonucleotides annealed to a polymerase chain reaction amplicon strand with detection by an enzyme immunoassay. In OLA-MDR, oligonucleotides were designed to detect MDR mutations. The method was validated with wild-type and MDR mutant clones mixed at different proportions. RESULTS K103N mutants were detected as minor populations (5%-30%) by OLA in 6 of 18 samples from patients treated with nonnucleoside reverse transcription inhibitors and classified as wild type by sequencing. In one patient, the kinetics of the increase of MDR mutants could be followed in sequential samples, with K103N being detected earlier by OLA than by sequencing. Q151M mutants were detected as minor populations (13%-24%) by OLA but not by sequencing in 4 samples. CONCLUSIONS Oligonucleotide ligation assay MDR exhibits higher sensitivity than sequencing for detection of minor MDR mutant populations.
INTRODUCTIONA tyrosine-based targeting signal in the intracytoplasmic domain of human immunodeficiency virus type 1 (HIV-1) envelope glycoprotein is required for basolateral targeting of viral budding in polarized epithelial cells, concentration of viral assembly at one pole of infected lymphocytes, and rapid endocytosis of the glycoprotein from the plasma membrane. In HIV-1, the process of viral assembly and budding is complex and involves the participation of viral accessory proteins.STUDY DESIGN/METHODSIn this study, we examined whether the functions of the Nef, Vif, and Vpu proteins can influence or be influenced by the presence of envelope targeting signal in epithelial cells or lymphocytes. A series of proviral DNAs combining a mutation that inactivates the targeting signal with independent mutations in the three accessory proteins was constructed for this purpose.RESULTSIt was found that none of these three accessory proteins affected the basolateral release of the virus in polarized MDCK cells. Reciprocally, a mutation abolishing targeting of the viral envelope glycoprotein did not affect the phenotype conferred by the accessory proteins. Interestingly, the mutation abolishing targeting increased viral infectivity only in the presence of the Vpu protein. This phenotype was found to be associated with the release-enhancing function of Vpu and with an increased incorporation of viral envelope glycoprotein in virions.CONCLUSIONSThese data clearly show that accessory protein functions, and more specifically Vpu modulation of viral infectivity, can be affected by variations in the viral envelope glycoprotein.
INTRODUCTION We studied the role of human papillomavirus (HPV) typing in predicting cervical dysplasia in women with abnormal Papanicolaou (Pap) test results. STUDY DESIGN/METHODS A university colposcopy clinic-based consecutive sample of 179 women completed a questionnaire and underwent colposcopy, HPV typing (Hybrid Capture System HPV DNA Assay II; Digene Diagnostics, Gaithersburg, MD, USA), and biopsy (if indicated). RESULTS No severe dysplasia was observed in women with low-risk HPV or in women with negative HPV test results who had a low-grade abnormality on the Pap test. High-risk (HR) HPV was present in every case of severe dysplasia on biopsy. The cumulative odds risk for cervical dysplasia was 1.11 in HIV(+) women with low-grade squamous intraepithelial lesion on the Pap test who were older than 21 years of age and HPV-HR(+). CONCLUSIONS In the population studied, HPV typing is a valuable adjunct to a low-grade abnormality on the Pap test in predicting the absence of cervical dysplasia on biopsy. Larger prospective population-based studies are needed to study the role of HPV as a negative predictor of disease in cervical dysplasia.
OBJECTIVES:To use two rapid human immunodeficiency virus (HIV) tests at labor, measure test acceptance and performance, and measure HIV prevalence in these women.METHODS:Between February and October 2000, two rapid tests (Determine; Abbott, Chicago, IL, U.S.A. and Double Check; Orgenics, Yavne, Israel) were used in three public maternities in Rio de Janeiro, Brazil. Enzyme-linked immunosorbent assay (ELISA) and Western blot (WB) analysis confirmed positive and discordant results.RESULTS:Of the 858 patients who were enrolled, the mean gestational age was 36 weeks (median = 39, mode = 40) and 17 (2%) refused testing. Of the 841 patients tested, 13 were positive by both tests, which represents a 1.5% prevalence (95% confidence interval: 0.7%-2.3%); all were confirmed by ELISA and WB analysis. Seven samples gave discordant results by the rapid tests; of these, six were ELISA-negative/WB-negative and one was ELISA-negative/WB-indeterminate. The positive predictive value for samples that were positive by both rapid tests simultaneously was 100%.CONCLUSIONS:Two rapid HIV tests used at labor were well accepted (98%). When the combined results of the two rapid tests (but not a single rapid test) were analyzed, this strategy was as efficient as the standard ELISA and WB HIV strategy for correctly classifying individuals.
