Persistence of episomal HIV-1 infection intermediates in patients on highly active anti-retroviral therapy.

Treatment of HIV-1-infected individuals with a combination of anti-retroviral agents results in sustained suppression of HIV-1 replication, as evidenced by a reduction in plasma viral RNA to levels below the limit of detection of available assays. However, even in patients whose plasma viral RNA levels have been suppressed to below detectable levels for up to 30 months, replication-competent virus can routinely be recovered from patient peripheral blood mononuclear cells and from semen. A reservoir of latently infected cells established early in infection may be involved in the maintenance of viral persistence despite highly active anti-retroviral therapy. However, whether virus replication persists in such patients is unknown. HIV-1 cDNA episomes are labile products of virus infection and indicative of recent infection events. Using episome-specific PCR, we demonstrate here ongoing virus replication in a large percentage of infected individuals on highly active anti-retroviral therapy, despite sustained undetectable levels of plasma viral RNA. The presence of a reservoir of 'covert' virus replication in patients on highly active anti-retroviral therapy has important implications for the clinical management of HIV-1-infected individuals and for the development of virus eradication strategies.

Hepatic venoocclusive disease in autologous bone marrow transplantation of solid tumors and lymphomas.

Retrospective review of 291 solid tumor and lymphoma patients undergoing autologous bone marrow transplantation (BMT) was performed to determine the influence of pretransplant characteristics and preparative regimen to the development of hepatic venoocclusive disease (VOD). Twelve patients (4.1%) developed a clinical syndrome of right upper quadrant (RUQ) tenderness or hepatomegaly, jaundice, and ascites, with or without encephalopathy, within 40 days of marrow reinfusion. Evidence of metastatic liver disease was the only pretransplant characteristic predictive for VOD (P = .0002). Sex, age, histology, hepatitis B serology, and elevated liver function tests were not predictive. No individual preparative agent had a significant effect on the development of VOD. However, a single 2-hour infusion of carmustine (BCNU) (greater than or equal to 450 mg/m2) led to an increased incidence of VOD when compared with the same dose administered in a fractionated schedule (P = .0258) when given with two other chemotherapeutic agents. Seven of eight autopsy specimens confirmed the clinical diagnosis of VOD. The four patients in whom clinical VOD resolved had lower median peak bilirubins (7.3 v 15.9 mg/dL), lower median peak creatinines (2.1 v 4.1 mg/dL), and relatively quick engraftment of neutrophils (mean, 18.7 days). One of the four patients in whom VOD resolved had other grade 4 (life-threatening) toxicities in contrast to eight of eight who succumbed. In summary, VOD is an uncommon complication in autotransplantation of solid tumors and lymphomas. Our data suggest caution in selecting patients with known metastatic liver disease and consideration of a fractionated BCNU schedule especially in combination with other alkylating agents.

Normal immune function and inability to isolate virus in culture in an individual with long-term human immunodeficiency virus type 1 infection.

A detailed, longitudinal study was undertaken to investigate the immunological and virological features of an individual with hemophilia infected with human immunodeficiency virus type-1 (HIV-1) for 10 years without disease. Methods applied to serial samples of peripheral blood included Western blot analysis, neutralizing antibody assays, antibody-dependent cell-mediated cytotoxicity (ADCC) titration, HIV-1 specific cytotoxic T lymphocyte (CTL) assays, viral cultures, and PCR with sequence analysis of viral regulatory genes. Strong antibody responses against HIV-1 antigens as measured by Western blot and ADCC assays have persisted throughout infection. Repeated attempts to isolate HIV-1 using sensitive culture techniques and to demonstrate viremia with standard PCR methods have failed. Using the "booster" PCR technique, a period of viremia in peripheral blood mononuclear cells was demonstrated. Concurrent with detection of circulating virus, titers of neutralizing antibodies and circulating HIV-1-specific CTLs became measurable. Sequencing studies of a portion of the viral genome showed no significant abnormalities of the regulatory genes. In this individual, the combination of low viral load in the peripheral blood and a strong, responsive immune system is associated with long-term, disease-free coexistence with HIV-1 infection.

Factors in adjustment to blindness.

We wished to explore the relationship between certain blinding eye diseases, residual vision and psychosocial adjustment, including acceptance of blindness. One hundred and fourteen patients were grouped according to level of vision, age, type of disease, general physical health and duration of blindness. Psychological symptoms were measured by the Minnesota Multiphasic Personality Inventory (M.M.P.I.) and social function by an adaptation to blindness of the Gunzberg Progress Chart of Social Function. Social adjustment was best and psychological morbidity least in those with non-diabetic retinal disorders, those who had the best vision and those who accepted their blindness. Non-acceptance of blindness was associated with the most psychological distress and the lowest scores in social adjustment. People with glaucoma and diabetic retinal disorders seemed more poorly adjusted. An attempt should be made to identify those most prone to maladjustment so as to assist them in rehabilitation.

Neutralization sensitivity of cell culture-passaged simian immunodeficiency virus.

CEMx174- and C8166-45-based cell lines which contain a secreted alkaline phosphatase (SEAP) reporter gene under the control of a tat-responsive promoter derived from either SIVmac239 or HIV-1(NL4-3) were constructed. Basal levels of SEAP activity from these cell lines were low but were greatly stimulated upon transfection of tat expression plasmids. Infection of these cell lines with simian immunodeficiency virus (SIV) or human immunodeficiency virus type 1 (HIV-1) resulted in a dramatic increase in SEAP production within 48 to 72 h that directly correlated with the amount of infecting virus. When combined with chemiluminescent measurement of SEAP activity in the cell-free supernatant, these cells formed the basis of a rapid, sensitive, and quantitative assay for SIV and HIV infectivity and neutralization. Eight of eight primary isolates of HIV-1 that were tested induced readily measurable SEAP activity in this system. While serum neutralization of cloned SIVmac239 was difficult to detect with other assays, neutralization of SIVmac239 was readily detected at low titers with this new assay system. The neutralization sensitivities of two stocks of SIVmac251 with different cell culture passage histories were tested by using sera from SIV-infected monkeys. The primary stock of SIVmac251 had been passaged only twice through primary cultures of rhesus monkey peripheral blood mononuclear cells, while the laboratory-adapted stock had been extensively passaged through the MT4 immortalized T-cell line. The primary stock of SIVmac251 was much more resistant to neutralization by a battery of polyclonal sera from SIV-infected monkeys than was the laboratory-adapted virus. Thus, SIVmac appears to be similar to HIV-1 in that extensive laboratory passage through T-cell lines resulted in a virus that is much more sensitive to serum neutralization.

Psychological and social adjustment of blind subjects and the 16PF.

Determined whether individuals who adapted well or poorly to the loss of their vision could be differentiated on the basis of the Cattell 16PF. Well adjusted individuals were defined as those who displayed minimal depression and high social independence, while poorly adjusted individuals were highly depressed and socially dependent. By the use of discriminant analysis based upon the standard 16PF, 84.5% of highly depressed and 81% of the minimally depressed group were classified accurately. In a second analysis, 75% of socially independent and 73% of socially dependent individuals were classified correctly. Premorbid characteristics of well and poorly adjusted blind Ss were described.

In vitro characterization of adult primary human immunodeficiency virus type 1: demonstration of distinctive single-cell killing phenotypes in spite of similar levels of viral replication.

Two primary human immunodeficiency virus (HIV)-1 biologic clones have been studied extensively in a system using CD4 T cell-enriched peripheral blood lymphocytes and anti-CD4 antibody to measure viral replication kinetics and single-cell cytopathicity. Biologic clones from a person with AIDS replicated to high levels and were cytopathic in the absence of syncytium formation. Unexpectedly, biologic clones from an adult long-term nonprogressor were noncytopathic in spite of similar levels of viral replication. A correlation has recently been demonstrated between reduced mitochondrial viability and cell death in HIV-1-infected cultures. Peripheral blood-derived CD4 T cells infected with the cytopathic clone showed a progressive reduction in mitochondrial viability, while those infected with the noncytopathic clone demonstrated functionally viable mitochondria. These studies demonstrate that primary HIV-1-induced cytopathicity is separable from syncytium formation and replication rate.

Human immunodeficiency virus type 1-specific cytotoxic T lymphocytes (CTL), virus load, and CD4 T cell loss: evidence supporting a protective role for CTL in vivo.

The relationships between primary human immunodeficiency virus type 1 (HIV-1) Gag-specific cytotoxic T lymphocyte (CTL) frequency, virus load, and CD4 T cell loss were evaluated in a group of 46 HIV-1-infected persons with hemophilia. Freshly isolated peripheral blood mononuclear cells in limiting dilution assays were used to measure HIV-1 Gag-specific CTL frequencies. Concurrent measurements of virus load and lymphocyte surface markers were obtained. No correlation between Gag-specific CTL frequency and concurrent CD4 cell count was observed. A significant inverse relationship was observed between HIV-1 Gag-specific CTL frequency and provirus load as measured by polymerase chain reaction. Subjects with higher CTL frequencies were found to have more stable CD4 cell counts over time. These results provide additional evidence to support the concept that the predominant role of this virus-specific cellular immune response is to limit viral replication and CD4 cell loss in HIV-1 infection.

Activity of human immunodeficiency virus type 1 promoter/TAR regions and tat1 genes derived from individuals with different rates of disease progression.

Different rates of disease progression may be associated with different human immunodeficiency virus type 1 (HIV-1) promoter and/or transactivator activities. We therefore analyzed the sequences and activities of the first exon of Tat, tat1, and the promoter/trans-acting responsive (TAR) regions amplified directly from peripheral blood mononuclear cells obtained from five long-term nonprogressors and eight progressing HIV-1-infected individuals. The majority of tat1 alleles and promoter/TAR regions from all patients were intact and showed comparable activities in transient reporter assays. A substantial number of point mutations and some length variations were observed in the promoter/TAR region. In a single nonprogressor, the Sp1 binding site 3 was consistently altered and the transcriptional activity in the presence of Tat was diminished. Some LTR clones from a rapid progressor contained a fourth Sp1 binding site, which was associated with an elevated basal promoter activity. These data suggest that defects in the promoter/TAR region or tat1 are rare and that different promoter/transactivator activities are not commonly associated with different progression rates.

Remodeling of sperm chromatin following fertilization: nucleosome repeat length and histone variant transitions in the absence of DNA synthesis.

Within the first cell cycle following fertilization the average nucleosomal repeat length of sea urchin male pronuclear chromatin declines by 30-40 base pairs to a value typical of that found in the embryo. This decline occurs after a lag of about 30 min postfertilization, and is accompanied by replication of the male chromatin and accumulation of cleavage-stage (CS) core histone variants. When replication is inhibited by greater than 95% with aphidicolin, the decline in repeat length still occurs, although it is slightly retarded. The decline in repeat length also occurs when protein synthesis is blocked by greater than 98% and DNA synthesis by 60-70% with emetine. The adjustment of nucleosome repeat length therefore can occur in vivo without extensive movement of replication forks across the length of the chromatin, or normal progression of the cell cycle, and appears to require no proteins synthesized postfertilization. Blocking of DNA synthesis or protein synthesis also does not prevent the normal histone variant transitions involved in male pronuclear chromatin remodeling. Although their accumulation is slowed, CS core variants eventually become the predominant male pronuclear histones in their classes when replication is inhibited. Since a shortening of the average nucleosomal repeat length of approximately 10-20% is not sufficient to account for this large acquisition of CS variants, some of the sperm (Sp) core histones are probably displaced from the replication-blocked pronucleus. Therefore, accumulation of CS H2A and CS H2B are temporally correlated with the repeat length transition, whereas replication, normal progression of the cell cycle, and the early histone transitions involving SpH1 and SpH2B are not.

Modulation of different human immunodeficiency virus type 1 Nef functions during progression to AIDS.

The human immunodeficiency virus type 1 (HIV-1) Nef protein has several independent functions that might contribute to efficient viral replication in vivo. Since HIV-1 adapts rapidly to its host environment, we investigated if different Nef properties are associated with disease progression. Functional analysis revealed that nef alleles obtained during late stages of infection did not efficiently downmodulate class I major histocompatibility complex but were highly active in the stimulation of viral replication. In comparison, functional activity in downregulation of CD4 and enhancement of HIV-1 infectivity were maintained or enhanced after AIDS progression. Our results demonstrate that various Nef activities are modulated during the course of HIV-1 infection to maintain high viral loads at different stages of disease progression. These findings suggest that all in vitro Nef functions investigated contribute to AIDS pathogenesis and indicate that nef variants with increased pathogenicity emerge in a significant number of HIV-1-infected individuals.

CD4 down-modulation by human immunodeficiency virus type 1 Nef correlates with the efficiency of viral replication and with CD4(+) T-cell depletion in human lymphoid tissue ex vivo.

The human immunodeficiency virus type 1 (HIV-1) Nef protein is an important virulence factor. Nef has several functions, including down-modulation of CD4 and class I major histocompatibility complex cell surface expression, enhancement of virion infectivity, and stimulation of viral replication in peripheral blood mononuclear cells. Nef also increases HIV-1 replication in human lymphoid tissue (HLT) ex vivo. We analyzed recombinant and primary nef alleles with highly divergent activity in different in vitro assays to clarify which of these Nef activities are functionally linked. Our results demonstrate that Nef activity in CD4 down-regulation correlates significantly with the efficiency of HIV-1 replication and with the severity of CD4(+) T-cell depletion in HLT. In conclusion, HIV-1 Nef variants with increased activity in CD4 down-modulation would cause severe depletion of CD4(+) T cells in lymphoid tissues and accelerate AIDS progression.

Partial "repair" of defective NEF genes in a long-term nonprogressor with human immunodeficiency virus type 1 infection.

A 36-bp deletion close to the 5' end of NEF that impaired Nef function was found in a long-term nonprogressor with human immunodeficiency virus type 1 (HIV-1) infection. Forms containing an adjacent duplication of 33 bp were also frequently observed. The duplication showed no homology to the deleted region but restored the overall length of the first variable loop of Nef. NEF alleles carrying the duplication were active in class I major histocompatibility complex (MHC-I) down-modulation and enhancement of virus infectivity. However, they showed little activity in CD4 down-regulation and were unable to stimulate viral replication in human peripheral blood mononuclear cells. Our study indicates that the enhancement of virion infectivity and the stimulation of HIV-1 replication in lymphocytes are distinct functions of Nef. Our findings also illustrate the capacity for repair of attenuating deletions in HIV-1 infection and suggest that a selective pressure for Nef-mediated MHC-I down-modulation and/or enhancement of virion infectivity exists.

High frequency of defective nef alleles in a long-term survivor with nonprogressive human immunodeficiency virus type 1 infection.

A large number of nef alleles were obtained from peripheral blood mononuclear cells (PBMC) of four long-term nonprogressing survivors of human immunodeficiency virus type 1 (HIV-1) infection and from five individuals with progressive HIV-1 infection. These primary nef alleles were characterized by DNA sequence analysis and for their ability to downregulate CD4 surface expression. Intact nef open reading frames that directed the expression of Nef protein were recovered from all of the individuals. Most of the Nef proteins derived from three of four individuals with nonprogressive infection and from all five individuals with progressive infection were functional as judged by their ability to induce a decrease in surface CD4 expression. In contrast, one individual with nonprogressive HIV-1 infection yielded an unusually high frequency of disrupted nef open reading frames and Nef proteins defective for CD4 downregulation. Approximately 70% of the nef clones obtained from the PBMC of this individual at eight time points over a 12-year period were disrupted or defective for CD4 downregulation. While functional Nef proteins were demonstrated early in the course of infection (1983), functional nef alleles have surprisingly not come to predominate over time in PBMC DNA in this individual.

Resistance to apoptosis in HIV-infected CD4+ T lymphocytes is mediated by macrophages: role for Nef and immune activation in viral persistence.

Apoptosis or programmed cell death may play a critical role in AIDS pathogenesis through depletion of both CD4(+) and CD8(+) T lymphocytes. Using a reporter virus, a recombinant HIV infectious clone expressing the green fluorescent protein (GFP), apoptosis was measured in productively infected CD4(+) T lymphocytes, in the presence and absence of autologous macrophages. The presence of macrophages in the culture increased the frequency of nonapoptotic GFP-positive productively infected CD4(+) T lymphocytes. The appearance of nonapoptotic productively infected CD4(+) T lymphocytes in the culture required intercellular contacts between macrophages and PBLs and the expression of the HIV Nef protein. The presence of macrophages did not reduce apoptosis when CD4(+) T lymphocytes were infected with a GFP-tagged virus deleted for the nef gene. TNF-alpha (TNF) expressed on the surface of macrophages prevented apoptosis in nef-expressing, productively infected CD4(+) T lymphocytes. Similarly, following TNF stimulation, apoptosis was diminished in Jurkat T cells transfected with a nef-expressing plasmid. TNF stimulation of nef-expressing Jurkat T cells resulted in NF-kappaB hyperactivation, which has been shown to deliver anti-apoptotic signals. Our results indicate that intercellular contacts with macrophages increase the rate of productively infected nonapoptotic CD4(+) T lymphocytes. The survival of productively infected CD4(+) T lymphocytes requires Nef expression as well as activation by TNF expressed on the surface of macrophages and might participate in the formation and maintenance of viral reservoirs in HIV-infected persons.

High-dose nevirapine: safety, pharmacokinetics, and antiviral effect in patients with human immunodeficiency virus infection.

Nevirapine, a potent nonnucleoside reverse transcriptase inhibitor, produces a transient antiviral effect at < or = 200 mg/day due to the selection of resistant virus. To examine if higher levels of nevirapine could produce sustained antiviral activity, its safety, pharmacokinetics, and antiviral activity at 400 mg/day were studied in 21 patients. There was a rapid reduction in immune complex-dissociated p24 antigen and serum human immunodeficiency virus RNA concentration in all patients, and 8 of 10 patients had > 50% reduction at 8 weeks. Nevirapine-resistant virus was isolated from all subjects tested at 12 weeks: The mean plasma trough level (4.0 micrograms/mL [15.8 microM]) exceeded the mean IC50 of resistant virus. Rash developed in 48% of patients and was a dose-limiting toxicity factor in 6. These data suggest that clinical testing of potent antiviral compounds that select for drug-resistant virus is justified to determine if serum levels of drug sufficient to overcome resistant virus can be attained.

Bartonella henselae endocarditis in an immunocompetent adult.

We describe a case of aggressive Bartonella henselae endocarditis in an immunocompetent man who owned a cat. Aortic valve replacement was required, and his infection was diagnosed by histology, serology, and polymerase chain reaction analysis. The manifestations of his disease included mediastinal lymphadenopathy, glomerulonephritis, myocarditis, and a petechial rash; the unusual finding of a positive titer of c-antineutrophil cytoplasmic antibodies was noted. Serological titers were markedly elevated for > 1 year despite clinical improvement.

Sequence variations in human immunodeficiency virus type 1 Nef are associated with different stages of disease.

nef alleles derived from a large number of individuals infected with human immunodeficiency virus type 1 (HIV-1) were analyzed to investigate the frequency of disrupted nef genes and to elucidate whether specific amino acid substitutions in Nef are associated with different stages of disease. We confirm that deletions or gross abnormalities in nef are rarely present. However, a comparison of Nef consensus sequences derived from 41 long-term nonprogressors and from 50 individuals with progressive HIV-1 infection revealed that specific variations are associated with different stages of infection. Five amino acid variations in Nef (T15, N51, H102, L170, and E182) were more frequently observed among nonprogressors, while nine features (an additional N-terminal PxxP motif, A15, R39, T51, T157, C163, N169, Q170, and M182) were more frequently found in progressors. Strong correlations between the frequency of these variations in Nef and both the CD4(+)-cell count and the viral load were observed. Moreover, analysis of sequential samples obtained from two progressors revealed that several variations in Nef, which were more commonly observed in patients with low CD4(+)-T-cell counts, were detected only during or after progression to immunodeficiency. Our results indicate that sequence variations in Nef are associated with different stages of HIV-1 infection and suggest a link between nef gene function and the immune status of the infected individual.