Biomedical subjects

L Corey

Publications and source records attributed to L Corey.

At least 127 records · Page 7Linked to original sources

PubMed1998

Functional analysis of the human cytomegalovirus US28 gene by insertion mutagenesis with the green fluorescent protein gene.

The protein encoded by the US28 gene of human cytomegalovirus (HCMV) has homology to G protein-coupled receptors (GCR). Previous studies demonstrated that recombinant US28 protein can bind the beta class of chemokines (K. Neote, D. DiGregorio, J. Y. Mak, R. Horuk, and T. J. Schall, Cell 72:415-425, 1993) and induce a rise in intracellular calcium after the binding of chemokines (J. L. Gao and P. M. Murphy, J. Biol. Chem. 269:28539-28542, 1994). In order to investigate the function of the US28 protein in virus-infected cells, a recombinant HCMV (HV5.8) was constructed, with the US28 open reading frame disrupted by the insertion of the Escherichia coli gpt gene and the gene for the green fluorescent protein. The US28 gene is not required for growth in human fibroblasts (HF). HF infected with wild-type HCMV bound RANTES at 24 h postinfection and demonstrated an intracellular calcium flux induced by RANTES. In cells infected with HV5.8, RANTES did not bind or induce a calcium flux, demonstrating that US28 is responsible for the beta-chemokine binding and induced calcium signaling in HCMV-infected cells. The ability of the US28 gene to bind chemokines was shown to cause a significant reduction in the concentration of RANTES in the medium of infected cells. Northern analysis of RNA from infected cells showed that US28 is an early gene, while US27 (another GCR) is a late gene.

Blotting, Northern↗

PubMed1998

Evolution of hepatitis C virus quasispecies in hypervariable region 1 and the putative interferon sensitivity-determining region during interferon therapy and natural infection.

To study hepatitis C virus (HCV) genetic mutation during interferon (IFN) therapy, the temporal changes in HCV quasispecies heterogeneity were compared before and after treatment for nine patients infected with HCV genotype 1, including four nonresponders, four responders who relapsed after therapy, and one responder who experienced a breakthrough of viremia during therapy. Nine untreated patients with an average time between specimens of 8.4 years served as controls. Sequences from the second envelope glycoprotein gene hypervariable region 1 (HVR1) and the putative IFN sensitivity-determining region (ISDR) of the nonstructural NS5A gene were analyzed by heteroduplex mobility assays and nucleotide sequencing. A strong positive correlation was found between the percent change in a heteroduplex mobility ratio (HMR) and percent change in nucleotide sequence (r = 0.941, P < 0.001). The rate of fixation of mutations in the HVR1 was significantly higher for IFN-treated patients than for controls (6.97 versus 1.31% change in HMR/year; P = 0.02). Similarly, a higher rate of fixation of mutations was observed in the ISDR for IFN-treated patients than for untreated controls, although the result was not significant (1.45 versus 0.15 amino acid changes/year; P = 0.12). On an individual patient basis, IFN therapy was associated with measurable HVR1 and ISDR mutation in nine of nine (100%) and two of nine (22.2%) patients, respectively. Evolution to IFN-resistant ISDR sequences was observed in only one of nine IFN-treated patients. These data suggest that IFN therapy frequently exerts pressure on the HCV envelope region, while pressure on the ISDR was evident in only a subset of patients. Thus, the selection pressures evoked on HCV genotype 1 quasispecies during IFN therapy appear to differ among different patients.

Amino Acid Sequence↗

PubMed1998

Human herpesvirus 8 in the prostate glands of men with Kaposi's sarcoma.

The epidemiology of human immunodeficiency virus (HIV)-associated Kaposi's sarcoma (KS) resembles that of a sexually transmitted pathogen. However, human herpesvirus 8 (HHV-8), the proposed cause of KS, is found in semen only infrequently and at low titers. To determine whether HHV-8 was present in the urogenital tract, transrectal ultrasound-guided prostate biopsies were obtained from six men with KS (five with concurrent HIV infection) and four without KS (three with concurrent HIV) and assayed for HHV-8 by PCR. Nine of the 10 men were seropositive for HHV-8. Five of nine HHV-8-seropositive men had HHV-8 DNA detected in prostate tissue by solution-based PCR. All five currently had KS or had it previously. In two subjects, prostate tissue was the only identified source of HHV-8. In situ PCR on serial sections of prostate indicated that HHV-8 infection was localized to discrete areas of the prostate. When detected, HHV-8 DNA was present in the nuclei of >90% of the glandular epithelial cells. In situ hybridization for HHV-8 mRNA revealed that between 1 and 5% of cells harboring HHV-8 DNA expressed viral transcripts associated with HHV-8 replication (T1.1 transcript), while >90% expressed gene products associated with viral latency (T0.7 transcript). Intermittent replication of HHV-8 in the prostate and subsequent shedding of virus in semen may be crucial factors for determining whether HHV-8 can be transmitted through sexual activity.

Adult↗

PubMed1998

Similarity of social security numbers among twins: data from the Virginia Twin Registry.

At least two twin registries in the United States have been or are being assembled using the similarity of Social Security Numbers in computerized records to help identify possible twin pairs. While the success of such enterprises depends directly on a high probability of twinness given Social Security Numbers, there are theoretical and practical reasons to study the probability of Social Security Number similarity given twinness. For example, the number of twin pairs with similar Social Security Numbers obviously determines the maximum number of twin pairs that can be discovered by similarity algorithms. To study this issue, we examined the similarity of known Social Security Numbers in twin pairs from the Virginia Twin Registry by age, sex, race, and zygosity of the pair. We found that similarity between the Social Security Numbers of twin pairs varies markedly by age, and MZ twin pairs have significantly more similar Social Security Numbers than DZ pairs at all ages. Among older twins, there are also significant differences by sex and race. For younger twins, algorithms that identify putative twin pairs on the basis of the similarity of their Social Security Numbers hold the promise of being able to identify a large proportion of all true twin pairs. Such algorithms will be substantially less successful, however, in identifying a large proportion of older twin pairs.

Adult↗

PubMed1997

Serial in vivo passage of HIV-1 infection in Macaca nemestrina.

In an earlier study we found that pigtailed macaques (Macaca nemestrina) that were experimentally infected with human immunodeficiency virus type 1 (HIV-1) initially became viremic and seroconverted, but HIV-1 replication diminished markedly over time. In an attempt to develop a longer term pathogenic model, blood from HIV-1-infected macaques was serially transfused into three groups of naive macaques. Transfer was successful through two transfusions as shown by repeated virus isolations and confirmed by the development of cell-free plasma viremia and by seroconversion. Three to five weeks after transfusion, plasma levels of HIV-1 RNA from several macaques in the first two groups exceeded those of the initially inoculated macaques. However, animals in the third group had diminished RNA levels, were virus culture negative, and did not seroconvert. Sequence analyses of env-region clones from infected animals revealed only minimal changes over the course of the passages. These results confirm HIV-1 replication in M. nemestrina during the acute phase of infection. However, adaptation of HIV-1 to a macaque-pathogenic variant did not occur during serial passage, possibly because the animals were able to restrict HIV-1 replication below a level required for a pathogenic variant to emerge. Whether such containment is a function of the host's immune response or a virus cell incompatibility remains to be determined.

Adaptation, Physiological↗

PubMed1997

Cytotoxic-T-cell responses, viral load, and disease progression in early human immunodeficiency virus type 1 infection.

BACKGROUND: Early in human immunodeficiency virus type 1 (HIV-1) infection there is a decline in viral replication that has been attributed to host immunity, but the components of this response, particularly the ability of cytotoxic T lymphocytes to control viral burden and influence the outcome of disease, are poorly understood. METHODS: We prospectively studied 33 patients with primary HIV-1 infection for HIV-specific activated cytotoxic T lymphocytes and memory cytotoxic T lymphocytes and compared these lymphocyte responses with changes in viral load and clinical status over the subsequent 18 to 24 months. RESULTS: Soon after infection, activated HIV-specific cytotoxic T lymphocytes, mediated primarily by CD8+ cells, were detected in 17 of 23 patients (74 percent). Memory cytotoxic T lymphocytes were found in 6 of 6 patients tested (100 percent) during the first three months of infection and in 17 of 21 patients (81 percent) tested during the first six months. The frequencies of memory cytotoxic T lymphocytes varied markedly over time, but overall they declined over the first 6 to 8 months and then stabilized over the next 12 to 18 months. The patients with higher frequencies of Env-specific memory cytotoxic T lymphocytes had a median level of plasma HIV-1 RNA about one third that of the patients with lower frequencies, (median number of RNA copies per milliliter, 22,000 vs. 62,000; P=0.006). Patients with low frequencies of Env-specific memory cytotoxic T lymphocytes (or none) in early infection had a more rapid decline to less than 300 CD4+ cells per cubic millimeter (P = 0.05). CONCLUSIONS: In early HIV-1 infection, the induction of memory cytotoxic T lymphocytes, particularly those specific for Env, helps control viral replication and is associated with slower declines in CD4+ cell counts. Host cytolytic effector responses appear to delay the progression of HIV-1 disease.

Adult↗

PubMed1997

Safety profile of phase I and II preventive HIV type 1 envelope vaccination: experience of the NIAID AIDS Vaccine Evaluation Group.

The NIAID-sponsored AIDS Vaccine Evaluation Group was established in 1988 to perform phase I/II clinical trials with candidate preventive HIV-1 vaccines. This report includes safety data from 1398 HIV-negative, healthy volunteers who were enrolled into 25 phase I and 1 phase H multicentered, randomized, double-blind studies evaluating seven recombinant HIV-1 envelope vaccines, two V3 loop synthetic peptide vaccines, and two live poxvirus-vectored recombinant envelope vaccines. All studies but three were placebo controlled; the placebo was either the adjuvant alone or, in studies of recombinant poxvirus vaccines, it was the vector with no gene insert or a non-HIV gene insert. All candidate vaccines were generally well tolerated. The only adverse effects that were clearly related to vaccination were occasional acute local and systemic reactions that were associated with the adjuvants. Three adjuvants in particular were associated with moderate to severe local reactions: alum plus deoxycholate (ImmunoAg), MTP-PE (Biocine Corp.), and QS21 (Genentech, Inc.). MTP-PE was also associated with self-limited severe systemic reactions. There were no serious adverse laboratory toxicities and no evidence of significant immunosuppressive events after receipt of the candidate vaccines. A few volunteers experienced symptoms that might relate to an underlying immunopathologic mechanism (rash, hemolytic anemia, arthralgia), but their presentations were mild and their incidence was low. Eleven volunteers were diagnosed with malignancies during or after their participation, which was within the 95% confidence interval of the number of cases predicted by the National Cancer Institute SEER (Program for cancer surveillance, epidemiology, and end result reporting) database. In conclusion, the envelope-based recombinant or synthetic candidate HIV-1 vaccines appear to be safe and this work has prepared the way for the testing of increasingly complex candidate HIV-1 vaccines.

AIDS Vaccines↗

PubMed1997

Severe genital herpes infections in HIV-infected individuals with impaired herpes simplex virus-specific CD8+ cytotoxic T lymphocyte responses.

The specific mechanisms underlying the varied susceptibility of HIV-infected (HIV+) individuals to opportunistic infections (OI) are still incompletely understood. One hypothesis is that quantitative differences in specific T cell responses to a colonizing organism determine the development of an AIDS-defining OI. We evaluated this hypothesis for herpes simplex virus (HSV) infection, a common OI in HIV+ patients. Using limiting dilution analyses, the frequency of HSV-specific CD8+ cytotoxic T lymphocyte precursors (pCTL) and proliferative precursors were quantitated in peripheral blood mononuclear cells from 20 patients coinfected with HIV and HSV-2. The frequency of HSV-specific CD8+ pCTL in HSV+HIV+ individuals was significantly lower than in HSV+HIV- individuals (1 in 77,000 vs. 1 in 6,000, P = .0005) and was not different than in HSV-HIV- individuals (1 in 100,000, P = .24). HIV+ patients who suffered more severe genital herpes recurrences had significantly lower HSV-specific CD8+ pCTL frequencies than those patients with mild recurrences (1 in 170,000 vs. 1 in 26,000, P = .03). In contrast, no significant difference was seen in proliferative precursor frequencies between those patients with mild vs. severe genital herpes (1 in 3,800 vs. 1 in 6,600, P > .5). Quantitative differences in pCTL frequency to HSV appear to be the most important host factor influencing the frequency and severity of HSV reactivation in HIV+ patients. Studies to reconstitute such immunity, especially in people with acyclovir-resistant HSV, appear warranted.

CD8-Positive T-Lymphocytes↗

PubMed1997

The acquisition of herpes simplex virus during pregnancy.

BACKGROUND: The acquisition of genital herpes during pregnancy has been associated with spontaneous abortion, prematurity, and congenital and neonatal herpes. The frequency of seroconversion, maternal symptoms of the disease, and the timing of its greatest effect on the outcome of pregnancy have not been systematically studied. METHODS: We studied 7046 pregnant women whom serologic tests showed to be at risk for herpes simplex virus (HSV) infection. Serum samples obtained at the first prenatal visit, at approximately 16 and 24 weeks, and during labor were tested for antibodies to HSV types 1 and 2 (HSV-1 and HSV-2) by the Western blot assay, and the results were correlated with the occurrence of antenatal genital infections. RESULTS: Ninety-four of the women became seropositive for HSV; 34 of the 94 women (36 percent) had symptoms consistent with herpes infection. Women who were initially seronegative for both HSV-1 and HSV-2 had an estimated chance of seroconversion for either virus of 3.7 percent; those who were initially seropositive only for HSV-1 had an estimated chance of HSV-2 seroconversion of 1.7 percent; and those who were initially HSV-2-seropositive had an estimated chance of zero for acquiring HSV-1 infection. Among the 60 of the 94 pregnancies for which the time of acquisition of HSV infection was known, 30 percent of the infections occurred in the first trimester, 30 percent in the second, and 40 percent in the third. HSV seroconversion completed by the time of labor was not associated with an increase in neonatal morbidity or with any cases of congenital herpes infection. However, among the infants born to nine women who acquired genital HSV infection shortly before labor, neonatal HSV infection occurred in four infants, of whom one died. CONCLUSIONS: Two percent or more of susceptible women acquire HSV infection during pregnancy. Acquisition of infection with seroconversion completed before labor does not appear to affect the outcome of pregnancy, but infection acquired near the time of labor is associated with neonatal herpes and perinatal morbidity.

Adult↗

PubMed1997

Frequent genital herpes simplex virus 2 shedding in immunocompetent women. Effect of acyclovir treatment.

Reactivation of herpes simplex virus type 2 (HSV-2) occurs intermittently as perceived clinically and by viral culture. We performed a series of studies to evaluate the frequency and pattern of HSV-2 reactivation using both viral isolation and HSV PCR assay. Daily samples of genital secretions were obtained from 27 HSV-2 seropositive women; a subset of subjects obtained samples while receiving oral acyclovir 400 mg PO twice a day. HSV DNA was detected in genital swab specimens on 28% of 1,410 d compared with 8.1% of days by viral isolation. 11 of 20 women had HSV DNA detected on > 20% of days, 4 on > 50%, and 2 on > 75% of days; in contrast, none of the women shed on > 21% of days by viral isolation. The daily administration of oral acyclovir promptly reduced the frequency of HSV DNA detection by a median of 80%. Within 3-4 d of discontinuing daily acyclovir, HSV DNA again appeared in the genital area. HSV-2 shedding in the genital mucosa occurs much more frequently than previously appreciated. This frequent reactivation likely plays a role in the epidemic spread of genital herpes worldwide.

Acyclovir↗

PubMed1997

The qualitative nature of the primary immune response to HIV infection is a prognosticator of disease progression independent of the initial level of plasma viremia.

Following infection of the host with a virus, the delicate balance between virus replication/spread and the immune response to the virus determines the outcome of infection, i.e., persistence versus elimination of the virus. It is unclear, however, what relative roles immunologic and virologic factors play during primary viral infection in determining the subsequent clinical outcome. By studying a cohort of subjects with primary HIV infection, it has been demonstrated that qualitative differences in the primary immune response to HIV, but not quantitative differences in the initial levels of viremia are associated with different clinical outcomes.

CD4 Lymphocyte Count↗

PubMed1997

Herpes simplex virus seropositivity and reactivation at delivery among pregnant women infected with human immunodeficiency virus-1.

OBJECTIVE: Our purpose was to determine whether pregnant women infected with human immunodeficiency virus-1 have an increased risk of herpes simplex virus-2 seropositivity and herpes simplex virus reactivation at delivery. STUDY DESIGN: Sixty women infected with human immunodeficiency virus and 8408 other patients who were delivered at the University of Washington between 1989 and 1995 had herpes simplex virus serologic determinations at delivery. Genital herpes simplex virus cultures were obtained for 48 (80%) of the human immunodeficiency virus-infected women and 5567 (66%) of the controls. Logistic regression was used to adjust for possible confounding factors. RESULTS: Forty-five (75%) of human immunodeficiency virus-infected women and 2709 (32%) controls were seropositive for herpes simplex virus-2 (p < 0.0001). Eight percent of human immunodeficiency virus-infected women and 2% of controls had herpes simplex virus reactivation in labor (p < 0.05). CONCLUSIONS: Infection with herpes simplex virus-2 is common among pregnant women infected with human immunodeficiency virus. Herpes simplex virus reactivation complicates labor in this group more often than in other obstetric patients. The role of herpes simplex virus in perinatal human immunodeficiency virus transmission warrants further study.

Acquired Immunodeficiency Syndrome↗

PubMed1997

Herpes simplex virus type 2 detection by culture and polymerase chain reaction and relationship to genital symptoms and cervical antibody status during the third trimester of pregnancy.

OBJECTIVES: Our goal was to define the frequency of asymptomatic herpes simplex virus type 2 shedding by culture and polymerase chain reaction and to correlate our findings with cervical anti-herpes simplex virus type 2 immunoglobulin A production. STUDY DESIGN: Women who were seropositive for herpes simplex virus type 2 collected daily genital tract samples during the third trimester for culture and deoxyribonucleic acid quantitation by polymerase chain reaction. Cervical secretions were collected weekly for anti-herpes simplex virus type 2 immunoglobulin A. Asymptomatic shedding by culture versus polymerase chain reaction and anti-herpes simplex virus type 2 immunoglobulin A detection with and without genital shedding were compared by means of McNemar's chi 2 test. RESULTS: Asymptomatic shedding was more frequent by polymerase chain reaction than by culture (13.8% vs 2.3%, p < 0.0001). When cervical anti-herpes simplex virus type 2 immunoglobulin A was present, patients were more likely to have negative results by polymerase chain reaction than positive results (66.7% vs 26.7%, p = 0.001). Anti-herpes simplex virus type 2 immunoglobulin A was detected beyond 37 weeks in only one subject. CONCLUSIONS: Polymerase chain reaction was more sensitive than culture for detecting asymptomatic genital herpes simplex virus. The role of immunoglobulin A in clearing genital herpes simplex virus remains to be determined.

Adult↗

PubMed1997

A randomized, double-blind trial of parenteral low dose versus high dose interferon-beta in combination with cryotherapy for treatment of condyloma acuminatum.

Forty-nine subjects were enrolled in a study comparing two dosages of parenterally administered interferon (IFN)-beta in combination with cryotherapy for the treatment of anogenital warts. Subjects were randomized to receive subcutaneous injections of either 2 x 10(6) or 4 x 10(6) IU/m2 of IFN-beta (Biogen) three times a week for a total of 6 weeks. Cryotherapy was administered concomitantly by aerosolization of liquid nitrogen at 10-day intervals. Systemic side- effects were modest in intensity and included fever, chills, myalgia, and headaches (flu-like symptoms). During the first 2 weeks of therapy, they were more common in the high dose group than in the low dose group (P = 0.02). Using survival analysis, there was no significant difference between the two groups in rates of resolution of warts present at baseline (P = 0.62). However, the rate of new lesion formation during the study was significantly lower in the high dose group (P = 0.04).

Adult↗

PubMed1997

Age changes in the causes of individual differences in conservatism.

Age-related changes are analyzed in the correlation of 3416 monozygotic and 3780 dizygotic U.S. twin pairs aged between 9 and 75+ years for conservatism scores derived from a 28-item social attitude inventory. The effects of the shared environment are overwhelming in twins aged 20 years or younger. In older twins, genetic effects appear to play a larger role. A more dynamic conception of the interaction between genes and environment in the development of complex human differences is needed.

Adolescent↗

PubMed1997

Frequent detection of Kaposi's sarcoma-associated herpesvirus (human herpesvirus 8) DNA in saliva of human immunodeficiency virus-infected men: clinical and immunologic correlates.

The prevalence, quantity, temporal pattern, and clinical and immunologic correlates of shedding of Kaposi's sarcoma (KS)-associated herpesvirus (KSHV; or human herpesvirus [HHV]-8) DNA in saliva were studied. KSHV DNA was detected in saliva from 18 (75%) of 24 human immunodeficiency virus (HIV)-positive patients with KS and from 1 of 1 HIV-negative patient with KS, 3 (15%) of 20 HIV-positive patients without KS, and none of 24 controls. KSHV DNA levels ranged from 10(2.4) to 10(6) copies/mL and were lower than levels for Epstein-Barr virus but comparable to those for HHV-6. Detection of KSHV DNA in saliva was not associated with oral KS or decreased peripheral blood CD4 cell counts. KSHV DNA was not detected in semen. Resistance of KSHV DNA from saliva to DNase treatment was consistent with the presence of virions. These data suggest that KSHV can replicate in the oropharynx and that salivary contact could contribute to KSHV transmission.

Antibodies, Viral↗

PubMed1997

Immunotherapy of recurrent genital herpes with recombinant herpes simplex virus type 2 glycoproteins D and B: results of a placebo-controlled vaccine trial.

To determine the safety, immunogenicity, and efficacy of a recombinant herpes simplex virus type 2 glycoprotein D and B vaccine in the treatment of recurrent genital herpes, a randomized, placebo-controlled trial was held at two referral centers. Healthy patients with 4-14 recurrences per year received injections of both glycoproteins in MF59 adjuvant or of MF59 alone at 0, 2, 12, and 14 months. For 18 study months, the rate and number of recurrences, the duration and severity of the first confirmed recurrence, vaccine immunogenicity, and rates of local and systemic reactions were determined. The monthly rate of recurrences was not significantly improved, but the duration and severity of the first study outbreak was reduced significantly by vaccination. Glycoprotein-specific and neutralizing antibodies were boosted by vaccination for the duration of the study. This vaccine is safe and immunogenic and ameliorated an observed first postvaccination genital recurrence, but it does not reduce recurrence frequency.

Adult↗

PubMed1997

Assessment of hepatitis C virus quasispecies heterogeneity by gel shift analysis: correlation with response to interferon therapy.

Hepatitis C virus (HCV) quasispecies heterogeneity was assessed in pretreatment sera of 22 patients treated with interferon (IFN). Quasispecies heterogeneity was quantitated by analysis of 490 hypervariable region 1 (HVR1) clones using gel shift analysis (GSA), which allowed determination of two components of HCV quasispecies heterogeneity: genetic complexity (number of variants) and genetic diversity (mean genetic distance between variants). HCV genotype and pretreatment RNA titer were similar between responders (n = 12) and nonresponders (n = 10). GSA correlated well with nucleotide sequencing for estimating HCV genetic diversity (R = .952; P < .001). A positive correlation of .666 (P < .001) was observed between genetic diversity and complexity, suggesting that these components of quasispecies heterogeneity were related. However, while there were no significant differences in pretreatment complexity or genetic diversity among response groups, higher pretreatment genetic diversity was predictive of response failure (P = .041). Assessment of HVR1 heterogeneity by GSA revealed important relationships between quasispecies genetic diversity, complexity, and response to IFN therapy and suggested a need for analysis of other HCV genes.

Cloning, Molecular↗