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Biomedical subjects

L Corey

Publications and source records attributed to L Corey.

At least 73 records · Page 4Linked to original sources

Sensitive method for detection of human herpesviruses 6 and 7 in saliva collected in field studies.

To facilitate studies of the epidemiology and natural history of human herpesviruses 6 and 7 in infants, a practical method for collecting and quantifying the DNA of these viruses was developed. Saliva was collected using small strips of filter paper, and virus was detected using a real-time quantitative fluorescent-probe PCR assay. The sensitivity and specificity of this method even after prolonged drying of the specimens compared favorably to those of our traditional method of collecting and assaying saliva.

DNA, Viral↗

HIV-specific cytotoxic T lymphocytes traffic to lymph nodes and localize at sites of HIV replication and cell death.

We have tracked the in vivo migration and have identified in vivo correlates of cytotoxic T-lymphocyte (CTL) activity in HIV-seropositive subjects infused with autologous gene-marked CD8(+) HIV-specific CTL. The number of circulating gene-marked CTL ranged from 1.6 to 3.5% shortly after infusion to less than 0.5% 2 weeks later. Gene-marked CTL were present in the lymph node at 4.5- to 11-fold excess and colocalized within parafollicular regions of the lymph node adjacent to cells expressing HIV tat fusion transcripts, a correlate of virus replication. The CTL clones expressed the CCR5 receptor and localized among HIV-infected cells expressing the ligands MIP-1alpha and MIP-1beta, CC-chemokines produced at sites of virus replication. Aggregates of apoptotic cells and cells expressing granzyme-B localized within these same sites. In contrast, lymph node sections from untreated HIV-seropositive subjects, all with significant viral burden (> 50,000 HIV RNA copies/mL plasma), showed no CC-chemokine expression and exhibited only sporadic and randomly distributed cells expressing granzymes and/or apoptotic cells. These studies show that the infused CTL specifically migrate to sites of HIV replication and retain their antigen-specific cytolytic potential. Moreover, these studies provide a methodology that will facilitate studies of both the magnitude and functional phenotype of Ag-specific CD8(+) T cells in vivo.

Adoptive Transfer↗

Increased incidence of cytomegalovirus disease after autologous CD34-selected peripheral blood stem cell transplantation.

High-dose therapy with autologous peripheral blood stem cell (PBSC) rescue is widely used for the treatment of malignant disease. CD34 selection of PBSC has been applied as a means of reducing contamination of the graft. Although CD34 selection results in a 2 to 3 log reduction in contaminating tumor cells without significantly delaying engraftment, many other types of cells are depleted from the CD34-enriched grafts and immune reconstitution may be impaired. In the present study, 31 cytomegalovirus (CMV)-seropositive patients who received myeloablative therapy followed by the infusion of CD34-selected autologous PBSC were assessed for the development of CMV disease in the first 100 days posttransplant. Seven patients (22.6%) developed CMV disease and 4 patients (12.9%) died from complications of their infection. In a contemporaneous group of 237 CMV-seropositive patients receiving unselected, autologous PBSC, only 10 patients (4.2%) developed CMV disease, with 5 deaths (2.1%). In a multivariate logistic regression analysis, the use of CD34-selected autologous PBSC after high-dose therapy was associated with a marked increase in the incidence of CMV disease and CMV-associated deaths.

Adolescent↗

A prospective study of new infections with herpes simplex virus type 1 and type 2. Chiron HSV Vaccine Study Group.

BACKGROUND AND METHODS: Herpes simplex virus (HSV) infections are endemic, but the clinical characteristics of newly acquired HSV type 1 (HSV-1) and HSV type 2 (HSV-2) infections in adults have not been rigorously defined. We monitored 2393 sexually active HSV-2-seronegative persons for clinical and serologic evidence of new HSV infection. Of the participants, 1508 were seropositive for HSV-1 and 885 were seronegative. Charts were reviewed in a blinded manner for classification of those with genitourinary or oropharyngeal symptoms. Charts were also reviewed for all 174 persons with HSV seroconversion. RESULTS: The rates of new HSV-1 and HSV-2 infections were 1.6 and 5.1 cases per 100 person-years, respectively. Of the 155 new HSV-2 infections, 57 (37 percent) were symptomatic, 47 of which (82 percent) were correctly diagnosed at presentation. Among the 74 patients given a clinical diagnosis of genital HSV-2 during the study, 60 were given a correct diagnosis and 14 were given an incorrect diagnosis of genital herpes, for a ratio of true positive results to false positive results of 4:1. Among the 98 persons with asymptomatic HSV-2 seroconversion, 15 percent had genital lesions at some time during follow-up. Women were more likely than men to acquire HSV-2 (P<0.01) and to have symptomatic infection. Previous HSV-1 infection did not reduce the rate of HSV-2 infection, but it did increase the likelihood of asymptomatic seroconversion, as compared with symptomatic seroconversion, by a factor of 2.6 (P<0.001). Of the 19 new HSV-1 infections, 12 were symptomatic. The rates of symptomatic genital HSV-1 infection and oropharyngeal HSV-1 infection were the same (0.5 case per 100 person-years). CONCLUSIONS: Nearly 40 percent of newly acquired HSV-2 infections and nearly two thirds of new HSV-1 infections are symptomatic. Among sexually active adults, new genital HSV-1 infections are as common as new oropharyngeal HSV-1 infections.

Adolescent↗

Risk factors for HIV-1 shedding in semen.

Semen is the body fluid most commonly associated with sexual transmission of human immunodeficiency virus type-1 (HIV-1). Because the male genitourinary tract is distinct immunologically from blood, compartment-dependent factors may determine HIV-1 shedding in semen. To identify these factors, the authors obtained 411 semen and blood specimens from 149 men seen up to three times. Seminal plasma was assayed for HIV-1 RNA and semen was cocultured for HIV-1 and cytomegalovirus (CMV), which may up-regulate HIV-1 replication. The best multivariate model for predicting a positive semen HIV-1 coculture included two local urogenital factors, increased seminal polymorphonuclear cell count (odds ratio (OR) = 12.6 for each log10 increase/mL, 95% confidence interval (CI) 12.2, 134.5) and a positive CMV coculture (OR = 3.0, 95% CI 1.2, 7.7). The best multivariate model for predicting semen HIV-1 RNA included two systemic host factors, CD4+ cell counts <200/microliter (OR = 3.0, 95 percent CI 1.3, 6.9) and nucleoside antiretroviral therapy (monotherapy: OR = 0.5, 95% CI 0.3, 1.0; combination therapy: OR = 0.4, 95% CI 0.2, 0.9), and a positive CMV coculture (OR = 1.7, 95% CI 1.0, 3.0). Thus, both systemic and local genitourinary tract factors influence the risk of semen HIV-1 shedding. These findings suggest that measures of systemic virus burden alone may not predict semen infectivity reliably.

Adult↗

Recombinant glycoprotein vaccine for the prevention of genital HSV-2 infection: two randomized controlled trials. Chiron HSV Vaccine Study Group.

CONTEXT: In the last 3 decades, herpes simplex virus type 2 (HSV-2) infection seroprevalence and neonatal herpes have increased substantially. An effective vaccine for the prevention of genital herpes could help control this epidemic. OBJECTIVE: To evaluate the efficacy of a vaccine for prevention of HSV-2 infection. DESIGN: Two randomized, double-blind, placebo-controlled multicenter trials of a recombinant subunit vaccine containing 30 microg each of 2 major HSV-2 surface glycoproteins (gB2 and gD2) against which neutralizing antibodies are directed, administered at months 0, 1, and 6. Control subjects were given a citrate buffer vehicle. Participants were followed up for 1 year after the third immunization. SETTING AND PARTICIPANTS: We enrolled 2393 persons from December 10, 1993, to April 4, 1995, who were HSV-2 and human immunodeficiency virus seronegative. One trial with 18 centers enrolled 531 HSV-2-seronegative partners of HSV-2-infected persons; the other, with 22 centers, enrolled 1862 persons attending sexually transmitted disease clinics. A total of 2268 (94.8%) met inclusion criteria and were included in the analysis with 1135 randomized to placebo and 2012 to vaccine. MAIN OUTCOME MEASURE: Time to acquisition of HSV-2 infection, defined by seroconversion or isolation of HSV-2 in culture during the study period by randomization group. RESULTS: Time-to-event curves indicated a 50% lower acquisition rate among vaccine vs placebo recipients during the initial 5 months of the trial; however, overall vaccine efficacy was 9% (95% confidence interval, -29% to 36%). Acquisition rates of HSV-2 were 4.6 and 4.2 per 100 patient-years in the placebo and vaccine recipients, respectively (P =.58). Follow-up of vaccine recipients acquiring HSV-2 infection showed vaccination had no significant influence on duration of clinical first genital HSV-2 episodes (vaccine, median of 7.1 days; placebo, 6.5 days; P>.10) or subsequent frequency of reactivation (median monthly recurrence rate with vaccine, 0.2; with placebo, 0.3; P>.10). The vaccine induced high levels of HSV-2-specific neutralizing antibodies in vaccinated persons who did and did not develop genital herpes. CONCLUSIONS: Efficient and sustained protection from sexual acquisition of HSV-2 infection will require more than high titers of specific neutralizing antibodies. Protection against sexually transmitted viruses involving exposure over a prolonged period will require a higher degree of vaccine efficacy than that achieved in this study.

Adolescent↗

Clinical reactivation of genital herpes simplex virus infection decreases in frequency over time.

BACKGROUND: Visits to physicians for genital herpes simplex virus (HSV) infection continue to increase. Most patients with symptomatic infections have recurrences, but no studies of the long-term clinical course of genital herpes are available. OBJECTIVE: To determine whether the frequency of HSV recurrences decreases over time. DESIGN: Observational cohort study. SETTING: University-based research clinic. PATIENTS: 664 persons with genital herpes followed for at least 14 months. MEASUREMENTS: Patients were classified as having initial or recurrent HSV-1 or HSV-2 infection. Patient-reported recurrences and observed recurrences were recorded in a database; more than 12,000 recurrences were analyzed. RESULTS: Median recurrence rates in the first year of follow-up were one and five per year in patients with newly acquired HSV-1 and HSV-2 infection, respectively; second-year rates were significantly lower in both groups. Patients presenting with recurrent HSV-2 infection had higher rates of recurrence in the first and second years and no significant decrease; significant decreases were detected with longer follow-up. One third of all patients experienced a decrease of two or more recurrences per year between years 1 and 2. Patients infected with HSV-2 who were followed for more than 4 years had a median decrease of two recurrences between years 1 and 5. However, 25% of these patients had an increase of at least one recurrence in year 5, illustrating the variability among HSV-infected persons. Decreases over time among patients who never received suppressive therapy were similar to decreases during untreated periods in patients who received suppressive therapy. CONCLUSIONS: Herpes simplex virus type 2 infection continues to be a chronic remitting illness. Over time, however, clinically significant reductions occur in a majority of patients. Physicians may wish to periodically assess the need for continued treatment with daily suppressive antiviral chemotherapy.

Acyclovir↗

Reversibility of the pathological changes in the follicular dendritic cell network with treatment of HIV-1 infection.

Over the course of HIV-1 infection, the lymphoid follicles where the humoral immune response is generated initially increase in size and number and then progressively involute. In advanced disease, the network of the processes of follicular dendritic cells (FDCs) that serve as antigen repositories and anatomical substrate for B and T cells and antigen to interact is destroyed, contributing to the breakdown of the immune system. Because destruction of FDCs is associated with deposition of HIV-1, and much of the virus can be cleared from the network with antiretroviral therapy, we investigated the reversibility of damage. We measured the immunohistochemically stainable FDC compartment by quantitative image analysis, and we documented changes in this compartment at different stages of disease. We show that treatment, initiated even at advanced stages of HIV-1 disease, can slowly reverse pathological changes in the FDC network.

Anti-HIV Agents↗

HIV-1MN recombinant glycoprotein 160 vaccine-induced cellular and humoral immunity boosted by HIV-1MN recombinant glycoprotein 120 vaccine. National Institute of Allergy and Infectious Diseases AIDS Vaccine Evaluation Group.

We evaluated prime-boost immunization with two recombinant envelope glycoprotein subunit vaccines (HIV-1MN recombinant gp160 vaccine in alum adjuvant [MN rgp160] and HIV-1MN recombinant gp120 vaccine in alum adjuvant [MN rgp120]) for safety and immunogenicity in healthy, HIV-1-uninfected adults. The rationale was to combine the helper T cell memory and binding antibody responses typically induced by rgp160 vaccines with the superior neutralizing antibody responses induced by rgp120 vaccines. In a double-blinded, controlled trial, volunteers were randomly assigned to receive MN rgp160 or adjuvant placebo, and a subset later received MN rgp120. The two vaccines were safe, but reactions to MN rgp160 and its adjuvant placebo exceeded those to MN rgp120. MN rgp160 induced IgG binding antibodies, including all IgG subclasses, to MN rgp160 in all vaccine recipients. HIV-1MN-neutralizing and anti-V3 MN peptide-binding antibodies were observed in a majority of volunteers after the fourth MN rgp160 immunization, but at lower levels compared with immunization with MN rgp120 in historical controls. HIV-1-binding, neutralizing, and fusion inhibition antibodies were boosted to the highest levels among MN rgp160 recipients after MN rgp120 booster injections. MN rgp120 boosting appeared to alter the distribution of MN rgp160 vaccine-induced, anti-MN rgp160 IgG subclass antibodies. MN rgp160 induced helper T cell memory, measured by lymphocyte proliferation, Thl and Th2 cytokine production, and skin testing. Strategies including both subunit vaccines may help maximize antibody and helper T cell memory responses to HIV-1 envelope glycoprotein.

AIDS Vaccines↗

Unintegrated HIV-1 circular 2-LTR proviral DNA as a marker of recently infected cells: relative effect of recombinant CD4, zidovudine, and saquinavir in vitro.

Unintegrated HIV-1 proviral DNA is one of the earliest detectable forms of HIV-1, and the influence of an antiretroviral drug on its appearance may reflect the efficacy of that agent in preventing infection of new cells. We characterized the dynamics of HIV-1 p24 (p24) antigen production, HIV-1 gag DNA, tandem long-terminal-repeat circular unintegrated proviral (2-LTR) HIV-1 DNA, HIV-1 tat mRNA, and cell viability in the presence of three antiretroviral agents: recombinant soluble CD4 (rsCD4), zidovudine, and saquinavir. Interference with HIV-1 entry by rsCD4 decreased p24 antigen levels modestly, decreased HIV-1 gag by twofold, and 2-LTR was detectable at the end of the culture period. Inhibition of reverse transcription by zidovudine decreased p24 antigen levels modestly, decreased HIV-1 gag by 19-fold, and inhibited detection of 2-LTR HIV-1 DNA. The protease inhibitor, saquinavir, had the greatest overall effect, with the lowest levels of p24 antigen and HIV-1 gag, and inhibition of 2-LTR. There was no detection of tat mRNA in the saquinavir-treated cultures. In addition, cell viability was significantly higher in cultures treated with saquinavir. In these experiments, 2-LTR HIV-1 DNA was indicative of the relative inhibitory effects of three antiretroviral agents acting at different steps of the HIV-1 replication cycle. We demonstrated in vitro that 2-LTR HIV-1 DNA was a useful indicator of an antiretroviral drug in preventing new cell infection and could be utilized as a dynamic marker of drug efficacy in HIV-1-infected patients.

Anti-HIV Agents↗

Antiretroviral therapy in primary HIV.

Initiation of antiretroviral therapy during primary HIV-1 infection may well redefine the course of the disease by controlling the burst of viral replication and subsequent immune dysfunction. At present, treatment of acute primary HIV-1 should remain largely in the domain of clinical investigation. There are significant problems in providing constant vigilance to medication and subsequent viral suppression. Only clinical trials can define the relative benefit of initiating antiretrovirals during this stage of infection.

Acquired Immunodeficiency Syndrome↗

In vivo migration and function of transferred HIV-1-specific cytotoxic T cells.

The persistence of HIV replication in infected individuals may reflect an inadequate host HIV-specific CD8+ cytotoxic T lymphocyte (CTL) response. The functional activity of HIV-specific CTLs and the ability of these effector cells to migrate in vivo to sites of infection was directly assessed by expanding autologous HIV-1 Gag-specific CD8+ CTL clones in vitro and adoptively transferring these CTLs to HIV-infected individuals. The transferred CTLs retained lytic function in vivo, accumulated adjacent to HIV-infected cells in lymph nodes and transiently reduced the levels of circulating productively infected CD4+ T cells. These results provide direct evidence that HIV-specific CTLs target sites of HIV replication and mediate antiviral activity, and indicate that the development of immunotherapeutic approaches to sustain a strong CTL response to HIV may be a useful adjunct to treatment of HIV infection.

Adoptive Transfer↗

Effect of interleukin-2 on the pool of latently infected, resting CD4+ T cells in HIV-1-infected patients receiving highly active anti-retroviral therapy.

The size of the pool of resting CD4+ T cells containing replication-competent HIV in the blood of patients receiving intermittent interleukin (IL)-2 plus highly active anti-retroviral therapy (HAART) was significantly lower than that of patients receiving HAART alone. Virus could not be isolated from the peripheral blood CD4+ T cells in three patients receiving IL-2 plus HAART, despite the fact that large numbers of resting CD4+ T cells were cultured. Lymph node biopsies were done in two of these three patients and virus could not be isolated. These results indicate that the intermittent administration of IL-2 with continuous HAART may lead to a substantial reduction in the pool of resting CD4+ T cells that contain replication-competent HIV.

Anti-HIV Agents↗

Human herpesvirus 6 infections after bone marrow transplantation: clinical and virologic manifestations.

Human herpesvirus 6 (HHV-6) DNA levels in peripheral blood mononuclear cells were prospectively evaluated in 20 cytomegalovirus-seronegative allogeneic marrow transplant patients and in 10 healthy control subjects. Blood and saliva specimens obtained weekly for 3 months after transplant were evaluated by quantitative HHV-6 polymerase chain reaction. One of 20 patients experienced primary HHV-6 infection after marrow transplant (seroconversion, HHV-6 viremia, skin rash); 18 of 20 had increased peripheral blood mononuclear cell HHV-6 DNA levels consistent with asymptomatic reactivations, and 1 patient experienced a reactivation-associated skin rash. Genotyping revealed HHV-6 variant B DNA in all cases. Therapy with acyclovir or intravenous immunoglobulin was not correlated with lower HHV-6 DNA levels. Thus, asymptomatic HHV-6 reactivations appear to be common following allogeneic marrow transplantation. Among HHV-6-seronegative and viral DNA-negative patients, primary HHV-6 infection can ensue in association with self-limited clinical symptoms, including diffuse maculopapular rash.

Adult↗

Protection against human immunodeficiency virus type 1 infection in persons with repeated exposure: evidence for T cell immunity in the absence of inherited CCR5 coreceptor defects.

It has been hypothesized that protection against human immunodeficiency virus (HIV)-1 infection may result from either acquired host immunity, inheritance of a dysfunctional CCR5 HIV-1 coreceptor, or a low or attenuated virus inoculum. Thirty-seven HIV-1-uninfected persons engaging in repeated high-risk sexual activity with an HIV-1-infected partner were prospectively studied to determine the contribution of these factors in protecting against HIV-1 transmission. More than one-third (13/36) demonstrated HIV-1-specific cytotoxicity, and this activity significantly correlated with the wild type CCR5 genotype (P=.03). Only 1 subject (3%) demonstrated the homozygous CCR5 32-bp deletion (Delta32/Delta32). Median plasma HIV-1 RNA levels from 18 HIV-1-infected sex partners were not statistically different from those of matched infected control patients. These results indicate that inheritance of the Delta32 CCR5 mutation does not account for the majority of persistently HIV-1-resistant cases, and the presence of cellular immunity in these persons suggests either undetected infection or protective immunity.

Acquired Immunodeficiency Syndrome↗