We have developed a system that isolates and replicates HCV in vitro. These isolates are called CIMM-HCV. This system has made it possible to analyze the biology, nature, and extent of HCV ...variability, among other things. Individuals that are infected with HIV-1 are often also infected with HCV and HHV-6. In addition to HCV, our lab has systems for replicating HIV-1 and HHV-6. We asked whether all these viruses could infect the same cells. We report here the successful infection of a T-cell (CEM) by CIMM-HCV, HHV-6, and HIV-1. PCR analyses demonstrated that the CEM cells were productively infected by HHV-6A. RT-PCR showed that the same cell culture was positive for HCV and HIV-1. Co-infection of a T-cell by all three viruses was confirmed by transmission electron microscopy (TEM). All these viruses are highly cytolytic; therefore, triply-infected cells were short lived. However, HIV-1 and HCV co-infected cells unexpectedly lasted for several weeks. Viral replication was unhindered and the phenomenon of 'dominance' was not observed in our experiments. In addition, CIMM-HCV was present in the perinuclear space, suggesting their possible synthesis in the nucleus. This report is based entirely on viruses produced in vitro in our laboratories. As part of the determinations of host ranges of these viruses, studies were designed to demonstrate the infection of a single cell by these viruses and to study the consequences of this phenomenon. All measurements were made on cultured cells and cell culture supernatants.
Isolation and self-replication of infectious HCV has been a difficult task. However, this is needed for the purposes of developing rational drugs and for the analysis of the natural virus. Our recent ...report of an in vitro system for the isolation of human HCV from infected patients and their replication in tissue culture addresses this challenge. At California Institute of Molecular Medicine several isolates of HCV, called CIMM-HCV, were grown for over three years in cell culture. This is a report of the analysis of CIMM-HCV isolates for subtypes and quasispecies using a 269 bp segment of the 5'UTR. HCV RNA from three patients and eleven CIMM-HCV were analyzed for this purpose. All isolates were essentially identical. Isolates of HCV from one patient were serially transmitted into fresh cells up to eight times and the progeny viruses from each transmission were compared to each other and also to the primary isolates from the patient's serum. Some isolates were also transmitted to different cell types, while others were cultured continuously without retransmission for over three years. We noted minor sequence changes when HCV was cultured for extended periods of time. HCV in T-cells and non-committed lymphoid cells showed a few differences when compared to isolates obtained from immortalized B-cells. These viruses maintained close similarity despite repeated transmissions and passage of time. There were no subtypes or quasispecies noted in CIMM-HCV.
Infection by human hepatitis C virus (HCV) is the principal cause of post-transfusion hepatitis and chronic liver diseases worldwide. A reliable in vitro culture system for the isolation and analysis ...of this virus is not currently available, and, as a consequence, HCV pathogenesis is poorly understood. We report here the first robust in vitro system for the isolation and propagation of HCV from infected donor blood. This system involves infecting freshly prepared macrophages with HCV and then transmission of macrophage-adapted virus into freshly immortalized B-cells from human fetal cord blood. Using this system, newly isolated HCV have been replicated in vitro in continuous cultures for over 130 weeks. These isolates were also transmitted by cell-free methods into different cell types, including B-cells, T-cells and neuronal precursor cells. These secondarily infected cells also produced in vitro transmissible infectious virus. Replication of HCV-RNA was validated by RT-PCR analysis and by in situ hybridization. Although nucleic acid sequencing of the HCV isolate reported here indicates that the isolate is probably of type 1a, other HCV types have also been isolated using this system. Western blot analysis shows the synthesis of major HCV structural proteins. We present here, for the first time, a method for productively growing HCV in vitro for prolonged periods of time. This method allows studies related to understanding the replication process, viral pathogenesis, and the development of anti-HCV drugs and vaccines.
We recently reported the isolation and in vitro replication of hepatitis C virus. These isolates were termed CIMM-HCV and analyzed to establish genotypes and subtypes, which are reported elsewhere. ...During this analysis, an HCV isolated from a patient was discovered that had large deletions in the 5'UTR. 57% of the HCV RNA found in this patient's sera had 113 or 116 bp deletions. Sequence data showed that domains IIIa to IIIc were missing. Previous studies have suggested that these domains may be important for translation. In vitro replicated HCV from this patient did not contain these deletions, however, it contained a 148 bp deletion in the 5'UTR. Whereas the patient HCV lacked domains IIIa through IIIc, the isolate lacked domains IIIa through IIId. HCV from this patient continues to produce large deletions in vitro, suggesting that the deletion may not be important for the assembly or replication of the virus. This is the first report describing these large deletions.
This final report evaluates five training courses delivered under the contract OC/EFSA/AMU/2016/03 ‐ Lot 1: four courses on Steering an Expert Knowledge Elicitation and one course on Use of the ...Expert Knowledge Elicitation Guidance in Risk Assessments for EFSA Management. Lot 2: one course on Conduct of the Sheffield protocol for an Expert Knowledge Elicitation. The report includes summaries of the participants' feedback and the final versions of the course material, revised in response to the feedback received
The predictive value of peripheral blood T cell subset monitoring in renal allograft recipients has been questionable, and there has been no information concerning the correlation of T cell subset ...changes with the clinical event related to cyclosporine nephrotoxicity. This study was conducted to investigate the clinical usefulness of serial T cell subset monitoring in 34 consecutive renal transplant patients treated with cyclosporine by determining the total peripheral lymphocyte count and T cell subset counts using Leu-4, Leu-3ab, and Leu-2a monoclonal antibodies and flow cytometry up to 6 months after transplantation. The absolute counts of all cells were lower in transplanted patients than those of normal controls, but were not different from those of hemodialysis patients. During infection, the helper/suppressor (H/S) ratio and the cell counts, except for suppressor cells, decreased significantly. Within one week prior to rejection, all cell counts also decreased significantly. Furthermore, cell counts before steroid-resistant rejection were significantly lower than those before steroid-responsive rejection. In contrast, lymphocyte and T cell counts were increased significantly within one week prior to cyclosporine nephrotoxicity being diagnosed; the H/S ratio was not correlated with rejection or toxicity. These results indicate that H/S ratio is not associated with clinical events of renal allograft recipients, but serial lymphocyte and T cell subset counts can provide valuable information for the differentiation of rejection from cyclosporine nephrotoxicity, and also for predicting the outcome of the allograft rejection.
Perinatal transmission of human immunodeficiency virus is thought to occur in 25% to 50% of the offspring of infected women. Standard diagnostic methods do not permit identification of the infected ...newborns. To assess diagnostic methods and document the natural history of perinatal human immunodeficiency virus infection, 20 children born to human immunodeficiency virus-infected women were followed prospectively for 18 months by measuring antibody titer, Western blot profiles, and antigenemia, and the results were compared with clinical outcome. Endogenous synthesis of anti-human immunodeficiency virus IgG was demonstrated in 6 of the 8 infected children. Four children synthesized IgM against human immunodeficiency virus. Five had demonstrable p24 antigenemia. No significant differences between infected and noninfected children were noted at birth except drug withdrawal, which occurred more frequently in noninfected infants. The incidence of adenopathy, hepatomegaly, and neurologic and immunologic abnormalities in the infected children were compared with noninfected children. The distinguishing illnesses were the opportunistic infections, lobar pneumonia, and failure to thrive. Seven of the 8 infected children had human immunodeficiency virus-mediated disease by 1 year of age (Centers for Disease Control Atlanta, Ga P2 classification), and four had acquired immunodeficiency syndrome (Centers for Disease Control P2D). These studies offer an approach to diagnosis of human immunodeficiency virus infection in infants and document the natural history and possible outcomes of infected children.
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