Biomedical subjects

Joeri L Aerts

Publications and source records attributed to Joeri L Aerts.

4 recordsLinked to original sources

PubMed2004

The interferon inducer ampligen [poly(I)-poly(C12U)] markedly protects mice against coxsackie B3 virus-induced myocarditis.

Viral replication, as well as an immunopathological component, is assumed to be involved in coxsackie B virus-induced myocarditis. We evaluated the efficacy of the interferon inducer Ampligen on coxsackie B3 virus-induced myocarditis in C3H/HeNHsd mice. The efficacy of Ampligen was compared with that of the interferon inducer poly(inosinic acid)-poly(cytidylic acid) [poly(IC)], alpha interferon 2b (INTRON A), and pegylated alpha interferon 2b (PEG-INTRON-alpha-2b). Ampligen at 20 mg/kg of body weight/day was able to reduce the severity of virus-induced myocarditis, as assessed by morphometric analysis, by 98% (P = 3.0 x 10(-8)). When poly(IC) was administered at 15 mg/kg/day, it reduced the severity of virus-induced myocarditis by 93% (P = 5.6 x 10(-5)). Alpha interferon 2b (1 x 10(5) U/day) and pegylated alpha interferon 2b (5 x 10(5) U/day) were less effective and reduced the severity of virus-induced myocarditis by 66% (P = 0.0009) and 78% (P = 0.0002), respectively. The observed efficacies of Ampligen and poly(IC) were corroborated by the observation that the drugs also markedly reduced the virus titers in the heart, as detected by (i) quantitative real-time reverse transcription-PCR and (ii) titration for infectious virus content. Whereas the electrocardiograms for untreated mice with myocarditis were severely disturbed, the electrocardiographic parameters were normalized in Ampligen- and poly(IC)-treated mice. Even when start of treatment with Ampligen was delayed until day 2 postinfection, a time at which lesions had already appeared in untreated control animals, a marked protective effect on the development of viral myocarditis (as assessed at day 6 postinfection) was still noted.

Animals↗

PubMed2004

Selection of appropriate control genes to assess expression of tumor antigens using real-time RT-PCR.

Real-time reverse transcription PCR (RT-PCR) is a sensitive and accurate method to monitor gene expression and is often used to profile the expression of putative tumor antigens in the context of immunotherapy. However, this technique consists of several steps, including cell processing, RNA extraction, RNA storage, assessment of RNA concentration, and cDNA synthesis prior to PCR. To compensate for potential variability introduced in this procedure, the expression of housekeeping genes is commonly assessed in parallel with the expression of the gene of interest. In this study, the expression of a variety of housekeeping genes in a panel of 26 different human tumor and embryonal cell lines was assessed using real-time RT-PCR. For some control genes, the variability in expression was significant between different cell lines, despite the equalization of quantities of input RNA. The greatest variability was found for GAPDH. The lowest variability was found for beta-glucuronidase (GUS) and 18S rRNA. While real-time RT-PCR is a powerful tool for gene expression analysis, these results suggest that the choice of control genes to normalize the expression of the gene of interest is critical to the interpretation of experimental results and should be tailored to the nature of the study.

Animals↗

PubMed2003

Mycophenolate mofetil inhibits the development of Coxsackie B3-virus-induced myocarditis in mice.

BACKGROUND: Viral replication as well as an immunopathological component are assumed to be involved in the development of coxsackie B virus (CBV)-induced myocarditis. We observed that mycophenolic acid (MPA), the active metabolite of the immunosuppressive agent mycophenolate mofetil (MMF), inhibits coxsackie B3 virus (CBV3) replication in primary Human myocardial fibroblasts. We therefore studied whether MMF, which is thus endowed with a direct antiviral as well as immunosuppressive effect, may prevent CBV-induced myocarditis in a murine model. RESULTS: Four week old C3H-mice were infected with CBV3 and received twice daily, for 7 consecutive days (from one day before to 5 days post-virus inoculation) treatment with MMF via oral gavage. Treatment with MMF resulted in a significant reduction in the development of CBV-induced myocarditis as assessed by morphometric analysis, i.e. 78% reduction when MMF was administered at 300 mg/kg/day (p < 0.001), 65% reduction at 200 mg/kg/day (p < 0.001), and 52% reduction at 100 mg/kg/day (p = 0.001). The beneficial effect could not be ascribed to inhibition of viral replication since titers of infectious virus and viral RNA in heart tissue were increased in MMF-treated animals as compared to untreated animals. CONCLUSION: The immunosuppressive agent MMF results in an important reduction of CBV3-induced myocarditis in a murine model.

Animals↗

PubMed2003

Real-time quantitative reverse transcriptase-polymerase chain reaction as a method for determining lentiviral vector titers and measuring transgene expression.

The use of lentiviral vectors for basic research and potential future clinical applications requires methodologies that can accurately determine lentiviral titers and monitor viral transgene expression within target cells, beyond the context of reporter genes typically used for this purpose. Here we describe a quantitative RT-PCR (qRT-PCR) method that achieves both goals using primer sequences that are specific for the woodchuck hepatitis virus posttranscriptional regulatory element (WPRE), an enhancer contained in many retroviral vectors and that is incorporated in the 3' UTR of nascent transgene transcripts. Quantitation of titers of three recombinant lentiviruses, genetically identical except for the transgene, demonstrated consistent differences in titer that were likely due to transgene-associated toxicity in producer cells and target cells. Viruses encoding the tumor-associated antigens tyrosinase and neo-poly(A) polymerase yielded reproducibly lower titers than a virus encoding enhanced green fluorescent protein (GFP) at the viral RNA, integrated DNA, and transgene mRNA levels, as measured by WPRE qPCR. Furthermore, the magnitude of differences in expression of the three transgenes in transduced target cells could not have been predicted by measuring vector DNA integration events. Since transgene expression in target cells is the most common goal of lentiviral transduction, and since methods to quantify transgene expression on the protein level are not always readily available, qRT-PCR based on a nucleotide sequence included in the transcript provides a useful tool for titering novel recombinant lentiviruses.

3' Untranslated Regions↗