The Immunogenicity of the Tumor-Associated Antigen α-Fetoprotein Is Enhanced by a Fusion with a Transmembrane Domain

Aim. To investigate the ability of recombinant modified vaccinia virus Ankara (rMVA) vector to induce an immune response against a well-tolerated self-antigen. Methods. rMVA vectors expressing different form of α-fetoprotein (AFP) were produced and characterized. Naïve mice were vaccinated with MVA vectors expressing the AFP antigen in either a secreted, or a membrane-bound, or an intracellular form. The immune response was monitored by an IFNΓ ELISpot assay and antibody detection. Results. Vaccination with the membrane-associated form of AFP induced a stronger CD8+ T-cell response compared to the ones obtained with the MVA encoding the secreted or the intracellular forms of AFP. Moreover, the vaccination with the membrane-bound AFP elicited the production of AFP-specific antibodies. Conclusions. The AFP transmembrane form is more immunogenic. Expressing a membrane-bound form in the context of an MVA vaccination could enhance the immunogenicity of a self-antigen

In vivo preclinical low field MRI monitoring of tumor growth following a suicide gene therapy in an orthotopic mice model of human glioblastoma

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A call for transparent reporting to optimize the predictive value of preclinical research

The US National Institute of Neurological Disorders and Stroke convened major stakeholders in June 2012 to discuss how to improve the methodological reporting of animal studies in grant applications and publications. The main workshop recommendation is that at a minimum studies should report on sample-size estimation, whether and how animals were randomized, whether investigators were blind to the treatment, and the handling of data. We recognize that achieving a meaningful improvement in the quality of reporting will require a concerted effort by investigators, reviewers, funding agencies and journal editors. Requiring better reporting of animal studies will raise awareness of the importance of rigorous study design to accelerate scientific progress

Biochemistry of Ensiling

The biochemistry of ensiling is essentially a simple process, which, however, can become complex when interactions among plant enzymes and the activities of numerous microbial species become involved. The desired effect is the conversion of simple plant sugars such as glucose and fructose to lactic acid by lactic acid bacteria (LAB) in an anaerobic fermentation. When sufficient lactic acid has been produced, all microbial activity is suppressed, primarily through the effect of undissociated lactic acid, and the silage can then be stored anaerobically until required for feeding. Complications arise because: 1. There are always aerobic periods at the start and end of the ensiling process. 2. Simple sugars are not the only substrates metabolized. 3. Plant enzymes and other microbial species apart from LAB compete for substrate. The complexity of ensilage is increased further when the difficulties of controlling large-scale processes like silage making on-farm are also considered

Studies on mechanism of action of AZT and HIV-1 drug resistance

The great adaptability of the Human Immunodeficiency Virus type 1 (HIV-1) and the exclusive use of zidovudine (3$sp prime$azido-3$sp prime$deoxythymidine or AZT) in the treatment of AIDS has motivated our search for HIV-1 strains resistant to this drug.Our first attempt at obtaining such strains was made by using an in vitro approach in which a lymphoid cell line, chronically infected with HIV-1, was exposed to various drug concentrations. Although this system has never generated such mutants, we found that the progeny virus population, present in the culture fluids of these chronically infected drug-treated cells lost infectivity. These results suggest a potential post-integrational role for zidovudine, possibly acting at the level of viral assembly or budding.However, we were successful in isolating zidovudine-resistant HIV-1 strains from the blood of patients undergoing AZT treatment. Our work shows that a minimum of 27 weeks of treatment is necessary for the appearance of the resistant phenotype and that the majority (75%) of patients treated with AZT for more than one year will generate such resistant strains. No correlation between the clinical status of the patients and the occurrence of resistant variants can be drawn from our work. However, in vitro experiments have shown that the resistant isolates are more cytopathic, although less infectious, than the sensitive strains. Reverse transcriptase enzymes from both AZT-resistant and -sensitive strains were virtually identical when their respective enzymatic activities or their affinity for the substrate or the inhibitor were compared. Finally, some zidovudine-resistant isolates demonstrate cross-resistance to other nucleoside analogs with potential clinical applications

Identification of new MUC1 epitopes using HLA-transgenic animals: implication for immunomonitoring

International audienceAbstractBackgroundThe success of immunotherapeutics in oncology and the search for further improvements has prompted revisiting the use of cancer vaccines. In this context, knowledge of the immunogenic epitopes and the monitoring of the immune response cancer vaccines generate are essential. MUC1 has been considered one of the most important tumor associated antigen for decades.MethodsTo identify HLA-restricted MUC1 peptides we used eight human MHC class I transgenic mouse lines, together covering more than 80% of the human population. MUC1 peptides were identified by vaccinating each line with full length MUC1 coding sequences and using an IFNγ ELIspot restimulation assay. Relevant peptides were tested in a flow cytometry-based tetramer assay and for their capacity to serve as target in an in vivo killing assay.ResultsFour previously identified MUC1 peptides were confirmed and five are described here for the first time. These nine peptide-MHC combinations were further characterized. Six gave above-background tetramer staining of splenocytes from immunized animals and three peptides were induced more than 5% specific in vivo killing.ConclusionsThese data describe for the first time five new HLA class I-restricted peptides and revisit some that were previously described. They also emphasize the importance of using in vivo/ex vivo models to screen for immunogenic peptides and define the functions for individual peptide-HLA combinations

A novel bio-orthogonal cross-linker for improved protein/protein interaction analysis

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