Expert Consideration on Regulatory Aspects for Perinatal Derivatives in Clinical Settings

Perinatal derivatives (PnD) are drawing growing interest among the scientific community as an unrestricted source of multipotent stem cells, secretome, and biological matrices. They are useful for the treatment of diseases that currently have limited or no effective therapeutic options, but they require the development of regenerative approaches. With this development, the question of regulation of donation, processing, and distribution has therefore become more important. Within the European Cooperation in Science and Technology (COST) community, we compiled a group of international experts on PnD technologies, who revised and compared existing EU national regulations. Notably, despite clear European directives, each EU Country has developed their own implementation and standard levels for cell- and tissue-based therapies. To enable extended applications of PnD treatments within the EU community and worldwide, harmonization is highly recommended. This paper aims to provide an overview of the various options available to introduce PnD into clinical practice. For this purpose, the different aspects resulting from (1) the type of PnD, (2) the amount of available data, (3) the degree of manipulation, and (4) the intended application and the process toward a possible commercialization will be presented. In the future, it will be important to find a balance between regulatory requirements and the best medical quality of the PnD product.

Pet cat personality linked to owner-reported predation frequency

The domestic cat, Felis catus, is one of the most popular and widespread domestic animals. Because domestic cats can reach high population densities and retain at least some tendency to hunt, their overall impact on wildlife can be severe. Domestic cats have highly variable predation rates depending on the availability of prey in their environment, their owners' practices, and individual cat characteristics. Among these characteristics, cat personality has recently been hypothesized to be an important factor contributing to variations in the hunting activity of cats. In this study, we surveyed 2508 cat owners living in France about their cats' personalities, using the Feline Five personality framework, and the frequency with which cats bring home prey. Personality traits were analyzed using factor analysis and related to predation frequency using cumulative logit models. For both birds and small mammals, cats with high levels of extraversion or low levels of neuroticism had significantly higher frequencies of prey return. Owners whose cats had low levels of agreeableness or high levels of dominance reported a significantly lower frequency of bird return. Personality differences therefore seem to contribute to the high variability in predation rates among domestic cats. We also found that the owner-reported prey return frequencies were significantly higher for cats spending more time outdoors, for non-pedigree cats, and for owners living in rural or suburban areas as opposed to urban areas. By contrast, we did not detect an effect of cat sex or age on their reported prey return rates.

Genome-edited, donor-derived allogeneic anti-CD19 chimeric antigen receptor T cells in paediatric and adult B-cell acute lymphoblastic leukaemia: results of two phase 1 studies

BACKGROUND

Genome-edited donor-derived allogeneic anti-CD19 chimeric antigen receptor (CAR) T cells offer a novel form of CAR-T-cell product that is available for immediate clinical use, thereby broadening access and applicability. UCART19 is one such product investigated in children and adults with relapsed or refractory B-cell acute lymphoblastic leukaemia. Two multicentre phase 1 studies aimed to investigate the feasibility, safety, and antileukaemic activity of UCART19 in children and adults with relapsed or refractory B-cell acute lymphoblastic leukaemia.

METHODS

We enrolled paediatric or adult patients in two ongoing, multicentre, phase 1 clinical trials to evaluate the safety and antileukaemic activity of UCART19. All patients underwent lymphodepletion with fludarabine and cyclophosphamide with or without alemtuzumab, then children received UCART19 at 1·1-2·3 × 10⁶ cells per kg and adults received UCART19 doses of 6 × 10⁶ cells, 6-8 × 10⁷ cells, or 1·8-2·4 × 10⁸ cells in a dose-escalation study. The primary outcome measure was adverse events in the period between first infusion and data cutoff. These studies were registered at ClinicalTrials.gov, NCT02808442 and NCT02746952.

FINDINGS

Between June 3, 2016, and Oct 23, 2018, seven children and 14 adults were enrolled in the two studies and received UCART19. Cytokine release syndrome was the most common adverse event and was observed in 19 patients (91%); three (14%) had grade 3-4 cytokine release syndrome. Other adverse events were grade 1 or 2 neurotoxicity in eight patients (38%), grade 1 acute skin graft-versus-host disease in two patients (10%), and grade 4 prolonged cytopenia in six patients (32%). Two treatment-related deaths occurred; one caused by neutropenic sepsis in a patient with concurrent cytokine release syndrome and one from pulmonary haemorrhage in a patient with persistent cytopenia. 14 (67%) of 21 patients had a complete response or complete response with incomplete haematological recovery 28 days after infusion. Patients not receiving alemtuzumab (n=4) showed no UCART19 expansion or antileukaemic activity. The median duration of response was 4·1 months with ten (71%) of 14 responders proceeding to a subsequent allogeneic stem-cell transplant. Progression-free survival at 6 months was 27%, and overall survival was 55%.

INTERPRETATION

These two studies show, for the first time, the feasibility of using allogeneic, genome-edited CAR T cells to treat patients with aggressive leukaemia. UCART19 exhibited in-vivo expansion and antileukaemic activity with a manageable safety profile in heavily pretreated paediatric and adult patients with relapsed or refractory B-cell acute lymphoblastic leukaemia. The results this study are an encouraging step forward for the field of allogeneic CAR T cells, and UCART19 offers the opportunity to treat patients with rapidly progressive disease and where autologous CAR-T-cell therapy is unavailable.

FUNDING

Servier.

Heart Failure with Preserved Ejection Fraction and 30-Day Readmission

OBJECTIVE

Several studies identify heart failure (HF) as a potential risk for hospital readmission; however, studies on predictability of heart failure readmission is limited. The objective of this work was to investigate whether a specific type of heart failure (HFpEF or HFrEF) has a higher association to the rate of 30-day hospital readmission and compare their predictability with the two risk scores: HOSPITAL score and LACE index.

DESIGN

Retrospective study from single academic center.

METHODS

Sample size included adult patients from an academic hospital in a two-year period (2015 - 2017). Exclusion criteria included death, transfer to another hospital, and unadvised leave from hospital. Baseline characteristics, diagnosis-related group, and ICD diagnosis codes were obtained. Variables affecting HOSPITAL score and LACE index and types of heart failure present were also extracted. Qualitative variables were compared using Pearson chi² or Fisher's exact test (reported as frequency) and quantitative variables using non-parametric Mann-Whitney U test (reported as mean ± standard deviation). Variables from univariate analysis with P values of 0.05 or less were further analyzed using multivariate logistic regression. Odds ratio was used to measure potential risk.

RESULTS

The sample size of adult patients in the study period was 1,916. All eligible cohort of patients who were readmitted were analyzed. Cumulative score indicators of HOSPITAL Score, LACE index (including the Charlson Comorbidity Index) predicted 30-day readmissions with P values of <0.001. The P value of HFpEF was found to be significant in the readmitted group (P < 0.001) compared to HFrEF (P = 0.141). Multivariate logistic regression further demonstrated the association of HFpEF with higher risk of readmission with odds ratio of 1.77 (95% CI: 1.25 - 2.50) and P value of 0.001.

CONCLUSIONS

Our data from an academic tertiary care center supports HFpEF as an independent risk factor for readmission. Multidisciplinary management of HFpEF may be an important target for interventions to reduce hospital readmissions.

Safety of CD34+ Hematopoietic Stem Cells and CD4+ T Lymphocytes Transduced with LVsh5/C46 in HIV-1 Infected Patients with High-Risk Lymphoma

Although the risk of developing lymphoma has decreased in the highly active antiretroviral therapy era, this cancer remains the major cause of mortality in HIV-infected patients. Autologous hematopoietic stem cell transplantation (ASCT) outcome does not differ for HIV-infected versus HIV-uninfected patients. We propose to develop a new treatment for HIV-associated high-risk lymphoma based on autologous transplantation of two genetically modified products: CD4⁺ T lymphocytes and CD34⁺ hematopoietic stem cells (HSPCs). The cells will be transduced ex vivo with the Cal-1 lentiviral vector encoding for both a short hairpin RNA (shRNA) against CCR5 (sh5) and the HIV-1 fusion inhibitor C46. The transduced cells will be resistant to HIV infection by two complementary mechanisms: impaired binding of the virus to the cellular CCR5 co-receptor and decreased fusion of the virus as C46 interacts with gp41 and inhibits HIV infection. This phase I/II pilot study, also entitled GENHIV, will involve two French participating centers: Saint Louis Hospital and Necker Hospital in Paris. We plan to enroll five HIV-1-infected patients presenting with high-risk lymphoma and require a treatment with ASCT. The primary objective of this study is to evaluate the safety, feasibility, and success of engraftment of Cal-1 gene-transduced CD4⁺ T lymphocytes and CD34⁺ HSPCs.

Characterization of Seven Kidney Tumors by Flow Cytometry: Analysis of Cell Cycle, DNA Content and P-Glycoprotein Expression

Seven kidney tumors obtained from patients aged from 5 to 76 years were analyzed by flow cytometry for cell cycle, DNA content and P-glycoprotein expression involved in multidrug resistance. The DNA index seems to be an important criterion since all the tumors were aneuploid. In a case of clear cell carcinoma, two aneuploid clones were identified. In 5 cases of kidney tumors a high proportion of cells in proliferation (S + (G2 + M)) was observed; it was comprised between 13 and 33%. As for P-glycoprotein it was detected only in few tumor cells (5-15%) respectively in a case of clear cell carcinoma and in a case of Wilms' tumor.

European regulation for therapeutic use of stem cells

The regulation for the use of stem cells has evolved during the past decade with the aim of ensuring a high standard of quality and safety for human derived products throughout Europe to comply with the provision of the Lisbon treaty. To this end, new regulations have been issued and the regulatory status of stem cells has been revised. Indeed, stem cells used for therapeutic purposes can now be classified as a cell preparation, or as advanced therapy medicinal products depending on the clinical indication and on the procedure of cell preparation. Furthermore, exemptions to the European regulation are applicable for stem cells prepared and used within the hospital. The aim of this review is to give the non-specialized reader a broad overview of this particular regulatory landscape.

Clinical Development and Commercialization of Advanced Therapy Medicinal Products in the European Union: How Are the Product Pipeline and Regulatory Framework Evolving?

The research and development of advanced therapy medicinal products (ATMPs) has been active in Europe and worldwide during recent years. Yet, the number of licensed products remains low. The main expected legal change in the near future in the European Union (EU) concerns the regulation on clinical trials (536/2014), which will come into force in 2018. With this new framework, a more harmonized and swift process for approval of clinical trials is anticipated, which is expected to support the entry of new innovations into the EU market. A survey on ATMPs in clinical trials during 2010-2015 in the EU was conducted in order to study the trends of ATMP development since the earlier survey published in 2012. According to the results, the number of clinical trials using ATMPs is slowly increasing in the EU. Yet, the focus is still in early development, and the projects are mainly carried out by small and medium-sized enterprises, academia, and hospitals. Oncology is the main area of clinical development. Yet, the balance between cell-based products and gene therapy medicinal products in this area may be changing in the future due to the new T-cell technologies. Many limitations and challenges are identified for ATMP development, requiring proportionate regulatory requirements. On the other hand, for such a novel field, the developers should be active in considering possible constraints and actively engage with authorities to look for solutions. This article provides up to-date information on forthcoming regulatory improvements and discusses the main challenges hampering the commercialization of ATMPs in the EU.

Alloantigen gene transfer to hepatocytes promotes tolerance to pancreatic islet graft by inducing CD8+ regulatory T cells

BACKGROUND & AIMS

Induction of donor-specific immune tolerance is a good alternative to chronic life-long immunosuppression for transplant patients. Donor major histocompatibility complex (MHC) molecules represent the main targets of the allogeneic immune response of transplant recipients. Liver targeted gene transfer with viral vectors induces tolerance toward the encoded antigen. The aim of this work was to determine whether alloantigen gene transfer to hepatocytes induces tolerance and promotes graft acceptance.

METHODS

C57BL/6 (H-2b) mice were treated with adeno-associated viral (AAV) vector targeting the expression of the MHC class I molecule H-2K^d to hepatocytes, before transplantation with fully allogeneic pancreatic islet from BALB/c mice (H-2d).

RESULTS

AAV H-2K^d treated mice were tolerant to the alloantigen, as demonstrated by its long-term expression by the hepatocytes, even after a highly immunogenic challenge with an adenoviral vector. After chemical induction of diabetes, the AAV treated mice had significantly delayed rejection of fully allogeneic pancreatic islet grafts, with more than 40% of recipients tolerant (>100days). AAV-mediated expression of H-2K^d in the liver induced the local expansion of CD8⁺ T lymphocytes with allo-specific suppressive properties. The adoptive transfer of these liver-generated CD8⁺ Tregs into naive diabetic mice promoted the long-term survival of allogeneic pancreatic islet grafts.

CONCLUSION

AAV-mediated long-term expression of a single MHC class I molecule in the liver induces the generation of a subset of allo-specific CD8⁺ Treg cells, which promote tolerance toward fully allogeneic graft. Liver gene transfer represents a promising strategy for in vivo induction of donor-specific tolerance.

LAY SUMMARY

The liver has a special immune system, biased toward tolerance. In this study, we investigated the possibility of harnessing this property of the liver to induce tolerance to an allogeneic transplantation. We demonstrate for the first time that the in vivo gene transfer of an allogeneic antigen with an adeno-associated viral vector to mouse hepatocytes induces the expansion of a population of CD8⁺ regulatory T lymphocytes. These Tregs are then instrumental in preventing the rejection of allogeneic pancreatic islets transplanted in these animals. Allogeneic transplantation is the main treatment for the end-stage diseases of a number of organs. Life-long immunosuppressive treatments are still required to limit graft rejection, and these treatments exhibit serious side effects. Our present findings open a new avenue for promoting allo-specific tolerance via in vivo induction of CD8⁺ Treg expansion.

Interspecific interference competition at the resource patch scale: do large herbivores spatially avoid elephants while accessing water?

Animals may anticipate and try to avoid, at some costs, physical encounters with other competitors. This may ultimately impact their foraging distribution and intake rates. Such cryptic interference competition is difficult to measure in the field, and extremely little is known at the interspecific level. We tested the hypothesis that smaller species avoid larger ones because of potential costs of interference competition and hence expected them to segregate from larger competitors at the scale of a resource patch. We assessed fine-scale spatial segregation patterns between three African herbivore species (zebra Equus quagga, kudu Tragelaphus strepsiceros and giraffe Giraffa camelopardalis) and a megaherbivore, the African elephant Loxodonta africana, at the scale of water resource patches in the semi-arid ecosystem of Hwange National Park, Zimbabwe. Nine waterholes were monitored every two weeks during the dry season of a drought year, and observational scans of the spatial distribution of all herbivores were performed every 15 min. We developed a methodological approach to analyse such fine-scale spatial data. Elephants increasingly used waterholes as the dry season progressed, as did the probability of co-occurrence and agonistic interaction with elephants for the three study species. All three species segregated from elephants at the beginning of the dry season, suggesting a spatial avoidance of elephants and the existence of costs of being close to them. However, contrarily to our expectations, herbivores did not segregate from elephants the rest of the dry season but tended to increasingly aggregate with elephants as the dry season progressed. We discuss these surprising results and the existence of a trade-off between avoidance of interspecific interference competition and other potential factors such as access to quality water, which may have relative associated costs that change with the time of the year.

A Collaborative Workflow for Computer-Aided Design in Ambient Assisted Living: The ASIM Project

In 2014, the worldwide context is that the population is increasingly both expanding and aging in industrial countries. In contrast, the personal health levels of individuals could decrease. Although retirement homes and health-care centers assume most of the demand, they will most probably overflow in the next few years. One of the current solutions is e-Health, which involves biomedical monitoring but also home automation functions to compensate for disabilities that tend to increase with age. In this context, several domains have to be merged while respecting the entire ecosystem: the users, their needs and environment, but also all the various actors/experts involved in this process. The issue, however, is that enormous effort is required to combine the multiple expert domains because these can be antinomic. Hence, this paper proposes a collaborative workflow that brings together these different actors and generates the control/command application. Applying model-driven engineering, this workflow makes a clear distinction between people’s health requirements, the home automation functions, and the user interface points of view. Thus, it allows experts in each field to adapt their system in terms of the user’s needs, disability, and health state.

Advanced Therapy Medicinal Products: How to Bring Cell-Based Medicinal Products Successfully to the Market - Report from the CAT-DGTI-GSCN Workshop at the DGTI Annual Meeting 2014

On September 11, 2014, a workshop entitled 'Advanced Therapy Medicinal Products: How to Bring Cell-Based Medicinal Product Successfully to the Market' was held at the 47th annual meeting of the German Society for Transfusion Medicine and Immunohematology (DGTI), co-organised by the European Medicines Agency (EMA) and the DGTI in collaboration with the German Stem Cell Network (GSCN). The workshop brought together over 160 participants from academia, hospitals, small- or medium-sized enterprise developers and regulators. At the workshop, speakers from EMA, the Committee for Advanced Therapies (CAT), industry and academia addressed the regulatory aspects of development and authorisation of advanced therapy medicinal products (ATMPs), classification of ATMPs and considerations on cell-based therapies for cardiac repair. The open forum discussion session allowed for a direct interaction between ATMP developers and the speakers from EMA and CAT.

Creating conditions for the success of the French industrial advanced therapy sector

Although the European Union merely followed the initiatives of the United States and Japan by introducing special regimes for orphan medicinal products, it has introduced a special status for a new category of biological medicinal products, advanced therapy medicinal products (ATMPs), adopting specific associated regulations. European Regulation (which constitutes the highest legal instrument in the hierarchy of European law texts) [EC] No. 1394/2007, published in 2007, uses this term to define somatic cell therapy medicinal products, tissue-engineered products, and gene therapy medicinal products, possibly combined with medical devices. The stated objective was two-fold: both to promote their industrialization and market access, while guaranteeing a high level of health protection for patients. Since publication of the regulation, few marketing authorizations have been granted in Europe, and these have not been accompanied by commercial success. However, certain recent studies show that this is a growing sector and that France remains the leading European nation in terms of clinical trials. This round table brought together a panel of representatives of French public and private protagonists from the advanced therapy sector. The discussions focused on the conditions to ensure the success of translational research and, more generally, the French advanced therapy sector. These enabled a number of obstacles to be identified, which once lifted, by means of recommendations, would facilitate the development and success of this sector.

Overview of the Regulatory Oversight Implemented by the French Regulatory Authorities for the Clinical Investigation of Gene Therapy and Cell Therapy Products

Advanced therapy medicinal products, a new class of products with promising therapeutic effects, have been classified as medicinal products and as such should be developed according to a well-structured development plan, to establish their quality, safety and efficacy profile and conclude, at the time of the marketing authorisation evaluation, on a positive risk/benefit balance for patients. An important part of this development plan is achieved through clinical trials, which have also to be approved according to a well-established regulatory process, prior any initiation. This chapter is dedicated to describe the regulatory pathway to be followed in France, before initiating any clinical trial with those investigational advanced therapy medicinal products. In France, to get the final authorisation to initiate a clinical trial, the legislation imposes to run in parallel two independent but complementary authorisation procedures. The first procedure is aimed at assessing the ethical aspect of the biomedical research, while the second has to review the safety and regulatory aspects. A third procedure has to be envisaged where in case the investigational product consists or contains a genetically modified organism. The French system herein described is in line with the EU regulation on clinical trial and follows the respective deadlines for granting the final approval. The complexity of the procedure is in fact more due to the complexity of the products and protocols to be assessed than to the procedure itself which is now very close to the well-known procedure applied routinely for more conventional chemical or biological candidate medicinal products.

Agonistic anti-CD137 antibody treatment leads to antitumor response in mice with liver cancer

Immunotherapy is a promising strategy against hepatocellular carcinoma (HCC). We assessed the therapeutic effects of stimulating CD137, a member of the TNF receptor family, with agonistic monoclonal antibodies (mAb). Agonistic anti-CD137 mAb treatment was tested on two in situ models of HCC in immunocompetent mice. We also studied the mediators involved at different time points. In an orthotopic HCC the treatment consistently leads to complete tumor regression in 40-60% of animals. The protection is long lasting in the animals responding to the treatment, which can reject a second tumor challenge more than 3 months after treatment and eradication of the first malignancy. The main mediators of the effect are T lymphocytes and NK cells, demonstrated through depletion experiments. In addition, adoptive transfer of splenocytes prepared from anti-CD137 mAb-treated and -cured mice to naive mice allowed them to, in turn, reject the tumor. The efficacy of anti-CD137 mAb treatment is associated with early, sustained recruitment of iNOS-positive macrophages within tumor nodules. Moreover, in the absence of treatment, tumor development is accompanied by infiltration by myeloid derived suppressor cells (MDSC) and regulatory T lymphocytes. In mice responding to the anti-CD137 mAb treatment, this infiltration is very limited, and a combination treatment with a depletion of MDSC leads to the recovery of 80% of the mice. These results demonstrate that agonistic anti-CD137 mAb is a promising therapeutic strategy for anti-tumor immunity stimulation against HCC.

[Abdominal perforator flap (DIEP) and autologous latissimus dorsi in breast reconstruction. A retrospective comparative study about the first 60 cases of a same surgeon]

INTRODUCTION

Autologous techniques for breast reconstruction get the best cosmetic results. Aesthetic satisfaction with breast reconstruction is an important evaluation criterion. The indication is based on technical criteria (morphological, medical history) and the wishes of the patient. A rigorous evaluation of the results is necessary to assist the patients in their choice of reconstruction.

METHODS

Thirty-three DIEP and 27 latissimus dorsi were involved. A satisfaction questionnaire was sent to patients to collect the aesthetic evaluation of their reconstructed breast, sequelae at the donor site of the flap as well as their overall satisfaction. Post-operative photographs of the patients were subject to aesthetical evaluation by two groups of observers. Complications were analyzed.

RESULTS

The DIEP tends to get higher aesthetic satisfaction regarding the symmetry of the breasts and the volume of the reconstructed breast (P=0.05), and a better overall satisfaction (P=0.02). The uniformity of the colour of the reconstructed breast was considered superior by observers in the latissimus dorsi group (P=0.005). Donor site scar of DIEP was considered more unsightly while the latissimus dorsi was considered more painful (P=0.04) and uncomfortable, with more frequently contour abnormalities (P=0.03). We noted two total flap necrosis and three partial necrosis in the group DIEP, and two partial flap necrosis in the group latissimus dorsi.

CONCLUSION

This study provides evidence that can guide the patient and the surgeon in the complex process of therapeutic decision, without exempting the latter from a careful selection of indications.

[The blood donors' haemovigilance in France]

This work aim to present the descriptive analysis of serious adverse reactions in donors (dSAR's), which were notified in 2010 and 2011 in the French national haemovigilance database "e-FIT" (Internet secured haemovigilance reporting system). Some data, which are necessary for this analysis, also come from the regional haemovigilance coordinators' reports (RHC). The other parts of haemovigilance in the context of donation, without donors adverse reactions, such as post-donation information (PDI), adverse events occurred in the blood collection steps of the transfusion chain and epidemiology are not subject to this work analysis. This work shows that the quality of the data gradually improved since the setting up of the notification system of dSAR's. These data are particularly rich in learning lessons, but are still improving. It allows us to confirm that donor's safety, blood components quality, while preserving the blood components self-sufficiency in France, remains a priority. For these reasons, it is important to continue this haemovigilance awareness and to implement necessary actions that would be required for the protection of the donor's health and comfort during donation.

No tumour-initiating risk associated with scAAV transduction in newborn rat liver

Delivery of recombinant adeno-associated virus (rAAV) vectors to the newborn liver is followed by a rapid loss of episomal vector copies because of hepatocyte proliferation. In selected hepatocytes, integration of rAAV genomes can lead to a sustained expression of the transgene. The safety of in vivo gene therapy with single-stranded AAV vectors has been questioned in a study reporting a high incidence of hepatocellular carcinoma, associated with provirus integration events in mice that receive an single-stranded AAV injection at birth. To investigate the tumour-initiating potential of the newly established self-complementary AAV (scAAV) vectors in the liver, groups of newborn rats received intravenous injection of a scAAV vector encoding the green fluorescent protein (GFP), or were injected with phosphate-buffered saline (PBS) or diethylnitrosamine (DEN), a well-known liver tumour initiator. The rats were fed on a diet containing 2-acetylaminofluorene, a potent liver tumour-promoting agent to accelerate the carcinogenic process. After 2 months, the animals were killed and their livers analysed. Preneoplastic nodules were identified by glutathion S-transferase-p (GSTp) staining, and GFP expression was detected by immunohistochemistry. Vector genome integration events were analysed. The numbers of GSTp-positive foci were comparable in the PBS and the scAAV-GFP groups and significantly higher in the DEN group. The proportion of GSTp-positive foci that also expressed GFP was low and in the range expected for random occurrence. No specific integration hot spots were detected by linear amplification-mediated-PCR in transduced liver. In conclusion, scAAV transduction of newborn rat liver does not trigger preneoplastic lesions suggesting an absence of liver tumourigenesis.

Polyploidization without mitosis improves in vivo liver transduction with lentiviral vectors

Lentiviral vectors are efficient gene delivery vehicles for therapeutic and research applications. In contrast to oncoretroviral vectors, they are able to infect most nonproliferating cells. In the liver, induction of cell proliferation dramatically improved hepatocyte transduction using all types of retroviral vectors. However, the precise relationship between hepatocyte division and transduction efficiency has not been determined yet. Here we compared gene transfer efficiency in the liver after in vivo injection of recombinant lentiviral or Moloney murine leukemia viral (MoMuLV) vectors in hepatectomized rats treated or not with retrorsine, an alkaloid that blocks hepatocyte division and induces megalocytosis. Partial hepatectomy alone resulted in a similar increase in hepatocyte transduction using either vector. In retrorsine-treated and partially hepatectomized rats, transduction with MoMuLV vectors dropped dramatically. In contrast, we observed that retrorsine treatment combined with partial hepatectomy increased lentiviral transduction to higher levels than hepatectomy alone. Analysis of nuclear ploidy in single cells showed that a high level of transduction was associated with polyploidization. In conclusion, endoreplication could be exploited to improve the efficiency of liver-directed lentiviral gene therapy.

Priming of hepatocytes enhances in vivo liver transduction with lentiviral vectors in adult mice

Lentiviral vectors are promising tools for liver disease gene therapy, because they can achieve protracted expression of transgenes in hepatocytes. However, the question as to whether cell division is required for optimal hepatocyte transduction has still not been completely answered. Liver gene-transfer efficiency after in vivo administration of recombinant lentiviral vectors carrying a green fluorescent protein reporter gene under the control of a liver-specific promoter in mice that were either hepatectomized or treated with cholic acid or phenobarbital was compared. Phenobarbital is known as a weak inducer of hepatocyte proliferation, whereas cholic acid has no direct effect on the cell cycle. This study shows that cholic acid is able to prime hepatocytes without mitosis induction. Both phenobarbital and cholic acid significantly increased hepatocyte transduction six- to ninefold, although cholic acid did not modify the mitotic index or cell-cycle entry. However, the effect of either compound was weaker than that observed after partial hepatectomy. In no cases was there a correlation between the expression of cell-cycle marker and transduction efficiency. We conclude that priming of hepatocytes should be considered a clinically applicable strategy to enhance in vivo liver gene therapy with lentiviral vectors.

Specific micro RNA-regulated TetR-KRAB transcriptional control of transgene expression in viral vector-transduced cells

Precise control of transgene expression in a tissue-specific and temporally regulated manner is desirable for many basic and applied investigations gene therapy applications. This is important to regulate dose of transgene products and minimize unwanted effects. Previously described methods have employed tissue specific promoters, miRNA-based transgene silencing or tetR-KRAB-mediated suppression of transgene promoters. To improve on versatility of transgene expression control, we have developed expression systems that use combinations of a tetR-KRAB artificial transgene-repressor, endogenous miRNA silencing machinery and tissue specific promoters. Precise control of transgene expression was demonstrated in liver-, macrophage- and muscle-derived cells. Efficiency was also demonstrated in vivo in murine muscle. This multicomponent and modular regulatory system provides a robust and easily adaptable method for achieving regulated transgene expression in different tissue types. The improved precision of regulation will be useful for many gene therapy applications requiring specific spatiotemporal transgene regulation.

[Macro-replantation of the upper limb: long-terms results and quality of life]

OBJECTIVES

The authors suggest standardized questionnaires of quality of life to perform a long term evaluation of patients who underwent a replantation of the proximal upper limb.

METHODS

This retrospective study is about patients who underwent a replantation of the proximal upper limb between 1979 and 2011. The functional assessment was conducted using several tools including the 400 points test, the sensory tests, the Disabilities of the Arm, Shoulder and Hand questionnaire and the CHEN's classification. Some questionnaires, like the Medical Outcome Study Short Form-36 dealt with the physical and the psychological sides of the quality of life. Other questionnaires were more specific, like the Body Image Scale.

RESULTS

Sixteen patients were included. The survival rate of the replanted limb was 75%. The mean follow-up was 12.7 years. We noted 20% good results with a mean DASH score to 24.5%. The quality of life was similar to the general population in most of 50% of cases. Some patients had depressive symptoms or body image troubles.

CONCLUSIONS

In our eyes, the evaluation of quality of life seems essential for these patients. Survival rates, functional results, follow-up, professional activity, gender and body image troubles influence the quality of life. Besides, the physical side and the psychological side must change together to affect the overall results of the quality of life.

Fatal overdose after ingestion of a transdermal fentanyl patch in two non-human primates

CASE HISTORY AND PRESENTATION: Two non-human primates (Macaca fascicularis), weight 3.5 kg, enrolled in an experimental protocol received a 25 μg hour(-1) transdermal fentanyl patch for postoperative analgesia. The following day both animals were clinically normal, but after a new induction of anaesthesia with ketamine, they developed severe and prolonged respiratory distress, profound coma and myosis. MANAGEMENT AND FOLLOW-UP: Attempted reversal with naloxone was ineffective. After several hours of ventilation, both primates eventually died, 7 and 15 hours after ketamine injection, respectively. In both cases, the patch was discovered in the animal's cheek pouch. Subsequent fentanyl serum concentration measurements (8.29 and 14.80 μg L(-1) ) confirmed fentanyl overdose.

CONCLUSIONS

This report of two fatal intoxications in non-human primates secondary to ingestion of a transdermal fentanyl patch demonstrates that this method of analgesia is inappropriate for non-human primates, because of their tendency to chew almost anything they can reach.

Immunotherapy of hepatocellular carcinoma: is there a place for regulatory T-lymphocyte depletion?

Immunotherapy represents a potential therapeutic option for patients with hepatocellular carcinoma (HCC), especially as secondary treatment to prevent recurrence. It has been shown that a patient's survival is directly correlated to the type and number of tumor-infiltrating immune cells, indicating that immune responses have a direct effect on the clinical course of the disease. We have assessed the potential of immunotherapy against HCC in preclinical models of low tumor burden. An antigen-specific strategy targeting α-fetoprotein, and consisting of immunization with a DNA-based synthetic vector (DNAmAFP/704), was tested on an autochthonous model of chemical hepatocarcinogenesis and led to an important (65%) reduction of the tumor burden. A nonspecific approach of CD25(+) T-cell depletion by injection of PC61 antibody was also tested on an orthotopic HCC model and led to a significant protection against tumor development. Antigen-specific immunotherapy and Treg depletion are promising strategies in physiologically relevant HCC preclinical models. Future clinical trials will demonstrate if a combination of Treg depletion with an antigen-specific immunotherapy will also translate into clinical responses in HCC patients.

Adeno-associated viral vector-mediated transgene expression is independent of DNA methylation in primate liver and skeletal muscle

Recombinant adeno-associated viral (rAAV) vectors can support long-term transgene expression in quiescent tissues. Intramuscular (i.m.) administration of a single-stranded AAV vector (ssAAV) in the nonhuman primate (NHP) results in a peak protein level at 2-3 months, followed by a decrease over several months before reaching a steady-state. To investigate transgene expression and vector genome persistence, we previously demonstrated that rAAV vector genomes associate with histones and form a chromatin structure in NHP skeletal muscle more than one year after injection. In the mammalian nucleus, chromatin remodeling via epigenetic modifications plays key role in transcriptional regulation. Among those, CpG hyper-methylation of promoters is a known hallmark of gene silencing. To assess the involvement of DNA methylation on the transgene expression, we injected NHP via the i.m. or the intravenous (i.v.) route with a recombinant ssAAV2/1 vector. The expression cassette contains the transgene under the transcriptional control of the constitutive Rous Sarcoma Virus promoter (RSVp). Total DNA isolated from NHP muscle and liver biopsies from 1 to 37 months post-injection was treated with sodium bisulfite and subsequently analyzed by pyrosequencing. No significant CpG methylation of the RSVp was found in rAAV virions or in vector DNA isolated from NHP transduced tissues. Direct de novo DNA methylation appears not to be involved in repressing transgene expression in NHP after gene transfer mediated by ssAAV vectors. The study presented here examines host/vector interactions and the impact on transgene expression in a clinically relevant model.

Insect-resistant biotech crops and their impacts on beneficial arthropods

With a projected population of 10 billion by 2050, an immediate priority for agriculture is to achieve increased crop yields in a sustainable and cost-effective way. The concept of using a transgenic approach was realized in the mid-1990s with the commercial introduction of genetically modified (GM) crops. By 2010, the global value of the seed alone was US $11.2 billion, with commercial biotech maize, soya bean grain and cotton valued at approximately US $150 billion. In recent years, it has become evident that insect-resistant crops expressing δ-endotoxin genes from Bacillus thuringiensis have made a significant beneficial impact on global agriculture, not least in terms of pest reduction and improved quality. However, because of the potential for pest populations to evolve resistance, and owing to lack of effective control of homopteran pests, alternative strategies are being developed. Some of these are based on Bacillus spp. or other insect pathogens, while others are based on the use of plant- and animal-derived genes. However, if such approaches are to play a useful role in crop protection, it is desirable that they do not have a negative impact on beneficial organisms at higher trophic levels thus affecting the functioning of the agro-ecosystem. This widely held concern over the ecological impacts of GM crops has led to the extensive examination of the potential effects of a range of transgene proteins on non-target and beneficial insects. The findings to date with respect to both commercial and experimental GM crops expressing anti-insect genes are discussed here, with particular emphasis on insect predators and parasitoids.

AFP-specific immunotherapy impairs growth of autochthonous hepatocellular carcinoma in mice

BACKGROUND AND AIMS

In this study, we have assessed the potential of antigen-specific immunotherapy against hepatocellular carcinoma (HCC) in conditions of low tumour burden, in an autochthonous HCC model.

METHODS

Diethylnitrosamine (DEN) injected into infant mice results in the development of multi-nodular HCC in which alpha-fetoprotein (AFP) is re-expressed. DEN-injected animals received an antigen-specific immunization with a synthetic vector consisting of a low dose of AFP-encoding plasmid formulated with the amphiphilic block copolymer 704 (DNAmAFP/704). Animals were treated at 4 and 5 months, before macroscopic nodules were detected, and were sacrificed at 8 months. The tumour burden, as well as liver histology, was assessed. AFP and MHC class I molecule expression in the nodules were monitored by qRT-PCR.

RESULTS

The AFP-specific immunotherapy led to a significant (65%) reduction in tumour size. The reduced expression of AFP and MHC class I molecules was measured in the remaining nodules taken from the DNAmAFP/704-treated group.

CONCLUSIONS

This is the first study demonstrating the relevance of antigen-specific immunotherapy in an autochthonous HCC model. In this context, we validated the use of an anti-tumour immunotherapy based on vaccination with nanoparticles consisting of low dose antigen-encoding DNA formulated with a block copolymer. Our results demonstrate the potential of this strategy as adjuvant immunotherapy to reduce the recurrence risk after local treatment of HCC patients.

Lentiviral vectors that express UGT1A1 in liver and contain miR-142 target sequences normalize hyperbilirubinemia in Gunn rats

BACKGROUND & AIMS

Crigler-Najjar type 1 (CN-I) is an inherited liver disease caused by an absence of bilirubin-uridine 5'-diphosphate-glucuronosyltransferase (UGT1A1) activity. It results in life-threatening levels of unconjugated bilirubin, and therapeutic options are limited. We used adult Gunn rats (an animal model of the disease) to evaluate the efficiency of lentiviral-based gene therapy to express UGT1A1 in liver.

METHODS

Gunn rats were given intraportal injections of VSVG-pseudotyped lentiviral vectors that encode UGT1A1 under the control of a liver-specific transthyretin promoter (mTTR.hUGT1A1); this vector does not contain target sequences for miR-142, a microRNA that is expressed specifically in hematopoietic cells. Rats were also injected with the vector mTTR.hUGT1A1.142T, which contains 4 copies of the miR-142 target sequences; its messenger RNA should be degraded in antigen-presenting cells. Bilirubinemia was monitored, and the presence of transduced hepatocytes was analyzed by quantitative polymerase chain reaction. Vector expression was tested in vitro in rat hematopoietic cells.

RESULTS

In Gunn rats, bilirubin levels normalized 2 weeks after administration of mTTR.hUGT1A1. However, hyperbilirubinemia resumed 8 weeks after vector administration, concomitant with the induction of an immune response. In contrast, in rats injected with mTTR-UGT1A1.142T, bilirubin levels normalized for up to 6 months and transduced cells were not eliminated.

CONCLUSIONS

Lentiviral vectors that express UGT1A1 reduce hyperbilirubinemia in immunocompetent Gunn rats for at least 6 months. The immune response against virally expressed UGT1A1 can be circumvented by inclusion of miR-142 target sequences, which reduce vector expression in antigen-presenting cells. This lentiviral-based gene therapy approach might be developed to treat patients with CN-I.

Transient increase in intrahepatic pressure mediates successful treatment of the Gunn rat with reduced doses of lentiviral vector

Lentiviral vectors can stably transduce hepatocytes and are promising tools for gene therapy of hepatic diseases. Although hepatocytes are accessible to blood-borne viral vectors through fenestrations of the hepatic endothelium, improved liver transduction after delivery of vectors to the blood stream is needed. As the normal endothelial fenestration and lentiviral vectors are similar in size (150 nm), we hypothesized that a transient increase in hepatic blood pressure may enhance in vivo gene transfer to hepatocytes. We designed a simple surgical procedure, by which the liver is temporarily excluded from blood flow. Lentiviral vectors were injected in a large volume to increase intrahepatic pressure. We demonstrated that in the Gunn rat, a model of Crigler-Najjar disease, the administration of low vector doses (corresponding to a multiplicity of infection of 0.2) by this procedure resulted in therapeutic correction of hyperbilirubinemia, without toxicity. The correction was sustained for 10 months (end of study). The same vector amounts yielded only partial correction after intraportal delivery. We believe that this new and clinically applicable strategy may broaden the range of genetic liver diseases accessible to gene therapy.

Selection of high-avidity CD8 T cells correlates with control of hepatitis C virus infection

Both strong antigenic avidity and acquisition of proper effector functions contribute to the efficacy of antiviral T cell responses. To correlate these parameters with the outcome of hepatitis C virus (HCV) infection, we characterized HCV-specific CD8 T cell lines isolated after immunomagnetic sorting of peripheral blood mononuclear cells from human leukocyte antigen A*02 (HLA-A*02) individuals with various HCV serological statuses, using recombinant HLA-A*0201 multimers loaded with three immunodominant HCV genotype 1-derived epitopes. CD8 T cells specific for these three epitopes were derived from most HLA-A*0201 individuals, regardless of their HCV serology or clinical outcome. Donors recovered from genotype 1 HCV infection were enriched for high-avidity T cells with enhanced interferon gamma (IFN-gamma), tumor necrosis factor alpha, and cytotoxic T lymphocyte responses, when compared with seronegative donors and seropositive patients infected with irrelevant HCV genotypes. Patients chronically infected with genotype 1 strain yielded almost exclusively low-avidity T cells, whose hyporesponsiveness was primarily attributable to low T cell receptor (TCR) avidity rather than intrinsic functional defects.

CONCLUSION

This study suggests that strong IFN-gamma responses associated with efficient viral clearance primarily result from Ag-driven selection/survival of HCV-specific T cells expressing high-avidity TCR. It also suggests a link between the quality of the initial HCV-specific T cell repertoire and susceptibility to chronic infection.