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.

Can an herbivore affect where a top predator kills its prey by modifying woody vegetation structure?

In large mammal communities, little is known about modification of interspecific interactions through habitat structure changes. We assessed the effects of African elephants (Loxodonta africana) on features of woody habitat structure that can affect predator-prey interactions. We then explored how this can influence where African lions (Panthera leo) kill their prey. Indeed, lions are stalk-and-ambush predators and habitat structure and concealment opportunities are assumed to influence their hunting success. During 2 years, in Hwange National Park, Zimbabwe, kill sites (n = 167) of GPS-collared lions were characterized (visibility distance for large mammals, distance to a potential ambush site and presence of elephant impacts). We compared characteristics of lion kill sites with characteristics of random sites (1) at a large scale (i.e. in areas intensively used by lions, n = 418) and (2) at the microhabitat scale (i.e. in the direct surrounding available habitat, < 150 m, n = 167). Elephant-impacted sites had a slightly higher visibility and a longer distance to a potential ambush site than non-impacted sites, but these relationships were characterized by a high variability. At large scale, kill sites were characterized by higher levels of elephant impacts compared to random sites. At microhabitat scale, compared to the direct nearby available habitat, kill sites were characterized by a reduced distance to a potential ambush site. We suggest a conceptual framework whereby the relative importance of habitat features and prey abundance could change upon the scale considered.

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.

Hepatic lentiviral gene transfer prevents the long-term onset of hepatic tumours of glycogen storage disease type 1a in mice.

Glycogen storage disease type 1a (GSD1a) is a rare disease due to the deficiency in the glucose-6-phosphatase (G6Pase) catalytic subunit (encoded by G6pc), which is essential for endogenous glucose production. Despite strict diet control to maintain blood glucose, patients with GSD1a develop hepatomegaly, steatosis and then hepatocellular adenomas (HCA), which can undergo malignant transformation. Recently, gene therapy has attracted attention as a potential treatment for GSD1a. In order to maintain long-term transgene expression, we developed an HIV-based vector, which allowed us to specifically express the human G6PC cDNA in the liver. We analysed the efficiency of this lentiviral vector in the prevention of the development of the hepatic disease in an original GSD1a mouse model, which exhibits G6Pase deficiency exclusively in the liver (L-G6pc(-/-) mice). Recombinant lentivirus were injected in B6.G6pc(ex3lox/ex3lox). SA(creERT2/w) neonates and G6pc deletion was induced by tamoxifen treatment at weaning. Magnetic resonance imaging was then performed to follow up the development of hepatic tumours. Lentiviral gene therapy restored glucose-6 phosphatase activity sufficient to correct fasting hypoglycaemia during 9 months. Moreover, lentivirus-treated L-G6pc(-/-) mice presented normal hepatic triglyceride levels, whereas untreated mice developed steatosis. Glycogen stores were also decreased although liver weight remained high. Interestingly, lentivirus-treated L-G6pc(-/-) mice were protected against the development of hepatic tumours after 9 months of gene therapy while most of untreated L-G6pc(-/-) mice developed millimetric HCA. Thus the treatment of newborns by recombinant lentivirus appears as an attractive approach to protect the liver from the development of steatosis and hepatic tumours associated to GSD1a pathology.

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-2Kd to hepatocytes, before transplantation with fully allogeneic pancreatic islet from BALB/c mice (H-2d). RESULTS: AAV H-2Kd 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-2Kd 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.

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.

Marketing Regulatory Oversight of Advanced Therapy Medicinal Products (ATMPs) in Europe: The EMA/CAT Perspective.

With the release of Regulation 1394/2007, a new framework for gene and cell therapy medicinal products and tissue-engineered products was established in the European Union. For all three product classes, called advanced therapy medicinal products, a centralised marketing authorisation became mandatory. The European Medicines Agency (EMA) together with its Committee for Advanced Therapies, Committee for Human Medicinal Products and the network of national agencies is responsible for scientific evaluation of the marketing authorisation applications. For a new application, data and information relating to manufacturing processes and quality control of the active substance and the final product have to be submitted for evaluation together with data from non-clinical and clinical safety and efficacy studies. Technical requirements for ATMPs are defined in the legislation, and guidance for different products is available through several EMA/CAT guidelines. Due to the diversity of ATMPs, a tailored approach for regulating these products is considered necessary. Thus, a risk-based approach has been introduced for ATMPs allowing flexibility for the regulatory requirements. Since the regulatory framework for ATMPs was established, five products have been licenced in the European Union. However, the pipeline of new ATMPs is much bigger, as seen from the significant numbers of different products discussed by the CAT in scientific advice and classification procedures. In 2013, a public consultation on the ATMP Regulation was conducted by the European Commission, and the results were published in 2014. The report proposes several improvements for the current framework and established procedures for the regulation of ATMPs.

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.

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.

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.

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.

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

UNLABELLED: 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.

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 expression of genes delivered to newborn rat liver using recombinant adeno-associated virus 2/8 vectors.

BACKGROUND: In vivo adeno-associated virus (AAV) delivery to adult liver results in sustained expression of the transgene. However, it has been suggested that AAV delivery to the newborn liver may result in transient expression. In the present study, we analysed transgene expression after AAV8 delivery of a therapeutic or a marker gene to newborn rat liver. METHODS: Recombinant AAV 8 vectors carrying either the human UGT1A1 cDNA or the lacZ gene were injected intravenously in 2-day-old Gunn or Wistar rats. Serum bilirubin level was recorded in Gunn rats and beta-galactosidase expression was monitored by immunohistochemistry or enzyme activity. The molecular forms of AAV genome were analysed by the polymerase chain reaction and Southern blotting in whole liver and by the quantitative polymerase chain reaction in macroscopically dissected beta-galactosidase clusters. RESULTS: In Gunn rat, complete serum bilirubin normalization occurred after AAV delivery but hyperbilirubinemia resumed thereafter. Similarly, beta-galactosidase expression was maximum at day 7, but only a few (less than 1%) beta-galactosidase positive cells were recorded at 1 or 3 months. These cells gathered in small clusters and the AAV copy number was 75-fold higher in positive cell clusters than in the surrounding parenchyma. CONCLUSIONS: The results obtained in the present study show that in vivo AAV delivery to newborn rats results in transient expression in most hepatocytes. Expression of the trangene was persistent in small clusters of cells and preliminary data support the hypothesis that integration of the viral genome occurs in these clusters. Altogether, our data confirm the low efficiency of AAV vectors for gene therapy of liver diseases when delivered in the newborn period.

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

UNLABELLED: 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.

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.