T-cell acute lymphoblastic leukemia (T-ALL) is a high-risk subtype of acute lymphoblastic leukemia (ALL) with gradually improved survival through introduction of intensified chemotherapy. However, therapy-resistant or refractory T-ALL remains a major clinical challenge. Here, we evaluated B-cell lymphoma (BCL)-2 inhibition by the BH3 mimetic ABT-199 as a new therapeutic strategy in humanT-ALL. The T-ALL cell line LOUCY, which shows a transcriptional program related to immature T-ALL, exhibited high in vitro and in vivo sensitivity for ABT-199 in correspondence with high levels of BCL-2. In addition, ABT-199 showed synergistic therapeutic effects with different chemotherapeutic agents including doxorubicin, L-asparaginase, and dexamethasone. Furthermore, in vitro analysis of primary patient samples indicated that some immature, TLX3-orHOXA-positive primary T-ALLs are highly sensitive to BCL-2 inhibition, whereas TAL1 driven tumors mostly showed poor ABT-199 responses. Because BCL-2 shows high expression in early T-cell precursors and gradually decreases during normal T-cell differentiation, differences in ABT-199 sensitivity could partially be mediated by distinct stages of differentiation arrest between different molecular genetic subtypes of human T-ALL. In conclusion, our study highlights BCL-2 as an attractive molecular target in specific subtypes of human T-ALL that could be exploited by ABT-199

We previously described chimeric recombinant adeno-associated virus (rAAV) vectors 2/4 and 2/5 as the most efficient vectors in rat retina. We now characterize these two vectors carrying the CMV.gfp genome following subretinal injection in the Wistar rat, beagle dog, and cynomolgus macaque. Both serotypes displayed stable GFP expression for the duration of the experiment (6 months) in all three animal models. Similar to the AAV-2 serotype, AAV-2/5 transduced both RPE and photoreceptor cells, with higher level of transduction in photoreceptors, whereas rAAV-2/4 transduction was unambiguously restricted to RPE cells. This unique specificity found conserved among all three species makes AAV-2/4-derived vectors attractive for retinal diseases originating in RPE such as Leber congenital amaurosis (RPE65) or retinitis pigmentosa due to a mutated mertk gene. To provide further important preclinical data, vector shedding was monitored by PCR in various biological fluids for 2 months post-rAAV administration. Following rAAV-2/4 and -5 subretinal delivery in dogs (n = 6) and in nonhuman primates (n = 2), vector genome was found in lacrymal and nasal fluids for up to 3-4 days and in the serum for up to 15-20 days. Overall, these findings will have a practical impact on the development of future gene therapy trials of retinal diseases.

IntroductionFanconi anemia (FA) is a rare recessive syndrome featuring progressive bone marrow (BM) failure, multiple developmental abnormalities and cancer predisposition. 1-3 BM failure and its related consequences, such as pancytopenia or acute myeloid leukemia (AML), are the major cause of morbidity and mortality of FA patients. 4 The cellular phenotype is characterized by chromosomal instability and hypersensitivity to DNA interstrand crosslink (ICL)-inducing agents such as mitomycin C (MMC), diepoxybutane, and cisplatin. [5][6][7][8] At least 13 complementation groups have been identified (FA-A, B, C, D1, D2, E, F, G, I, J, L, M, and N) and the genes for all of these groups have been cloned. 9 One of the major functions of FANC proteins is to deal with DNA damage, thus participating in an as-yet-undefined manner to the repair of DNA lesions induced by cross-linking agents. [10][11][12] However, the spectrum of clinical and cellular abnormalities of the syndrome suggests that FANC proteins could have other functions or participate in pathways other than DNA repair. 13,14 Whether the hematologic problems of the FA patients are a consequence of a defect in DNA repair or in other potential functions of the FANC proteins remains to be determined.Tumor necrosis factor-␣ (TNF-␣) is a major cytokine involved in hematopoiesis, inflammation, and apoptosis. 15,16 TNF-␣ is synthesized as a membrane-bound precursor of 26 kDa that can be processed to generate a secreted 17-kDa mature TNF-␣. 17,18 Soluble mature TNF-␣ is released from the cells by cleavage of the precursor at the Ala76-Val77 bond by the TNF-␣ converting enzyme (TACE or ADAM17) 19,20 or, less efficiently, by the matrix metalloproteinase 7 (MMP-7 or matrilysin). 21,22 TNF-␣ signals through 2 distinct cell-surface receptors, TNFR-1 and TNFR-2. 16 The binding of TNF-␣ to its receptors results, among other events, in the activation of both the mitogen-activated protein kinases (MAPKs) stress signaling cascade 16 and the NF-B transcription factor. 23 Activation of the MAPKs and NF-B plays an important role in the induction of many cytokines including the TNF-␣ itself. 24,25 TNF-␣ negatively regulates the expansion and selfrenewal of pluripotent hematopoietic stem cells (HSCs) 26,27 and has inhibitory effects on normal human hematopoietic progenitor cells as well as leukemia progenitor cells. [28][29][30] Consistently, TNF-␣ overproduction has been associated with different hematopoietic disorders such as myelodysplastic syndrome (MDS), AML, and aplastic anemia. [31][32][33] FA syndrome recapitulates all these abnormalities, that is, impaired HSC expansion and development of the myeloid lineages, MDS, aplastic anemia, and AML. 2-4 FA is also characterized by TNF-␣ overproduction, both in vivo and in vitro. Indeed, it has been reported that TNF-␣ is (1) overexpressed in BM of FA patients, 34,35 (2) increased in the serum of patients, 35,36 and (3) overproduced by Epstein-Barr virus (EBV)-transformed FA lymphoblasts. 36 Moreover, hematopoietic progenitors from ...