IGH 3'RR recombination uncovers a non-germinal center imprint and c-MYC-dependent IGH rearrangement in unmutated chronic lymphocytic leukemia.

Chronic lymphocytic leukemia (CLL) is an incurable indolent non-Hodgkin lymphoma characterized by tumor B cells that weakly express a B-cell receptor. The mutational status of the variable region (IGHV) within the immunoglobulin heavy chain (IGH) locus is an important prognosis indicator and raises the question of the CLL cell of origin. Mutated IGHV gene CLL are genetically imprinted by activation-induced cytidine deaminase (AID). AID is also required for IGH rearrangements: class switch recombination and recombination between switch Mu (Sµ) and the 3' regulatory region (3'RR) (Sµ-3'RRrec). The great majority of CLL B cells being unswitched led us to examine IGH rearrangement blockade in CLL. Our results separated CLL into two groups on the basis of Sµ-3'RRrec counts per sample: Sµ-3'RRrecHigh cases (mostly unmutated CLL) and Sµ-3'RRrecLow cases (mostly mutated CLL), but not based on the class switch recombination junction counts. Sµ-3'RRrec appeared to be ongoing in Sµ-3'RRrecHigh CLL cells and comparison of Sµ-3'RRrec junction structural features pointed to different B-cell origins for both groups. In accordance with IGHV mutational status and PIM1 mutation rate, Sµ-3'RRrecHigh CLL harbor a non-germinal center experienced B-cell imprint while Sµ-3'RRrecLow CLL are from AID-experienced B cells from a secondary lymphoid organ. In addition to the proposals already made concerning the CLL cell of origin, our study highlights that analysis of IGH recombinatory activity can identify CLL cases from different origins. Finally, on-going Sµ-3'RRrec in Sµ-3'RRrecHigh cells appeared to presumably be the consequence of high c-MYC expression, as c-MYC overexpression potentiated IGH rearrangements and Sµ-3'RRrec, even in the absence of AID for the latter.

Targeting IgE polyadenylation signal with antisense oligonucleotides decreases IgE secretion and plasma cell viability.

BACKGROUND: Allergy regroups numerous complex and various diseases classified as IgE-dependent or non-IgE-dependent hypersensitivities. IgEs are expressed as membrane and secreted forms by B cells and plasma cells, respectively. In IgE-mediated hypersensitivity, IgE secretion and binding to the high-affinity IgE receptor FcεRI on effector cells are responsible for the onset of allergic symptoms; in contrast, surface IgE expression as a B-cell receptor is barely detectable. OBJECTIVE: Our aim was to test an innovative antisense approach to reducing IgE secretion. METHODS: We designed an antisense oligonucleotide (ASO) targeting the polyadenylation signal of human secreted IgE to redirect IgE transcript polyadenylation from the secreted form to the membrane form. ASO treatments were performed on B cells from transgenic mice expressing humanized IgE (InEps mice), as well as on human primary B cells and myeloma cells. In vivo ASO delivery was tested by using an InEps mouse model. RESULTS: We demonstrated that treatment with a morpholino ASO targeting the secreted IgE polyadenylation signal drastically decreased IgE secretion and inversely increased membrane IgE mRNA expression. In addition, ASO treatment induced apoptosis of IgE-expressing U266 myeloma cells, and RNA sequencing revealed attenuation of their plasma cell phenotype. Remarkably, systemic administration of an ASO coupled with Pip6a as an arginine-rich cell-penetrating peptide decreased IgE secretion in vivo. CONCLUSION: Altogether, this ASO strategy could be an effective way to decrease IgE secretion and allergic symptoms in patients with IgE-dependent allergies, and it could also promote allergen tolerance through apoptosis of IgE+ antibody-secreting cells.

Impact of video on the understanding and satisfaction of patients receiving informed consent before elective inpatient coronary angiography: A randomized trial.

BACKGROUND: Appropriate information about the benefits and risks of invasive procedures is crucial, but limited data is available in this field. The aim of this study was to evaluate the incremental value of a short video about coronary angiography compared with standard information, in terms of patient understanding, satisfaction and anxiety. METHODS: This prospective multicenter study included patients admitted for scheduled coronary angiography, who were randomized to receive either standard information or video information by watching a three-dimensional educational video. After information was delivered, patients were asked to complete a dedicated 16-point information questionnaire, as well as satisfaction and anxiety scales. RESULTS: From 21 September to 4 October 2015, 821 consecutive patients were randomized to receive either standard information (n=415) or standard information with an added educational video (n=406). The information score was higher in the video information group than in the standard group (11.8±2.8 vs 9.5±3.1; P<.001). This result was consistent across age and education level subgroups. Self-reported satisfaction was also higher in the video information group (8.4±1.9 vs. 7.7±2.3; P<.001), while anxiety level did not differ between groups. The variables associated with a higher information score were the use of the educational video, younger age, higher level of education, previous follow-up by a cardiologist, prior information about coronary angiography and previous coronary angiography. CONCLUSIONS: In comparison with standard information, viewing a dedicated educational video improved patients' understanding and satisfaction before scheduled coronary angiography. These results are in favor of widespread use of this incremental information tool.

Cesarean section for HIV-infected women in the combination antiretroviral therapies era, 2000-2010.

OBJECTIVE: Elective cesarean section (CS) is a proven method to prevent mother-to-child transmission (MTCT), but is no longer recommended for women with antiretroviral therapy resulting in a low viral load (VL): <400 copies/mL in French and <1000 copies/mL in US guidelines. We sought to describe mode of delivery practices in human immunodeficiency virus (HIV)-infected women and their association with MTCT and postpartum complications. STUDY DESIGN: All deliveries from HIV-1-infected women in the French Perinatal Cohort (Agence Nationale de Recherches sur le Sida/Enquête Périnatale Française) 2000 through 2010 (N = 8977) were analyzed, with additional details for 2005 through 2010 (n = 4717). RESULTS: Vaginal deliveries increased from 25% in 2000 to 53% in 2010. Over 2005 through 2010, 4300 women had VL before delivery <400 copies/mL; among them only 49.3% delivered vaginally, 22.0% had nonelective CS, and 28.7% had elective CS. Elective CS were performed for scarred uterus in 45.4%, other obstetrical indications in 37.1%, and solely because of HIV in 15.7%. Of the 417 women with VL ≥400 copies/mL, 48.9% had elective CS as recommended, 25.9% had nonelective CS, and 25.2% had vaginal delivery. The MTCT rate did not differ according to the mode of delivery in term deliveries (≥37 gestational weeks) in 2000 through 2010: 0.3% after both vaginal delivery and elective CS with VL <50 copies/mL, 4.0% vs 5.3%, respectively, with VL ≥10,000 copies/mL. In case of preterm delivery, MTCT rates tended to be higher with vaginal delivery. Postpartum complications were more frequent following CS than vaginal deliveries (6.5% vs 2.9, P < .01). CONCLUSION: Our findings suggest that HIV-infected women on antiretroviral therapy with low VL can safely opt for vaginal delivery in the absence of obstetrical risk factors.

A dual function for the chromatin organizer Special A-T rich Binding Protein 1 in B-lineage cells.

SATB1 (Special A-T rich Binding protein 1) is a cell type-specific factor that regulates the genetic network in developing T cells and neurons. In T cells, SATB1 is required for lineage commitment, VDJ recombination, development and maturation. Considering that its expression varies during B-cell differentiation, the involvement of SATB1 needs to be clarified in this lineage. Using a KO mouse model in which SATB1 was deleted from the pro-B-cell stage, we examined the consequences of SATB1 deletion in naive and activated B-cell subsets. Our model indicates first, unlike its essential function in T cells, that SATB1 is dispensable for B-cell development and the establishment of a broad IgH repertoire. Second, we show that SATB1 exhibits an ambivalent function in mature B cells, acting sequentially as a positive and negative regulator of Ig gene transcription in naive and activated cells, respectively. Third, our study indicates that the negative regulatory function of SATB1 in B cells extends to the germinal center response, in which this factor limits somatic hypermutation of Ig genes.

Comparative analysis of histopathological parameters, genome-wide copy number alterations, and variants in genes involved in cell cycle regulation in chordomas of the skull base and sacrum.

Chordomas are rare tumors of the axial skeleton that are refractory to conventional therapy. Few studies have compared the morphological and molecular characteristics of chordomas according to the skull base and sacral locations. Histopathological data and changes revealed by array comparative genomic hybridization (CGH) and next-generation sequencing (NGS) of cell cycle regulation genes were analyzed for 28 skull base (SBCs) and 15 sacral (SC) chordomas. All cases were conventional chordomas. SBCs were significantly more frequent in patients aged <40 years and SCs predominated in patients aged >60 years. Mitotic indices ≥2 mitoses/10 high-power fields were correlated with high degrees of nuclear atypia and Ki67 labeling indices ≥6%. We identified 321 genomic positions, and copy number variation losses were more frequent than gain. Moreover, we report a panel of 85 genetic variants of cell cycle genes and the presence of molecular clusters for chordoma as well in CGH as in NGS. These new data strengthen the view that the chordoma should not be considered as a single molecular entity.

CD95/Fas suppresses NF-κB activation through recruitment of KPC2 in a CD95L/FasL-independent mechanism.

CD95 expression is preserved in triple-negative breast cancers (TNBCs), and CD95 loss in these cells triggers the induction of a pro-inflammatory program, promoting the recruitment of cytotoxic NK cells impairing tumor growth. Herein, we identify a novel interaction partner of CD95, Kip1 ubiquitination-promoting complex protein 2 (KPC2), using an unbiased proteomic approach. Independently of CD95L, CD95/KPC2 interaction contributes to the partial degradation of p105 (NF-κB1) and the subsequent generation of p50 homodimers, which transcriptionally represses NF-κB-driven gene expression. Mechanistically, KPC2 interacts with the C-terminal region of CD95 and serves as an adaptor to recruit RelA (p65) and KPC1, which acts as E3 ubiquitin-protein ligase promoting the degradation of p105 into p50. Loss of CD95 in TNBC cells releases KPC2, limiting the formation of the NF-κB inhibitory homodimer complex (p50/p50), promoting NF-κB activation and the production of pro-inflammatory cytokines, which might contribute to remodeling the immune landscape in TNBC cells.