Co-operation of BRCA1 and POH1 relieves the barriers posed by 53BP1 and RAP80 to resection

In G2 phase cells, DNA double-strand break repair switches from DNA non-homologous end-joining to homologous recombination. This switch demands the promotion of resection. We examine the changes in 53BP1 and RAP80 ionizing radiation induced foci (IRIF) in G2 phase, as these are factors that restrict resection. We observed a 2-fold increase in the volume of 53BP1 foci by 8 h, which is not seen in G1 cells. Additionally, an IRIF core devoid of 53BP1 arises where RPA foci form, with BRCA1 IRIF forming between 53BP1 and replication protein A (RPA). Ubiquitin chains assessed using a-FK2 antibodies are similarly repositioned. Repositioning of all these components requires BRCA1’s BRCT but not the ring finger domain. 53BP1, RAP80 and ubiquitin chains are enlarged following POH1 depletion by small interfering RNA, but a devoid core does not form and RPA foci formation is impaired. Co-depletion of POH1 and RAP80, BRCC36 or ABRAXAS allows establishment of the 53BP1 and ubiquitin chain-devoid core. Thus, the barriers posed by 53BP1 and RAP80 are relieved by BRCA1 and POH1, respectively. Analysis of combined depletions shows that these represent distinct but interfacing barriers to promote loss of ubiquitin chains in the IRIF core, which is required for subsequent resection. We propose a model whereby BRCA1 impacts on 53BP1 to allow access of POH1 to RAP80. POH1-dependent removal of RAP80 within the IRIF core enables degradation of ubiquitin chains, which promotes loss of 53BP1. Thus, POH1 represents a novel component regulating the switch from nonhomologous end-joining to homologous recombination

Application to the Analysis of Germinal Center Reactions In Vivo

Simultaneous detection of multiple cellular and molecular players in their native environment, one of the keys to a full understanding of immune processes, remains challenging for in vivo microscopy. Here, we present a synergistic strategy for spectrally multiplexed in vivo imaging composed of (i) triple two-photon excitation using spatiotemporal synchronization of two femtosecond lasers, (ii) a broad set of fluorophores with emission ranging from blue to near infrared, (iii) an effective spectral unmixing algorithm. Using our approach, we simultaneously excite and detect seven fluorophores expressed in distinct cellular and tissue compartments, plus second harmonics generation from collagen fibers in lymph nodes. This enables us to visualize the dynamic interplay of all the central cellular players during germinal center reactions. While current in vivo imaging typically enables recording the dynamics of 4 tissue components at a time, our strategy allows a more comprehensive analysis of cellular dynamics involving 8 single-labeled compartments. It enables to investigate the orchestration of multiple cellular subsets determining tissue function, thus, opening the way for a mechanistic understanding of complex pathophysiologic processes in vivo. In the future, the design of transgenic mice combining a larger spectrum of fluorescent proteins will reveal the full potential of our method

Epistatic Interactions Between Mutations of Deoxyribonuclease 1-Like 3 and the Inhibitory Fc Gamma Receptor IIB Result in Very Early and Massive Autoantibodies Against Double-Stranded DNA

Autoantibodies against double-stranded DNA (anti-dsDNA) are a hallmark of systemic lupus erythematosus (SLE). It is well documented that anti-dsDNA reactive B lymphocytes are normally controlled by immune self-tolerance mechanisms operating at several levels. The evolution of high levels of IgG anti-dsDNA in SLE is dependent on somatic hypermutation and clonal selection, presumably in germinal centers from non-autoreactive B cells. Twin studies as well as genetic studies in mice indicate a very strong genetic contribution for the development of anti-dsDNA as well as SLE. Only few single gene defects with a monogenic Mendelian inheritance have been described so far that are directly responsible for the development of anti-dsDNA and SLE. Recently, among other mutations, rare null-alleles for the deoxyribonuclease 1 like 3 (DNASE1L3) and the Fc gamma receptor IIB (FCGR2B) have been described in SLE patients and genetic mouse models. Here, we demonstrate that double Dnase1l3- and FcgR2b-deficient mice in the C57BL/6 background exhibit a very early and massive IgG anti-dsDNA production. Already at 10 weeks of age, autoantibody production in double-deficient mice exceeds autoantibody levels of diseased 9-month-old NZB/W mice, a long established multigenic SLE mouse model. In single gene-deficient mice, autoantibody levels were moderately elevated at early age of the mice. Premature autoantibody production was accompanied by a spontaneous hyperactivation of germinal centers, early expansions of T follicular helper cells, and elevated plasmablasts in the spleen. Anti-dsDNA hybridomas generated from double-deficient mice show significantly elevated numbers of arginines in the CDR3 regions of the heavy-chain as well as clonal expansions and diversification of B cell clones with moderate numbers of somatic mutations. Our findings show a strong epistatic interaction of two SLE-alleles which prevent early and high-level anti-dsDNA autoantibody production. Both genes apparently synergize to keep in check excessive germinal center reactions evolving into IgG anti-dsDNA antibody producing B cells

Plasma cell output from germinal centers is regulated by signals from Tfh and stromal cells

Germinal centers (GCs) are the sites where B cells undergo affinity maturation. The regulation of cellular output from the GC is not well understood. Here, we show that from the earliest stages of the GC response, plasmablasts emerge at the GC-T zone interface (GTI). We define two main factors that regulate this process: Tfh-derived IL-21, which supports production of plasmablasts from the GC, and TNFSF13 (APRIL), which is produced by a population of podoplanin+CD157highfibroblastic reticular cells located in the GTI that are also rich in message for IL-6 and chemokines CXCL12, CCL19, and CCL21. Plasmablasts in the GTI express the APRIL receptor TNFRSF13B (TACI), and blocking TACI interactions specifically reduces the numbers of plasmablasts appearing in the GTI. Plasma cells generated in the GTI may provide an early source of affinity-matured antibodies that may neutralize pathogens or provide feedback regulating GC B cell selection

First-in-Human Dose Escalation Trial To Evaluate the Clinical Safety and Efficacy of an Anti-MAGEA1 Autologous Tcr-Transgenic T Cell Therapy in Relapsed and Refractory Solid Tumors

RATIONALE OF THE TRIAL: Although the use of engineered T cells in cancer immunotherapy has greatly advanced the treatment of hematological malignancies, reaching meaningful clinical responses in the treatment of solid tumors is still challenging. We investigated the safety and tolerability of IMA202 in a first-in-human, dose escalation basket trial in human leucocyte antigen A*02:01 positive patients with melanoma-associated antigen A1 (MAGEA1)-positive advanced solid tumors. TRIAL DESIGN: The 2+2 trial design was an algorithmic design based on a maximally acceptable dose-limiting toxicity (DLT) rate of 25% and the sample size was driven by the algorithmic design with a maximum of 16 patients. IMA202 consists of autologous genetically modified cytotoxic CD8 CONCLUSION: In conclusion, IMA202 had a manageable safety profile, and it was associated with biological and potential clinical activity of MAGEA1-targeting genetically engineered TCR-T cells in a poor prognosis, multi-indication solid tumor cohort

Delivering the EU Green Deal - Progress towards targets

This report provides a comprehensive assessment of progress towards the European Green Deal (EGD), the European Union’s transformative agenda for achieving climate neutrality by 2050. The analysis encompasses 154 quantifiable targets from 44 policy documents between 2019 and 2024 across key sectors such as climate, energy, circular economy, transport, agriculture and food, ecosystems and biodiversity, water, soil and air pollution. The study shows that significant achievement has been delivered so far but progress needs to accelerate in many areas. As of mid-2024, 32 of the 154 targets are currently “on track” and 64 are identified as “acceleration needed” meaning that more progress is needed to meet the targets on time. Furthermore, 15 of the targets are found to be “not progressing” or “regressing”, and for 43 of the targets no data is currently available. The timing of the binding policies, most of which have been recently agreed and are expected to deliver results in the coming years, is a significant factor influencing these assessments. This report integrates all EGD actions and related policies, offering an assessment of the EU’s green transition based on robust data and science. It identifies priority areas for intensified efforts to meet short-term implementation goals and contribute to the long-term ambition of a sustainable, fair, just, and climate-neutral Europe by 2050. This collective work serves as a benchmarking tool, providing scientifically grounded guidance for future EU policies and programmes.JRC.D.1 - Forests and Bio-Econom

Prior Knowledge and Entrepreneurial Innovative Success

This paper is concerned with the relationship between innovative success of entrepreneurs and their prior knowledge at the stage of firm formation. We distinguish between different kinds of experience an entrepreneur can possess and find evidence that the innovative success subsequent to firm formation is enhanced by entrepreneurs prior technological knowledge but not by prior market and organizational knowledge. Moreover we find that prior technological knowledge gathered through embeddedness within a research community has an additionally positive influence on post start-up innovative success. This is a first hint towards the importance of collective innovation activities

Do External Technology Acquisitions Matter for Innovative Efficiency and Productivity?

To quickly adapt to technological change and developments, and thus remain competitive, firms increasingly resort to the use of external technology. This paper investigates whether and to what extent the acquisition of external disembodied technology affects the efficiency and productivity in innovation of technology acquiring firms. Using the stochastic frontier analysis combined with a difference-in-difference matching approach and firm-level panel from the German Innovation Survey for the period 1992-2004, we find that manufacturing firms that acquire disembodied technology experience more growth in innovative productivity than non-acquiring firms do. Thus, this study provides evidence on complementarity between internal and external R&D in innovation production, which is attributed by increasing returns to R&D scale and increasing technical efficiency. Moreover, we find that firm size significantly contributes to innovative efficiency and productivity of external technology acquirers

The Long Persistence of Regional Entrepreneurship Culture: Germany 1925-2005

We investigate the persistence of levels of self-employment and new business formation in different time periods and under different framework conditions. The analysis shows that high levels of regional self-employment and new business formation tend to be persistent for periods as long as 80 years and that such an entrepreneurial culture can even survive abrupt and drastic changes in the politic-economic environment. We thus conclude that regional entrepreneurship cultures do exist and that they have long-lasting effects