| 1. |
- Ankowski, A., et al.
(author)
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Energy reconstruction of electromagnetic showers from Ν0 decays with the ICARUS T600 liquid argon TPC
- 2010
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In: Acta Physica Polonica, Series B.. - 1509-5770 .- 0587-4254. ; 41:1, s. 103-125
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Journal article (peer-reviewed)abstract
- We discuss the ICARUS T600 detector capabilities in electromagnetic shower reconstruction through the analysis of a sample of 212 events, coming from the 2001 Pavia surface test run, of hadronic interactions leading to the production of π 0 mesons. Methods of shower energy and shower direction measurements were developed and the invariant mass of the photon pairs was reconstructed. The (γγ) invariant mass was found to be consistent with the value of the π 0 mass. The resolution of the reconstructed π 0 mass was found to be equal to 27.3%. An improved analysis, carried out in order to clean the full event sample from the events measured in the crowded environment, mostly due to the trigger conditions, gave a π 0 mass resolution of 16.1%, significantly better than the one evaluated for the full event sample. The trigger requirement of the coincidence of at least four photo-multiplier signals favored the selection of events with a strong pile up of cosmic ray tracks and interactions. Hence a number of candidate π 0 events were heavily contaminated by other tracks and had to be rejected. Monte Carlo simulations of events with π 0 production in hadronic and neutrino interactions confirmed the validity of the shower energy and shower direction reconstruction methods applied to the real data.
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| 2. |
- Ankowski, A, et al.
(author)
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Energy reconstruction of electromagnetic showers from π0 decays with the ICARUS T600 liquid argon TPC
- 2010
-
In: Acta Physica Polonica B. - : Jagellonian University. - 0587-4254 .- 1509-5770. ; 41:1, s. 103-125
-
Journal article (peer-reviewed)abstract
- We discuss the ICARUS T600 detector capabilities in electromagnetic shower reconstruction through the analysis of a sample of 212 events, coming from the 2001 Pavia surface test run, of hadronic interactions leading to the production of π0 mesons. Methods of shower energy and shower direction measurements were developed and the invariant mass of the photon pairs was reconstructed. The (γ,γ) invariant mass was found to be consistent with the value of the π0 mass. The resolution of the reconstructed π0 mass was found to be equal to 27.3%. An improved analysis, carried out in order to clean the full event sample from the events measured in the crowded environment, mostly due to the trigger conditions, gave a π0 mass resolution of 16.1%, significantly better than the one evaluated for the full event sample. The trigger requirement of the coincidence of at least four photo-multiplier signals favored the selection of events with a strong pile up of cosmic ray tracks and interactions. Hence a number of candidate π0 events were heavily contaminated by other tracks and had to be rejected. Monte Carlo simulations of events with π0 production in hadronic and neutrino interactions confirmed the validity of the shower energy and shower direction reconstruction methods applied to the real data.
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| 3. |
- Grimsholm, O., et al.
(author)
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The Interplay between CD27(dull) and CD27(brig)(ht) B Cells Ensures the Flexibility, Stability, and Resilience of Human B Cell Memory
- 2020
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In: Cell Reports. - : Elsevier BV. - 2211-1247. ; 30:9
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Journal article (peer-reviewed)abstract
- Memory B cells (MBCs) epitomize the adaptation of the immune system to the environment. We identify two MBC subsets in peripheral blood, CD27(dull) and CD27(bright) MBCs, whose frequency changes with age. Heavy chain variable region (VH) usage, somatic mutation frequency replacement-to-silent ratio, and CDR3 property changes, reflecting consecutive selection of highly antigen-specific, low cross-reactive antibody variants, all demonstrate that CD27(du)(ll) and CD27(bright) MBCs represent sequential MBC developmental stages, and stringent antigen-driven pressure selects CD27(du)(ll) into the CD27(bright) MBC pool. Dynamics of human MBCs are exploited in pregnancy, when 50% of maternal MBCs are lost and CD27(du)(ll) MBCs transit to the more differentiated CD27 bright stage. In the postpartum period, the maternal MBC pool is replenished by the expansion of persistent CD27(du)(ll) clones. Thus, the stability and flexibility of human B cell memory is ensured by CD27(du)(ll) MBCs that expand and differentiate in response to change.
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| 4. |
- Rosado, M. M., et al.
(author)
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Spleen development is modulated by neonatal gut microbiota
- 2018
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In: Immunology Letters. - : Elsevier BV. - 0165-2478. ; 199, s. 1-15
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Journal article (peer-reviewed)abstract
- The full development of the mammalian immune system occurs after birth upon exposure to non self-antigens. The gut is the first site of bacterial colonization where it is crucial to create the appropriate microenvironment able to balance effector or tolerogenic responses to external stimuli. It is a well-established fact that at mucosal sites bacteria play a key role in developing the immune system but we ignore how colonising bacteria impact the maturation of the spleen. Here we addressed this issue. Taking advantage of the fact that milk SIgA regulates bacterial colonization of the newborn intestine, we generated immunocompetent mice born either from IgA pro-efficient or IgA deficient females. Having demonstrated that SIgA in maternal milk modulates neonatal gut microbiota by promoting an increased diversity of the colonizing species we also found that immunocompetent pups, not exposed to milk SIgA, fail to properly develop the FDC network and primary follicles in the spleen compromising the response to T-dependent antigens. The presence of a less diverse microbiota with a higher representation of pathogenic species leads to a fast replenishment of the marginal zone and the IgM plasma cell compartment of the spleen as well as IgA plasma cells in the gut. © 2018 European Federation of Immunological Societies
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| 5. |
- Del Padre, M., et al.
(author)
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Dual stimulation by autoantigen and CpG fosters the proliferation of exhausted rheumatoid factor-specific CD21(low) B cells in hepatitis C virus-cured mixed cryoglobulinemia
- 2023
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In: FRONTIERS IN IMMUNOLOGY. - : Frontiers Media SA. - 1664-3224. ; 14
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Journal article (peer-reviewed)abstract
- IntroductionHepatitis C virus (HCV) causes mixed cryoglobulinemia (MC) by driving clonal expansion of B cells expressing B cell receptors (BCRs), often encoded by the VH1-69 variable gene, endowed with both rheumatoid factor (RF) and anti-HCV specificity. These cells display an atypical CD21low phenotype and functional exhaustion evidenced by unresponsiveness to BCR and Toll-like receptor 9 (TLR9) stimuli. Although antiviral therapy is effective on MC vasculitis, pathogenic B cell clones persist long thereafter and can cause virus-independent disease relapses. MethodsClonal B cells from patients with HCV-associated type 2 MC or healthy donors were stimulated with CpG or heath-aggregated IgG (as surrogate immune complexes) alone or in combination; proliferation and differentiation were then evaluated by flow cytometry. Phosphorylation of AKT and of the p65 NF-kB subunit were measured by flow cytometry. TLR9 was quantified by qPCR and by intracellular flow cytometry, and MyD88 isoforms were analyzed using RT-PCR. DiscussionWe found that dual triggering with autoantigen and CpG restored the capacity of exhausted VH1-69pos B cells to proliferate. The signaling mechanism for this BCR/TLR9 crosstalk remains elusive, since TLR9 mRNA and protein as well as MyD88 mRNA were normally expressed and CpG-induced phosphorylation of p65 NF-kB was intact in MC clonal B cells, whereas BCR-induced p65 NF-kB phosphorylation was impaired and PI3K/Akt signaling was intact. Our findings indicate that autoantigen and CpG of microbial or cellular origin may unite to foster persistence of pathogenic RF B cells in HCV-cured MC patients. BCR/TLR9 crosstalk might represent a more general mechanism enhancing systemic autoimmunity by the rescue of exhausted autoreactive CD21low B cells.
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