541 research outputs found
Multispecific Aspergillus T Cells Selected by CD137 or CD154 Induce Protective Immune Responses Against the Most Relevant Mold Infections
Background. Aspergillus and Mucorales species cause severe infections in patients after hematopoietic stem cell transplantation (HSCT). Induction of antifungal CD4+ T-helper type 1 (Th1) immunity is an appealing strategy to combat these infections. Immunotherapeutic approaches are so far limited because of a lack of antigens inducing protective T cells, their elaborate production, and the need of targeting a broad spectrum of pathogenic fungi. Methods. We examined the response to different Aspergillus fumigatus proteins in healthy individuals and patients after HSCT and compared rapid selection protocols for fungus-specific T cells based on CD137 or CD154 expression. Results. The A. fumigatus proteins Crf1, Gel1, and Pmp20 induced strong Th1 responses in healthy individuals. T cells specific for these antigens expanded in patients with active invasive aspergillosis, indicating their contribution to infection control. Th1 cells specific for the 3 proteins can be selected with similar specificity within 24 hours, based on CD137 or CD154 expression. These cells recognize naturally processed A. fumigatus and the multispecific T-cell lines, directed against all 3 proteins, especially those selected by CD154, additionally cross-react to different Aspergillus and Mucorales species. Conclusions. These findings may form the basis for adoptive T-cell transfer for prophylaxis or treatment in patients with these devastating infection
Scaling fixed field accelerators: theory and modelling of horizontal- and vertical-excursion accelerators
Fixed Field Accelerators, or FFAs, are accelerators that use time-independent magnetic fields, permitting the orbit to move as the beam is accelerated. Spatially-dependent magnetic fields allow for the control of orbit geometry during acceleration and the control of focussing strength along the orbit. Scaling FFAs represent the subset of fixed field accelerators in which the magnetic fields follow scaling laws that ensure geometric similarity between closed orbits of different energies and energy-independent focussing behaviour. Vertical-excursion FFAs (vFFAs) present a novel variant on the scaling FFA template where higher-energy orbits are vertically translated copies of lower energy ones, introducing complexities in optics and orbits due to coupled particle motion across the two transverse planes and non-planar orbit behaviour. Because of this, previous design and study of vFFA rings has depended entirely on numerical integration methods.
This study presents analytical methods for studying optics in both horizontal- and vertical-excursion FFAs, deriving for the first time an analytic model of the vFFA. A multipole decomposition approach, termed ‘harmonic analysis,’ is developed to study vFFA optics in cases where the analytic model has limitations. This technique is then further used in the study of nonlinear (higher-order) effects in conventional FFAs beyond the capabilities of the linear analytic modelling. The nonlinear effects studies are additionally benchmarked with experimental studies of amplitude-dependent tune shift, showing good agreement. To demonstrate the strength of the newly-developed analytic techniques, the vFFA as a muon accelerator stage for a muon collider is studied, where insights provided by the analytic model enable an optimisation that was not previously possible
Restoration of CD28 Expression in CD28− CD8+ Memory Effector T Cells Reconstitutes Antigen-induced IL-2 Production
The control of many persistent viral infections by Ag-specific cytolytic CD8+ T cells requires a concurrent virus-specific CD4+ Th cell response. This reflects in part a requirement of activated effector CD8+ T cells for paracrine IL-2 production as a growth and survival factor. In human CMV and HIV infection, the majority of differentiated virus-specific CD8+ T cells notably lose the ability to produce IL-2 but also lose expression of CD28, a costimulatory molecule. Analysis of the fraction of memory CD8+ T cells that continue to express CD28 revealed these cells retain the ability to produce IL-2. Therefore, we examined if IL-2 production by CD28− CD8+ T cells could be restored by introduction of a constitutively expressed CD28 gene. Expression of CD28 in CD28− CD8+ CMV- and HIV-specific CD8+ T cells reconstituted the ability to produce IL-2, which could sustain an autocrine proliferative response after Ag recognition. These results suggest that the loss of CD28 expression during differentiation of memory/effector CD8+ T cells represents a decisive step in establishing regulation of responding CD8+ T cells, increasing the dependence on CD4+ Th for proliferation after target recognition, and has implications for the treatment of viral disease with adoptively transferred CD8+ T cells
Measurement of the forward Z boson production cross-section in pp collisions at TeV
A measurement of the production cross-section of Z bosons in pp collisions at TeV is presented using dimuon and dielectron final states in LHCb data. The cross-section is measured for leptons with pseudorapidities in the range , transverse momenta GeV and dilepton invariant mass in the range GeV. The integrated cross-section from averaging the two final states is \begin{equation*}\sigma_{\text{Z}}^{\ell\ell} = 194.3 \pm 0.9 \pm 3.3 \pm 7.6\text{ pb,}\end{equation*} where the first uncertainty is statistical, the second is due to systematic effects, and the third is due to the luminosity determination. In addition, differential cross-sections are measured as functions of the Z boson rapidity, transverse momentum and the angular variable
CcpA- and Shm2-pulsed myeloid dendritic cells induce T-cell activation and enhance the neutrophilic oxidative burst response to aspergillus fumigatus
Aspergillus fumigatus causes life-threatening opportunistic infections in immunocompromised patients. As therapeutic outcomes of invasive aspergillosis (IA) are often unsatisfactory, the development of targeted immunotherapy remains an important goal. Linking the innate and adaptive immune system, dendritic cells are pivotal in anti-Aspergillus defense and have generated interest as a potential immunotherapeutic approach in IA. While monocyte-derived dendritic cells (moDCs) require ex vivo differentiation, antigen-pulsed primary myeloid dendritic cells (mDCs) may present a more immediate platform for immunotherapy. To that end, we compared the response patterns and cellular interactions of human primary mDCs and moDCs pulsed with an A. fumigatus lysate and two A. fumigatus proteins (CcpA and Shm2) in a serum-free, GMP-compliant medium. CcpA and Shm2 triggered significant upregulation of maturation markers in mDCs and, to a lesser extent, moDCs. Furthermore, both A. fumigatus proteins elicited the release of an array of key pro-inflammatory cytokines including TNF-α, IL-1β, IL-6, IL-8, and CCL3 from both DC populations. Compared to moDCs, CcpA- and Shm2-pulsed mDCs exhibited greater expression of MHC class II antigens and stimulated stronger proliferation and IFN-γ secretion from autologous CD4+ and CD8+ T-cells. Moreover, supernatants of CcpA- and Shm2-pulsed mDCs significantly enhanced the oxidative burst in allogeneic neutrophils co-cultured with A. fumigatus germ tubes. Taken together, our in vitro data suggest that ex vivo CcpA- and Shm2-pulsed primary mDCs have the potential to be developed into an immunotherapeutic approach to tackle IA
Interobserver agreement rates on CXCR4-directed PET/CT in patients with marginal zone lymphoma
Abstract
C-X-C motif chemokine receptor 4 (CXCR4)-directed molecular imaging provides excellent read-out capabilities in patients with marginal zone lymphoma (MZL). We aimed to determine the interobserver agreement rate of CXCR4-targeted PET/CT among readers with different levels of experience.
Methods
50 subjects with MZL underwent CXCR4-targeted PET/CT, which were reviewed by four readers (including two experienced and two less experienced observers). The following 8 parameters were investigated: overall scan result, CXCR4 density in lymphoma tissue, extranodal organ involvement, No. of affected extranodal organs and extranodal organ metastases, lymph node (LN) involvement and No. of affected LN areas and LN metastases. We applied intraclass correlation coefficients (ICC; 0.74 excellent agreement rates).
Results
Among all readers, fair agreement was recorded for No. of affected extranodal organs (ICC, 0.40; 95% confidence interval [CI], 0.25–0.68), overall scan result (ICC, 0.42; 95%CI, 0.28–0.57), CXCR4 density in lymphoma tissue (ICC, 0.52; 95%CI, 0.38–0.66), and No. of extranodal organ metastases (ICC, 0.55; 95%CI, 0.41–0.61) and LN involvement (ICC, 0.59; 95%CI, 0.46–0.71). Good agreement rates were observed for No. of LN metastases (ICC, 0.71; 95%CI, 0.60–0.81) and No. of LN areas (ICC, 0.73; 95%CI, 0.63–0.82), while extranodal organ involvement (ICC, 0.35; 95%CI, 0.21–0.51) achieved poor concordance. On a reader-by-reader comparison, the experienced readers achieved significantly higher agreement rates in 4/8 (50%) investigated scan items (ICC, range, 0.21–0.90, P < / = 0.04). In the remaining 4/8 (50%), a similar trend with higher ICCs for the experienced readers was recorded (n.s.).
Conclusion
CXCR4-directed PET/CT mainly provided fair to good agreement rates for scan assessment, while a relevant level of experience seems to be required for an accurate imaging read-out
Chemokine receptor–targeted PET/CT provides superior diagnostic performance in newly diagnosed marginal zone lymphoma patients: a head-to-head comparison with [18F]FDG
Background
In patients with marginal zone lymphoma (MZL), [18F]FDG PET/CT provided inconsistent diagnostic accuracy. C-X-C motif chemokine receptor 4 (CXCR4) is overexpressed in MZL and thus, may emerge as novel theranostic target. We aimed to evaluate the diagnostic performance of CXCR4-targeting [68Ga]Ga-PentixaFor when compared to [18F]FDG PET/CT in MZL.
Methods
Thirty-two untreated MZL patients (nodal, n = 17; extranodal, n = 13; splenic, n = 2) received [68Ga]Ga-PentixaFor and [18F]FDG PET/CT within median 2 days. We performed a visual and quantitative analysis of the total lymphoma volume by measuring maximum/peak standardized uptake values (SUVmax/peak), and calculating target-to-background ratios (TBR, defined as lesion-based SUVpeak divided by SUVmean from blood pool). Visual comparisons for both radiotracers were carried out for all target lesions (TL), and quantitative analysis of concordant TL evident on both scans. Last, MZL subtype analyses were also conducted.
Results
On a patient-based level, [68Ga]Ga-PentixaFor identified MZL manifestations in 32 (100%) subjects (vs. [18F]FDG, 25/32 [78.1%]). Of the 256 identified TL, 127/256 (49.6%) manifestations were evident only on CXCR4-directed imaging, while only 7/256 (2.7%) were identified on [18F]FDG but missed by [68Ga]Ga-PentixaFor. In the remaining 122/256 (47.7%) concordant TL, [68Ga]Ga-PentixaFor consistently provided increased metrics when compared to [18F]FDG: SUVmax, 10.3 (range, 2.53–37.2) vs. 5.72 (2.32–37.0); SUVpeak, 6.23 (1.58–25.7) vs. 3.87 (1.54–27.7); P < 0.01, respectively. Concordant TL TBR on [68Ga]Ga-PentixaFor (median, 3.85; range, 1.05–16.0) was also approximately 1.8-fold higher relative to [18F]FDG (median, 2.08; range, 0.81–28.8; P < 0.01). Those findings on image contrast, however, were driven by nodal MZL (P < 0.01), and just missed significance for extranodal MZL (P = 0.06).
Conclusions
In newly diagnosed MZL patients, [68Ga]Ga-PentixaFor identified more sites of disease when compared to [18F]FDG, irrespective of MZL subtype. Quantitative PET parameters including TBR were also higher on [68Ga]Ga-PentixaFor PET/CT, suggesting improved diagnostic read-out using chemokine receptor-targeted imaging
Les droits disciplinaires des fonctions publiques : « unification », « harmonisation » ou « distanciation ». A propos de la loi du 26 avril 2016 relative à la déontologie et aux droits et obligations des fonctionnaires
The production of tt‾ , W+bb‾ and W+cc‾ is studied in the forward region of proton–proton collisions collected at a centre-of-mass energy of 8 TeV by the LHCb experiment, corresponding to an integrated luminosity of 1.98±0.02 fb−1 . The W bosons are reconstructed in the decays W→ℓν , where ℓ denotes muon or electron, while the b and c quarks are reconstructed as jets. All measured cross-sections are in agreement with next-to-leading-order Standard Model predictions.The production of , and is studied in the forward region of proton-proton collisions collected at a centre-of-mass energy of 8 TeV by the LHCb experiment, corresponding to an integrated luminosity of 1.98 0.02 \mbox{fb}^{-1}. The bosons are reconstructed in the decays , where denotes muon or electron, while the and quarks are reconstructed as jets. All measured cross-sections are in agreement with next-to-leading-order Standard Model predictions
Single- and double-hit events in genes encoding immune targets before and after T cell-engaging antibody therapy in MM
T cell-engaging immunotherapies exert unprecedented single-agent activity in multiple myeloma (MM), thereby putting a yet unexplored selective pressure on the clonal architecture. In this study, we report on homozygous BCMA (TNFRSF17) gene deletion after BCMA-targeting T cell-redirecting bispecific antibody therapy in a heavily pretreated MM patient. Loss of BCMA protein expression persisted over subsequent relapses, with no response to treatmentwith anti-BCMA antibody drug conjugate. In light of the multiple alternative targets that are emerging in addition to BCMA, we extended our analyses to delineate a more complete picture of genetic alterations that may have an impact on immunotherapy targets in MM. We performed wholegenome sequencing and RNA sequencing in 100 MM patients (50 were newly diagnosed; 50 were relapsed/refractory) and identified a significant proportion of patientswith aberrations in genes encoding immunotherapy targets; GPRC5D ranked firstwith 15% heterozygous deletions, followed by CD38 (10%), SDC1 (5%), and TNFRSF17 (4%). Notably, these heterozygous deletions did not lower the expression levels of respective genes, but they may represent a first hit that drives the acquisition of homozygous deletions and subsequent antigen-loss relapse upon targeted immunotherapy. In summary, we show preexisting vulnerability in genes encoding immunotargets before and homozygous deletions after T cell-engaging immunotherapy
Approaches for bridging therapy prior to chimeric antigen receptor T cells for relapsed/refractory acute lymphoblastic B-lineage leukemia in children and young adults
The ongoing development of immunotherapies, including chimeric antigen receptor (CAR) T cells, has revolutionized cancer treatment. In pediatric relapsed/refractory B-lineage acute leukemia antiCD19-CAR induce impressive initial response rates, with event-free survival plateauing at 30-50% according to long-term follow-up data. During the interval between diagnosis of relapse or refractoriness and CAR T-cell infusion, patients require a bridging therapy. To date, this therapy has consisted of highly variable approaches based on local experience. Here, in an European collaborative effort of pediatric and adult hematologists, we summarize current knowledge with the aim of establishing guidance for bridging therapy. We discuss treatment strategies for different subgroups of patients, the advantages and disadvantages of low- and high-intensity regimens, and the potential impact of bridging therapy on outcomes after CAR T-cell infusion. This guidance is a step towards cross-institutional harmonization of bridging therapy, including personalized approaches. This will allow better comparability of clinical data and increase the level of evidence for the treatment of children and young adults with relapsed/ refractory B-lineage acute leukemia until they can receive CAR T-cell infusion
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