Search Results Heading

MBRLSearchResults

mbrl.module.common.modules.added.book.to.shelf
Title added to your shelf!
View what I already have on My Shelf.
Oops! Something went wrong.
Oops! Something went wrong.
While trying to add the title to your shelf something went wrong :( Kindly try again later!
Are you sure you want to remove the book from the shelf?
Oops! Something went wrong.
Oops! Something went wrong.
While trying to remove the title from your shelf something went wrong :( Kindly try again later!
    Done
    Filters
    Reset
  • Language
      Language
      Clear All
      Language
  • Subject
      Subject
      Clear All
      Subject
  • Item Type
      Item Type
      Clear All
      Item Type
  • Discipline
      Discipline
      Clear All
      Discipline
  • Year
      Year
      Clear All
      From:
      -
      To:
  • More Filters
19 result(s) for "Rogel, Anne"
Sort by:
Fcγ receptor binding is required for maximal immunostimulation by CD70-Fc
T cell expressed CD27 provides costimulation upon binding to inducible membrane expressed trimeric CD70 and is required for protective CD8 T cell responses. CD27 agonists could therefore be used to bolster cellular vaccines and anti-tumour immune responses. To date, clinical development of CD27 agonists has focussed on anti-CD27 antibodies with little attention given to alternative approaches. Here, we describe the generation and activity of soluble variants of CD70 that form either trimeric (t) or dimer-of-trimer proteins and conduct side-by-side comparisons with an agonist anti-CD27 antibody. To generate a dimer-of-trimer protein (dt), we fused three extracellular domains of CD70 to the Fc domain of mouse IgG1 in a 'string of beads' configuration (dtCD70-Fc). Whereas tCD70 failed to costimulate CD8 T cells, both dtCD70-Fc and an agonist anti-CD27 antibody were capable of enhancing T cell proliferation . Initial studies demonstrated that dtCD70-Fc was less efficacious than anti-CD27 in boosting a CD8 T cell vaccine response , concomitant with rapid clearance of dtCD70-Fc from the circulation. The accelerated plasma clearance of dtCD70-Fc was not due to the lack of neonatal Fc receptor binding but was dependent on the large population of oligomannose type glycosylation. Enzymatic treatment to reduce the oligomannose-type glycans in dtCD70-Fc improved its half-life and significantly enhanced its T cell stimulatory activity surpassing that of anti-CD27 antibody. We also show that whereas the ability of the anti-CD27 to boost a vaccine response was abolished in Fc gamma receptor (FcγR)-deficient mice, dtCD70-Fc remained active. By comparing the activity of dtCD70-Fc with a variant (dtCD70-Fc(D265A)) that lacks binding to FcγRs, we unexpectedly found that FcγR binding to dtCD70-Fc was required for maximal boosting of a CD8 T cell response . Interestingly, both dtCD70-Fc and dtCD70-Fc(D265A) were effective in prolonging the survival of mice harbouring BCL1 B cell lymphoma, demonstrating that a substantial part of the stimulatory activity of dtCD70-Fc in this setting is retained in the absence of FcγR interaction. These data reveal that TNFRSF ligands can be generated with a tunable activity profile and suggest that this class of immune agonists could have broad applications in immunotherapy.
Fcγ receptor–mediated cross-linking codefines the immunostimulatory activity of anti-human CD96 antibodies
New strategies that augment T cell responses are required to broaden the therapeutic arsenal against cancer. CD96, TIGIT, and CD226 are receptors that bind to a communal ligand, CD155, and transduce either inhibitory or activating signals. The function of TIGIT and CD226 is established, whereas the role of CD96 remains ambiguous. Using a panel of engineered antibodies, we discovered that the T cell stimulatory activity of anti-CD96 antibodies requires antibody cross-linking and is potentiated by Fcγ receptors. Thus, soluble \"Fc silent\" anti-CD96 antibodies failed to stimulate human T cells, whereas the same antibodies were stimulatory after coating onto plastic surfaces. Remarkably, the activity of soluble anti-CD96 antibodies was reinstated by engineering the Fc domain to a human IgG1 isotype, and it was dependent on antibody trans-cross-linking by FcγRI. In contrast, neither human IgG2 nor variants with increased Fcγ receptor IIB binding possessed stimulatory activity. Anti-CD96 antibodies acted directly on T cells and augmented gene expression networks associated with T cell activation, leading to proliferation, cytokine secretion, and resistance to Treg suppression. Furthermore, CD96 expression correlated with survival in HPV+ head and neck squamous cell carcinoma, and its cross-linking activated tumor-infiltrating T cells, thus highlighting the potential of anti-CD96 antibodies in cancer immunotherapy.
MELOE-1 Antigen Contains Multiple HLA Class II T Cell Epitopes Recognized by Th1 CD4+ T Cells from Melanoma Patients
MELOE-1 is an overexpressed melanoma antigen containing a HLA-A2 restricted epitope, involved in melanoma immunosurveillance of patients adoptively transferred with tumour infiltrating lymphocytes (TIL). The use of the full-length antigen (46 aa) for anti-melanoma vaccination could be considered, subject to the presence of Th epitopes all along MELOE-1 sequence. Thus, in this study we evaluated in vitro the immunoprevalence of the different regions of MELOE-1 (i.e. their ability to induce CD4 T cell responses in vitro from PBMC). Stimulation of PBMC from healthy subjects with MELOE-1 induced the amplification of CD4 T cells specific for various regions of the protein in multiple HLA contexts, for each tested donor. We confirmed these results in a panel of melanoma patients, and documented that MELOE-1 specific CD4 T cells, were mainly Th1 cells, presumably favourable to the amplification of CD8 specific T cells. Using autologous DC, we further showed that these class II epitopes could be naturally processed from MELOE-1 whole protein and identified minimal epitopes derived from each region of MELOE-1, and presented in four distinct HLA contexts. In conclusion, vaccination with MELOE-1 whole polypeptide should induce specific Th1 CD4 responses in a majority of melanoma patients, stimulating the amplification of CD8 effector cells, reactive against melanoma cells.
Akt signaling is critical for memory CD8⁺ T-cell development and tumor immune surveillance
Memory CD8⁺ T cells confer long-term immunity against tumors, and anticancer vaccines therefore should maximize their generation. Multiple memory CD8⁺ T-cell subsets with distinct functional and homing characteristics exist, but the signaling pathways that regulate their development are ill defined. Here we examined the role of the serine/threonine kinase Akt in the generation of protective immunity by CD8⁺ T cells. Akt is known to be activated by the T-cell antigen receptor and the cytokine IL-2, but its role in T-cell immunity in vivo has not been explored. Using CD8⁺ T cells from pdk1K465E/K465E knockin mice, we found that decreased Akt activity inhibited the survival of T cells during the effector-to-memory cell transition and abolished their differentiation into C-X-C chemokine receptor 3 (CXCR3)loCD43lo effector-like memory cells. Consequently, antitumor immunity by CD8⁺ T cells that display defective Akt signaling was substantially diminished during the memory phase. Reduced memory T-cell survival and altered memory cell differentiation were associated with up-regulation of the proapoptotic protein Bim and the T-box transcription factor eomesodermin, respectively. These findings suggest an important role for effector-like memory CD8⁺ T cells in tumor immune surveillance and identify Akt as a key signaling node in the development of protective memory CD8⁺ T-cell responses.
long peptide from MELOE-1 contains multiple HLA class II T cell epitopes in addition to the HLA-A0201 epitope: an attractive candidate for melanoma vaccination
CD4⁺ T cells contribute importantly to the antitumor T cell response, and thus, long peptides comprising CD4 and CD8 epitopes may be efficient cancer vaccines. We have previously identified an overexpressed antigen in melanoma, MELOE-1, presenting a CD8⁺ T cell epitope, MELOE-1₃₆₋₄₄, in the HLA-A*0201 context. A T cell repertoire against this epitope is present in HLA-A*0201+ healthy subjects and melanoma patients and the adjuvant injection of TIL containing MELOE-1 specific CD8⁺ T cells to melanoma patients was shown to be beneficial. In this study, we looked for CD4⁺ T cell epitopes in the vicinity of the HLA-A*0201 epitope. Stimulation of PBMC from healthy subjects with MELOE-1₂₆₋₄₆ revealed CD4 responses in multiple HLA contexts and by cloning responsive CD4⁺ T cells, we identified one HLA-DRβ1*1101-restricted and one HLA-DQβ1*0603-restricted epitope. We showed that the two epitopes could be efficiently presented to CD4⁺ T cells by MELOE-1-loaded dendritic cells but not by MELOE-1+ melanoma cell-lines. Finally, we showed that the long peptide MELOE-1₂₂₋₄₆, containing the two optimal class II epitopes and the HLA-A*0201 epitope, was efficiently processed by DC to stimulate CD4⁺ and CD8⁺ T cell responses in vitro, making it a potential candidate for melanoma vaccination.
A gut microbiota rheostat forecasts responsiveness to PD-L1 and VEGF blockade in mesothelioma
Malignant mesothelioma is a rare tumour caused by asbestos exposure that originates mainly from the pleural lining or the peritoneum. Treatment options are limited, and the prognosis is dismal. Although immune checkpoint blockade (ICB) can improve survival outcomes, the determinants of responsiveness remain elusive. Here, we report the outcomes of a multi-centre phase II clinical trial (MiST4, NCT03654833) evaluating atezolizumab and bevacizumab (AtzBev) in patients with relapsed mesothelioma. We also use tumour tissue and gut microbiome sequencing, as well as tumour spatial immunophenotyping to identify factors associated with treatment response. MIST4 met its primary endpoint with 50% 12-week disease control, and the treatment was tolerable. Aneuploidy, notably uniparental disomy (UPD), homologous recombination deficiency (HRD), epithelial-mesenchymal transition and inflammation with CD68 + monocytes were identified as tumour-intrinsic resistance factors. The log-ratio of gut-resident microbial genera positively correlated with radiological response to AtzBev and CD8 + T cell infiltration, but was inversely correlated with UPD, HRD and tumour infiltration by CD68 + monocytes. In summary, a model is proposed in which both intrinsic and extrinsic determinants in mesothelioma cooperate to modify the tumour microenvironment and confer clinical sensitivity to AtzBev. Gut microbiota represent a potentially modifiable factor with potential to improve immunotherapy outcomes for individuals with this cancer of unmet need. Although immune checkpoint blockade is a standard treatment for patients with malignant mesothelioma, only a minority of patients exhibit radiological response. In a phase II clinical trial (MIST4) investigating the efficacy, safety and molecular correlates of response following treatment with atezolizumab and bevacizumab, the authors demonstrate that the gut microbiota may modulate responsiveness to treatment.
Incidence of major smoking-related cancers: Trends among adults aged 20–44 in France from 1982 to 2012
•Cancer registry data over the last 30 years among young adults were modeled.•In men, a decline was observed for lung, lip-oral cavity-pharynx and esophagus.•In women, a large increase was observed for lung cancer.•Incidence trends of smoking-related cancers among women aged 20–44 is worrying. Tobacco is currently the largest risk factor for cancers of the lung, lip/oral cavity/pharynx (LOCP) and esophagus. Variations in tobacco consumption over time have led to changes in cancer incidence in the general population. Data on the incidence of cancers at these sites in adults aged 20–44 years old are scarce. Our objective was to provide estimates of incidence trends for these cancers in France among this age group over the last 30 years. Observed incidence data over the period 1982–2010 for the 20–44 age group were provided from six cancer registries (eight for esophagus) covering approximately 6% of the French population. Age–period–cohort models were used on the observed period, and estimates of cancer incidence for France in 2012 were provided on the basis of short-term predictions. In men, a sharp decline was observed over time for LOCP and esophageal cancers, while lung cancer saw only a slight decline. In women, a large increase was seen in lung cancer incidence, while LOCP cancer incidence did not vary significantly. Smoking behaviors among adults aged 20–44 impact incidence trends in cancers of the lung, LOCP and esophagus, although other factors are involved, particularly in LOCP and esophageal cancers. Our results highlight the importance of preventative efforts which particularly target women aged 20–44. Efforts to curb tobacco smoking in men should also be pursued.
Fabrication of polycrystalline silicon nanowires using conventional UV lithography
Silicon nanowires are processed by using the sidewall spacer formation technique. This technique uses craftily a drawback of anisotropic etching to go beyond optical limits with conventional UV lithography for precision patterns. The final width of the spacer is controlled by the steepness of the etching side and by the uniformity of the wall recovering layer. In our process, a polysilicon layer is deposited by low pressure chemical vapour deposition technique on SiO2 wall network patterned by conventional UV lithography technique. Accurate control of the etching rate of the polysilicon leads to the formation of nanometric size sidewall spacers with a curvature radius below 100nm. Networks of such parallel polysilicon nanowires were electrically tested in function of temperature (530K300K) with thermal activation EA ∼ 0.3 eV