Tumor immune escape in acute myeloid leukemia: Class II-associated invariant chain peptide expression as result of deficient antigen presentation

In this overview, we discuss the role of class II-associated invariant chain peptide (CLIP) in acute myeloid leukemia (AML), one of the few tumors expressing HLA class II. The clinical impact, function and regulation of CLIP expression on leukemic cells is addressed, indicating its potential as immunotherapeutic target in AML

A new class of exact solutions of the Schrodinger equation

The aim of this paper is to find the exact solutions of the Schrodinger equation. As is known, the Schrodinger equation can be reduced to the continuum equation. In this paper, using the non-linear Legendre transform the equation of continuity is linearized. Particular solutions of such a linear equation are found in the paper and an inverse Legendre transform is considered for them with subsequent construction of solutions of the Schrodinger equation. Examples of the classical and quantum systems are considered.Comment: 26 pages, 34 figure

Human B Cells Engage the NCK/PI3K/RAC1 Axis to Internalize Large Particles via the IgM-BCR

Growing evidence indicate that large antigen-containing particles induce potent T cell-dependent high-affinity antibody responses. These responses require large particle internalization after recognition by the B cell receptor (BCR) on B cells. However, the molecular mechanisms governing BCR-mediated internalization remain unclear. Here we use a high-throughput quantitative image analysis approach to discriminate between B cell particle binding and internalization. We systematically show, using small molecule inhibitors, that human B cells require a SYK-dependent IgM-BCR signaling transduction via PI3K to efficiently internalize large anti-IgM-coated particles. IgM-BCR-mediated activation of PI3K involves both the adaptor protein NCK and the co-receptor CD19. Interestingly, we here reveal a strong NCK-dependence without profound requirement of the co-receptor CD19 in B cell responses to large particles. Furthermore, we demonstrate that the IgM-BCR/NCK signaling event facilitates RAC1 activation to promote actin cytoskeleton remodeling necessary for particle engulfment. Thus, we establish NCK/PI3K/RAC1 as an attractive IgM-BCR signaling axis for biological intervention to prevent undesired antibody responses to large particles

Patient-reported daily functioning after SARS-CoV-2 vaccinations in autoimmune neuromuscular diseases

Background and purpose: There are concerns for safety regarding SARS-CoV-2 vaccines for patients with autoimmune neuromuscular disease. We compared daily functioning using disease-specific patient-reported outcome measures (PROMs) before and after SARS-CoV-2 vaccinations. Methods: In this substudy of a prospective observational cohort study (Target-to-B!), patients with myasthenia gravis (MG), chronic inflammatory demyelinating polyneuropathy (CIDP), multifocal motor neuropathy (MMN), and idiopathic inflammatory myopathy (IIM) vaccinated against SARS-CoV-2 were included. Surveys of daily functioning (Myasthenia Gravis Activities of Daily Living, Inflammatory Rasch-Built Overall Disability Scale, Multifocal Motor Neuropathy Rasch-Built Overall Disability Scale, and Health Assessment Questionnaire-Disability Index) were sent before first vaccination and every 60 days thereafter for up to 12 months. Regression models were constructed to assess differences in PROM scores related to vaccination, compared to scores unrelated to vaccination. We also assessed the proportion of patients with deterioration of at least the minimal clinically important difference (MCID) between before first vaccination and 60 days thereafter. Results: We included 325 patients (median age = 59 years, interquartile range = 47-67, 156 [48%] female sex), of whom 137 (42%) had MG, 79 (24%) had CIDP, 43 (13%) had MMN, and 66 (20%) had IIM. PROM scores related to vaccination did not differ from scores unrelated to vaccination. In paired PROMs, MCID for deterioration was observed in three of 49 (6%) MG patients, of whom none reported a treatment change. In CIDP, MCID for deterioration was observed in eight of 29 patients (28%), of whom two of eight (25%) reported a treatment change. Conclusions: SARS-CoV-2 vaccination had no effect on daily functioning in patients with autoimmune neuromuscular diseases, confirming its safety in these patients

Clinical use of tolerogenic dendritic cells-harmonization approach in european collaborative effort

Altres ajuts: IWT/TBM/140191The number of patients with autoimmune diseases and severe allergies and recipients of transplants increases worldwide. Currently, these patients require lifelong administration of immunomodulatory drugs. Often, these drugs are expensive and show immediate or late-occurring severe side effects. Treatment would be greatly improved by targeting the cause of autoimmunity, that is, loss of tolerance to self-antigens. Accumulating knowledge on immune mechanisms has led to the development of tolerogenic dendritic cells (tolDC), with the specific objective to restrain unwanted immune reactions in the long term. The first clinical trials with tolDC have recently been conducted and more tolDC trials are underway. Although the safety trials have been encouraging, many questions relating to tolDC, for example, cell-manufacturing protocols, administration route, amount and frequency, or mechanism of action, remain to be answered. Aiming to join efforts in translating tolDC and other tolerogenic cellular products (e.g., Tregs and macrophages) to the clinic, a European COST (European Cooperation in Science and Technology) network has been initiated-A FACTT (action to focus and accelerate cell-based tolerance-inducing therapies). A FACTT aims to minimize overlap and maximize comparison of tolDC approaches through establishment of minimum information models and consensus monitoring parameters, ensuring that progress will be in an efficient, safe, and cost-effective way

Induction of brain-infiltrating T-bet–expressing B cells in multiple sclerosis

Objective: Results from anti-CD20 therapies demonstrate that B- and T-cell interaction is a major driver of multiple sclerosis (MS). The local presence of B-cell follicle-like structures and oligoclonal bands in MS patients indicates that certain B cells infiltrate the central nervous system (CNS) to mediate pathology. Which peripheral triggers underlie the development of CNS-infiltrating B cells is not fully understood. Methods: Ex vivo flow cytometry was used to assess chemokine receptor profiles of B cells in blood, cerebrospinal fluid, meningeal, and brain tissues of MS patients (n = 10). Similar analyses were performed for distinct memory subsets in the blood of untreated and natalizumab-treated MS patients (n = 38). To assess T-bet(CXCR3)+ B-cell differentiation, we cultured B cells from MS patients (n = 21) and healthy individuals (n = 34) under T helper 1- and TLR9-inducing conditions. Their CNS transmigration capacity was confirmed using brain endothelial monolayers. Results: CXC chemokine receptor 3 (CXCR3)-expressing B cells were enriched in different CNS compartments of MS patients. Treatment with the clinically effective drug natalizumab prevented the recruitment of CXCR3high IgG1+ subsets, corresponding to their increased ability to cross CNS barriers in vitro. Blocking of interferon-γ (IFNγ) reduced the transmigration potential and antigen-presenting function of these cells. IFNγ-induced B cells from MS patients showed increased T-bet expression and plasmablast development. Additional TLR9 triggering further upregulated T-bet and CXCR3, and was essential for IgG1 switching. Interpretation: This study demonstrates that T-bethigh IgG1+ B cells are triggered by IFNγ and TLR9 signals, likely contributing to enhanced CXCR3-mediated recruitment and local reactivity in the CNS of MS patients. ANN NEUROL 2019

Can hysterosalpingo-foam sonography replace hysterosalpingography as first-choice tubal patency test? A randomized non-inferiority trial

Funding Information: The FOAM study was an investigator-initiated study funded by ZonMw, The Netherlands organization for Health Research and Development (project number 837001504). ZonMw funded the whole project. IQ Medical Ventures provided the ExEm-foamVR kits free of charge. The funders had no role in study design, collection, analysis and interpretation of the data. The corresponding author had full access to all the data in the study and had final responsibility for the decision to submit for publication.Peer reviewedPublisher PD

Promiscuous Binding of Invariant Chain-Derived CLIP Peptide to Distinct HLA-I Molecules Revealed in Leukemic Cells

Antigen presentation by HLA class I (HLA-I) and HLA class II (HLA-II) complexes is achieved by proteins that are specific for their respective processing pathway. The invariant chain (Ii)-derived peptide CLIP is required for HLA-II-mediated antigen presentation by stabilizing HLA-II molecules before antigen loading through transient and promiscuous binding to different HLA-II peptide grooves. Here, we demonstrate alternative binding of CLIP to surface HLA-I molecules on leukemic cells. In HLA-II-negative AML cells, we found plasma membrane display of the CLIP peptide. Silencing Ii in AML cells resulted in reduced HLA-I cell surface display, which indicated a direct role of CLIP in the HLA-I antigen presentation pathway. In HLA-I-specific peptide eluates from B-LCLs, five Ii-derived peptides were identified, of which two were from the CLIP region. In vitro peptide binding assays strikingly revealed that the eluted CLIP peptide RMATPLLMQALPM efficiently bound to four distinct HLA-I supertypes (-A2, -B7, -A3, -B40). Furthermore, shorter length variants of this CLIP peptide also bound to these four supertypes, although in silico algorithms only predicted binding to HLA-A2 or -B7. Immunization of HLA-A2 transgenic mice with these peptides did not induce CTL responses. Together these data show a remarkable promiscuity of CLIP for binding to a wide variety of HLA-I molecules. The found participation of CLIP in the HLA-I antigen presentation pathway could reflect an aberrant mechanism in leukemic cells, but might also lead to elucidation of novel processing pathways or immune escape mechanisms

Alternative Ii-independent antigen-processing pathway in leukemic blasts involves TAP-dependent peptide loading of HLA class II complexes

During HLA class II synthesis in antigen-presenting cells, the invariant chain (Ii) not only stabilizes HLA class II complexes in the endoplasmic reticulum, but also mediates their transport to specialized lysosomal antigen-loading compartments termed MIICs. This study explores an alternative HLA class II presentation pathway in leukemic blasts that involves proteasome and transporter associated with antigen processing (TAP)-dependent peptide loading. Although HLA-DR did associate with Ii, Ii silencing in the human class II-associated invariant chain peptide (CLIP)-negative KG-1 myeloid leukemic cell line did not affect total and plasma membrane expression levels of HLA-DR, as determined by western blotting and flow cytometry. Since HLA-DR expression does require peptide binding, we examined the role of endogenous antigen-processing machinery in HLA-DR presentation by CLIP− leukemic blasts. The suppression of proteasome and TAP function using various inhibitors resulted in decreased HLA-DR levels in both CLIP− KG-1 and ME-1 blasts. Simultaneous inhibition of TAP and Ii completely down-modulated the expression of HLA-DR, demonstrating that together these molecules form the key mediators of HLA class II antigen presentation in leukemic blasts. By the use of a proteasome- and TAP-dependent pathway for HLA class II antigen presentation, CLIP− leukemic blasts might be able to present a broad range of endogenous leukemia-associated peptides via HLA class II to activate leukemia-specific CD4+ T cells

Hysterosalpingo-foam sonography versus hysterosalpingography during fertility work-up: an economic evaluation alongside a randomized controlled trial

STUDY QUESTION: What are the costs and effects of tubal patency testing by hysterosalpingo-foam sonography (HyFoSy) compared to hysterosalpingography (HSG) in infertile women during the fertility work-up? SUMMARY ANSWER: During the fertility work-up, clinical management based on the test results of HyFoSy leads to slightly lower, though not statistically significant, live birth rates, at lower costs, compared to management based on HSG results. WHAT IS KNOWN ALREADY: Traditionally, tubal patency testing during the fertility work-up is performed by HSG. The FOAM trial, formally a non-inferiority study, showed that management decisions based on the results of HyFoSy resulted in a comparable live birth rate at 12 months compared to HSG (46% versus 47%; difference −1.2%, 95% CI: −3.4% to 1.5%; P¼ 0.27). Compared to HSG, HyFoSy is associated with significantly less pain, it lacks ionizing radiation and exposure to iodinated contrast medium. Moreover, HyFoSy can be performed by a gynaecologist during a one-stop fertility work-up. To our knowledge, the costs of both strategies have never been compared. STUDY DESIGN, SIZE, DURATION: We performed an economic evaluation alongside the FOAM trial, a randomized multicenter study conducted in the Netherlands. Participating infertile women underwent, both HyFoSy and HSG, in a randomized order. The results of both tests were compared and women with discordant test results were randomly allocated to management based on the results of one of the tests. The follow-up period was twelve months. PARTICIPANTS/MATERIALS, SETTING, METHODS: We studied 1160 infertile women (18–41 years) scheduled for tubal patency testing. The primary outcome was ongoing pregnancy leading to live birth. The economic evaluation compared costs and effects of management based on either test within 12 months. We calculated incremental cost-effectiveness ratios (ICERs): the difference in total costs and chance of live birth. Data were analyzed using the intention to treat principle. MAIN RESULTS AND THE ROLE OF CHANCE: Between May 2015 and January 2019, 1026 of the 1160 women underwent both tubal tests and had data available: 747 women with concordant results (48% live births), 136 with inconclusive results (40% live births), and 143 with discordant results (41% had a live birth after management based on HyFoSy results versus 49% with live birth after management based on HSG results). When comparing the two strategies—management based on HyfoSy results versus HSG results—the estimated chance of live birth was 46% after HyFoSy versus 47% after HSG (difference −1.2%; 95% CI: −3.4% to 1.5%). For the procedures itself, HyFoSy cost e136 and HSG e280. When costs of additional fertility treatments were incorporated, the mean total costs per couple were e3307 for the HyFoSy strategy and e3427 for the HSG strategy (mean difference e−119; 95% CI: e−125 to e−114). So, while HyFoSy led to lower costs per couple, live birth rates were also slightly lower. The ICER was e10 042, meaning that by using HyFoSy instead of HSG we would save e10 042 per each additional live birth lost. LIMITATIONS, REASONS FOR CAUTION: When interpreting the results of this study, it needs to be considered that there was a considerable uncertainty around the ICER, and that the direct fertility enhancing effect of both tubal patency tests was not incorporated as women underwent both tubal patency tests in this study. WIDER IMPLICATION OF THE FINDINGS: Compared to clinical management based on HSG results, management guided by HyFoSy leads to slightly lower live birth rates (though not statistically significant) at lower costs, less pain, without ionizing radiation and iodinated contrast exposure. Further research on the comparison of the direct fertility-enhancing effect of both tubal patency tests is needed. STUDY FUNDING/COMPETING INTEREST(S): FOAM trial was an investigator-initiated study, funded by ZonMw, a Dutch organization for Health Research and Development (project number 837001504). IQ Medical Ventures provided the ExEm®-FOAM kits free of charge. The funders had no role in study design, collection, analysis, and interpretation of the data. K.D. reports travel-and speakers fees from Guerbet and her department received research grants from Guerbet outside the submitted work. H.R.V. received consulting—and travel fee from Ferring. A.M.v.P. reports received consulting fee from DEKRA and fee for an expert meeting from Ferring, both outside the submitted work. C.H.d.K. received travel fee from Merck. F.J.M.B. received a grant from Merck and speakers fee from Besins Healthcare. F.J.M.B. is a member of the advisory board of Merck and Ferring. J.v.D. reported speakers fee from Ferring. J.S. reports a research agreement with Takeda and consultancy for Sanofi on MR of motility outside the submitted work. M.v.W. received a travel grant from Oxford Press in the role of deputy editor for Human Reproduction and participates in a DSMB as independent methodologist in obstetrics studies in which she has no other role. B.W.M. received an investigator grant from NHMRC GNT1176437. B.W.M. reports consultancy for ObsEva, Merck, Guerbet, iGenomix, and Merck KGaA and travel support from Merck KGaA. V.M. received research grants from Guerbet, Merck, and Ferring and travel and speakers fees from Guerbet. The other authors do not report conflicts of interest. TRIAL REGISTRATION NUMBER: International Clinical Trials Registry Platform No. NTR4746