Search

Copyright of Transfusiology & Haematology Today / Transfuze a Hematologie Dnes is the property of Czech Medical Association of JE Purkyne and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Transfusiology & Haematology Today / Transfuze a Hematologie Dnes is the property of Czech Medical Association of JE Purkyne and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

cThe author draws attention to the importance of m. semispinalis capitis, which enables quick to perform rotation movement of the head. It is a highly useful target in cervical dystonia with predominant rotation. [ABSTRACT FROM AUTHOR]

Aims: To evaluate antibody response to mRNA vaccine, identify subgroups with poor response and to determine long-term antibody durability in hematological patients., Materials and Methods: We have vaccinated 292 patients with all hematological malignancies with a third dose of mRNA COMIRNATY vaccine with a 12-month follow-up period in our center in Ostrava, Czech Republic., Results: Antibody response for the whole cohort exceeded 74% through the whole 12-month follow-up. Lowest seroconversion was observed in CLL cohort (20/41, 48.8%), patients who received anti-CD20 therapy < 6 months before vaccination (8/30, 26.7%) and BTK inhibitors (3/6, 50.0%). On the contrary, patients with chronic myeloproliferative neoplasms and acute leukemia performed comparably with healthy population (33/33; 100% and 12/13; 92.3%, respectively). We have seen better results if the time interval between anti-CD20 therapy and additional vaccine dose was longer than 6 months (5/8 patients achieved seroconversion on 4th booster dose after previous failure). Also, 36 patients received a 4th dose of vaccine as a booster with measurable increase in protective antibodies in 50% (18/36)., Conclusions: Additional doses show promise for a well-timed revaccination even in poor responders. To our knowledge, no study comparable to our work in terms of follow-up length, vaccine consistency or variety of hematological malignancies and/or treatment has been reported yet. Our findings shed more light on long-term antibody response to mRNA vaccines against SARS-CoV-2 in patients with hematological cancer and bring important data for the evaluation of possible vaccine failure and scheduling of subsequent doses., (© 2024 The Author(s). Cancer Medicine published by John Wiley & Sons Ltd.)

Gonorrhoea, caused by Neisseria gonorrhoeae, is a common sexually transmitted infection. Increasing multi-drug resistance and the impact of asymptomatic infections on sexual and reproductive health underline the need for an effective gonococcal vaccine. Outer membrane vesicles (OMVs) from Neisseria meningitidis induce modest cross-protection against gonococcal infection. However, the presence of proteins in OMVs derived from N. gonorrhoeae that manipulate immune responses could hamper their success as a vaccine. Here we modified two key immunomodulatory proteins of the gonococcus; RmpM, which can elicit 'blocking antibodies', and PorB, an outer membrane porin which contributes to immunosuppression. As meningococcal PorB has adjuvant properties, we replaced gonococcal PorB with a meningococcal PorB. Immunisation with OMVs from N. gonorrhoeae lacking rmpM and expressing meningococcal porB elicited higher antibody titres against model antigens in mice compared to OMVs with native PorB. Further, a gonococcal protein microarray revealed stronger IgG antibody responses to a more diverse range of antigens in the Nm PorB OMV immunised group. Finally, meningococcal PorB OMVs resulted in a Th1-skewed response, exemplified by increased serum IgG2a antibody responses and increased IFNɣ production by splenocytes from immunised mice. In summary, we demonstrate that the replacement of PorB in gonococcal OMVs enhances immune responses and offers a strategy for gonococcal vaccine development., Competing Interests: RAJ and CMT are co-inventors on a patent describing the use of gonococcal OMVs with meningococcal PorB., (Copyright: This is an open access article, free of all copyright, and may be freely reproduced, distributed, transmitted, modified, built upon, or otherwise used by anyone for any lawful purpose. The work is made available under the Creative Commons CC0 public domain dedication.)

Introduction: Communities of Practice (CoP) were created to up-skill educators and to mitigate the disruption to physical therapist assistant (PTA) education because of the COVID-19 pandemic. Understanding CoP involves considering individuals and their interactions, making this project significant for pioneering CoP among PTA educators, and using social network analysis (SNA). The research question for this mixed-methods concurrent triangulation study was "To what extent did the network structure of virtual CoP reflect PTA educators' perceptions of participation and mentorship?", Subjects: Forty of 60 CoP members participated in this study., Methods: We analyzed 8 virtual PTA educator CoP that met over 4 months. Study participants completed a questionnaire about their experiences, engagement, and network connections. Individual and group-level friendship and mentorship network measures were studied using SNA. Qualitative responses were analyzed using the case study design approach. All results were integrated to draw out the complexity of the PTA educator CoP., Results: There was high engagement, with 97.5% (n = 39) reporting they would participate again, and 80% (n = 32) resolved an immediate issue affecting their role. Moreover, 92.5% (n = 37) reported a perception of encouragement with the environment. Study participants reported being mentored by an average of 1.2 individuals (median 0, range 0-5) and serving as mentors to an average of 1.4 individuals (median 0, range 0-7). Two themes, unity and knowledge, emerged through the qualitative analysis., Discussion and Conclusion: Participation by PTA educators in CoP, whether focused on administration, teaching methods, or clinical education, brings valuable outcomes. Our research supports existing literature in physical therapy education. We discovered that participant engagement, nurturing mentor relationships, encouraging knowledge sharing, and promoting a sense of unity among educators are all important factors., Competing Interests: The authors declare no conflicts of interest., (Copyright © 2024 Academy of Physical Therapy Education, APTA.)

Background: To evaluate the outcomes of first-line imatinib versus nilotinib treatment for chronic myeloid leukemia in the chronic phase (CML-CP) in real-world clinical practice., Methods: A propensity score analysis was performed to eliminate imbalances between the treatment groups. In the analysis, 163 patients in the nilotinib group and 163 patients in the matched imatinib group were retrospectively evaluated., Results: Nilotinib-treated patients achieved complete cytogenetic response (CCyR) and major molecular response more rapidly than imatinib-treated patients. However, there was no significant difference in 5-year overall survival (OS) or progression-free survival (PFS) between the two groups (OS: 94.3% vs. 90.5%, p = 0.602; PFS: 92.9% vs. 88.0%, p = 0.614). Nilotinib-treated patients had a higher failure-free survival (FFS) and event-free survival (EFS) than imatinib-treated patients (FFS: 71.7% vs. 54.3%, p = 0.040; EFS: 71.7% vs. 53.5%, p = 0.025)., Conclusions: This retrospective analysis from clinical practice did not confirm any benefit of frontline nilotinib treatment for OS and PFS; however, it did demonstrate higher FFS and EFS in the nilotinib cohort., (© 2024 The Author(s). Cancer Medicine published by John Wiley & Sons Ltd.)

Development of a vaccine against gonorrhoea is a global priority, driven by the rise in antibiotic resistance. Although Neisseria gonorrhoeae (Ng) infection does not induce substantial protective immunity, highly exposed individuals may develop immunity against re-infection with the same strain. Retrospective epidemiological studies have shown that vaccines containing Neisseria meningitidis (Nm) outer membrane vesicles (OMVs) provide a degree of cross-protection against Ng infection. We conducted a clinical trial (NCT04297436) of 4CMenB (Bexsero, GSK), a licensed Nm vaccine containing OMVs and recombinant antigens, comprising a single arm, open label study of two doses with 50 adults in coastal Kenya who have high exposure to Ng. Data from a Ng antigen microarray established that serum IgG and IgA reactivities against the gonococcal homologs of the recombinant antigens in the vaccine peaked at 10 but had declined by 24 weeks. For most reactive OMV-derived antigens, the reverse was the case. A cohort of similar individuals with laboratory-confirmed gonococcal infection were compared before, during, and after infection: their reactivities were weaker and differed from the vaccinated cohort. We conclude that the cross-protection of the 4CMenB vaccine against gonorrhoea could be explained by cross-reaction against a diverse selection of antigens derived from the OMV component., (© 2024. The Author(s).)

Smoldering multiple myeloma (SMM) is an asymptomatic precursor to active multiple myeloma (MM). The aim of this study was to report clinical characteristics and outcomes of patients with SMM stratified based on their risk of progression to MM using the Mayo 20/2/20 criteria. Data were leveraged from the Czech Myeloma Group Registry of Monoclonal Gammopathies (RMG). Key outcomes included progression-free survival from SMM diagnosis to active MM diagnosis or death (PFS), progression-free survival from SMM diagnosis to progression on first line (1 L) MM treatment or death (PFS2), and overall survival (OS). Of 498 patients, 174 (34.9%) were classified as high risk and 324 (65.1%) as non-high risk. Median follow-up was approximately 65 months. During follow-up, more patients in the high-risk vs non-high-risk group received 1 L MM treatment (76.4% vs 46.6%, p < 0.001). PFS, PFS2, and OS were significantly shorter in high-risk vs non-high-risk patients (13.2 vs 56.6 months, p < 0.001; 49.9 vs 84.9 months, p < 0.001; 93.2 vs 131.1 months, p = 0.012, respectively). The results of this study add to the growing body of evidence that patients with high-risk vs non-high-risk SMM have significantly worse outcomes, including OS., (© 2023. Springer Nature Limited.)

Patients with chronic lymphocytic leukemia (CLL) have a high risk of poor outcomes related to coronavirus disease 2019 (COVID-19). This multicenter cohort study evaluated the impact of COVID-19 infection on the population of CLL patients in the Czech Republic. Between March 2020 and May 2021, 341 patients (237 males) with CLL and COVID-19 disease were identified. The median age was 69 years (range 38-91). Out of the 214 (63%) patients with the history of therapy for CLL, 97 (45%) were receiving CLL-directed treatment at diagnosis of COVID-19: 29% Bruton tyrosine kinase inhibitor (BTKi), 16% chemoimmunotherapy (CIT), 11% Bcl-2 inhibitor, and 4% phosphoinositide 3-kinase inhibitor. Regarding the severity of COVID-19, 60% pts required admission to the hospital, 21% pts were admitted to the intensive care unit (ICU), and 12% received invasive mechanical ventilation. The overall case fatality rate was 28%. Major comorbidities, age over 72, male gender, CLL treatment in history, CLL-directed treatment at COVID-19 diagnosis were associated with increased risk of death. Of note, concurrent therapy with BTKi compared to CIT was not associated with better outcome of COVID-19., (© 2023. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

The emergence of SARS-CoV-2 variants has exacerbated the COVID-19 global health crisis. Thus far, all variants carry mutations in the spike glycoprotein, which is a critical determinant of viral transmission being responsible for attachment, receptor engagement and membrane fusion, and an important target of immunity. Variants frequently bear truncations of flexible loops in the N-terminal domain (NTD) of spike; the functional importance of these modifications has remained poorly characterised. We demonstrate that NTD deletions are important for efficient entry by the Alpha and Omicron variants and that this correlates with spike stability. Phylogenetic analysis reveals extensive NTD loop length polymorphisms across the sarbecoviruses, setting an evolutionary precedent for loop remodelling. Guided by these analyses, we demonstrate that variations in NTD loop length, alone, are sufficient to modulate virus entry. We propose that variations in NTD loop length act to fine-tune spike; this may provide a mechanism for SARS-CoV-2 to navigate a complex selection landscape encompassing optimisation of essential functionality, immune-driven antigenic variation and ongoing adaptation to a new host., (© 2022 The Authors. Published under the terms of the CC BY 4.0 license.)

E1 and E2 (E1E2), the fusion proteins of Hepatitis C Virus (HCV), are unlike that of any other virus yet described, and the detailed molecular mechanisms of HCV entry/fusion remain unknown. Hypervariable region-1 (HVR-1) of E2 is a putative intrinsically disordered protein tail. Here, we demonstrate that HVR-1 has an autoinhibitory function that suppresses the activity of E1E2 on free virions; this is dependent on its conformational entropy. Thus, HVR-1 is akin to a safety catch that prevents premature triggering of E1E2 activity. Crucially, this mechanism is turned off by host receptor interactions at the cell surface to allow entry. Mutations that reduce conformational entropy in HVR-1, or genetic deletion of HVR-1, turn off the safety catch to generate hyper-reactive HCV that exhibits enhanced virus entry but is thermally unstable and acutely sensitive to neutralising antibodies. Therefore, the HVR-1 safety catch controls the efficiency of virus entry and maintains resistance to neutralising antibodies. This discovery provides an explanation for the ability of HCV to persist in the face of continual immune assault and represents a novel regulatory mechanism that is likely to be found in other viral fusion machinery., Competing Interests: LS, MK, CL, MP, LW, TD, WL, DM, MK, GG, DB, WR, CI, AS, JG No competing interests declared, ZK Where authors are identified as personnel of the International Agency for Research on Cancer/WHO, the authors alone are responsible for the views expressed in this article and they do not necessarily represent the decisions, policy or views of the International Agency for Research on Cancer/WHO, (© 2022, Stejskal, Kalemera et al.)

Objectives: This study compared the use of bortezomib in different combination regimens in newly diagnosed multiple myeloma (NDMM) patients who were transplant ineligible., Patients and Methods: We analyzed data from the Registry of Monoclonal Gammopathies (RMG) of the Czech Myeloma Group (CMG) to provide real-world evidence of outcome for 794 newly diagnosed MM transplant ineligible patients. The most frequently used regimen was VCd (bortezomib-cyclophosphamide-dexamethasone) (47.5%) over VMP (bortezomib-melphalan-prednisone) (21.7%), BDd (bortezomib-doxorubicin-dexamethasone) (9.8%), and VTd (bortezomib-thalidomide-dexamethasone) (2.9%)., Results: The overall response rate (ORR) was 69.2% (478/691), including 12.6% (≥ CR); 34.7% very good partial responses (VGPR); and 21.9% partial responses (PR). Among triplet regimens, VMP was the most effective regimen compared to VCd, BDd, and VTd. Median PFS was 22.3 vs. 18.5 vs. 13.7 vs. 13.8 mo, (P = .275), respectively, and median OS was 49 vs. 41.7 vs. 37.9 vs. 32.2 mo (P = .004), respectively. The most common grade 3-4 toxicities were anemia in 17.4% and infections in 18% of patients., Conclusion: Our study confirmed that bortezomib-based treatment is effective and safe in NDMM transplant ineligible patients, especially VMP, which was identified as superior between bortezomib-based induction regimens not only in clinical trials, but also in real clinical practice., (© 2021 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

There is an emerging body of evidence that patients with chronic myeloid leukaemia (CML) may carry not only breakpoint cluster region-Abelson murine leukaemia viral oncogene homologue 1 (BCR-ABL1) kinase domain mutations (BCR-ABL1 KD mutations), but also mutations in other genes. Their occurrence is highest during progression or at failure, but their impact at diagnosis is unclear. In the present study, we prospectively screened for mutations in 18 myeloid neoplasm-associated genes and BCR-ABL1 KD in the following populations: bulk leucocytes, CD34 + CD38 + progenitors and CD34 + CD38 - stem cells, at diagnosis and early follow-up. In our cohort of chronic phase CML patients, nine of 49 patients harboured somatic mutations in the following genes: six ASXL1 mutations, one SETBP1, one TP53, one JAK2, but no BCR-ABL1 KD mutations. In seven of the nine patients, mutations were detected in multiple hierarchical populations including bulk leucocytes at diagnosis. The mutation dynamics reflected the BCR-ABL1 transcript decline induced by treatment in eight of the nine cases, suggesting that mutations were acquired in the Philadelphia chromosome (Ph)-positive clone. In one patient, the JAK2 V617F mutation correlated with a concomitant Ph-negative myeloproliferative neoplasm and persisted despite a 5-log reduction of the BCR-ABL1 transcript. Only two of the nine patients with mutations failed first-line therapy. No correlation was found between the mutation status and survival or response outcomes., (© 2021 British Society for Haematology and John Wiley & Sons Ltd.)

Therapeutic options used to be very limited for treatment-naïve elderly/comorbid patients with chronic lymphocytic leukaemia/small lymphocytic lymphoma (CLL/SLL) before the introduction of chemo-immunotherapy. Because dose-reduced fludarabine-based regimens yielded promising results, the Czech CLL Study Group initiated a prospective observational study to assess safety and efficacy of low-dose fludarabine and cyclophosphamide combined with rituximab (FCR) in elderly/comorbid patients. Between March 2009 and July 2012, we enrolled 107 patients considered ineligible for full-dose FCR (median age, 70 years; median Cumulative Illness Rating Scale score, 5; median creatinine clearance, 69 ml/min). Notably, 77% patients had unfavourable biological prognosis [unmutated immunoglobulin heavy-chain variable-region gene (IGHV), 74%; deletion 17p, 9%). Fludarabine was reduced to 12 mg/m 2 intravenously (iv) or 20 mg/m 2 orally on days 1-3 and cyclophosphamide to 150 mg/m 2 iv/orally on days 1-3. Grade 3-4 neutropenia occurred in 56% of the patients, but there were serious infections in only 15%. The median progression-free survival was 29 months, but was markedly longer in patients with mutated IGHV (median 53 months), especially in absence of del 11q or 17p (median 74 months). Low-dose FCR is a well-tolerated and effective first-line regimen for selected elderly/comorbid patients with CLL/SLL with favourable biology. The study was registered at clinicaltrials.gov (NCT02156726)., (© 2021 British Society for Haematology and John Wiley & Sons Ltd.)

Background: We have performed a head to head comparison of all-oral triplet combination of ixazomib, lenalidomide and dexamethasone (IRD) versus lenalidomide and dexamethasone (RD) in patients with relapsed and refractory multiple myeloma (RRMM) in the routine clinical practice., Methods: A total of 344 patients treated with IRD (N = 127) or RD (N = 217) were selected for analysis from the Czech Registry of Monoclonal Gammopathies (RMG). Descriptive statistics were used to assess patient's characteristics associated with the respective therapy. The primary endpoint was progression free survival (PFS), secondary end points included response rates and overall survival (OS). Survival endpoints were plotted using Kaplan-Meier methodology at 95% Greenwood confidence interval. Univariable and multivariable Cox proportional hazards models were used to evaluate the effect of treatment regimens and the significance of uneven variables. Statistical tests were performed at significance level 0.05., Results: In the whole cohort, median PFS for IRD was 17.5 and for RD was 11.5 months favoring the all-oral triplet, p = 0.005; in patients within relapse 1-3, the median PFS was 23.1 vs 11.6 months, p = 0.001. The hazard ratio for PFS was 0.67 (95% confidence interval [CI] 0.51-0.89, p = 0.006). The PFS advantage translated into improved OS for patients treated with IRD, median 36.6 months vs 26.0 months (p = 0.008). The overall response rate (ORR) was 73.0% in the IRD group vs 66.2% in the RD group with a complete response rate (CR) of 11.1% vs 8.8%, and very good partial response (VGPR) 22.2% vs 13.9%, IRD vs RD respectively. The IRD regimen was most beneficial in patients ≤75 years with ISS I, II, and in the first and second relapse. Patients with the presence of extramedullary disease did not benefit from IRD treatment (median PFS 6.5 months). Both regimens were well tolerated, and the incidence of total as well as grade 3/4 toxicities was comparable., Conclusions: Our analysis confirms the results of the TOURMALINE-MM1 study and shows benefit of all-oral triplet IRD treatment versus RD doublet. It demonstrates that the addition of ixazomib to RD improves key survival endpoints in patients with RRMM in a routine clinical setting.

To evaluate long-term real-life results of dasatinib therapy among chronic phase chronic myeloid leukemia patients resistant or intolerant to imatinib, we retrospectively analyzed data of 118 patients treated in centers participating in the database INFINITY. With median follow-up of 37 months, estimated 5-year cumulative incidences of complete cytogenetic and major molecular responses were 78% and 68%, respectively. The estimated 5-year probability of overall survival (OS) and event-free survival (EFS) were 86% and 83%, respectively. Both OS and EFS were significantly improved among patients with BCR-ABL1 transcript level ≤10% at 3 months. Dasatinib toxicity was tolerable however persistent in almost half our patients, even after years of therapy. Pleural effusion occurred in 29% of patients and was responsible for 30% of dasatinib discontinuations. Our results confirmed very good efficacy and acceptable toxicity of dasatinib in second line setting and support the evidence and importance of high-quality real-life CML patient management.

CD81 plays a central role in a variety of physiological and pathological processes. Recent structural analysis of CD81 indicates that it contains an intramembrane cholesterol-binding pocket and that interaction with cholesterol may regulate a conformational switch in the large extracellular domain of CD81. Therefore, CD81 possesses a potential cholesterol-sensing mechanism; however, its relevance for protein function is thus far unknown. In this study we investigate CD81 cholesterol sensing in the context of its activity as a receptor for hepatitis C virus (HCV). Structure-led mutagenesis of the cholesterol-binding pocket reduced CD81-cholesterol association but had disparate effects on HCV entry, both reducing and enhancing CD81 receptor activity. We reasoned that this could be explained by alterations in the consequences of cholesterol binding. To investigate this further we performed molecular dynamic simulations of CD81 with and without cholesterol; this identified a potential allosteric mechanism by which cholesterol binding regulates the conformation of CD81. To test this, we designed further mutations to force CD81 into either the open (cholesterol-unbound) or closed (cholesterol-bound) conformation. The open mutant of CD81 exhibited reduced HCV receptor activity, whereas the closed mutant enhanced activity. These data are consistent with cholesterol sensing switching CD81 between a receptor active and inactive state. CD81 interactome analysis also suggests that conformational switching may modulate the assembly of CD81-partner protein networks. This work furthers our understanding of the molecular mechanism of CD81 cholesterol sensing, how this relates to HCV entry, and CD81's function as a molecular scaffold; these insights are relevant to CD81's varied roles in both health and disease., Competing Interests: Conflict of interest—The authors declare that they have no conflicts of interest with the contents of this article., (© 2020 Palor et al.)

Smouldering multiple myeloma (SMM) presents without MM defining symptoms. We aimed to identify patients with SMM with an 80% risk of progression within 2 years using only serum parameters. In total, 527 patients with SMM were included and divided into a training group (287 patients from the Czech Myeloma Group [CMG]) and an independent validation group (240 patients from Heidelberg). The median follow-up was 2·4 and 2·5 years, respectively. Progression to MM occurred in 51·9% of the CMG and 38·8% of the Heidelberg patients, respectively. The median risk of progression was 11·0% (CMG) and 9·7% (Heidelberg) per year, during the 5 years after diagnosis. A serum involved/uninvolved free light-chain ratio of >30, immunoparesis, and serum monoclonal (M) protein of ≥2·3 g/dl emerged as powerful predictors of 2-year progression rate with a hazard ratio (HR) of 2·49 (95% confidence interval [CI] 1·49-4·17), HR of 2·01 (95% CI 1·36-2·96) and HR of 2·00 (95% CI 1·44-2·79) (P < 0·001) in univariate Cox regression analysis, respectively. Based on this, the CMG model identified patients with SMM with a 2-year risk of progression of 78·7% (95% CI 53·1-95·7; HR 6·8; P < 0·001, CMG) and 81·3% (95% CI 47·1-98·8; HR 38·63; P < 0·001, Heidelberg). Serum parameters in the CMG model allow identification of patients with SMM with an 80% risk of progression to symptomatic MM within 2 years., (© 2020 British Society for Haematology and John Wiley & Sons Ltd.)

The glycoproteins of hepatitis C virus, E1E2, are unlike any other viral fusion machinery yet described, and are the current focus of immunogen design in HCV vaccine development; thus, making E1E2 both scientifically and medically important. We used pre-existing, but fragmentary, structures to model a complete ectodomain of the major glycoprotein E2 from three strains of HCV. We then performed molecular dynamic simulations to explore the conformational landscape of E2, revealing a number of important features. Despite high sequence divergence, and subtle differences in the models, E2 from different strains behave similarly, possessing a stable core flanked by highly flexible regions, some of which perform essential functions such as receptor binding. Comparison with sequence data suggest that this consistent behaviour is conferred by a network of conserved residues that act as hinge and anchor points throughout E2. The variable regions (HVR-1, HVR-2 and VR-3) exhibit particularly high flexibility, and bioinformatic analysis suggests that HVR-1 is a putative intrinsically disordered protein region. Dynamic cross-correlation analyses demonstrate intramolecular communication and suggest that specific regions, such as HVR-1, can exert influence throughout E2. To support our computational approach we performed small-angle X-ray scattering with purified E2 ectodomain; this data was consistent with our MD experiments, suggesting a compact globular core with peripheral flexible regions. This work captures the dynamic behaviour of E2 and has direct relevance to the interaction of HCV with cell-surface receptors and neutralising antibodies., Competing Interests: The authors have declared that no competing interests exist.

Borrelia are microaerophilic spirochetes capable of causing multisystemic diseases such as Lyme disease and Relapsing Fever. The ubiquitous Fe/Mn-dependent superoxide dismutase (SOD) provides essential protection from oxidative damage by the superoxide anion. Borrelia possess a single SOD enzyme - SodA that is essential for virulence, providing protection against host-derived reactive oxygen species (ROS). Here we present a method for recombinant expression and purification of Borrelia burgdorferi SodA in E. coli. Metal exchange or insertion into the Fe/Mn-SOD is inhibited in the folded state. We therefore present a method whereby the recombinant Borrelia SodA binds to Mn under denaturing conditions and is subsequently refolded by a reduction in denaturant. SodA purified by metal affinity chromatography and size exclusion chromatography reveals a single band on SDS-PAGE. Protein folding is confirmed by circular dichroism. A coupled enzyme assay demonstrates SOD activity in the presence of Mn, but not Fe. The apparent molecular weight determined by size exclusion corresponds to a dimer of SodA; a homology model of dimeric SodA is presented revealing a surface Cys distal to the dimer interface. The method presented of acquiring a target metal under denaturing conditions may be applicable to the refolding of other metal-binding proteins., (Copyright © 2019 Elsevier Inc. All rights reserved.)

This study used data from the Czech Myeloma Group Registry of Monoclonal Gammopathies to validate the International Myeloma Working Group (IMWG) and revised International Staging System (R-ISS) indices for risk stratification in patients with multiple myeloma (MM) in clinical practice. Patients were included if they had symptomatic MM, complete data allowing R-ISS and IMWG staging (including cytogenetic information regarding t(4;14), t(14;16), and del(17p)), and key parameters for treatment evaluation. Median overall survival (OS) in included patients (n = 550) was 47.7 (95% CI: 39.5-55.9) and 46.2 (95% CI: 38.9-53.5) months from diagnosis and initiation of first-line therapy, respectively. Patients categorized as higher vs lower risk had reduced survival; median OS from diagnosis was 35.4 (95% CI: 30.5-40.3) vs 58.3 (95% CI: 53.8-62.9) months in high-risk vs other patients (IMWG; P = .001) and 34.1 (95% CI: 30.2-38.0) vs 47.2 (95% CI: 43.4-51.0) months in Stage III vs Stage II patients (R-ISS; P < .001). In conclusion, IMWG and R-ISS risk stratification indices are applicable to patients with MM in a real-world setting., (© 2018 The Authors. Cancer Medicine published by John Wiley & Sons Ltd.)

In studying the binding of host antibodies to the surface antigens of pathogens, the structural and functional characterization of antibody-antigen complexes by X-ray crystallography and binding assay is important. However, the characterization requires experiments that are typically time consuming and expensive: thus, many antibody-antigen complexes are under-characterized. For vaccine development and disease surveillance, it is often vital to assess the impact of amino acid substitutions on antibody binding. For example, are there antibody substitutions capable of improving binding without a loss of breadth, or antigen substitutions that lead to antigenic escape? The questions cannot be answered reliably from sequence variation alone, exhaustive substitution assays are usually impractical, and alanine scans provide at best an incomplete identification of the critical residue-residue interactions. Here, we show that, given an initial structure of an antibody bound to an antigen, molecular dynamics simulations using the energy method molecular mechanics with Generalized Born surface area (MM/GBSA) can model the impact of single amino acid substitutions on antibody-antigen binding energy. We apply the technique to three broad-spectrum antibodies to influenza A hemagglutinin and examine both previously characterized and novel variant strains observed in the human population that may give rise to antigenic escape. We find that in some cases the impact of a substitution is local, while in others it causes a reorientation of the antibody with wide-ranging impact on residue-residue interactions: this explains, in part, why the change in chemical properties of a residue can be, on its own, a poor predictor of overall change in binding energy. Our estimates are in good agreement with experimental results-indeed, they approximate the degree of agreement between different experimental techniques. Simulations were performed on commodity computer hardware; hence, this approach has the potential to be widely adopted by those undertaking infectious disease research. Novel aspects of this research include the application of MM/GBSA to investigate binding between broadly binding antibodies and a viral glycoprotein; the development of an approach for visualizing substrate-ligand interactions; and the use of experimental assay data to rescale our predictions, allowing us to make inferences about absolute, as well as relative, changes in binding energy.

The deep evolutionary history of the Spirochetes places their branch point early in the evolution of the diderms, before the divergence of the present day Proteobacteria. As a spirochete, the morphology of the Borrelia cell envelope shares characteristics of both Gram-positive and Gram-negative bacteria. A thin layer of peptidoglycan, tightly associated with the cytoplasmic membrane, is surrounded by a more labile outer membrane (OM). This OM is rich in lipoproteins but with few known integral membrane proteins. The outer membrane protein A (OmpA) domain is an eight-stranded membrane-spanning β-barrel, highly conserved among the Proteobacteria but so far unknown in the Spirochetes. In the present work, we describe the identification of four novel OmpA-like β-barrels from Borrelia afzelii, the most common cause of erythema migrans (EM) rash in Europe. Structural characterization of one these proteins (BAPKO&#95;0422) by SAXS and CD indicate a compact globular structure rich in β-strand consistent with a monomeric β-barrel. Ab initio molecular envelopes calculated from the scattering profile are consistent with homology models and demonstrate that BAPKO&#95;0422 adopts a peanut shape with dimensions 25×45 Å (1 Å=0.1 nm). Deviations from the standard C-terminal signature sequence are apparent; in particular the C-terminal phenylalanine residue commonly found in Proteobacterial OM proteins is replaced by isoleucine/leucine or asparagine. BAPKO&#95;0422 is demonstrated to bind human factor H (fH) and therefore may contribute to immune evasion by inhibition of the complement response. Encoded by chromosomal genes, these proteins are highly conserved between Borrelia subspecies and may be of diagnostic or therapeutic value., (© 2015 Authors.)