73 research outputs found
Cause-specific or relative survival setting to estimate population-based net survival from cancer? An empirical evaluation using women diagnosed with breast cancer in Geneva between 1981 and 1991 and followed for 20 years after diagnosis.
BACKGROUND: Both cause-specific and relative survival settings can be used to estimate net survival, the survival that would be observed if the only possible underlying cause of death was the disease under study. Both resulting net survival estimators are biased by informative censoring and prone to biases related to the data settings within which each is derived. We took into account informative censoring to derive theoretically unbiased estimators and examine which of the two data settings was the most robust against incorrect assumptions in the data. PATIENTS AND METHODS: We identified 2489 women in the Geneva Cancer Registry, diagnosed with breast cancer between 1981 and 1991, and estimated net survival up to 20-years using both cause-specific and relative survival settings, by tackling the informative censoring with weights. To understand the possible origins of differences between the survival estimates, we performed sensitivity analyses within each setting. We evaluated the impact of misclassification of cause of death and of using inappropriate life tables on survival estimates. RESULTS: Net survival was highest using the cause-specific setting, by 1% at one year and by up to around 11% twenty years after diagnosis. Differences between both sets of net survival estimates were eliminated after recoding between 15% and 20% of the non-specific deaths as breast cancer deaths. By contrast, a dramatic increase in the general population mortality rates was needed to see the survival estimates based on relative survival setting become closer to those derived from cause-specific setting. CONCLUSION: Net survival estimates derived using the cause-specific setting are very sensitive to misclassification of cause of death. Net survival estimates derived using the relative-survival setting were robust to large changes in expected mortality. The relative survival setting is recommended for estimation of long-term net survival among patients with breast cancer
Estimation of net survival for cancer patients: Relative survival setting more robust to some assumption violations than cause-specific setting, a sensitivity analysis on empirical data.
Net survival is the survival that would be observed if the only possible underlying cause of death was the disease under study. It can be estimated with either cause-specific or relative survival data settings, if the informative censoring is properly considered. However, net survival estimators are prone to specific biases related to the data setting itself. We examined which data setting was the most robust against violation of key assumptions (erroneous cause of death and inappropriate life tables). We identified 4285 women in the Geneva Cancer Registry, diagnosed with breast, colorectal, lung cancer and melanoma between 1981 and 1991 and estimated net survival up to 20 years using cause-specific and relative survival settings. We used weights to tackle informative censoring in both settings and performed sensitivity analyses to evaluate the impact of misclassification of cause of death in the cause-specific setting or of using inappropriate life tables on net survival estimates in the relative survival setting. For all the four cancers, net survival was highest when using the cause-specific setting and the absolute difference between the two estimators increased with time since diagnosis. The sensitivity analysis showed that (i) the use of different life tables did not compromise net survival estimation in the relative survival setting, whereas (ii) a small level of misclassification for the cause of death led to a large change in the net survival estimate in the cause-specific setting. The relative survival setting was more robust to the above assumptions violations and is therefore recommended for estimation of net survival
Mammalian frataxin directly enhances sulfur transfer of NFS1 persulfide to both ISCU and free thiols
Friedreich's ataxia is a severe neurodegenerative disease caused by the decreased expression of frataxin, a mitochondrial protein that stimulates iron sulfur (Fe-S) cluster biogenesis. In mammals, the primary steps of Fe-S cluster assembly are performed by the NFS1 ISD11 ISCU complex via the formation of a persulfide intermediate on NFS1. Here we show that frataxin modulates the reactivity of NFS1 persulfide with thiols. We use maleimide-peptide com- pounds along with mass spectrometry to probe cysteine-persulfide in NFS1 and ISCU. Our data reveal that in the presence of ISCU, frataxin enhances the rate of two similar reactions on NFS1 persulfide: sulfur transfer to ISCU leading to the accumulation of a persulfide on the cysteine C104 of ISCU, and sulfur transfer to small thiols such as DTT, L-cysteine and GSH leading to persulfuration of these thiols and ultimately sulfide release. These data raise important questions on the physiological mechanism of Fe-S cluster assembly and point to a unique function of frataxin as an enhancer of sulfur transfer within the NFS1 ISD11 ISCU complex
An investigation of cancer survival inequalities associated with individual-level socio-economic status, area-level deprivation, and contextual effects, in a cancer patient cohort in England and Wales
BackgroundPeople living in more deprived areas of high-income countries have lower cancer survival than those in less deprived areas. However, associations between individual-level socio-economic circumstances and cancer survival are relatively poorly understood. Moreover, few studies have addressed contextual effects, where associations between individual-level socio-economic status and cancer survival vary depending on area-based deprivation. MethodsUsing 9,276 individual-level observations from a longitudinal study in England and Wales, we examined the association with cancer survival of area-level deprivation and individual-level occupation, education, and income, for colorectal, prostate and breast cancer patients aged 20-99 at diagnosis. With flexible parametric excess hazard models, we estimated excess mortality across individual-level and area-level socio-economic variables and investigated contextual effects. ResultsFor colorectal cancers, we found evidence of an association between education and cancer survival in men with Excess Hazard Ratio EHR=0.80, 95% CI [0.60;1.08] comparing “degree-level qualification and higher” to “no qualification” and EHR=0.74 [0.56;0.97] comparing “apprenticeships and vocational qualification” to “no qualification”, adjusted on occupation and income; and between occupation and cancer survival for women with EHR=0.77 [0.54;1.10] comparing “managerial/professional occupations” to “manual/technical,” and EHR=0.81 [0.63;1.06] comparing “intermediate” to “manual/technical”, adjusted on education and income. For breast cancer in women, we found evidence of an association with income (EHR=0.52 [0.29;0.95] for the highest income quintile compared to the lowest, adjusted on education and occupation), while for prostate cancer, all three individual-level socio-economic variables were associated to some extent with cancer survival. We found contextual effects of area-level deprivation on survival inequalities between occupation types for breast and prostate cancers, suggesting wider individual-level inequalities in more deprived areas compared to least deprived areas. Individual-level income inequalities for breast cancer were more evident than an area-level differential, suggesting that area-level deprivation might not be the most effective measure of inequality for this cancer. For colorectal cancer in both sexes, we found evidence suggesting area- and individual-level inequalities, but no evidence of contextual effects. ConclusionsFindings highlight that both individual and contextual effects contribute to inequalities in cancer outcomes. These insights provide potential avenues for more effective policy and practice
Health related quality of life measure in systemic pediatric rheumatic diseases and its translation to different languages: an international collaboration
Background: Rheumatic diseases in children are associated with significant morbidity and poor health-related quality of life (HRQOL). There is no health-related quality of life (HRQOL) scale available specifically for children with less common rheumatic diseases. These diseases share several features with systemic lupus erythematosus (SLE) such as their chronic episodic nature, multi-systemic involvement, and the need for immunosuppressive medications. HRQOL scale developed for pediatric SLE will likely be applicable to children with systemic inflammatory diseases.Findings: We adapted Simple Measure of Impact of Lupus Erythematosus in Youngsters (SMILEY (c)) to Simple Measure of Impact of Illness in Youngsters (SMILY (c)-Illness) and had it reviewed by pediatric rheumatologists for its appropriateness and cultural suitability. We tested SMILY (c)-Illness in patients with inflammatory rheumatic diseases and then translated it into 28 languages. Nineteen children (79% female, n= 15) and 17 parents participated. the mean age was 12 +/- 4 years, with median disease duration of 21 months (1-172 months). We translated SMILY (c)-Illness into the following 28 languages: Danish, Dutch, French (France), English (UK), German (Germany), German (Austria), German (Switzerland), Hebrew, Italian, Portuguese (Brazil), Slovene, Spanish (USA and Puerto Rico), Spanish (Spain), Spanish (Argentina), Spanish (Mexico), Spanish (Venezuela), Turkish, Afrikaans, Arabic (Saudi Arabia), Arabic (Egypt), Czech, Greek, Hindi, Hungarian, Japanese, Romanian, Serbian and Xhosa.Conclusion: SMILY (c)-Illness is a brief, easy to administer and score HRQOL scale for children with systemic rheumatic diseases. It is suitable for use across different age groups and literacy levels. SMILY (c)-Illness with its available translations may be used as useful adjuncts to clinical practice and research.Rutgers State Univ, Robert Wood Johnson Med Sch, New Brunswick, NJ 08903 USARutgers State Univ, Child Hlth Inst New Jersey, New Brunswick, NJ 08901 USAHosp Special Surg, New York, NY 10021 USAUniv Michigan, Ann Arbor, MI 48109 USARed Cross War Mem Childrens Hosp, Cape Town, South AfricaAin Shams Univ, Pediat Allergy Immunol & Rheumatol Unit, Cairo, EgyptAin Shams Univ, Pediat Rheumatol Pediat Allergy Immunol & Rheum, Cairo, EgyptKing Faisal Specialist Hosp & Res Ctr, Riyadh 11211, Saudi ArabiaCharles Univ Prague, Prague, Czech RepublicGen Univ Hosp, Prague, Czech RepublicUniv Hosp Motol, Dept Pediat, Prague, Czech RepublicAarhus Univ, Hosp Skejby, Aarhus, DenmarkRigshosp, Juliane Marie Ctr, DK-2100 Copenhagen, DenmarkUniv Med Ctr, Dept Pediat Immunol, Utrecht, NetherlandsWilhelmina Childrens Hosp, Utrecht, NetherlandsGreat Ormond St Hosp Sick Children, Children NHS Fdn Trust, Renal Unit, London, EnglandLyon Univ, Hosp Civils Lyon, Rheumatol & Dermatol Dept, Lyon, FranceMed Univ Innsbruck, A-6020 Innsbruck, AustriaPrim Univ Doz, Bregenz, AustriaHamburg Ctr Pediat & Adolescence Rheumatol, Hamburg, GermanyAsklepios Clin Sankt, Augustin, GermanyUniv Zurich, Childrens Hosp, Zurich, SwitzerlandAristotle Univ Thessaloniki, Pediat Immunol & Rheumatol Referral Ctr, GR-54006 Thessaloniki, GreeceIsrael Meir Hosp, Kefar Sava, IsraelSanjay Gandhi Postgrad Inst Med Sci, Lucknow, Uttar Pradesh, IndiaSemmelweis Univ, H-1085 Budapest, HungaryAnna Meyer Hosp, Florence, ItalyUniv Siena, Res Ctr System Autoimmune & Autoinflammatory Dis, I-53100 Siena, ItalyUniv Florence, Florence, ItalyOsped Pediat Bambino Gesu, IRCCS, Pediat Rheumatol Unit, Rome, ItalyUniv Genoa Pediat II Reumatol, Ist G Gaslini EULAR, Ctr Excellence Rheumatol, Genoa, ItalyUniv Cattolica Sacro Cuore, Inst Pediat, Rome, ItalyUniv Padua, Dept Pediat, Pediat Rheumatol Unit, Padua, ItalyYokohama City Univ, Sch Med, Yokohama, Kanagawa 232, JapanUniv Estadual Paulista, UNESP, Botucatu, SP, BrazilUniversidade Federal de São Paulo, Dept Pediat, São Paulo, BrazilUniv Estadual Campinas, Dept Med, Campinas, SP, BrazilUniv Fed Rio de Janeiro, Dept Pediat, Rio de Janeiro, BrazilUniv Estado do, Adolescent Hlth Care Unit, Div Pediat Rheumatol, Rio de Janeiro, BrazilUniv São Paulo, Fac Med, Childrens Inst, Dept Pediat,Pediat Rheumatol Unit, São Paulo, BrazilChildrens Inst, Pediat Rheumatol Unit, São Paulo, BrazilClin Pediat I, Cluj Napoca, RomaniaInst Rheumatol, Belgrade, SerbiaUniv Childrens Hosp, Univ Med Ctr Ljubljana, Ljubljana, SloveniaHead Rheumatol Hosp Pedro Elizalde, Buenos Aires, DF, ArgentinaHosp Gen Mexico City, Mexico City, DF, MexicoHosp Infantil Mexico Fed Gomez, Mexico City, DF, MexicoHosp San Juan Dios, Barcelona, SpainHosp Univ Valle Hebron, Barcelona, SpainMt Sinai Med Ctr, New York, NY 10029 USAMt Sinai Med Ctr, Miami Beach, FL 33140 USAComplejo Hosp Univ Ruiz & Paez, Bolivar, VenezuelaHacettepe Univ, Dept Pediat, Ankara, TurkeyIstanbul Univ, Cerrahpasa Med Sch, Istanbul, TurkeyFMF Arthrit Vasculitis & Orphan Dis Res Ctr, Inst Hlth Sci, Ankara, TurkeyUniv Calgary, Dept Pediat, Alberta Childrens Hosp, Res Inst, Calgary, AB T2N 1N4, CanadaUniversidade Federal de São Paulo, Dept Pediat, São Paulo, BrazilWeb of Scienc
Genetic and phenotypic spectrum associated with IFIH1 gain-of-function
IFIH1 gain-of-function has been reported as a cause of a type I interferonopathy encompassing a spectrum of autoinflammatory phenotypes including Aicardi–Goutières syndrome and Singleton Merten syndrome. Ascertaining patients through a European and North American collaboration, we set out to describe the molecular, clinical and interferon status of a cohort of individuals with pathogenic heterozygous mutations in IFIH1. We identified 74 individuals from 51 families segregating a total of 27 likely pathogenic mutations in IFIH1. Ten adult individuals, 13.5% of all mutation carriers, were clinically asymptomatic (with seven of these aged over 50 years). All mutations were associated with enhanced type I interferon signaling, including six variants (22%) which were predicted as benign according to multiple in silico pathogenicity programs. The identified mutations cluster close to the ATP binding region of the protein. These data confirm variable expression and nonpenetrance as important characteristics of the IFIH1 genotype, a consistent association with enhanced type I interferon signaling, and a common mutational mechanism involving increased RNA binding affinity or decreased efficiency of ATP hydrolysis and filament disassembly rate
Autoantibodies against type I IFNs in patients with critical influenza pneumonia
In an international cohort of 279 patients with hypoxemic influenza pneumonia, we identified 13 patients (4.6%) with autoantibodies neutralizing IFN-alpha and/or -omega, which were previously reported to underlie 15% cases of life-threatening COVID-19 pneumonia and one third of severe adverse reactions to live-attenuated yellow fever vaccine. Autoantibodies neutralizing type I interferons (IFNs) can underlie critical COVID-19 pneumonia and yellow fever vaccine disease. We report here on 13 patients harboring autoantibodies neutralizing IFN-alpha 2 alone (five patients) or with IFN-omega (eight patients) from a cohort of 279 patients (4.7%) aged 6-73 yr with critical influenza pneumonia. Nine and four patients had antibodies neutralizing high and low concentrations, respectively, of IFN-alpha 2, and six and two patients had antibodies neutralizing high and low concentrations, respectively, of IFN-omega. The patients' autoantibodies increased influenza A virus replication in both A549 cells and reconstituted human airway epithelia. The prevalence of these antibodies was significantly higher than that in the general population for patients 70 yr of age (3.1 vs. 4.4%, P = 0.68). The risk of critical influenza was highest in patients with antibodies neutralizing high concentrations of both IFN-alpha 2 and IFN-omega (OR = 11.7, P = 1.3 x 10(-5)), especially those <70 yr old (OR = 139.9, P = 3.1 x 10(-10)). We also identified 10 patients in additional influenza patient cohorts. Autoantibodies neutralizing type I IFNs account for similar to 5% of cases of life-threatening influenza pneumonia in patients <70 yr old
Global surveillance of cancer survival 1995-2009: analysis of individual data for 25,676,887 patients from 279 population-based registries in 67 countries (CONCORD-2)
BACKGROUND:
Worldwide data for cancer survival are scarce. We aimed to initiate worldwide surveillance of cancer survival by central analysis of population-based registry data, as a metric of the effectiveness of health systems, and to inform global policy on cancer control.
METHODS:
Individual tumour records were submitted by 279 population-based cancer registries in 67 countries for 25·7 million adults (age 15-99 years) and 75,000 children (age 0-14 years) diagnosed with cancer during 1995-2009 and followed up to Dec 31, 2009, or later. We looked at cancers of the stomach, colon, rectum, liver, lung, breast (women), cervix, ovary, and prostate in adults, and adult and childhood leukaemia. Standardised quality control procedures were applied; errors were corrected by the registry concerned. We estimated 5-year net survival, adjusted for background mortality in every country or region by age (single year), sex, and calendar year, and by race or ethnic origin in some countries. Estimates were age-standardised with the International Cancer Survival Standard weights.
FINDINGS:
5-year survival from colon, rectal, and breast cancers has increased steadily in most developed countries. For patients diagnosed during 2005-09, survival for colon and rectal cancer reached 60% or more in 22 countries around the world; for breast cancer, 5-year survival rose to 85% or higher in 17 countries worldwide. Liver and lung cancer remain lethal in all nations: for both cancers, 5-year survival is below 20% everywhere in Europe, in the range 15-19% in North America, and as low as 7-9% in Mongolia and Thailand. Striking rises in 5-year survival from prostate cancer have occurred in many countries: survival rose by 10-20% between 1995-99 and 2005-09 in 22 countries in South America, Asia, and Europe, but survival still varies widely around the world, from less than 60% in Bulgaria and Thailand to 95% or more in Brazil, Puerto Rico, and the USA. For cervical cancer, national estimates of 5-year survival range from less than 50% to more than 70%; regional variations are much wider, and improvements between 1995-99 and 2005-09 have generally been slight. For women diagnosed with ovarian cancer in 2005-09, 5-year survival was 40% or higher only in Ecuador, the USA, and 17 countries in Asia and Europe. 5-year survival for stomach cancer in 2005-09 was high (54-58%) in Japan and South Korea, compared with less than 40% in other countries. By contrast, 5-year survival from adult leukaemia in Japan and South Korea (18-23%) is lower than in most other countries. 5-year survival from childhood acute lymphoblastic leukaemia is less than 60% in several countries, but as high as 90% in Canada and four European countries, which suggests major deficiencies in the management of a largely curable disease.
INTERPRETATION:
International comparison of survival trends reveals very wide differences that are likely to be attributable to differences in access to early diagnosis and optimum treatment. Continuous worldwide surveillance of cancer survival should become an indispensable source of information for cancer patients and researchers and a stimulus for politicians to improve health policy and health-care systems
Extracorporeal Membrane Oxygenation for Severe Acute Respiratory Distress Syndrome associated with COVID-19: An Emulated Target Trial Analysis.
RATIONALE: Whether COVID patients may benefit from extracorporeal membrane oxygenation (ECMO) compared with conventional invasive mechanical ventilation (IMV) remains unknown. OBJECTIVES: To estimate the effect of ECMO on 90-Day mortality vs IMV only Methods: Among 4,244 critically ill adult patients with COVID-19 included in a multicenter cohort study, we emulated a target trial comparing the treatment strategies of initiating ECMO vs. no ECMO within 7 days of IMV in patients with severe acute respiratory distress syndrome (PaO2/FiO2 <80 or PaCO2 ≥60 mmHg). We controlled for confounding using a multivariable Cox model based on predefined variables. MAIN RESULTS: 1,235 patients met the full eligibility criteria for the emulated trial, among whom 164 patients initiated ECMO. The ECMO strategy had a higher survival probability at Day-7 from the onset of eligibility criteria (87% vs 83%, risk difference: 4%, 95% CI 0;9%) which decreased during follow-up (survival at Day-90: 63% vs 65%, risk difference: -2%, 95% CI -10;5%). However, ECMO was associated with higher survival when performed in high-volume ECMO centers or in regions where a specific ECMO network organization was set up to handle high demand, and when initiated within the first 4 days of MV and in profoundly hypoxemic patients. CONCLUSIONS: In an emulated trial based on a nationwide COVID-19 cohort, we found differential survival over time of an ECMO compared with a no-ECMO strategy. However, ECMO was consistently associated with better outcomes when performed in high-volume centers and in regions with ECMO capacities specifically organized to handle high demand. This article is open access and distributed under the terms of the Creative Commons Attribution Non-Commercial No Derivatives License 4.0 (http://creativecommons.org/licenses/by-nc-nd/4.0/)
Structural and functional study of the Rhabdovirus glycoprotein
Les Rhabdovirus sont des virus enveloppés à ARN simple brin de polarité négative. Ils possèdent une unique protéine transmembranaire à leur surface, la glycoprotéine G. G est impliquée dans les étapes précoces du cycle viral. G lie dans un premier temps un récepteur cellulaire, menant à l’endocytose du virus. Ensuite, G orchestre la fusion membranaire entre les membranes virale et endosomale. Cette fusion membranaire permet la libération du génome viral dans le cytoplasme de la cellule infectée.Le récepteur des lipoprotéines de basse densité (LDLR) est le récepteur principal du VSV. L’ectodomaine du LDLR est composé d’un grand site de liaison au ligand constitué de domaines riches en cystéines (CR1 à CR7).Afin de comprendre les bases moléculaires de l’interaction entre G et son récepteur, nous avons réalisé des tests de fixation de G aux différents domaines CR du LDLR. Cela a révélé que seuls les domaines CR2 et CR3 pouvaient lier G. Lorsque CR2 et CR3 sont incubés avec VSV dans l’inoculum, ils protègent les cellules de l’infection par VSV. Nous avons cristallisé G en complexe avec chacun de ces domaines CR. Les structures révèlent que le site de liaison de CR2 et de CR3 sur G sont identiques, et que les mêmes résidus sur G sont impliqués dans la liaison des deux domaines CR. Des cellules HAP-1 dans lesquelles le gène codant pour le LDLR a été invalidé, sont toujours sensibles à l’infection par VSV. Ceci confirme que VSV peut utiliser d’autres récepteurs que le LDLR pour entrer dans les cellules. Cependant la mutation des résidus de G qui sont clefs dans l’interaction avec les domaines CR du LDLR abolissent l’infectiosité de VSV aussi bien dans les cellules de mammifères que dans les cellules d’insectes. Ceci indique que les seuls récepteurs de VSV dans ces cellules sont des membres de la famille du LDLR et que VSV G a spécifiquement évolué pour interagir avec leur domaines CR. Par ailleurs nous avons montré que les G dont les résidus clef pour l’interaction avec les domaines CR sont mutés, ont conservé leur activité de fusion. Ces travaux montrent que les activités de reconnaissance du récepteur et de fusion de G peuvent être découplées. Ceci ouvre la possibilité de développer des glycoprotéines dérivées de G au tropisme modifié.Chez les Rhabdovirus, G est la seule cible des anticorps neutralisants. A ce jour il n’existe aucune structure de G de Rhabdovirus en complexe avec un anticorps. L’anticorps 8G5F11 neutralise plusieurs génotypes du genre Vésiculovirus dont VSV. Nous avons montré que les FAB 8G5F11 empêchent l’infection des cellules par VSV Indiana d’une part et qu’ils reconnaissent la forme pré- et post-fusion de VSV G avec une stœchiométrie G : FAB de 1 : 1 d’autre part. Nous avons mis au point les conditions d’observation du complexe G-FAB en cryo-microscopie électronique, ce qui permet d’envisager à terme une résolution de la structure du complexe G-FAB.Enfin, nous avons débuté une étude visant à caractériser les glycoprotéines d’autres Rhabdovirus du genre Lyssavirus. Pour cela, nous avons produit et purifié les ectodomaines de G du virus de la rage (RABV), du virus Mokola (MOKV) et du virus de la chauve-souris ouest-caucasienne (WCBV). Ces G ont été caractérisées par microscopie électronique à différents pH. Les mesures effectuées sur G à pH 8 sont compatibles avec celles attendues pour un monomère de G pré-fusion. A pH 6, les ectodomaines observés pourraient correspondre à un intermédiaire monomérique allongé apparaissant tardivement lors de la transition structurale. Ces résultats pourraient être prochainement validés par l’obtention de la structure cristallographique de l’ectodomaine de G MOKV.Rhabdoviruses are single stranded RNA enveloped viruses. They own a unique glycoprotein G anchored on the viral membrane. G is involved in the early stages of the viral cycle. At first G binds a cellular receptor, leading to the virus endocytosis. Then G orchestrates the membrane fusion between the viral and endosomal membranes. Membrane fusion allows the release of the viral genome into the cytoplasm of the infected cell.The low-density lipoprotein receptor (LDLR) is the main receptor of VSV. The ectodomain of the LDLR is composed of a large ligand binding domain constituted of cysteine-rich domains (CR1 to CR7).In order to understand the molecular basis of the interaction between G and its receptor, we performed binding test of G with all the CR domains of the LDLR. This revealed that only CR2 and CR3 domains could bind G. When CR2 and CR3 are present in the VSV inoculum, they protect the cells from VSV infection. We crystallized G in complex with each of these CR domains. The structures reveal that CR2 and CR3 binding sites on G are identical, and that the same residues on G are involved in the binding of the two CR domains. HAP-1 cells in which the gene encoding the LDLR has been invalidated are still susceptible to VSV infection. This confirms that VSV can use other receptors than the LDLR itself to enter the cells. However, mutation of G residues that are key in the interaction with the CR domains of the LDLR abolish the infectivity of VSV in mammalian and insect cells. This indicates that the only VSV receptors in these cells are members of the LDLR family and that VSV G has specifically evolved to interact with their CR domains. Moreover, we have shown that G mutated for key residues involved in the interaction with CR domains, are still able to induce fusion. This work shows that receptor recognition and G fusion activities can be decoupled. This paves the way to develop glycoproteins derived from G with modified tropism.In Rhabdoviruses, G is the only target of neutralizing antibodies. There is no structure of a Rhabdovirus G in complex with an antibody. The 8G5F11 antibody neutralizes several genotypes of the genus Vesiculovirus including VSV. We have shown that FAB 8G5F11 prevents infection of cells by VSV Indiana on the one hand and that they recognize the pre- and post-fusion form of VSV G with a 1: 1 G: FAB stoichiometry on the other hand. We have developed the observation conditions of the G-FAB complex in cryo-electron microscopy, which could be useful to obtain the structure of the G-FAB complex.We also started a study to characterize the glycoproteins of other Rhabdoviruses of the Lyssavirus genus. We produced and purified G ectodomains of rabies virus (RABV), Mokola virus (MOKV) and West Caucasian bat virus (WCBV). We characterize these G by electron microscopy at different pHs. The measurements made on G at pH 8 are compatible with those expected for a pre-fusion monomer of G. At pH 6, these ectodomains could correspond to a monomeric late intermediate in the structural transition. Obtaining the crystallographic structure of the G ectodomain of MOKV could validate these results
- …