Publications
97 results found
Jackson H, Calle IR, Broderick C, et al., 2022, Characterisation of the blood RNA host response underpinning severity in COVID-19 patients, Scientific Reports, Vol: 12, ISSN: 2045-2322
Infection with SARS-CoV-2 has highly variable clinical manifestations, ranging from asymptomatic infection through to life-threatening disease. Host whole blood transcriptomics can offer unique insights into the biological processes underpinning infection and disease, as well as severity. We performed whole blood RNA Sequencing of individuals with varying degrees of COVID-19 severity. We used differential expression analysis and pathway enrichment analysis to explore how the blood transcriptome differs between individuals with mild, moderate, and severe COVID-19, performing pairwise comparisons between groups. Increasing COVID-19 severity was characterised by an abundance of inflammatory immune response genes and pathways, including many related to neutrophils and macrophages, in addition to an upregulation of immunoglobulin genes. Our insights into COVID-19 severity reveal the role of immune dysregulation in the progression to severe disease and highlight the need for further research exploring the interplay between SARS-CoV-2 and the inflammatory immune response.
Kaforou M, Broderick C, Vito O, et al., 2022, Transcriptomics for child and adolescent tuberculosis, Immunological Reviews, Vol: 309, ISSN: 0105-2896
Tuberculosis (TB) in humans is caused by Mycobacterium tuberculosis (Mtb). It is estimated that 70 million children (<15 years) are currently infected with Mtb, with 1.2 million each year progressing to disease. Of these, a quarter die. The risk of progression from Mtb infection to disease and from disease to death is dependent on multiple pathogen and host factors. Age is a central component in all these transitions. The natural history of TB in children and adolescents is different to adults, leading to unique challenges in the development of diagnostics, therapeutics, and vaccines. The quantification of RNA transcripts, encoded in the genome in specific cells or in the peripheral blood, using high-throughput methods, such as microarray analysis or RNA sequencing, are emerging technologies. RNA sequencing can shed light into the host immune response to Mtb during infection and disease, as well as understanding treatment response, disease severity and vaccination, in a global hypothesis-free manner. Additionally, gene expression profiling can be used for biomarker discovery, to diagnose disease, predict future disease progression and to monitor response to treatment. Here, we review the role of transcriptomics in children and adolescents, focussed mainly on work done in blood, to understand disease biology and to discriminate disease states to assist clinical decision-making. In recent years, studies with a specific paediatric and adolescent focus have identified blood gene expression markers with diagnostic or prognostic potential that meet or exceed the current sensitivity and specificity targets for diagnostic tools. Diagnostic and prognostic gene expression signatures identified through high-throughput methods are currently being translated into diagnostic tests.
Takele Y, Adem E, Franssen SU, et al., 2022, Impaired in vitro Interferon-gamma production in patients with visceral leishmaniasis is improved by inhibition of PD1/PDL-1 ligation, PLoS Neglected Tropical Diseases, Vol: 16, Pages: 1-12, ISSN: 1935-2727
Visceral leishmaniasis (VL) is a neglected tropical disease that causes substantial morbidity and mortality and is a growing health problem in Ethiopia, where this study took place. Most individuals infected with Leishmania donovani parasites will stay asymptomatic, but some develop VL that, if left untreated, is almost always fatal. This stage of the disease is associated with a profound immunosuppression, characterised by impaired production of Interferonγ (IFNγ), a cytokine that plays a key role in the control of Leishmania parasites, and high expression levels of an inhibitory receptor, programmed cell death 1 (PD1) on CD4+ T cells. Here, we tested the contribution of the interaction between the immune checkpoint PD1 and its ligand PDL-1 on the impaired production of IFNγ in VL patients. Our results show that in the blood of VL patients, not only CD4+, but also CD8+ T cells express high levels of PD1 at the time of VL diagnosis. Next, we identified PDL-1 expression on different monocyte subsets and neutrophils and show that PDL-1 levels were significantly increased in VL patients. PD1/PDL-1 inhibition resulted in significantly increased production of IFNγ, suggesting that therapy using immune checkpoint inhibitors might improve disease control in these patients.
Pantazi P, Kaforou M, Guller S, et al., 2022, CHARACTERIZATION OF EXTRACELLULAR VESICLES FROM PLACENTAL MACROPHAGES (HOFBAUER CELLS) IN NORMAL PHYSIOLOGY AND INFECTION, 9th Latin American Symposium of the Latin-American-Society-for-Maternal-Fetal-Interaction-and-Placenta on Maternal-Fetal Interaction and Placenta (SLIMP), Publisher: W B SAUNDERS CO LTD, Pages: E76-E76, ISSN: 0143-4004
Pantazi P, Kaforou M, Tang Z, et al., 2022, Placental Macrophage (Hofbauer Cell) Responses to Infection During Pregnancy: A Systematic Scoping Review, Frontiers in Immunology, ISSN: 1664-3224
Bacterial and viral infections of the placenta are associated with inflammation and adverse pregnancy outcomes. Hofbauer cells (HBCs) are specialised fetal-origin macrophages in the placental villi and are proposed to protect the fetus from vertical transmission of pathogens; however, they are poorly understood. Here, we have performed quantitative proteomics on term HBCs under resting conditions and following exposure to bacterial and viral pathogen associated molecular patterns (PAMPs), and investigated the contribution of fetal sex to these responses. Resting HBCs expressed a plethora of proteins pertinent to macrophage function, including chemokines, cytokines, Toll-like receptors, and classical and non-classical major histocompatibility complex class I and II molecules. HBCs mounted divergent responses to bacterial versus viral PAMPs but exhibited protein expression changes suggestive of a switch towards a more pro-inflammatory phenotype. A comparison between male and female HBCs, showed that the latter mounted a much stronger and wider response. Sexual dimorphism in HBCs was primarily associated with lipid metabolism in males and cytoskeleton organisation in females. We provide a novel and comprehensive understanding regarding the phenotype of term placental macrophages and their sex-dependent responses to infectious triggers.
Mehta R, Chekmeneva E, Jackson H, et al., 2022, Antiviral metabolite 3’-Deoxy-3’,4’-didehydro-cytidine is detectable in serum and identifies acute viral infections including COVID-19, Med, Vol: 3, Pages: 204-215.e6, ISSN: 2666-6340
Background:There is a critical need for rapid viral infection diagnostics to enable prompt case identification in pandemic settings and support targeted antimicrobial prescribing.Methods:Using untargeted high-resolution liquid chromatography coupled with mass spectrometry, we compared the admission serum metabolome of emergency department patients with viral infections including COVID-19, bacterial infections, inflammatory conditions, and healthy controls. Sera from an independent cohort of emergency department patients admitted with viral or bacterial infections underwent profiling to validate findings. Associations between whole-blood gene expression and the identified metabolite of interest were examined.Findings:3'-Deoxy-3',4'-didehydro-cytidine (ddhC), a free base of the only known human antiviral small molecule ddhC-triphosphate (ddhCTP), was detected for the first time in serum. When comparing 60 viral to 101 non-viral cases in the discovery cohort, ddhC was the most differentially abundant metabolite, generating an area under the receiver operating characteristic curve (AUC) of 0.954 (95% CI: 0.923-0.986). In the validation cohort, ddhC was again the most significantly differentially abundant metabolite when comparing 40 viral to 40 bacterial cases, generating an AUC of 0.81 (95% CI 0.708-0.915). Transcripts of viperin and CMPK2, enzymes responsible for ddhCTP synthesis, were amongst the five genes most highly correlated to ddhC abundance.Conclusions:The antiviral precursor molecule ddhC is detectable in serum and an accurate marker for acute viral infection. Interferon-inducible genes viperin and CMPK2 are implicated in ddhC production in vivo. These findings highlight a future diagnostic role for ddhC in viral diagnosis, pandemic preparedness, and acute infection management.
Channon-Wells S, Coote D, Wright V, et al., 2022, VALIDATION OF TRANSCRIPTOMIC SIGNATURES FOR FEBRILE CHILDREN USING NANOSTRING TECHNOLOGY AND EXPLORATION OF MULTI-CLASS PREDICTION MODELS, The European Society For Paediatric Infectious Diseases Conference 2022
Backgrounds: Many host transcript signatures for paediatric inflammatory and infectious diseases are in development, but require validation in independent cohorts; their translation to clinically useful test platforms lags behind discovery. We used NanoString technology to efficiently validate multiple signatures in parallel and explore the potential for more sophisticated multi-class classification models. Methods: We validated five transcriptomic diagnostic signatures using prospectively recruited patients from multiple paediatric cohorts. Final phenotypes were assigned using pre-agreed definitions after review of clinical and laboratory data. We quantified 69 transcripts on a custom NanoString nCounter cartridge, normalising expression values using reference genes. Signature performance was assessed using Area Under ROC Curve (AUC) statistics. We explored two approaches to multiclassification diagnostics to develop proof-of-concept methods: a mixed test combining four independent one-vs-all models, and a multinomial model. Results: Our cohort of 92 paediatric patients included 23 definite bacterial and 20 definite viral infections, 15 Kawasaki disease, 18 with tuberculosis and 16 healthy controls. The signatures achieved AUCs above 0.82 (Table 1), with confidence intervals overlapping those of the respective discovery studies. However, performance declined in all signatures when tasked with differentiating additional groups. For example, the single-transcript BATF2 had AUC of 0.910 differentiating TB from healthy individuals, reducing to 0.745 when differentiating TB from other febrile diseases. In comparison, the multinomial approach identified a 24-transcript model that correctly classified all 76 non-control patients (0% in-sample error), outperforming the mixed-model (19 transcripts, 19.8% in-sample error).
Takele Y, Mulaw, Adem, et al., 2022, Immunological factors, but not clinical features, predict visceral leishmaniasis relapse in patients co-infected with HIV, Cell Reports Medicine, Vol: 3, ISSN: 2666-3791
Visceral leishmaniasis (VL) has emerged as a clinically important opportunistic infection in HIV patients, as VL/HIV co-infected patients suffer from frequent VL relapse. Here, we follow cohorts of VL patients with or without HIV in Ethiopia. By the end of the study 78.1% of VL/HIV, but none of the VL patients, experience VL relapse. Despite clinically defined cure, VL/HIV patients maintain higher parasite loads, lower BMI, hepatosplenomegaly and pancytopenia. We identify three immunological markers associated with VL relapse in VL/HIV patients: i) failure to restore antigen-specific production of IFNg, ii) persistently lower CD4+ T cell counts, and iii) higher expression of PD1 on CD4+ and CD8+ T cells. We show that these three markers, that can be measured in primary hospital settings in Ethiopia, combine well in predicting VL relapse. The use of our prediction model has the potential to improve disease management and patient care.
Georgiadou A, Dunican C, Sorro-Barrio P, et al., 2022, Comparative transcriptomic analysis reveals translationally relevant processes in mouse models of malaria, eLife, Vol: 11, ISSN: 2050-084X
Recent initiatives to improve translation of findings from animal models to human disease have focussed on reproducibility but quantifying the relevance of animal models remains a challenge. Here, we use comparative transcriptomics of blood to evaluate the systemic host response and its concordance between humans with different clinical manifestations of malaria and five commonly used mouse models. Plasmodium yoelii 17XL infection of mice most closely reproduces the profile of gene expression changes seen in the major human severe malaria syndromes, accompanied by high parasite biomass, severe anemia, hyperlactatemia, and cerebral microvascular pathology. However, there is also considerable discordance of changes in gene expression between the different host species and across all models, indicating that the relevance of biological mechanisms of interest in each model should be assessed before conducting experiments. These data will aid the selection of appropriate models for translational malaria research, and the approach is generalizable to other disease models.
Peacock TP, Brown JC, Zhou J, et al., 2022, The altered entry pathway and antigenic distance of the SARS-CoV-2 Omicron variant map to separate domains of spike protein
<jats:title>Abstract</jats:title><jats:p>The SARS-CoV-2 Omicron/BA.1 lineage emerged in late 2021 and rapidly displaced the Delta variant before being overtaken itself globally by, the Omicron/BA.2 lineage in early 2022. Here, we describe how Omicron BA.1 and BA.2 show a lower severity phenotype in a hamster model of pathogenicity which maps specifically to the spike gene. We further show that Omicron is attenuated in a lung cell line but replicates more rapidly, albeit to lower peak titres, in human primary nasal cells. This replication phenotype also maps to the spike gene. Omicron spike (including the emerging Omicron lineage BA.4) shows attenuated fusogenicity and a preference for cell entry via the endosomal route. We map the altered Omicron spike entry route and partially map the lower fusogenicity to the S2 domain, particularly the substitution N969K. Finally, we show that pseudovirus with Omicron spike, engineered in the S2 domain to confer a more Delta-like cell entry route retains the antigenic properties of Omicron. This shows a distinct separation between the genetic determinants of these two key Omicron phenotypes, raising the concerning possibility that future variants with large antigenic distance from currently circulating and vaccine strains will not necessarily display the lower intrinsic severity seen during Omicron infection.</jats:p>
Li HK, Kaforou M, Rodriguez-Manzano J, et al., 2021, Discovery and validation of a 3-gene signature to distinguish COVID-19 and other viral infections in emergency infectious disease presentations; a case-control then observational cohort study, The Lancet Microbe, Vol: 2, Pages: 594-603, ISSN: 2666-5247
Background: Emergency admissions for infection often lack initial diagnostic certainty. COVID-19 has highlighted a need for novel diagnostic approaches to indicate likelihood of viral infection in a pandemic setting. We sought to derive and validate a blood transcriptional signature to detect viral infections including COVID-19 among adults with suspected infection presenting to the Emergency Department (ED).Methods: Blood RNA sequencing was performed on a discovery cohort of adults attending the ED with suspected infection who had subsequently-confirmed viral, bacterial, or no infection diagnoses. Differentially expressed host genes were subjected to feature selection to derive the most parsimonious discriminating signature. RT-qPCR validation of the signature was then performed in a prospective cohort of ED patients presenting with undifferentiated fever, and a second case-control cohort of ED patients with COVID-19 or bacterial infection. Signature performance was assessed by calculating area under receiver-operating characteristic curves (AUC-ROCs), sensitivities, and specificities.Findings: A 3-gene transcript signature was derived from the discovery cohort of 56 bacterial and 27 viral infection cases. In the validation cohort of 200 cases, the signature differentiated bacterial from viral infections with an AUC-ROC of 0.976 (95% CI: 0.919-1.000), sensitivity 97.3% and specificity of 100%. The AUC-ROC for C-reactive protein (CRP) and leucocyte count (WCC) was 0.833 (95% CI: 0.694-0.944) and 0.938 (95% CI: 0.840-0.986) respectively. The signature achieved higher net benefit in decision curve analysis than either CRP or WCC for discriminating viral infections from all other cases. In the second validation analysis the signature discriminated 35 bacterial infections from 34 SARS-CoV-2 positive COVID-19 infections with AUC-ROC of 0.953 (95% CI: 0.893-0.992), sensitivity 88.6% and specificity of 94.1%.Interpretation: This novel 3-gene signature discriminates viral i
Nijman R, Oostenbrink R, Moll HA, et al., 2021, A novel framework for phenotyping children with suspected or confirmed infection for future biomarker studies, Frontiers in Pediatrics, Vol: 9, Pages: 1-18, ISSN: 2296-2360
Background: The limited diagnostic accuracy of biomarkers in children at risk of a serious bacterial infection (SBI) might be due to the imperfect reference standard of SBI. We aimed to evaluate the diagnostic performance of a new classification algorithm for biomarker discovery in children at risk of SBI.Methods: We used data from five previously published, prospective observational biomarker discovery studies, which included patients aged 0– <16 years: the Alder Hey emergency department (n = 1,120), Alder Hey pediatric intensive care unit (n = 355), Erasmus emergency department (n = 1,993), Maasstad emergency department (n = 714) and St. Mary's hospital (n = 200) cohorts. Biomarkers including procalcitonin (PCT) (4 cohorts), neutrophil gelatinase-associated lipocalin-2 (NGAL) (3 cohorts) and resistin (2 cohorts) were compared for their ability to classify patients according to current standards (dichotomous classification of SBI vs. non-SBI), vs. a proposed PERFORM classification algorithm that assign patients to one of eleven categories. These categories were based on clinical phenotype, test outcomes and C-reactive protein level and accounted for the uncertainty of final diagnosis in many febrile children. The success of the biomarkers was measured by the Area under the receiver operating Curves (AUCs) when they were used individually or in combination.Results: Using the new PERFORM classification system, patients with clinically confident bacterial diagnosis (“definite bacterial” category) had significantly higher levels of PCT, NGAL and resistin compared with those with a clinically confident viral diagnosis (“definite viral” category). Patients with diagnostic uncertainty had biomarker concentrations that varied across the spectrum. AUCs were higher for classification of “definite bacterial” vs. “definite viral” following the PERFORM algorithm than using the “SBI” vs. “non-SBI” c
McArdle AJ, Vito O, Patel H, et al., 2021, Treatment of multisystem inflammatory syndrome in children, New England Journal of Medicine, Vol: 385, Pages: 11-22, ISSN: 0028-4793
BACKGROUNDEvidence is urgently needed to support treatment decisions for children with multisystem inflammatory syndrome (MIS-C) associated with severe acute respiratory syndrome coronavirus 2.METHODSWe performed an international observational cohort study of clinical and outcome data regarding suspected MIS-C that had been uploaded by physicians onto a Web-based database. We used inverse-probability weighting and generalized linear models to evaluate intravenous immune globulin (IVIG) as a reference, as compared with IVIG plus glucocorticoids and glucocorticoids alone. There were two primary outcomes: the first was a composite of inotropic support or mechanical ventilation by day 2 or later or death; the second was a reduction in disease severity on an ordinal scale by day 2. Secondary outcomes included treatment escalation and the time until a reduction in organ failure and inflammation.RESULTSData were available regarding the course of treatment for 614 children from 32 countries from June 2020 through February 2021; 490 met the World Health Organization criteria for MIS-C. Of the 614 children with suspected MIS-C, 246 received primary treatment with IVIG alone, 208 with IVIG plus glucocorticoids, and 99 with glucocorticoids alone; 22 children received other treatment combinations, including biologic agents, and 39 received no immunomodulatory therapy. Receipt of inotropic or ventilatory support or death occurred in 56 patients who received IVIG plus glucocorticoids (adjusted odds ratio for the comparison with IVIG alone, 0.77; 95% confidence interval [CI], 0.33 to 1.82) and in 17 patients who received glucocorticoids alone (adjusted odds ratio, 0.54; 95% CI, 0.22 to 1.33). The adjusted odds ratios for a reduction in disease severity were similar in the two groups, as compared with IVIG alone (0.90 for IVIG plus glucocorticoids and 0.93 for glucocorticoids alone). The time until a reduction in disease severity was similar in the three groups.CONCLUSIONSWe found n
Sancho-Shimizu V, Brodin P, Cobat A, et al., 2021, SARS-CoV-2–related MIS-C: A key to the viral and genetic causes of Kawasaki disease?, Journal of Experimental Medicine, Vol: 218, Pages: 1-16, ISSN: 0022-1007
Multisystem inflammatory syndrome in children (MIS-C) emerged in April 2020 in communities with high COVID-19 rates. This new condition is heterogenous but resembles Kawasaki disease (KD), a well-known but poorly understood and clinically heterogenous pediatric inflammatory condition for which weak associations have been found with a myriad of viral illnesses. Epidemiological data clearly indicate that SARS-CoV-2 is the trigger for MIS-C, which typically occurs about 1 mo after infection. These findings support the hypothesis of viral triggers for the various forms of classic KD. We further suggest that rare inborn errors of immunity (IEIs) altering the immune response to SARS-CoV-2 may underlie the pathogenesis of MIS-C in some children. The discovery of monogenic IEIs underlying MIS-C would shed light on its pathogenesis, paving the way for a new genetic approach to classic KD, revisited as a heterogeneous collection of IEIs to viruses.
Jackson H, Menikou S, Hamilton M, et al., 2021, Kawasaki Disease patient stratification and pathway analysis based on host transcriptomic and proteomic profiles, International Journal of Molecular Sciences, Vol: 11, Pages: 1-24, ISSN: 1422-0067
The aetiology of Kawasaki Disease (KD), an acute inflammatory disorder of childhood, remains unknown despite various triggers of KD having been proposed. Host ‘omic profiles offer insights into the host response to infection and inflammation, with the interrogation of multiple ‘omic levels in parallel providing a more comprehensive picture. We used differential abundance analysis, pathway analysis, clustering and classification techniques to explore whether the host response in KD is more similar to the response to bacterial or viral infection at the transcriptomic and proteomic levels through comparison of ‘omic profiles from children with KD to those with bacterial and viral infections. Pathways activated in patients with KD included those involved in anti-viral and anti-bacterial responses. Unsupervised clustering showed that the majority of KD patients clustered with bacterial patients on both ‘omic levels, whilst application of diagnostic signatures specific for bacterial and viral infections revealed that many transcriptomic KD samples had low probabilities of having bacterial or viral infections, suggesting that KD may be triggered by a different process not typical of either common bacterial or viral infections. Clustering based on the transcriptomic and proteomic responses during KD revealed three clusters of KD patients on both ‘omic levels, suggesting heterogeneity within the inflammatory response during KD. The observed heterogeneity may reflect differences in the host response to a common trigger, or variation dependent on different triggers of the condition.
Argiz L, Infante S, Machinena A, et al., 2021, Children with acute food protein-induced enterocolitis syndrome from Spain and Italy usually tolerate all other food groups, Clinical and Experimental Allergy, Vol: 51, Pages: 1238-1241, ISSN: 0954-7894
Georgiadou A, Dunican C, Soro-Barrio P, et al., 2021, Comparative transcriptomic analysis reveals translationally relevant processes in mouse models of malaria
<jats:title>Abstract</jats:title><jats:p>Recent initiatives to improve translation of findings from animal models to human disease have focussed on reproducibility but quantifying the relevance of animal models remains a challenge. Here we use comparative transcriptomics of blood to evaluate the systemic host response and its concordance between humans with different clinical manifestations of malaria and five commonly used mouse models. <jats:italic>Plasmodium yoelii</jats:italic> 17XL infection of mice most closely reproduces the profile of gene expression changes seen in the major human severe malaria syndromes, accompanied by high parasite biomass, severe anemia, hyperlactatemia, and cerebral microvascular pathology. However, there is also considerable discordance of changes in gene expression between species and across all models, indicating that the relevance of biological mechanisms of interest in each model should be assessed before conducting experiments. Our data will aid selection of appropriate models for translational malaria research, and the approach is generalizable to other disease models.</jats:p>
Rivero-Calle I, Gomez-Rial J, Bont L, et al., 2021, TIPICO X: report of the 10th interactive infectious disease workshop on infectious diseases and vaccines, HUMAN VACCINES & IMMUNOTHERAPEUTICS, Vol: 17, Pages: 759-772, ISSN: 2164-5515
Gliddon H, Kaforou M, Alikian M, et al., 2021, Identification of reduced host transcriptomic signatures for tuberculosis disease and digital PCR-based validation and quantification, Frontiers in Immunology, Vol: 12, ISSN: 1664-3224
Recently, host whole blood gene expression signatures have been identified for diagnosis of tuberculosis (TB). Absolute quantification of the concentrations of signature transcripts in blood have not been reported, but would facilitate diagnostic test development. To identify minimal transcript signatures, we applied a transcript selection procedure to microarray data from African adults comprising 536 patients with TB, other diseases (OD) and latent TB (LTBI), divided into training and test sets. Signatures were further investigated using reverse transcriptase (RT)—digital PCR (dPCR). A four-transcript signature (GBP6, TMCC1, PRDM1, and ARG1) measured using RT-dPCR distinguished TB patients from those with OD (area under the curve (AUC) 93.8% (CI95% 82.2–100%). A three-transcript signature (FCGR1A, ZNF296, and C1QB) differentiated TB from LTBI (AUC 97.3%, CI95%: 93.3–100%), regardless of HIV. These signatures have been validated across platforms and across samples offering strong, quantitative support for their use as diagnostic biomarkers for TB.
Broderick C, Cliff JM, Lee J-S, et al., 2021, Host transcriptional response to TB preventive therapy differentiates two sub-groups of IGRA-positive individuals, Tuberculosis, Vol: 127, Pages: 1-10, ISSN: 1472-9792
We hypothesised that individuals with immunological sensitisation to Mycobacterium tuberculosis (Mtb), conventionally regarded as evidence of latent tuberculosis infection (LTBI), would demonstrate binary responses to preventive therapy (PT), reflecting the differential immunological consequences of the sterilisation of viable infection in those with active Mtb infection versus no Mtb killing in those who did not harbour viable bacilli.We investigated longitudinal whole blood transcriptional profile responses to PT of Interferon gamma release assay (IGRA)-positive tuberculosis contacts and IGRA-negative, tuberculosis-unexposed controls. Longitudinal unsupervised clustering analysis with a subset of 474 most variable genes in antigen-stimulated blood separated the IGRA-positive participants into two distinct subgroups, one of which clustered with the IGRA-negative controls. 117 probes were differentially expressed over time between the two cluster groups, many of them associated with immunological pathways important in mycobacterial control.We contend that the differential host RNA response reflects lack of Mtb viability in the group that clustered with the IGRA-negative unexposed controls, and Mtb viability in the group (1/3 of IGRA-positives) that clustered away.Gene expression patterns in the blood of IGRA-positive individuals emerging during the course of PT, which reflect Mtb viability, could have major implications in the identification of risk of progression, treatment stratification and biomarker development.
Gómez-Carballa A, Barral-Arca R, Cebey-López M, et al., 2021, Host transcriptomic response following administration of rotavirus vaccine in infants' mimics wild type infection, Frontiers in Immunology, Vol: 11, ISSN: 1664-3224
Background: Rotavirus (RV) is an enteric pathogen that has devastating impact on childhood morbidity and mortality worldwide. The immunologic mechanism underlying the protection achieved after RV vaccination is not yet fully understood. Methods: We compared the transcriptome of children affected by community-acquired RV infection and children immunized with a live attenuated RV vaccine (RotaTeq®). Results: RV vaccination mimics the wild type infection causing similar changes in children's transcriptome, including transcripts associated with cell cycle, diarrhea, nausea, vomiting, intussusception, and abnormal morphology of midgut. A machine learning approach allowed to detect a combination of nine-transcripts that differentiates vaccinated from convalescent-naturally infected children (AUC: 90%; 95%CI: 70-100) and distinguishes between acute-infected and healthy control children (in both cases, AUC: 100%; 95%CI: 100-100). We identified a miRNA hsa-mir-149 that seems to play a role in the host defense against viral pathogens and may have an antiviral role. Discussion: Our findings might shed further light in the understanding of RV infection, its functional link to intussusception causes, as well as guide development of antiviral treatments and safer and more effective vaccines. The nine-transcript signature may constitute a marker of vaccine protection and helps to differentiate vaccinated from naturally infected or susceptible children.
Pennisi I, Rodriguez Manzano J, Moniri A, et al., 2021, Translation of a host blood RNA Signature distinguishing bacterial from viral infection into a platform suitable for development as a point-of-care test, JAMA Pediatrics, Vol: 175, Pages: 417-419, ISSN: 2168-6203
Menikou S, McArdle AJ, Li M-S, et al., 2020, A proteomics-based method for identifying antigens within immune complexes, PLoS One, Vol: 15, ISSN: 1932-6203
A novel approach to recover and identify immune complexes (ICs) was developed using size exclusion chromatography (SEC) and affinity chromatography on immunoglobulin binding columns (HiTrap Protein G). The purification process was monitored by 1D SDS-PAGE, protein staining, Western blotting and, finally, liquid chromatography tandem mass spectrometry (LC MS/MS) was used to identify the recovered antigens. This approach was applied to serum with artificially created immune complexes (ICs) comprising vaccine antigen (influenza) and antibody, which led to recovery and identification of influenza peptides within the recovered ICs. This approach was compared with the established method for IC detection and recovery, polyethylene glycol (PEG) precipitation, followed by LC MS/MS. Both approaches successfully enabled capture, recovery and characterization of immunoglobulins and influenza antigen(s) in complex with the immunoglobulins. However, PEG precipitation has the advantage of simplicity and is more suited for large scale studies.
Channon-Wells S, O'Connor D, Valente-Pinto M, et al., 2020, RNA EXPRESSION RELIABLY DISTINGUISHES BACTERIAL INFECTION FROM TRANSIENT VACCINE REACTIONS IN YOUNG CHILDREN, The European Society For Paediatric Infectious Diseases Conference 2020
Background: Current diagnostics do not reliably differentiate serious bacterial infections from transient vaccine reactions in febrile young infants. We hypothesised that analysis of host RNA-expression could provide novel diagnostics for this specific common clinical setting. Methods: RNA-sequencing was used to compare whole-blood RNA expression in healthy postvaccination infants at 4-months of age with gene expression in young children under 5 years with definite bacterial infection from two distinct cohorts. Vaccinated infants received routine vaccinations according to the UK vaccination schedule, with half also receiving the 4CMenB vaccine. Batch correction was performed using the COCONUT R-package. Cases were split into training and test sets. To distinguish bacterial infection from vaccine reaction three minimal transcript signatures were selected using differential expression analysis and three separate machine learning tools on the training set. The performance of these signatures was evaluated on the test set. Results: On the training set of 86 children (42 infections, 44 post-vaccination) we identified three signatures with 3-, 6- and 11-transcripts. In the test set (52 children) all three signatures performed similarly, with AUCs all above 0.99 (Figure 1). The best performing signature (11-transcripts) distinguished bacterial infection from vaccine reaction with 97% sensitivity and 93% specificity in the test set, outperforming both CRP and WCC in the whole cohort (CRP: sensitivity 83%, specificity 90%). Conclusions: This preliminary work has identified novel transcript-sets that discriminate bacterial infection from vaccine reaction. Further testing is required to validate these findings. Our aim is to develop a quantitative PCR assay for clinical use, to help minimise admissions and antibiotic administrations in children suffering from a transient vaccine response. Clinical Trial Registration: Not applicable
Tregoning J, Busse D, Kaforou M, et al., 2020, Interferon-induced Protein-44 and Interferon-induced Protein 44-like restrict replication of Respiratory Syncytial Virus, Journal of Virology, Vol: 94, Pages: 1-15, ISSN: 0022-538X
Cellular intrinsic immunity, mediated by the expression of an array of interferon-stimulated antiviral genes, is a vital part of host defence. We have previously used a bioinformatic screen to identify two interferon stimulated genes (ISG) with poorly characterised function, Interferon-induced protein 44 (IFI44) and interferon-induced protein 44-like (IFI44L), as potentially being important in Respiratory Syncytial Virus (RSV) infection. Using overexpression systems, CRISPR-Cas9-mediated knockout, and a knockout mouse model we investigated the antiviral capability of these genes in the control of RSV replication. Over-expression of IFI44 or IFI44L was sufficient to restrict RSV infection at an early time post infection. Knocking out these genes in mammalian airway epithelial cells increased levels of infection. Both genes express antiproliferative factors that have no effect on RSV attachment but reduce RSV replication in a minigenome assay. The loss of Ifi44 was associated with a more severe infection phenotype in a mouse model of infection. These studies demonstrate a function for IFI44 and IFI44L in controlling RSV infection.
Pennisi I, Rodriguez Manzano J, Miscourides N, et al., 2020, A method for determining a diagnostic outcome
Montaldo P, Cunnington A, Oliveira V, et al., 2020, Transcriptomic profile of adverse neurodevelopmental outcomes after neonatal encephalopathy, Scientific Reports, Vol: 10, Pages: 1-7, ISSN: 2045-2322
A rapid and early diagnostic test to identify the encephalopathic babies at risk of adverse outcome may accelerate the development of neuroprotectants. We examined if a whole blood transcriptomic signature measured soon after birth,predicts adverse neurodevelopmental outcomeeighteenmonths after neonatal encephalopathy.We performed next generation sequencing on whole blood ribonucleic acid obtained within sixhours of birth from the first 47encephalopathic babies recruited to the Hypothermia for Encephalopathy in Low and middle-income countries (HELIX)trial. Two infants with blood culture positive sepsis were excluded, and the data from remaining 45 were analysed. A total of 855genes were significantly differentially expressed between the good and adverse outcome groups, of which RGS1and SMC4 werethe most significant. Biological pathway analysis adjusted for gender, trial randomisation allocation (cooling therapy versus usual care) and estimated blood leukocyte proportions revealed over-representation of genes from pathways related to melatoninand polo-like kinase in babieswith adverse outcome. These preliminary data suggest that transcriptomic profiling may be a promising tool for rapid risk stratification in neonatal encephalopathy. It may provide insights into biological mechanismsand identify novel therapeutic targetsfor neuroprotection.
Broderick C, Cliff JM, Lee J-S, et al., 2020, Host transcriptional response to TB preventive therapy differentiates two sub-groups of IGRA-positive individuals
<jats:title>Abstract</jats:title><jats:p>We investigated the longitudinal whole blood transcriptional profile responses to tuberculosis preventive therapy of 18 IGRA-positive tuberculosis contacts and IGRA-negative, tuberculosis-unexposed healthy controls.</jats:p><jats:p>Longitudinal unsupervised clustering analysis with a subset of 474 most variable genes in antigen-stimulated blood separated the IGRA+ participants into two distinct subgroups, one of which clustered with the IGRA-negative controls. 117 probes were significantly differentially expressed over time between the two cluster groups, many of them associated with immunological pathways important in mycobacterial control.</jats:p><jats:p>We contend that the differential host RNA response reflects lack of <jats:italic>M.tuberculosis</jats:italic> (<jats:italic>Mtb</jats:italic>) viability in the group that clustered with the IGRA-unexposed healthy controls, and <jats:italic>Mtb</jats:italic> viability in the group (1/3 of IGRA-positives) that clustered away.</jats:p><jats:p>Gene expression patterns in the blood of IGRA+ individuals emerging during the course of PT, which reflect <jats:italic>Mtb</jats:italic> viability, could have major implications in the identification of risk of progression, treatment stratification and biomarker development.</jats:p>
Kaforou M, 2020, Screening for candidate biomarkers of TB in stimulated blood: another step in the quest for a test?, Thorax, Vol: 75, Pages: 534-535, ISSN: 0040-6376
Whittaker E, Bamford A, Kenny J, et al., 2020, Clinical characteristics of 58 children with a pediatric inflammatory multisystem syndrome temporally associated with SARS-CoV-2, JAMA, Vol: 324, Pages: 259-269, ISSN: 0098-7484
Importance In communities with high rates of coronavirus disease 2019, reports have emerged of children with an unusual syndrome of fever and inflammation.Objectives To describe the clinical and laboratory characteristics of hospitalized children who met criteria for the pediatric inflammatory multisystem syndrome temporally associated with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) (PIMS-TS) and compare these characteristics with other pediatric inflammatory disorders.Design, Setting, and Participants Case series of 58 children from 8 hospitals in England admitted between March 23 and May 16, 2020, with persistent fever and laboratory evidence of inflammation meeting published definitions for PIMS-TS. The final date of follow-up was May 22, 2020. Clinical and laboratory characteristics were abstracted by medical record review, and were compared with clinical characteristics of patients with Kawasaki disease (KD) (n = 1132), KD shock syndrome (n = 45), and toxic shock syndrome (n = 37) who had been admitted to hospitals in Europe and the US from 2002 to 2019.Exposures Signs and symptoms and laboratory and imaging findings of children who met definitional criteria for PIMS-TS from the UK, the US, and World Health Organization.Main Outcomes and Measures Clinical, laboratory, and imaging characteristics of children meeting definitional criteria for PIMS-TS, and comparison with the characteristics of other pediatric inflammatory disorders.Results Fifty-eight children (median age, 9 years [interquartile range {IQR}, 5.7-14]; 33 girls [57%]) were identified who met the criteria for PIMS-TS. Results from SARS-CoV-2 polymerase chain reaction tests were positive in 15 of 58 patients (26%) and SARS-CoV-2 IgG test results were positive in 40 of 46 (87%). In total, 45 of 58 patients (78%) had evidence of current or prior SARS-CoV-2 infection. All children presented with fever and nonspecific symptoms, including v
This data is extracted from the Web of Science and reproduced under a licence from Thomson Reuters. You may not copy or re-distribute this data in whole or in part without the written consent of the Science business of Thomson Reuters.