There is a reciprocal relationship between extracellular matrix (ECM) remodelling and inflammation that could be operating in the progression of severe COVID-19. To explore the immune-driven ECM ...remodelling in COVID-19, we in this explorative study analysed these interactions in hospitalised COVID-19 patients. RNA sequencing and flow analysis were performed on peripheral blood mononuclear cells. Inflammatory mediators in plasma were measured by ELISA and MSD, and clinical information from hospitalised COVID-19 patients (N=15) at admission was included in the analysis. Further, we reanalysed two publicly available datasets: (1) lung tissue RNA-sequencing dataset (N=5) and (2) proteomics dataset from PBCM. ECM remodelling pathways were enriched in PBMC from COVID-19 patients compared to healthy controls. Patients treated at the intensive care unit (ICU) expressed distinct ECM remodelling gene profiles compared to patients in the hospital ward. Several markers were strongly correlated to immune cell subsets, and the dysregulation in the ICU patients was positively associated with plasma levels of inflammatory cytokines and negatively associated with B-cell activating factors. Finally, our analysis of publicly accessible datasets revealed (i) an augmented ECM remodelling signature in inflamed lung tissue compared to non-inflamed tissue and (ii) proteomics analysis of PBMC from severe COVID-19 patients demonstrated an up-regulation in an ECM remodelling pathway. Our results may suggest the presence of an interaction between ECM remodelling, inflammation, and immune cells, potentially initiating or perpetuating pulmonary pathology in severe COVID-19.
Results showing that sera from double vaccinated individuals have minimal neutralizing activity against Omicron have been interpreted as indicating the need for a third vaccine dose for protection. ...However, there is little information about early immune responses to Omicron infection in double vaccinated individuals.
We measured inflammatory mediators, antibodies to the SARS-CoV-2 spike and nucleocapsid proteins, and spike peptide-induced release of interferon gamma in whole blood in 51 double-vaccinated individuals infected with Omicron, in 14 infected with Delta, and in 18 healthy controls. The median time points for the first and second samples were 7 and 14 days after symptom onset, respectively.
Infection with Omicron or Delta led to a rapid and similar increase in antibodies to the receptor-binding domain (RBD) of Omicron protein and spike peptide-induced interferon gamma in whole blood. Both the Omicron- and the Delta-infected patients had a mild and transient increase in inflammatory parameters.
The results suggest that two vaccine doses are sufficient to mount a rapid and potent immune response upon infection in healthy individuals of with the Omicron variant.
The study was funded by the Oslo University Hospital, and by grants from The Coalition for Epidemic Preparedness Innovations, Research Council of Norway (no 312780, 324272), South-Eastern Norway Regional Health Authority (no 2019067, 2021071, 10357, 2021047, 33612, 2021087, 2017092), EU Horizon 2020 grant no 848099, a philantropic donation from Vivaldi Invest A/S, and The European Virus Archive Global.
DNA double-strand breaks (DSBs) trigger the Ataxia telangiectasia mutated (ATM)-dependent DNA damage response (DDR), which consists of histone H2AX, MDC1, RNF168, 53BP1, PTIP, RIF1, Rev7, and ...Shieldin. Early stages of B and T lymphocyte development are dependent on recombination activating gene (RAG)-induced DSBs that form the basis for further V(D)J recombination. Non-homologous end joining (NHEJ) pathway factors recognize, process, and ligate DSBs. Based on numerous loss-of-function studies, DDR factors were thought to be dispensable for the V(D)J recombination. In particular, mice lacking Mediator of DNA Damage Checkpoint Protein 1 (MDC1) possessed nearly wild-type levels of mature B and T lymphocytes in the spleen, thymus, and bone marrow. NHEJ factor XRCC4-like factor (XLF)/Cernunnos is functionally redundant with ATM, histone H2AX, and p53-binding protein 1 (53BP1) during the lymphocyte development in mice. Here, we genetically inactivated
,
, or both
and
in murine vAbl pro-B cell lines and, using chromosomally integrated substrates, demonstrated that MDC1 stimulates the V(D)J recombination in cells lacking XLF. Moreover, combined inactivation of
and
in mice resulted in synthetic lethality. Together, these findings suggest that MDC1 and XLF are functionally redundant during the mouse development, in general, and the V(D)J recombination, in particular.
We recently showed that interleukin (IL)-6 inhibition by tocilizumab improves myocardial salvage in ST-elevation myocardial infarction (STEMI). However, the mechanisms for this effect are not clear.
...In this exploratory sub-study of the ASSAIL-MI trial, we examined leukocyte differential counts and their relation to myocardial salvage and peak troponin T (TnT) in STEMI patients randomised to tocilizumab (n = 101) or placebo (n = 98). We performed RNA-sequencing on whole blood (n = 40) and T cells (n = 20). B and T cell subpopulations were examined by flow cytometry (n = 69).
(i) STEMI patients had higher neutrophil counts at hospitalisation compared with stable angina patients. (ii) After percutaneous coronary intervention there was a gradual decline in neutrophils, which was significantly more pronounced in the tocilizumab group. (iii) The decrease in neutrophils in the tocilizumab group was associated with improved myocardial salvage and lower peak TnT. (iv) RNA-sequencing suggested that neutrophil function was also attenuated by tocilizumab. (v) B and T cell sub-populations changed only minimally after STEMI with minor effects of tocilizumab, supported as well by RNA-sequencing analyses of T cells. (vi) However, a low CD8+ count was associated with improved myocardial salvage in patients admitted to the hospital > 3 h after symptom onset.
Tocilizumab induced a rapid reduction in neutrophils and seemed to attenuate neutrophil function in STEMI patients potentially related to the beneficial effects of tocilizumab on myocardial salvage.
South-Eastern Norway Regional Health Authority (Nos. 2019067, 2017084), the Central Norway Regional Health Authority and Norwegian Research Council (No. 283867).
BackgroundTocilizumab improves myocardial salvage index (MSI) in patients with ST-elevation myocardial infarction (STEMI), but its mechanisms of action are unclear. Here, we explored how cytokines ...were affected by tocilizumab and their correlations with neutrophils, C-reactive protein (CRP), troponin T, MSI and infarct size.MethodsSTEMI patients were randomised to receive a single dose of 280 mg tocilizumab (n=101) or placebo (n=98) before percutaneous coronary intervention. Blood samples were collected before infusion of tocilizumab or placebo at baseline, during follow-up at 24–36, 72–168 hours, 3 and 6 months. 27 cytokines were analysed using a multiplex cytokine assay. Cardiac MRI was performed during hospitalisation and 6 months.ResultsRepeated measures analysis of variance showed significant (p<0.001) between-group difference in changes for IL-6, IL-8 and IL-1ra due to an increase in the tocilizumab group during hospitalisation. IL-6 and IL-8 correlated to neutrophils in the placebo group (r=0.73, 0.68, respectively), which was attenuated in the tocilizumab group (r=0.28, 0.27, respectively). A similar pattern was seen for MSI and IL-6 and IL-8 in the placebo group (r=−0.29, –0.25, respectively) in patients presenting ≤3 hours from symptom onset, which was attenuated in the tocilizumab group (r=−0.09,–0.14, respectively).ConclusionsTocilizumab increases IL-6, IL-8 and IL-1ra in STEMI. IL-6 and IL-8 show correlations to neutrophils/CRP and markers of cardiac injury in the placebo group that was attenuated in the tocilizumab group. This may suggest a beneficial effect of tocilizumab on the ischaemia-reperfusion injury in STEMI patients.Trial registration numberNCT03004703.
Background
Prognostic markers for disease severity and identification of therapeutic targets in COVID‐19 are urgently needed. We have studied innate and adaptive immunity on protein and ...transcriptomic level in COVID‐19 patients with different disease severity at admission and longitudinally during hospitalization.
Methods
Peripheral blood mononuclear cells (PBMCs) were collected at three time points from 31 patients included in the Norwegian SARS‐CoV‐2 cohort study and analysed by flow cytometry and RNA sequencing. Patients were grouped as either mild/moderate (n = 14), severe (n = 11) or critical (n = 6) disease in accordance with WHO guidelines and compared with patients with SARS‐CoV‐2‐negative bacterial sepsis (n = 5) and healthy controls (n = 10).
Results
COVID‐19 severity was characterized by decreased interleukin 7 receptor alpha chain (CD127) expression in naïve CD4 and CD8 T cells. Activation (CD25 and HLA‐DR) and exhaustion (PD‐1) markers on T cells were increased compared with controls, but comparable between COVID‐19 severity groups. Non‐classical monocytes and monocytic HLA‐DR expression decreased whereas monocytic PD‐L1 and CD142 expression increased with COVID‐19 severity. RNA sequencing exhibited increased plasma B‐cell activity in critical COVID‐19 and yet predominantly reduced transcripts related to immune response pathways compared with milder disease.
Conclusion
Critical COVID‐19 seems to be characterized by an immune profile of activated and exhausted T cells and monocytes. This immune phenotype may influence the capacity to mount an efficient T‐cell immune response. Plasma B‐cell activity and calprotectin were higher in critical COVID‐19 while most transcripts related to immune functions were reduced, in particular affecting B cells. The potential of these cells as therapeutic targets in COVID‐19 should be further explored.
Abstract Background Abnormal remodelling of the extracellular matrix (ECM) has generally been linked to pulmonary inflammation and fibrosis and may also play a role in the pathogenesis of severe ...COVID‐19. To further elucidate the role of ECM remodelling and excessive fibrogenesis in severe COVID‐19, we examined circulating levels of mediators involved in various aspects of these processes in COVID‐19 patients. Methods Serial blood samples were obtained from two cohorts of hospitalised COVID‐19 patients ( n = 414). Circulating levels of ECM remodelling mediators were quantified by enzyme immunoassays in samples collected during hospitalisation and at 3‐month follow‐up. Samples were related to disease severity (respiratory failure and/or treatment at the intensive care unit), 60‐day total mortality and pulmonary pathology after 3‐months. We also evaluated the direct effect of inactivated SARS‐CoV‐2 on the release of the different ECM mediators in relevant cell lines. Results Several of the measured markers were associated with adverse outcomes, notably osteopontin (OPN), S100 calcium‐binding protein A12 and YKL‐40 were associated with disease severity and mortality. High levels of ECM mediators during hospitalisation were associated with computed tomography thorax pathology after 3‐months. Some markers (i.e. growth differential factor 15, galectin 3 and matrix metalloproteinase 9) were released from various relevant cell lines (i.e. macrophages and lung cell lines) in vitro after exposure to inactivated SARS‐CoV‐2 suggesting a direct link between these mediators and the causal agent of COVID‐19. Conclusion Our findings highlight changes to ECM remodelling and particularly a possible role of OPN, S100A12 and YKL‐40 in the pathogenesis of severe COVID‐19.
Abstract
Background
Abnormal remodelling of the extracellular matrix (ECM) has generally been linked to pulmonary inflammation and fibrosis and may also play a role in the pathogenesis of severe ...COVID‐19. To further elucidate the role of ECM remodelling and excessive fibrogenesis in severe COVID‐19, we examined circulating levels of mediators involved in various aspects of these processes in COVID‐19 patients.
Methods
Serial blood samples were obtained from two cohorts of hospitalised COVID‐19 patients (
n
= 414). Circulating levels of ECM remodelling mediators were quantified by enzyme immunoassays in samples collected during hospitalisation and at 3‐month follow‐up. Samples were related to disease severity (respiratory failure and/or treatment at the intensive care unit), 60‐day total mortality and pulmonary pathology after 3‐months. We also evaluated the direct effect of inactivated SARS‐CoV‐2 on the release of the different ECM mediators in relevant cell lines.
Results
Several of the measured markers were associated with adverse outcomes, notably osteopontin (OPN), S100 calcium‐binding protein A12 and YKL‐40 were associated with disease severity and mortality. High levels of ECM mediators during hospitalisation were associated with computed tomography thorax pathology after 3‐months. Some markers (i.e. growth differential factor 15, galectin 3 and matrix metalloproteinase 9) were released from various relevant cell lines (i.e. macrophages and lung cell lines)
in vitro
after exposure to inactivated SARS‐CoV‐2 suggesting a direct link between these mediators and the causal agent of COVID‐19.
Conclusion
Our findings highlight changes to ECM remodelling and particularly a possible role of OPN, S100A12 and YKL‐40 in the pathogenesis of severe COVID‐19.
Background: Results showing that sera from double vaccinated individuals have minimal neutralizing activity against Omicron have been interpreted as indicating the need for a third vaccine dose for ...protection. However, there is little information about early immune responses to Omicron infection in double vaccinated individuals. Methods: We measured inflammatory mediators, antibodies to the SARS-CoV-2 spike and nucleocapsid proteins, and spike peptide-induced release of interferon gamma in whole blood in 51 double-vaccinated individuals infected with Omicron, in 14 infected with Delta, and in 18 healthy controls. The median time points for the first and second samples were 7 and 14 days after symptom onset, respectively. Findings: Infection with Omicron or Delta led to a rapid and similar increase in antibodies to the receptor-binding domain (RBD) of Omicron protein and spike peptide-induced interferon gamma in whole blood. Both the Omicron- and the Delta-infected patients had a mild and transient increase in inflammatory parameters. Interpretation: The results suggest that two vaccine doses are sufficient to mount a rapid and potent immune response upon infection in healthy individuals of with the Omicron variant.
Background In cardiovascular diseases, atherosclerotic disorder are the most frequent and important with respect to morbidity and mortality. Inflammation mediated by immune cells is central in all ...parts of the atherosclerotic progress, and further understanding of the underlying mechanisms is needed. Growing evidence suggests that deamination of adenosine‐to‐inosine in RNA is crucial for a correct immune response; nevertheless, the role of adenosine‐to‐inosine RNA editing in atherogenesis has barely been studied. Several proteins have affinity for inosines in RNA, one being ENDOV (endonuclease V), which binds and cleaves RNA at inosines. Data on ENDOV in atherosclerosis are lacking. Methods and Results Quantitative polymerase chain reaction on ENDOV mRNA showed an increased level in human carotid atherosclerotic plaques compared with control veins. Inosine‐ribonuclease activity as measured by an enzyme activity assay is detected in immune cells relevant for the atherosclerotic process. Abolishing EndoV in atherogenic apolipoprotein E‐deficient ( ApoE −/− ) mice reduces the atherosclerotic plaque burden, both in size and lipid content. In addition, in a brain stroke model, mice without ENDOV suffer less damage than control mice. Finally, lack of EndoV reduces the recruitment of monocytes to atherosclerotic lesions in atherogenic ApoE −/− mice. Conclusions ENDOV is upregulated in human atherosclerotic lesions, and data from mice suggest that ENDOV promotes atherogenesis by enhancing the monocyte recruitment into the atherosclerotic lesion, potentially by increasing the effect of CCL2 activation on these cells.
PDF
