Circulating multimeric immune complexes contribute to immunopathology in COVID-19

SARS-CoV-2 S1 protein induces IgG-mediated platelet activation and is prevented by 1.8-cineole

COVID-19 patients face an increased risk of thromboembolic complications, yet the exact pathophysiological role of platelets in the disease remains unclear. Considering the multifaceted nature of COVID-19 symptoms, including platelet hyperactivation and inflammation, the development of compounds that simultaneously target both represents a promising therapeutic strategy. The monoterpene 1.8-cineole (CNL-1976) is known for its anti-inflammatory and anti-aggregatory effects. Thus, understanding the mechanism behind platelet hyperactivation and the effect of 1.8-cineole during COVID-19 is crucial when aiming for a reduction of disease severity. In this study, we investigated the mechanism of platelet activation triggered by the SARS-CoV-2 S1 spike protein (S1). Utilizing S1-coupled beads, we discovered that platelet activation and aggregation were dependent on plasma components, particularly S1-specific IgG antibodies. The formation of immune complexes through IgG binding to S1 facilitated the crosslinking of the platelet expressed FcγRIIa receptor, initiating platelet activation and aggregation, as well as formation of platelet-leukocyte aggregates (PLAs). Importantly, treatment with 1.8-cineole significantly inhibited S1-bead-induced platelet activity and PLA formation. These findings strongly suggest that antibody-mediated platelet activation via FcγRIIa directly contributes to the well-recognized prothrombotic environment during COVID-19. Moreover, our data indicate that 1.8-cineole can serve as a potential therapeutic compound, alleviating platelet-driven thromboinflammatory complications associated with COVID-19 and post-acute sequelae of SARS-CoV-2 (PASC).

Autoreactive IgG levels and Fc receptor γ subunit upregulation drive mechanical allodynia after nerve constriction or crush injury

B cells contribute to the development of pain after sciatic nerve chronic constriction injury (CCI) via binding of immunoglobulin G (IgG) to Fc gamma receptors (FcγRs) in the lumbar dorsal root ganglia (DRG) and spinal cord. Yet the contribution of B cells to pain after different types of peripheral nerve injury is uncertain. Using male and female mice, we demonstrate a divergent role for B cell-IgG-FcγR signaling underlying mechanical allodynia between CCI, nerve crush (NC), spared nerve injury (SNI), and spinal nerve ligation (SNL). Depletion (monoclonal anti-CD20) or genetic deletion (muMT mice) of B cells prevented development of allodynia following NC and CCI, but not SNI or SNL. In apparent contradiction, circulating levels of autoreactive IgG and circulating immune complexes were increased in all models, though more prominent following NC and CCI. Passive transfer of IgG from SNI donor mice induced allodynia in CCI muMT recipient mice, demonstrating that IgG secreted after SNI is pronociceptive. To investigate why pronociceptive IgG did not contribute to mechanical allodynia after SNI, we evaluated levels of the Fc receptor γ subunit. SNI or SNL did not increase γ subunit levels in the DRG and spinal cord, whereas CCI and NC did, in agreement with B cell-dependent allodynia in these models. Together, the results suggest that traumatic peripheral nerve injury drives secretion of autoreactive IgG from B cells. However, levels of cognate FcγRs are increased following sciatic nerve constriction and crush, but not transection, to differentially regulate pain through the B cell-IgG-FcγR axis.

Serotonergic psychedelics as potential therapeutics for post-COVID-19 syndrome (or Long COVID): A comprehensive review

RATIONALE

In our ongoing battle against the coronavirus 2019 (COVID-19) pandemic, a major challenge is the enduring symptoms that continue after acute infection. Also known as Long COVID, post-COVID-19 syndrome (PCS) often comes with debilitating symptoms like fatigue, disordered sleep, olfactory dysfunction, and cognitive issues ("brain fog"). Currently, there are no approved treatments for PCS. Recent research has uncovered that the severity of PCS is inversely linked to circulating serotonin levels, highlighting the potential of serotonin-modulating therapeutics for PCS. Therefore, we propose that serotonergic psychedelics, acting mainly via the 5-HT2A serotonin receptor, hold promise for treating PCS.

OBJECTIVES

Our review aims to elucidate potential mechanisms by which serotonergic psychedelics may alleviate the symptoms of PCS.

RESULTS

Potential mechanisms through which serotonergic psychedelics may alleviate PCS symptoms are discussed, with emphasis on their effects on inflammation, neuroplasticity, and gastrointestinal function. Additionally, this review explores the potential of serotonergic psychedelics in mitigating endothelial dysfunction, a pivotal aspect of PCS pathophysiology implicated in organ dysfunction. This review also examines the potential role of serotonergic psychedelics in alleviating specific PCS symptoms, which include olfactory dysfunction, cognitive impairment, sleep disturbances, and mental health challenges.

CONCLUSIONS

Emerging evidence suggests that serotonergic psychedelics may alleviate PCS symptoms. However, further high-quality research is needed to thoroughly assess their safety and efficacy in treating patients with PCS.

CoupleVAE: coupled variational autoencoders for predicting perturbational single-cell RNA sequencing data

With the rapid advances in single-cell sequencing technology, it is now feasible to conduct in-depth genetic analysis in individual cells. Study on the dynamics of single cells in response to perturbations is of great significance for understanding the functions and behaviors of living organisms. However, the acquisition of post-perturbation cellular states via biological experiments is frequently cost-prohibitive. Predicting the single-cell perturbation responses poses a critical challenge in the field of computational biology. In this work, we propose a novel deep learning method called coupled variational autoencoders (CoupleVAE), devised to predict the postperturbation single-cell RNA-Seq data. CoupleVAE is composed of two coupled VAEs connected by a coupler, initially extracting latent features for controlled and perturbed cells via two encoders, subsequently engaging in mutual translation within the latent space through two nonlinear mappings via a coupler, and ultimately generating controlled and perturbed data by two separate decoders to process the encoded and translated features. CoupleVAE facilitates a more intricate state transformation of single cells within the latent space. Experiments in three real datasets on infection, stimulation and cross-species prediction show that CoupleVAE surpasses the existing comparative models in effectively predicting single-cell RNA-seq data for perturbed cells, achieving superior accuracy.

Virus-Induced Pathogenic Antibodies: Lessons from Long COVID and Dengue Hemorrhage Fever

Virus-induced antibodies represent a dual-edged sword in the immune response to viral infections. While antibodies are critical for neutralizing pathogens, some can paradoxically exacerbate disease severity through mechanisms such as antibody-dependent enhancement (ADE), autoantibody, and prolonged inflammation. Long coronavirus disease (COVID) and dengue hemorrhagic fever (DHF) exemplify conditions where pathogenic antibodies play a pivotal role in disease progression. Long COVID is associated with persistent immune dysregulation and autoantibody production, leading to chronic symptoms and tissue damage. In DHF, pre-existing antibodies against dengue virus contribute to ADE, amplifying viral replication, immune activation, and vascular permeability. This review explores the mechanisms underlying these pathogenic antibody responses, highlighting the shared pathways of immune dysregulation and comparing the distinct features of both conditions. By examining these studies, we identify key lessons for therapeutic strategies, vaccine design, and future research aimed at mitigating the severe outcomes of viral infections.

Immune complexome analysis reveals an autoimmune signature predictive of COVID-19 severity

BACKGROUND

The factors contributing to the development of severe coronavirus disease 2019 (COVID-19) following infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) remain unclear. Although the presence of immune complexes (ICs), formed between antibodies and their antigens, has been linked to COVID-19 severity, their role requires further investigation, and the antigens within these ICs are yet to be characterized.

METHOD

Here, a C1q enzyme-liked immunosorbent assay and immune complexome analysis were used to determine IC concentrations and characterize IC antigens, respectively, in the sera of 64 unvaccinated COVID-19 patients with PCR-confirmed SARS-CoV-2 infection, enrolled at seven participating centers in 2020. For the analysis, the patients were split into the severe (n = 35) and non-severe (n = 28) groups on the basis of their COVID-19 symptoms.

RESULTS

We found that neither serum IC concentration nor IC antigen number was associated with COVID-19 severity. However, we identified six IC antigens, which were significantly enriched in the severe versus non-severe group. These IC antigens were all derived from human proteins, namely haptoglobin, the serum amyloid A-2 protein, the serum amyloid A-1 protein, clusterin, and lipopolysaccharide-binding protein, and complement-factor-H-related protein 3. Meanwhile, we found no association between COVID-19 severity and IC antigens derived from SARS-CoV-2 proteins. Collectively, the six IC antigens predicted COVID-19 severity with a moderate degree of accuracy (area under the receiver operating characteristic curve = 0.90, sensitivity = 94 %, specificity = 79 %).

CONCLUSIONS

The IC antigen signature identified in this study may have important implications for the diagnosis and treatment of severe COVID-19.

Impaired mucosal IgA response in patients with severe COVID-19

Several studies have investigated the antibody response to SARS-CoV-2, focusing particularly on the systemic humoral immune response and the production of immunoglobulin G (IgG) antibodies. IgA antibodies play a crucial role in protecting against respiratory viral infections but have also been associated with the pathophysiology of COVID-19. We performed a prospective study of 169 COVID-19 patients - 50 with critical/severe (ICU), 47 with moderate (Non-ICU), and 72 with asymptomatic COVID-19 - to explore the humoral immune response to SARS-CoV-2 infection. We found that the early systemic IgA response strongly induced in patients with severe disease did not block IgG neutralization functions and activated FcRs more effectively than IgG. However, even if SIgA levels were high, mucosal IgA antibodies could not control the infection effectively in patients with severe disease. Our findings highlight the complexity of the immune response to SARS-CoV-2 exhibiting high systemic levels of IgA with strong neutralizing capacity in severe cases, together with higher levels of IgA-FcR activation than in asymptomatic patients. They also suggest the need for further research to fully understand the role of IgA and its structural alterations in mucosal tissues in cases of severe disease and the impact of these antibodies on disease progression.

Fcγ-receptor-IIIA bioactivity of circulating and synovial immune complexes in rheumatoid arthritis

OBJECTIVE

Previous technical limitations prevented the proof of Fcγ-receptor (FcγR)-activation by soluble immune complexes (sICs) in patients. FcγRIIIa (CD16) is a risk factor in rheumatoid arthritis (RA). We aimed at determining the presence of CD16-activating sICs in RA and control diseases.

METHODS

Sera from an exploratory cohort (n=50 patients with RA) and a validation cohort (n=106 patients with RA, 20 patients with psoriasis arthritis (PsA), 22 patients with systemic lupus erythematosus (SLE) and 31 healthy controls) were analysed using a new reporter cell assay. Additionally, 26 synovial fluid samples were analysed, including paired serum/synovial samples.

RESULTS

For the first time using a reliable and sensitive functional assay, the presence of sICs in RA sera was confirmed. sICs possess an intrinsic capacity to activate CD16 and can be found in both synovial fluid and in blood. In low experimental dilutions, circulating sICs were also detected in a subset of healthy people and in PsA. However, we report a significantly increased frequency of bioactive circulating sICs in RA. While the bioactivity of circulating sICs was low and did not correlate with clinical parameters, synovial sICs were highly bioactive and correlated with serum autoantibody levels. Receiver operator curves indicated that sICs bioactivity in synovial fluid could be used to discriminate immune complex-associated arthritis from non-associated forms. Finally, circulating sICs were more frequently found in SLE than in RA. The degree of CD16 bioactivity showed strong donor-dependent differences, especially in SLE.

CONCLUSIONS

RA is characterised by the presence of circulating and synovial sICs that can engage and activate CD16.

Unraveling the enigma of long COVID: novel aspects in pathogenesis, diagnosis, and treatment protocols

Long COVID, now unmistakably identified as a syndromic entity encompassing a complex spectrum of symptoms, demands immediate resolution of its elusive pathogenic underpinnings. The intricate interplay of diverse factors presents a complex puzzle, difficult to resolve, and thus poses a substantial challenge. As instances of long COVID manifest by repeated infections of SARS-CoV-2 and genetic predisposition, a detailed understanding in this regard is needed. This endeavor is a comprehensive exploration and analysis of the cascading pathogenetic events driven by viral persistence and replication. Beyond its morbidity, long COVID, more disabling than fatal, exacts one of the most substantial tolls on public health in contemporary times, with the potential to cripple national economies. The paper introduces a unified theory of long COVID, detailing a novel pathophysiological framework that interlinks persistent SARS-CoV-2 infection, autoimmunity, and systemic vascular pathology. We posit a model where viral reservoirs, immune dysregulation, and genetic predispositions converge to perpetuate disease. It challenges prevailing hypotheses with new evidence, suggesting innovative diagnostic and therapeutic approaches. The paper aims to shift the paradigm in long COVID research by providing an integrative perspective that encapsulates the multifaceted nature of the condition. We explain the immunological mechanisms, hypercoagulability states, and viral reservoirs in the skull that feed NeuroCOVID in patients with long COVID. Also, this study hints toward a patient approach and how to prioritize treatment sequences in long COVID patients in hospitals and clinics.

Functional diversification of innate and inflammatory immune responses mediated by antibody fragment crystallizable activities against SARS-CoV-2

Monoclonal antibodies (mAb) targeting the SARS-CoV-2 Spike (S) glycoprotein have been exploited for the treatment of severe COVID-19. In this study, we evaluated the immune-regulatory features of two neutralizing anti-S mAbs (nAbs), named J08 and F05, with wild-type (WT) conformation or silenced Fc functions. In the presence of D614G SARS-CoV-2, WT nAbs enhance intracellular viral uptake in immune cells and amplify antiviral type I Interferon and inflammatory cytokine and chemokine production without viral replication, promoting the differentiation of CD16+ inflammatory monocytes and innate/adaptive PD-L1+ and PD-L1+CD80+ plasmacytoid Dendritic Cells. In spite of a reduced neutralizing property, WT J08 nAb still promotes the IL-6 production and differentiation of CD16+ monocytes once binding Omicron BA.1 variant. Fc-mediated regulation of antiviral and inflammatory responses, in the absence of viral replication, highlighted in this study, might positively tune immune response during SARS-CoV-2 infection and be exploited also in mAb-based therapeutic and prophylactic strategies against viral infections.

Structural properties of immune complexes formed by viral antigens and specific antibodies shape the inflammatory response of macrophages

Data on the course of viral infections revealed severe inflammation as a consequence of antiviral immune response. Despite extensive research, there are insufficient data on the role of innate immune cells in promoting inflammation mediated by immune complexes (IC) of viral antigens and their specific antibodies. Recently, we demonstrated that antigens of human polyomaviruses (PyVs) induce an inflammatory response in macrophages. Here, we investigated macrophage activation by IC. We used primary murine macrophages as a cell model, virus-like particles (VLPs) of PyV capsid protein as antigens, and a collection of murine monoclonal antibodies (mAbs) of IgG1, IgG2a, IgG2b subclasses. The inflammatory response was investigated by analysing inflammatory chemokines and activation of NLRP3 inflammasome. We observed a diverse pattern of chemokine secretion in macrophages treated with different IC compared to VLPs alone. To link IC properties with cell activation status, we characterised the IC by advanced optical and acoustic techniques. Ellipsometry provided precise real-time kinetics of mAb-antigen interactions, while quartz crystal microbalance measurements showed changes in conformation and viscoelastic properties during IC formation. These results revealed differences in mAb-antigen interaction and mAb binding parameters of the investigated IC. We found that IC-mediated cell activation depends more on IC characteristics, including mAb affinity, than on mAb affinity for the activating Fc receptor. IC formed by the highest affinity mAb showed a significant enhancement of inflammasome activation. This may explain the hyperinflammation related to viral infection and vaccination. Our findings demonstrate that IC promote the viral antigen-induced inflammatory response depending on antibody properties.

Enhancement of NETosis by ACE2-cross-reactive anti-SARS-CoV-2 RBD antibodies in patients with COVID-19

BACKGROUND

High levels of neutrophil extracellular trap (NET) formation or NETosis and autoantibodies are related to poor prognosis and disease severity of COVID-19 patients. Human angiotensin-converting enzyme 2 (ACE2) cross-reactive anti-severe acute respiratory syndrome coronavirus 2 spike protein receptor-binding domain (SARS-CoV-2 RBD) antibodies (CR Abs) have been reported as one of the sources of anti-ACE2 autoantibodies. However, the pathological implications of CR Abs in NET formation remain unknown.

METHODS

In this study, we first assessed the presence of CR Abs in the sera of COVID-19 patients with different severity by serological analysis. Sera and purified IgG from CR Abs positive COVID-19 patients as well as a mouse monoclonal Ab (mAb 127) that can recognize both ACE2 and the RBD were tested for their influence on NETosis and the possible mechanisms involved were studied.

RESULTS

An association between CR Abs levels and the severity of COVID-19 in 120 patients was found. The CR Abs-positive sera and IgG from severe COVID-19 patients and mAb 127 significantly activated human leukocytes and triggered NETosis, in the presence of RBD. This NETosis, triggered by the coexistence of CR Abs and RBD, activated thrombus-related cells but was abolished when the interaction between CR Abs and ACE2 or Fc receptors was disrupted. We also revealed that CR Abs-induced NETosis was suppressed in the presence of recombinant ACE2 or the Src family kinase inhibitor, dasatinib. Furthermore, we found that COVID-19 vaccination not only reduced COVID-19 severity but also prevented the production of CR Abs after SARS-CoV-2 infection.

CONCLUSIONS

Our findings provide possible pathogenic effects of CR Abs in exacerbating COVID-19 by enhancing NETosis, highlighting ACE2 and dasatinib as potential treatments, and supporting the benefit of vaccination in reducing disease severity and CR Abs production in COVID-19 patients.

Clinical characteristics and influencing factors of severe fever with thrombocytopenia syndrome complicated by viral myocarditis: a retrospective study

OBJECTIVE

This study aimed to investigate the clinical characteristics of severe fever with thrombocytopenia syndrome complicated by viral myocarditis (SFTS-VM) and analyze relevant influencing factors.

METHODS

Retrospective analysis was conducted on clinical data from 79 SFTS-VM patients, categorized into common (SFTS-CVM, n = 40) and severe groups (SFTS-SVM, n = 39). Clinical manifestations, laboratory results, cardiac ultrasonography, and electrocardiogram features were analyzed. Univariate and multivariate analyses identified significant indicators, which were further assessed using ROC curves to predict SFTS-SVM.

RESULTS

SFTS-SVM group exhibited higher rates of hypotension, shock, abdominal pain, cough with sputum, and consciousness disorders compared to SFTS-CVM group. Laboratory findings showed elevated platelet count, ALT, AST, amylase, lipase, LDH, D-dimer, procalcitonin, TNI, and NT-proBNP in SFTS-SVM. Abnormal electrocardiograms, especially atrial fibrillation, were more prevalent in SFTS-SVM (P < 0.05). Multivariate analysis identified elevated LDH upon admission (OR = 1.004, 95% CI: 1-1.008, P = 0.050), elevated NT-proBNP (OR = 1.005, 95% CI: 1.001-1.008, P = 0.007), and consciousness disorders (OR = 112.852, 95% CI: 3.676 ~ 3464.292, P = 0.007) as independent risk factors for SFTS-SVM. LDH and NT-proBNP had AUCs of 0.728 and 0.744, respectively, in predicting SFTS-SVM. Critical values of LDH (> 978.5U/L) and NT-proBNP (> 857.5pg/ml)) indicated increased likelihood of SFTS progression into SVM.

CONCLUSION

Elevated LDH, NT-proBNP, and consciousness disorders independently correlate with SFTS-SVM. LDH and NT-proBNP can aid in early identification of SFTS-SVM development when above specified thresholds.

Identification of new drugs to counteract anti-spike IgG-induced hyperinflammation in severe COVID-19

Previously, we and others have shown that SARS-CoV-2 spike-specific IgG antibodies play a major role in disease severity in COVID-19 by triggering macrophage hyperactivation, disrupting endothelial barrier integrity, and inducing thrombus formation. This hyperinflammation is dependent on high levels of anti-spike IgG with aberrant Fc tail glycosylation, leading to Fcγ receptor hyperactivation. For development of immune-regulatory therapeutics, drug specificity is crucial to counteract excessive inflammation whereas simultaneously minimizing the inhibition of antiviral immunity. We here developed an in vitro activation assay to screen for small molecule drugs that specifically counteract antibody-induced pathology. We identified that anti-spike-induced inflammation is specifically blocked by small molecule inhibitors against SYK and PI3K. We identified SYK inhibitor entospletinib as the most promising candidate drug, which also counteracted anti-spike-induced endothelial dysfunction and thrombus formation. Moreover, entospletinib blocked inflammation by different SARS-CoV-2 variants of concern. Combined, these data identify entospletinib as a promising treatment for severe COVID-19.

Evaluation of autoantibody profile in healthy subjects after mRNA vaccination against COVID-19

BACKGROUND

SARS-CoV-2 severe acute respiratory syndrome has rapidly spread worldwide since 2019. All scientific and technological forces have concentrated towards the formulation of vaccines to contain the disease. In less than one year (December 2020) a first messenger RNA vaccine (Comirnaty, BioNTech/Pfizer) was authorized. However, the research community has wondered about possible side effects on the immune system, given the vaccines administration in phase 4.

AIM

This study aims to evaluate the mRNA vaccine impact on the development of possible positive autoantibody profile in healthcare workers without any previous underlying pathology, after first, second and booster dose of Pfizer vaccine, by determining: circulating immune complexes concentrations (CIC); anti-myeloperoxidase (MPO) and anti-proteinase 3 (PR3) autoantibodies, the presence of antinuclear antibodies (ANA) and subsequent second level tests (extractable nuclear antigen (ENA) screen, double-strand DNA, extractable nuclear antigen (ANA) profile).

METHODS

The subjects were divided according to anti-SARS-CoV-2 IgG RBD antibodies increasing concentrations in: Group I < 10 BAU/ml (N = 114); Group II > 1000 BAU/ml (N = 112); Group III > 2500 BAU/ml (N = 78).

RESULTS

Our data show no autoreactive response changes over time in healthy subjects after vaccination. In fact, evaluation of ANA, CIC, anti-MPO, anti-PR3 and the detection of specific autoantigens, did not display significant variations.

CONCLUSIONS

The results suggest the exclusion of a correlation between the administration of the vaccine and the possible onset of autoimmune disorders. Nevertheless, further investigations will be needed to test for any long-term side effects on an ever-growing population.

Preliminary Comparison of Molecular Antioxidant and Inflammatory Mechanisms Determined in the Peripheral Blood Granulocytes of COVID-19 Patients

The aim of this study was to evaluate selected parameters of redox signaling and inflammation in the granulocytes of COVID-19 patients who recovered and those who died. Upon admission, the patients did not differ in terms of any relevant clinical parameter apart from the percentage of granulocytes, which was 6% higher on average in those patients who died. Granulocytes were isolated from the blood of 15 healthy people and survivors and 15 patients who died within a week, and who were selected post hoc for analysis according to their matching gender and age. They differed only in the lethal outcome, which could not be predicted upon arrival at the hospital. The proteins level (respective ELISA), antioxidant activity (spectrophotometry), and lipid mediators (UPUPLC-MS) were measured in the peripheral blood granulocytes obtained via gradient centrifugation. The levels of Nrf2, HO-1, NFκB, and IL-6 were higher in the granulocytes of COVID-19 patients who died within a week, while the activity of cytoplasmic Cu,Zn-SOD and mitochondrial Mn-SOD and IL-2/IL-10 were lower in comparison to the levels observed in survivors. Furthermore, in the granulocytes of those patients who died, an increase in pro-inflammatory eicosanoids (PGE2 and TXB2), together with elevated cannabinoid receptors 1 and 2 (associated with a decrease in the anti-inflammatory 15d-PGJ2), were found. Hence, this study suggests that by triggering transcription factors, granulocytes activate inflammatory and redox signaling, leading to the production of pro-inflammatory eicosanoids while reducing cellular antioxidant capacity through SOD, thus expressing an altered response to COVID-19, which may result in the onset of systemic oxidative stress, ARDS, and the death of the patient.

SARS-CoV-2 and Its Bacterial Co- or Super-Infections Synergize to Trigger COVID-19 Autoimmune Cardiopathies

Autoimmune cardiopathies (AC) following COVID-19 and vaccination against SARS-CoV-2 occur at significant rates but are of unknown etiology. This study investigated the possible roles of viral and bacterial mimicry, as well as viral-bacterial co-infections, as possible inducers of COVID-19 AC using proteomic methods and enzyme-linked immunoadsorption assays. BLAST and LALIGN results of this study demonstrate that SARS-CoV-2 shares a significantly greater number of high quality similarities to some cardiac protein compared with other viruses; that bacteria such as Streptococci, Staphylococci and Enterococci also display very significant similarities to cardiac proteins but to a different set than SARS-CoV-2; that the importance of these similarities is largely validated by ELISA experiments demonstrating that polyclonal antibodies against SARS-CoV-2 and COVID-19-associated bacteria recognize cardiac proteins with high affinity; that to account for the range of cardiac proteins targeted by autoantibodies in COVID-19-associated autoimmune myocarditis, both viral and bacterial triggers are probably required; that the targets of the viral and bacterial antibodies are often molecularly complementary antigens such as actin and myosin, laminin and collagen, or creatine kinase and pyruvate kinase, that are known to bind to each other; and that the corresponding viral and bacterial antibodies recognizing these complementary antigens also bind to each other with high affinity as if they have an idiotype-anti-idiotype relationship. These results suggest that AC results from SARS-CoV-2 infections or vaccination complicated by bacterial infections. Vaccination against some of these bacterial infections, such as Streptococci and Haemophilus, may therefore decrease AC risk, as may the appropriate and timely use of antibiotics among COVID-19 patients and careful screening of vaccinees for signs of infection such as fever, diarrhea, infected wounds, gum disease, etc.

Systems analysis of human innate immunity in COVID-19

Recent developments in sequencing technologies, the computer and data sciences, as well as increasingly high-throughput immunological measurements have made it possible to derive holistic views on pathophysiological processes of disease and treatment effects directly in humans. We and others have illustrated that incredibly predictive data for immune cell function can be generated by single cell multi-omics (SCMO) technologies and that these technologies are perfectly suited to dissect pathophysiological processes in a new disease such as COVID-19, triggered by SARS-CoV-2 infection. Systems level interrogation not only revealed the different disease endotypes, highlighted the differential dynamics in context of disease severity, and pointed towards global immune deviation across the different arms of the immune system, but was already instrumental to better define long COVID phenotypes, suggest promising biomarkers for disease and therapy outcome predictions and explains treatment responses for the widely used corticosteroids. As we identified SCMO to be the most informative technologies in the vest to better understand COVID-19, we propose to routinely include such single cell level analysis in all future clinical trials and cohorts addressing diseases with an immunological component.

Uncovering the information immunology journals transmitted for COVID-19: A bibliometric and visualization analysis

BACKGROUND

Since the global epidemic of the coronavirus disease 2019 (COVID-19), a large number of immunological studies related to COVID-19 have been published in various immunology journals. However, the results from these studies were discrete, and no study summarized the important immunological information about COVID-19 released by these immunology journals. This study aimed to comprehensively summarize the knowledge structure and research hotspots of COVID-19 published in major immunology journals through bibliometrics.

METHODS

Publications on COVID-19 in major immunology journals were obtained from the Web of Science Core Collection. CiteSpace, VOSviewer, and R-bibliometrix were comprehensively used for bibliometric and visual analysis.

RESULTS

1,331 and 5,000 publications of 10 journals with high impact factors and 10 journals with the most papers were included, respectively. The USA, China, England, and Italy made the most significant contributions to these papers. University College London, National Institute of Allergy and Infectious Diseases, Harvard Medical School, University California San Diego, and University of Pennsylvania played a central role in international cooperation in the immunology research field of COVID-19. Yuen Kwok Yung was the most important author in terms of the number of publications and citations, and the H-index. CLINICAL INFECTIOUS DISEASES and FRONTIERS IN IMMUNOLOGY were the most essential immunology journals. These immunology journals mostly focused on the following topics: "Delta/Omicron variants", "cytokine storm", "neutralization/neutralizing antibody", "T cell", "BNT162b2", "mRNA vaccine", "vaccine effectiveness/safety", and "long COVID".

CONCLUSION

This study systematically uncovered a holistic picture of the current research on COVID-19 published in major immunology journals from the perspective of bibliometrics, which will provide a reference for future research in this field.