Influenza A (H1N1) virus infection triggers severe pulmonary inflammation in lupus-prone mice following viral clearance

COVID-19 in patients with systemic lupus erythematosus: lessons learned from the inflammatory disease

As the world navigates the coronavirus disease 2019 (COVID-19) pandemic, there is a growing need to assess its impact in patients with autoimmune rheumatic diseases, such as systemic lupus erythematosus (SLE). Patients with SLE are a unique population when considering the risk of contracting COVID-19 and infection outcomes. The use of systemic glucocorticoids and immunosuppressants, and underlying organ damage from SLE are potential susceptibility factors. Most patients with SLE have evidence of high type I interferon activity, which may theoretically act as an antiviral line of defense or contribute to the development of a deleterious hyperinflammatory response in COVID-19. Other immunopathogenic mechanisms of SLE may overlap with those described in COVID-19, thus, studies in SLE could provide some insight into immune responses occurring in severe cases of the viral infection. We reviewed the literature to date on COVID-19 in patients with SLE and provide an in-depth review of current research in the area, including immune pathway activation, epidemiology, clinical features, outcomes, and the psychosocial impact of the pandemic in those with autoimmune disease.

Coronavirus infection (SARS-CoV-2) in obesity and diabetes comorbidities: is heat shock response determinant for the disease complications?

Chronic inflammation is involved in the pathogenesis of several metabolic diseases, such as obesity and type 2 diabetes mellitus (T2DM). With the recent worldwide outbreak of coronavirus disease (SARS-CoV-2), it has been observed that individuals with these metabolic diseases are more likely to develop complications, increasing the severity of the disease and a poorer outcome. Coronavirus infection leads to the activation of adaptive and innate immune responses, resulting in massive inflammation (to so called cytokine storm), which in turn can lead to damage to various tissues, septic shock and multiple organ failure. Recent evidence suggests that the common link between metabolic diseases and SARS-CoV-2 is the inflammatory response (chronic/low-grade for metabolic diseases and acute/intense in coronavirus infection). However, the ability of the infected individuals to resolve the inflammation has not yet been explored. The heat shock response (HSR), an important anti-inflammatory pathway, is reduced in patients with metabolic diseases and, consequently, may impair inflammation resolution and control in patients with SARS-CoV-2, thus enabling its amplification and propagation through all tissues. Herein, we present a new hypothesis that aims to explain the increased severity of SARS-CoV-2 infection in people with metabolic diseases, and the possible benefits of HSR-inducing therapies to improve the inflammatory profile in these patients.

Viruses and Autoimmunity: A Review on the Potential Interaction and Molecular Mechanisms

For a long time, viruses have been shown to modify the clinical picture of several autoimmune diseases, including type 1 diabetes (T1D), systemic lupus erythematosus (SLE), rheumatoid arthritis (RA), Sjögren’s syndrome (SS), herpetic stromal keratitis (HSK), celiac disease (CD), and multiple sclerosis (MS). Best examples of viral infections that have been proposed to modulate the induction and development of autoimmune diseases are the infections with enteric viruses such as Coxsackie B virus (CVB) and rotavirus, as well as influenza A viruses (IAV), and herpesviruses. Other viruses that have been studied in this context include, measles, mumps, and rubella. Epidemiological studies in humans and experimental studies in animal have shown that viral infections can induce or protect from autoimmunopathologies depending on several factors including genetic background, host-elicited immune responses, type of virus strain, viral load, and the onset time of infection. Still, data delineating the clear mechanistic interaction between the virus and the immune system to induce autoreactivity are scarce. Available data indicate that viral-induced autoimmunity can be activated through multiple mechanisms including molecular mimicry, epitope spreading, bystander activation, and immortalization of infected B cells. Contrarily, the protective effects can be achieved via regulatory immune responses which lead to the suppression of autoimmune phenomena. Therefore, a better understanding of the immune-related molecular processes in virus-induced autoimmunity is warranted. Here we provide an overview of the current understanding of viral-induced autoimmunity and the mechanisms that are associated with this phenomenon.

Influenza and sudden unexpected death: the possible role of peptide cross-reactivity

This study investigates the hypothesis that cross-reactions may occur between human cardiac proteins and influenza antigens, thus possibly representing the molecular mechanism underlying influenzaassociated sudden unexpected death (SUD). Using titin protein as a research model, data were obtained on (1) the occurrence of the titin octapeptide AELLVLLE or its mimic AELLVALE in influenza A virus hemagglutinin (HA) sequences; (2) the immunological potential of AELLVLLE and its mimic AELLVALE; (3) the possible role of the flanking amino acid aa) context of the two octapeptide determinants in eliciting cross-reactivity between the human cardiac titin protein and HA antigens.

Key genes and functional coexpression modules involved in the pathogenesis of systemic lupus erythematosus

We performed a systematic review of genome-wide gene expression datasets to identify key genes and functional modules involved in the pathogenesis of systemic lupus erythematosus (SLE) at a systems level. Genome-wide gene expression datasets involving SLE patients were searched in Gene Expression Omnibus and ArrayExpress databases. Robust rank aggregation (RRA) analysis was used to integrate those public datasets and identify key genes associated with SLE. The weighted gene coexpression network analysis (WGCNA) was adapted to identify functional modules involved in SLE pathogenesis, and the gene ontology enrichment analysis was utilized to explore their functions. The aberrant expressions of several randomly selected key genes were further validated in SLE patients through quantitative real-time polymerase chain reaction. Fifteen genome-wide gene expression datasets were finally included, which involved a total of 1,778 SLE patients and 408 healthy controls. A large number of significantly upregulated or downregulated genes were identified through RRA analysis, and some of those genes were novel SLE gene signatures and their molecular roles in etiology of SLE remained vague. WGCNA further successfully identified six main functional modules involved in the pathogenesis of SLE. The most important functional module involved in SLE included 182 genes and mainly enriched in biological processes, including defense response to virus, interferon signaling pathway, and cytokine-mediated signaling pathway. This study identifies a number of key genes and functional coexpression modules involved in SLE, which provides deepening insights into the molecular mechanism of SLE at a systems level and also provides some promising therapeutic targets.