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Sepsis results from a dyshomeostatic response to infection, which may lead to hyper or hypoimmune states. Monocytes are central regulators of the inflammatory response, but our understanding of their role in the genesis and resolution of sepsis is still limited. Here, we report a comprehensive exploration of monocyte molecular responses in a cohort of patients with septic shock via proteomic profiling. The acute stage of septic shock was associated with an impaired inflammatory phenotype, indicated by the down-regulation of MHC class II molecules and proinflammatory cytokine pathways. Simultaneously, there was an up-regulation of glycolysis enzymes and a decrease in proteins related to the citric acid cycle and oxidative phosphorylation. On the other hand, the restoration of immunocompetence was the hallmark of recovering patients, in which an upregulation of interferon signaling pathways was a notable feature. Our results provide insights into the immunopathology of sepsis and propose that, pending future studies, immunometabolism pathway components could serve as therapeutic targets in septic patients.

As the severe acute respiratory syndrome coronavirus (SARS-CoV)-2 is a new virus, the current knowledge on the immunopathogenesis of this newly emerged SARS-CoV-2 is beginning to unravel with intensive ongoing global research efforts. Although a plethora of new studies have been published in a short space of time describing how the virus causes disease and incurs insults on the host immune system and the underlying immunopathogenic mechanisms remain to be elucidated. Thus, the discussion in this review is based on the most current knowledge on the immunopathogenesis of SARS-CoV-2 that has emerged in the past 12 months. The main objective is to shed light on the most current concepts in immunopathological aspects of the lung, bloodstream, and brain caused by the SARS-CoV-2, which has led to the current pandemic resulting in > 100 million infections and > 2 million deaths, and ongoing.

Interferons are potent antiviral cytokines that modulate immunity in response to infection or other danger signals. In addition to their antiviral functions, type I interferons (IFNα and IFNβ) are important in the pathogenesis of autoimmune diseases. Type III interferons (IFNλs) were initially described as a specialized system that inhibits viral replication at epithelial barrier surfaces while limiting inflammatory damage. However, evidence now suggests that type III interferons have complex effects on both innate and adaptive immune responses and might also be pathogenic in systemic autoimmune diseases. Concentrations of IFNλs are increased in blood and tissues in a number of autoimmune rheumatic diseases, including systemic lupus erythematosus, and are further associated with specific clinical and laboratory parameters. This Review is aimed at providing a critical evaluation of the current literature on IFNλ biology and how type III interferons might contribute to immune dysregulation and tissue damage in autoimmunity. The potential effects of type III interferons on treatment strategies for autoimmune rheumatic diseases, such as interferon blockade, are also considered., Type III interferons (IFNλs) affect innate and adaptive immune responses and are associated with the pathogenesis of autoimmune rheumatic diseases. In this Review, the authors provide an overview of IFNλs in rheumatic diseases and discuss therapeutic strategies to target them., Key points Type III interferons (IFNλs) are critical for immune defence against pathogens at epithelial barrier surfaces and were initially described as an anti-inflammatory counterpart to the type I interferon system. IFNλs have complex effects on both innate and adaptive immunity and can promote inflammation in certain contexts. Similar to type I interferons, type III interferon concentrations are increased in the blood and affected tissues of patients with autoimmune rheumatic diseases such as systemic lupus erythematosus (SLE). Concentrations of IFNλs correlate with clinical and immunological parameters and seem to have non-redundant effects on cell-specific and tissue-specific disease processes in SLE. Current biologic therapies that target IFNα or its receptor do not block the effects of IFNλs. Additional research is needed to fully characterize the context-dependent effects of IFNλs and to optimize treatment for patients with autoimmune rheumatic diseases.

Alopecia areata is a common inflammatory immune-mediated disorder in which autoimmune response is triggered against hair follicles, thus leading to non-scarring hair loss on the scalp, face and other parts of the skin. Despite numerous studies concerning this issue, today there is no consensus on the etiology and pathogenesis of focal alopecia. In the literature, special attention is paid to association of focal alopecia with autoimmune diseases, such as rheumatoid arthritis, celiac disease, type 1 diabetes, psoriasis, autoimmune thyroiditis, vitiligo. Recent studies have identified the association of focal alopecia with atopic diseases (allergic rhinitis, bronchial asthma, atopic dermatitis) and the early debut of severe forms of hair loss. The aim of this study was to present a clinical case of focal alopecia in an 8-year-old girl with atopic bronchial asthma and seasonal allergic rhinitis. As based on detection of eosinophilia in peripheral blood and a high concentration of total IgE in serum, one may assume that atopic alopecia is the cause of focal hair losses in a child with atopy. The patient underwent skin prick testing, in order to determine sensitization for food components, pollen and fungal allergens. As a result of skin testing, a hyperergic reaction (> 15 mm in diameter) to tree pollen was revealed, a positive response (6-9 mm) to oatmeal, a weakly positive reaction (3-5 mm) to whole chicken egg, carrots, tomato, apple, pear, pollen of meadow, cereal, weed grasses was also revealed. With regard of these allergological data, an individual diet was recommended with the elimination of causally significant allergens (including those eliciting weakly positive reactions), external treatment, i.e., topical calcineurin inhibitors administered for 1 month. One month later, an improvement of the pathological process was registered, and 6 months from the start of therapy, complete restoration of hair follicles was noted in the focus of alopecia. The patient was monitored for a year, no complaints of hair loss were noted. The positive effect of elimination against the background of the appropriate elimination diet with respect to causally significant allergens, was also noted when treating her for respiratory allergy, i.e., the patient did not have seasonal manifestations of hay fever over the next pollination period. This clinical case is demonstrated in order to draw special attention of dermatologists, allergologists, immunologists, general practitioners to the issues of focal alopecia in children against the background of typical allergic diseases.

This brief analytical review is devoted to spreading, etiology, pathogenesis, prophylaxis, and treatment of COVID-19 and “swine flu” causing pandemics in the 21st century. Both pandemics were caused by respiratory viruses belonging to different families, i.e., Coronaviridae (SARS-CoV-2) and Orthomyxoviridae (influenza A(H1N1)pdm09 virus), respectively. In most cases, pathogens enter human organisms via epithelial cells of the upper airways. Sometimes, these viruses infect intestinal epithelium. Given that symptoms of influenza and COVID-19 are similar, its diagnostics should always be based on laboratory results, especially, PCR evidence for specific RNA presence in clinical material. The paper describes similarities and differences in immune pathogenesis of the diseases. The main characteristics of two pandemic courses caused by SARS-CoV-2 and influenza A(H1N1)pdm09 are revealed. The presence of influenza vaccine and etiotropic chemotherapeutic agents, as well as preexisting immunity to influenza virus among elderly people in 2009 had a significant influence on morbidity and mortality during the influenza pandemic. The presence of antibodies to A(H1N1)pdm09 virus in sera of elderly people before the pandemic can be explained by the fact that some antigenic properties of A(H1N1) virus which circulated before 1957 were similar to that of A/California/07/09 (H1N1)pdm09. Consequently, morbidity and mortality among people older than 65 (main risk group) were low, while children and young adults suffered more often. The opposite pattern is observed for COVID-19, since mortality among the elderly population is high, while the children and young adults have an asymptomatic or mild form of a disease. A suggestion is made that population in the South-East Asia may have immunity against SARS-CoV-2, since coronaviruses with antigenic features similar to the pandemic one could circulate in that region and infect population without evident symptoms, while one or several recent virus variants caused severe disease and COVID-19 outbreak in Wuhan.

Crimean-Congo hemorrhagic fever virus (CCHFV) is responsible for widespread tick-borne zoonotic viral disease CCHF in African, Middle Eastern, Asian, and European countries. CCHFV can be spread to humans through tick bites or contact with infected animals or humans, and it often progresses from asymptomatic to severe/lethal illness, with fatality rates ranging from 10% to 40% in humans. Today, CCHF is growing into a significant public health concern due to its very high prevalence, severity of the condition, and lack of available vaccines and specific treatments. Recent research has been drawn towards a more accurate study of CCHFV characteristics, including the structure, genetic diversity, mechanisms involved in pathogenesis and immunopathogenesis, and clinical features. In addition, the use of animal models (mouse and non-human primates) and advanced diagnostic tools in recent years has resulted in a significant advance in CCHF related studies. In this context, we summarized the latest findings about CCHF research, its health complications, animal models, current diagnosis, vaccination, and CCHF treatments, and therapeutic strategies. Furthermore, we discussed existing deficiencies and problems in CCHFV analysis, as well as areas that still need to yield conclusive answers.

Alopecia areata (AA) is an autoimmune disorder resulting in hair loss. It has numerous variants or patterns, including diffuse type, patchy type, AA totalis, AA universalis, and more. In this graphical review, we provide an overview of AA immunopathogenesis, highlighting loss of immune privilege in the hair follicle as well as key immune cell types, cytokines and chemokines that drive autoimmune attack of the hair follicle. We also summarize recent literature identifying agents that block these pathways that could serve as new immunomodulatory treatments for AA.

Psoriatic arthritis (PsA) is a chronic, progressive, inflammatory arthropathy associated with psoriasis as well as a complex pathogenesis. Genetic and environmental factors trigger the development of the immune-mediated auto-inflammatory response in different sites: skin, bone marrow, entheses and synovial tissues. Studies of the last two decades have changed the view of PsA from a mild, non-progressive arthritis to an inflammatory systemic disease with serious health consequences, not only associated with joint dysfunction, but also with an increased risk of cardiovascular disease and socioeconomic consequences with significantly reduced quality of life. The joint damage starts early in the course of the disease, thus early recognition and treatment with modern biological treatments, which may modify the natural history and slow down progression of this debilitating disease, is essential for the patient long-term outcome.

Severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) is a new member of the coronavirus family that can cause coronavirus disease 2019 (COVID‐19). COVID‐9 has become a global pandemic with severe health issues around the world. Identifying the accurate immunopathogenesis of the COVID‐19 and the immune response against SARS‐CoV‐2 is necessary for the development of therapeutic approaches and rational drug design. This paper aims to overview the updated clinical data on the immunopathogenesis of the COVID‐19 and review the innate and adaptive immune response to SARS‐CoV‐2. Also, challenges of the immune response to SARS‐CoV‐2 leading to dysfunctional immune response and their contribution to the progression of the disease have been discussed. To achieve a more efficient immune response, multiple methods could be applied, including regulation of the immune response, augmentation of the immune system against the virus, inhibition of the dysfunctional immune checkpoints, and inhibition of the viral replication/infection. Based on the immune response against SARS‐CoV‐2 and its dysfunction, we introduce potential immunotherapies as well as reviewing recruiting/completed clinical trials of COVID‐19., Understanding the immunology of coronavirus disease 2019 (COVID‐19) is necessary for rational drug and vaccine design against it. In this paper, we have reviewed the updated data on immunobiology and immunotherapeutic‐based approaches for COVID‐19.

Coronavirus Disease 19 (COVID-19) is a respiratory disease caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which has grown to a worldwide pandemic with substantial mortality. Immune mediated damage has been proposed as a pathogenic factor, but immune responses in lungs of COVID-19 patients remain poorly characterized. Here we show transcriptomic, histologic and cellular profiles of post mortem COVID-19 (n = 34 tissues from 16 patients) and normal lung tissues (n = 9 tissues from 6 patients). Two distinct immunopathological reaction patterns of lethal COVID-19 are identified. One pattern shows high local expression of interferon stimulated genes (ISGhigh) and cytokines, high viral loads and limited pulmonary damage, the other pattern shows severely damaged lungs, low ISGs (ISGlow), low viral loads and abundant infiltrating activated CD8+ T cells and macrophages. ISGhigh patients die significantly earlier after hospitalization than ISGlow patients. Our study may point to distinct stages of progression of COVID-19 lung disease and highlights the need for peripheral blood biomarkers that inform about patient lung status and guide treatment., The immunopathological features of SARS-CoV-2 infection in the lungs remain unclear. Here, the authors provide a comprehensive characterization of post mortem lung tissues of COVID-19 patients and find two distinct patterns characterized by differential expression of interferon stimulated genes (ISGs), which correlate to viral loads, cytokines, lung damage and time of hospitalization, suggesting ISG profiles to mark disease progression

Candidiasis is the most common fungal infection predominantly affecting the mucous membrane. The fungus Candida causes these lesions. There are strains resistant to modern antimycotic drugs among Candida spp. Due to the increase in candidiasis prevalence and the widespread use of antifungal agents, the issue of effective treatment is becoming increasingly important. Liability of C. albicans to antigenic mimicry and suppression of the immune response mediates the evasion of the fungus from the immune response and development of excessive inflammation. The evasion of the fungus Candida from the local nonspecific immunity factors contributes to the breakdown of the antibody response initiation and cellular reactions of the acquired immunity, which are of key importance for anti-candidiasis protection. Therefore, the lack of an adequate local immune response from the mucous membranes is a possible reason for the development of a recurrent vulvovaginal candidiasis. Modern treatment for recurrent candidiasis in the formed risk groups involves the use of prophylactic aggressive etiotropic therapy, but at a lower dose, and the pathogenetically substantiated treatment involves regulating the local immune response in the vagina through the use of immunomodulatory drugs that inhibit the growth of fungi by activating the innate and acquired components of mucosal immunity. In addition, local immunomodulators contribute to the recovery of damaged mucous membranes and additional lubrication of tissues in contrast to antimycotics, which tend to increase the clinical manifestations of infection and dryness of mucous membranes when applied topically in the early stages of treatment.

Objective:Melatonin (MLT) hormone has been reported to play a role in the immunopathogenesis and aetiology of many chronic inflammatory diseases. We aimed to investigate the role of MLT in Behçet’s disease (BD) by determining the serum MLT levels of patients with BD.Materials and Methods:A total of 40 patients (mean age, 35.3±9.0 years; age range, 19-57 years), including 19 women and 21 men, and 40 healthy individuals, including 20 women and 20 men, matched for age and gender (mean age, 37.7±11.2 years; age range, 19-65 years) were included in this study. Serum MLT levels of the participants were determined, and their demographic data, laboratory parameters, and clinical features were recorded. Disease activity was evaluated according to the BD current activity form 2006. The relationship between disease activity and serum MLT level was examined.Results:There were no significant differences in the demographic characteristics and other laboratory parameters between the groups, except for serum MLT levels and mean platelet volume values (p

Background: Despite compelling evidence that cigarette smoking impacts the risk of developing multiple sclerosis (MS), little is known about smoking-associated changes in the primary exposed lung cells of patients. Objectives: We aimed to examine molecular changes occurring in bronchoalveolar lavage (BAL) cells from MS patients in relation to smoking and in comparison to healthy controls (HCs). Methods: We profiled DNA methylation in BAL cells from female MS ( n = 17) and HC ( n = 22) individuals, using Illumina Infinium EPIC and performed RNA-sequencing in non-smokers. Results: The most prominent changes were found in relation to smoking, with 1376 CpG sites (adjusted P Conclusions: Our study provides insights into the impact of smoking on lung inflammation and immunopathogenesis of MS.

Reports of widespread thromboses and disseminated intravascular coagulation (DIC) in patients with coronavirus disease 19 (COVID-19) have been rapidly increasing in number. Key features of this disorder include a lack of bleeding risk, only mildly low platelet counts, elevated plasma fibrinogen levels, and detection of both severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and complement components in regions of thrombotic microangiopathy (TMA). This disorder is not typical DIC. Rather, it might be more similar to complement-mediated TMA syndromes, which are well known to rheumatologists who care for patients with severe systemic lupus erythematosus or catastrophic antiphospholipid syndrome. This perspective has critical implications for treatment. Anticoagulation and antiviral agents are standard treatments for DIC but are gravely insufficient for any of the TMA disorders that involve disorders of complement. Mediators of TMA syndromes overlap with those released in cytokine storm, suggesting close connections between ineffective immune responses to SARS-CoV-2, severe pneumonia and life-threatening microangiopathy., A subset of patients with coronavirus disease 19 (COVID-19) develop a thrombotic disorder that resembles a virally induced, complement-mediated thrombotic microangiopathy. Here, the authors present the theory and evidence for this disease model and discuss important considerations for treatment.

Kawasaki disease is an acute febrile illness and systemic vasculitis of unknown aetiology that predominantly afflicts young children, causes coronary artery aneurysms and can result in long-term cardiovascular sequelae. Kawasaki disease is the leading cause of acquired heart disease among children in the USA. Coronary artery aneurysms develop in some untreated children with Kawasaki disease, leading to ischaemic heart disease and myocardial infarction. Although intravenous immunoglobulin (IVIG) treatment reduces the risk of development of coronary artery aneurysms, some children have IVIG-resistant Kawasaki disease and are at increased risk of developing coronary artery damage. In addition, the lack of specific diagnostic tests and biomarkers for Kawasaki disease make early diagnosis and treatment challenging. The use of experimental mouse models of Kawasaki disease vasculitis has considerably improved our understanding of the pathology of the disease and helped characterize the cellular and molecular immune mechanisms contributing to cardiovascular complications, in turn leading to the development of innovative therapeutic approaches. Here, we outline the pathophysiology of Kawasaki disease and summarize and discuss the progress gained from experimental mouse models and their potential therapeutic translation to human disease., This Review outlines the pathophysiology of Kawasaki disease and discusses the progress gained from experimental mouse models and their potential therapeutic translation to human disease., Key points Kawasaki disease is a childhood systemic vasculitis leading to the development of coronary artery aneurysms; it is the leading cause of acquired heart disease in children in developed countries.The cause of Kawasaki disease is unknown, although it is suspected to be triggered by an unidentified infectious pathogen in genetically predisposed children.Kawasaki disease might not be a normal immune response to an unusual environmental stimulus, but rather a genetically determined unusual and uncontrolled immune response to a common stimulus.Although the aetiological agent in humans is unknown, mouse models of Kawasaki disease vasculitis demonstrate similar pathological features and have substantially accelerated discoveries in the field.Genetic and transcriptomic analysis of blood samples from patients with Kawasaki disease and experimental evidence generated using mouse models have demonstrated the critical role of IL-1β in the pathogenesis of this disease and the therapeutic potential of targeting this pathway (currently under investigation in clinical trials).

Psoriasis (PS) is a chronic skin inflammation. Up to 30% of the patients with PS develop psoriatic arthritis (PsA), a condition characterized by inflammatory arthritis that affects joints or entheses. Although there is mounting evidence for a critical role of interleukin-23 (IL-23) signaling in the pathogenesis of both PS and PsA, it remains unclear whether IL-23-induced skin inflammation drives joint disease. Here, we show that mice expressing increased levels of IL-23 in the skin (K23 mice) develop a PS-like disease that is characterized by acanthosis, parakeratosis, hyperkeratosis, and inflammatory infiltrates in the dermis. Skin disease preceded development of PsA, including enthesitis, dactylitis, and bone destruction. The development of enthesitis and dactylitis was not due to high circulating levels of IL-23, as transgenic animals and controls had similar levels of this cytokine in circulation. IL-22, a downstream cytokine of IL-23, was highly increased in the serum of K23 mice. Although IL-22 deficiency did not affect skin disease development, IL-22 deficiency aggravated the PsA-like disease in K23 mice. Our results demonstrate a central role for skin expressed IL-23 in the initiation of PS and on pathogenic processes leading to PsA.

Based on the III International Consensus on the definition of Sepsis and Septic Shock (Sepsis-3), the modern definition of septic shock was proposed: “Septic shock is a type of sepsis that is accompanied by severe hemodynamic, metabolic and cellular disorders, and these disorders are associated with a higher risk fatal outcome”. Despite the classic idea of septic shock development (proinflammatory, immunosuppressive phases and, finally, multiple organ failure with distinct shock organs), the theory of activation of the caspase, endocannabioid system and system of protein of programmed death-1 in evolving septic shock are promising approaches to development of new diagnostic and therapeutic methods. Lymphopenia is already observed at an early stage of septic shock, which further leads to deep immunosuppression. Previous experimental studies have revealed some treatment methods to reduce the pro-inflammatory stage, which, however, did not show desired results in clinics. Now it is necessary to look for ways to inhibit apoptosis, depletion of lymphocytes, macrophages and other immune cells in the course of septic shock. It is known that caspases mediate innate detection of pathogenic microorganisms, cause pyroptosis, activation of monocytes. It has been proven that inhibition of caspase-8, caspase-11 leads to decreased monocyte functioning and cytokine release, which plays an important role in immunopathogenesis of septic shock. Associations of PD-1 and PD-2 expression on CD4+ lymphocytes and monocytes are also shown to be connected with immune dysfunctions, decrease in lymphocyte proliferation, and increased interleukin-10 concentration. Stimulation of the cannabinoid receptors is able to reduce inflammation by inhibiting cytopathic and immunosuppressive effects of pathogens. It has been shown that classic septic shock biomarkers (pro-inflammatory, anti-inflammatory cytokines; procalcitonin, lactate, etc.) do not have predictive power in relation to the outcome of the disease. Circulating and citrullated histones, determined by mass spectrometry, may serve as potential diagnostic markers of septic shock, but they require further study. Use of oxidized phospholipid oxPAPC (Oxidized 1-palmitoyl-2-arachidonoyl-snglycero-3-phosphocholine), hydrogen sulfide and Fasciola hepatica fatty acid binding proteins (hepatic fluke) prevents oxidative stress, synthesis of pro-inflammatory cytokines and provides maturation of macrophages and dendritic cells. Further study of immunological reactions during septic shock is of great importance for substantiation of new approaches to the diagnostics and therapy of septic shock.

The relationship between ambient particulate matter exposure and health has been well established. Ultrafine particles (UFP) with a diameter of 100 nm or less are known to increase pulmonary disease risk. Biological factors in dust containing UFP can cause severe inflammatory reactions. Pulmonary diseases develop primarily as a result of chronic inflammation caused by immune dysfunction. Thus, this review focuses on the adverse pulmonary effects of biological UFP, principally lipopolysaccharide (LPS), and bacterial extracellular vesicles (EVs), in indoor dust and the pathophysiological mechanisms involved in the development of chronic pulmonary diseases. The impact of LPS-induced pulmonary inflammation is based primarily on the amount of inhaled LPS. When relatively low levels of LPS are inhaled, a cascade of immune responses leads to Th2 cell induction, and IL-5 and IL-13 released by Th2 cells contributes to asthma development. Conversely, exposure to high levels of LPS induces a Th17 cell response, leading to increased production of IL-17, which is associated with asthma, COPD, and lung cancer incidence. Responses to bacterial EV exposure can similarly be broadly divided based on whether one of two mechanisms, either intracellular or extracellular, is activated, which depends on the type of the parent cell. Extracellular bacteria-derived EVs can cause neutrophilic inflammation via Th17 cell induction, which is associated with asthma, emphysema, COPD, and lung cancer. On the other hand, intracellular bacteria-derived EVs lead to mononuclear inflammation via Th1 cell induction, which increases the risk of emphysema. In conclusion, future measures should focus on the overall reduction of LPS sources in addition to the improvement of the balance of inhaled bacterial EVs in the indoor environment to minimize pulmonary disease risk., Chronic lung disease: Hazards in indoor dust from bacteria Tiny bacterial particles found in ultrafine airborne dust in homes and workplaces can trigger inflammation in the airways and increase the risk of developing chronic lung disease. Yoon-Keun Kim at MD Healthcare Inc in Seoul, South Korea, and co-workers review current understanding of the impact of ultrafine particles on disease development. Persistent, long-term exposure to molecules and extracellular vesicles from bacteria can trigger excess proinflammatory protein production in the body. Over time, this exacerbates immune dysfunction and increases the chances of developing conditions such as asthma, chronic obstructive pulmonary disease and lung cancer. Breathing in lipopolysaccharides shed from the membranes of certain bacteria may pose the greatest risk of developing chronic lung disease. The researchers call for urgent research to find ways of limiting lipopolysaccharides in indoor environments and optimizing air quality.

There is a new public health crises threatening globally with the emergence and spread of 2019 novel coronavirus or the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). It is the seventh member of the coronavirus (CoV) family, which infects humans and to which the Middle East Respiratory Syndrome CoV (MERS)-and SARS-CoV also belong. SARS-CoV-2 is a newly emerging human infectious CoV that causes COVID-19, which has been recognized as a pandemic by the World Health Organization on March 11. The most recent outbreak initially presented as pneumonia of unknown etiology as COVID-19 is a pneumonia-like disease with a group of symptoms including fever, dry cough and shortness of breath in a cluster of patients in December 2019 Wuhan, China. The body's immune system tries to protect the body from this pathogen. And as due to its surge in the body, various respiratory and other system-related complications increased. Therefore, in this article, COVID-19 immunopathogenesis is briefly reviewed. Through this review, we try to explain the molecular immune pathogenesis and diagnosis of COVID-19 (SARS-CoV-2) infection, based on the recent research progress of SARS-CoV-2 and the knowledge from researches on SARS-CoV and MERS-CoV.

The Janus kinase/signal transducer and activator of transcription (JAK/STAT) signaling pathway was discovered more than a quarter-century ago. As a fulcrum of many vital cellular processes, the JAK/STAT pathway constitutes a rapid membrane-to-nucleus signaling module and induces the expression of various critical mediators of cancer and inflammation. Growing evidence suggests that dysregulation of the JAK/STAT pathway is associated with various cancers and autoimmune diseases. In this review, we discuss the current knowledge about the composition, activation, and regulation of the JAK/STAT pathway. Moreover, we highlight the role of the JAK/STAT pathway and its inhibitors in various diseases.

Herpes simplex virus type-1(HSV-1) ocular infection is one of the leading causes of infectious blindness in developed countries. The resultant herpetic keratitis (HK) is caused by an exacerbated reaction of the adaptive immune response that persists beyond virus clearance causing substantial damage to the cornea. Intramuscular immunization of mice with the HSV-1(VC2) live-attenuated vaccine strain has been shown to protect mice against lethal ocular challenge. Herein, we show that following ocular challenge, VC2 vaccinated animals control ocular immunopathogenesis in the absence of neutralizing antibodies on ocular surfaces. Ocular protection is associated with enhanced intracorneal infiltration of γδ T cells compared to mock-vaccinated animals and animals vaccinated with inactivated HSV-1(VC2) virus. The observed γδ T cellular infiltration was inversely proportional to the infiltration of neutrophils, the latter associated with exacerbated tissue damage. Inhibition of T cell migration into ocular tissues by the S1P receptors agonist FTY720 produced significant ocular disease in vaccinated mice and marked increased in neutrophil infiltration. These results indicate that ocular challenge of mice immunized with the VC2 vaccine induce a unique ocular mucosal response that leads into the infiltration of extracorporeal γδ T cells resulting in the amelioration of infection-associated immunopathogenesis.

The coronavirus disease-19 (COVID-19) elicited by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has caused devastating health, economic and social impact worldwide. Its clinical spectrum ranges from asymptomatic to respiratory failure and multi-organ failure or death. The pathogenesis of SARS-CoV-2 infection is attributed to a complex interplay between virus and host immune response. It involves activation of multiple inflammatory pathways leading to hyperinflammation and cytokine storm, resulting in tissue damage, acute respiratory distress syndrome (ARDS) and multi-organ failure. Accumulating evidence has raised concern over the long-term health effects of COVID-19. Importantly, the neuroinvasive potential of SARS-CoV-2 may have devastating consequences in the brain. This review provides a conceptual framework on how the virus tricks the host immune system to induce infection and cause severe disease. We also explore the key differences between mild and severe COVID-19 and its short- and long-term effects, particularly on the human brain.

Leukocytoclastic vasculitis (LCV) is a systemic autoimmune disease characterized by the inflammation of the vascular endothelium. Cutaneous small vessel vasculitis (CSVV) and anti-neutrophil cytoplasmic antibodies (ANCA)-associated vasculitis (AAV) are two examples of LCV. Advancements in genomic technologies have identified risk haplotypes, genetic variants, susceptibility loci and pathways that are associated with vasculitis immunopathogenesis. The discovery of these genetic factors and their corresponding cellular signaling aberrations have enabled the development and use of novel therapeutic strategies for vasculitis. Personalized medicine aims to provide targeted therapies to individuals who show poor response to conventional interventions. For example, monoclonal antibody therapies have shown remarkable efficacy in achieving disease remission. Here, we discuss pathways involved in disease pathogenesis and the underlying genetic associations in different populations worldwide. Understanding the immunopathogenic pathways in vasculitis and identifying associated genetic variations will facilitate the development of novel and targeted personalized therapies for patients.

Cryptococcal meningoencephalitis (CM) is a leading cause of central nervous system (CNS) infection-related mortality worldwide, with surviving patients often developing neurological deficiencies. While CNS inflammation has been implicated in the pathogenesis of CM, little is known about the relative contribution of the specific inflammatory/immune pathways to CNS pathology versus fungal clearance. Increased cerebrospinal fluid level of C-C chemokine receptor 2 (CCR2) ligand CCL2 is associated with disease deterioration in patients with CM. Using a murine model, we investigated the role of the CCR2 pathway in the development of CNS inflammation and pathology during CM. We found that CCR2-deficient mice exhibited improved 28-day survival and alleviated neurological disease scores despite a brain fungal burden higher than that of the WT mice. Reduced CM pathology in CCR2-deficient mice was accompanied by markedly decreased neuronal cell death around cryptococcal microcysts and restored expression of genes involved in neurotransmission, connectivity, and neuronal cell structure in the brains. Results show that CCR2 axis is the major pathway recruiting CD45hiCD11b+Ly6C+ inflammatory monocyte to the brain and indirectly modulates the accumulation of CD4+ T cells and CD8+ T cells. In particular, CCR2 axis promotes recruitment of interferon gamma (IFN-γ)-producing CD4+ T cells and classical activation of myeloid cells. In this context, CCR2 deletion limits the immune network dysregulation we see in CM and attenuates neuropathology. Thus, the CCR2 axis is a potential target for interventions aimed to limit inflammatory CNS pathology in CM patients. IMPORTANCE Cryptococcal meningoencephalitis (CM) causes nearly 200,000 deaths worldwide each year, and survivors frequently develop long-lasting neurological sequelae. The high rate of mortality and neurologic sequelae in CM patients indicate that antifungal therapies alone are often insufficient to control disease progression. Here, we reveal that CM disease progression in mice is accompanied by inflammatory monocytes infiltration at the periphery of the infected foci that overlap locally perturbed neuronal function and death. Importantly, we identified that CCR2 signaling is a critical pathway driving neuroinflammation, especially inflammatory monocyte recruitment, as well as CNS pathology and mortality in CM mice. Our results imply that targeting the CCR2 pathway may be beneficial as a therapy complementary to antifungal drug treatment, helping to reduce CNS damage and mortality in CM patients.

Patients with psoriatic arthritis (PsA) are suffering from a decreased quality of life despite currently available treatments. In the latest years, novel therapies targeting the IL-17/IL-23 and TNF pathways improved clinical outcome. Despite this, remission of disease is not achieved in a considerable group of patients, continuous treatment is very often required to reach clinical remission, and prevention of PsA in patients with psoriasis (PsO) is currently impossible. A better understanding of PsA pathogenesis is required to develop novel treatment strategies that target inflammation and destruction more effectively and at an early stage of the disease, or even before clinically manifest disease. The skin is considered as one of the sites of onset of immune activation, triggering the inflammatory cascade in PsA. PsO develops into PsA in 30% of the PsO patients. Influenced by environmental and genetic factors, the inflammatory process in the skin, entheses, and/or gut may evolve into synovial tissue inflammation, characterized by influx of immune cells. The exact role of the innate and adaptive immune cells in disease pathogenesis is not completely known. The involvement of activated IL-17A+ T cells could implicate early immunomodulatory events generated in lymphoid organs thereby shaping the pathogenic inflammatory response leading to disease. In this perspective article, we provide the reader with an overview of the current literature regarding the immunological changes observed during the earliest stages of PsA. Moreover, we will postulate future areas of translational research aimed at increasing our knowledge on the molecular mechanisms driving disease development, which will aid the identification of novel potential therapeutic targets to limit the progression of PsA.

Children are unique in the context of the COVID-19 pandemic. Overall, SARS-CoV-2 has a lower medical impact in children as compared to adults. A higher proportion of children than adults remain asymptomatic following SARS-CoV-2 infection and severe disease and death are also less common. This relative resistance contrasts with the high susceptibility of children to other respiratory tract infections. The mechanisms involved remain incompletely understood but could include the rapid development of a robust innate immune response. On the other hand, children develop a unique and severe complication, named multisystem inflammatory syndrome in children, several weeks after the onset of symptoms. Although children play an important role in the transmission of many pathogens, their contribution to the transmission of SARS-CoV-2 appears lower than that of adults. These unique aspects of COVID-19 in children must be considered in the benefit–risk analysis of vaccination. Several COVID-19 vaccines have been authorized for emergency use in adolescents and clinical studies are ongoing in children. As the vaccination of adolescents is rolled out in several countries, we shall learn about the impact of this strategy on the health of children and on transmission within communities., SCOPUS: re.j, info:eu-repo/semantics/published

Chronic hepatitis C (CHC) pathogenic mechanisms as well as the participation of the immune response in the generation of liver damage are still a topic of interest. Here, we evaluated immune cell populations and cytokines in the liver and peripheral blood (PB) to elucidate their role in CHC pathogenesis. B, CTL, Th, Treg, Th1, Th17, and NK cell localization and frequency were evaluated on liver biopsies by immunohistochemistry, while frequency, differentiation, and functional status on PB were evaluated by flow cytometry. TNF-α, IL-23, IFN-γ, IL-1β, IL-6, IL-8, IL-17A, IL-21, IL-10, and TGF-β expression levels were quantified in fresh liver biopsy by RT-qPCR and in plasma by CBA/ELISA. Liver CTL and Th1 at the lobular area inversely correlated with viral load (r = −0.469, p =0.003 and r = −0.384, p = 0.040). Treg correlated with CTL and Th1 at the lobular area (r = 0.784, p < 0.0001; r = 0.436, p = 0.013). Th17 correlated with hepatic IL-8 (r = 0.52, p < 0.05), and both were higher in advanced fibrosis cases (Th17 p = 0.0312, IL-8 p = 0.009). Hepatic cytokines were higher in severe hepatitis cases (IL-1β p = 0.026, IL-23 p = 0.031, IL-8 p = 0.002, TGF-β, p= 0.037). Peripheral NK (p = 0.008) and NK dim (p = 0.018) were diminished, while NK bright (p = 0.025) was elevated in patients vs. donors. Naïve Th (p = 0.011) and CTL (p = 0.0007) were decreased, while activated Th (p = 0.0007) and CTL (p = 0.0003) were increased. IFN-γ production and degranulation activity in NK and CTL were normal. Peripheral cytokines showed an altered profile vs. donors, particularly elevated IL-6 (p = 0.008) and TGF-β (p = 0.041). Total hepatic CTLs favored damage. Treg could not prevent fibrogenesis triggered by Th17 and IL-8. Peripheral T-lymphocyte differentiation stage shift, elevated cytokine levels and NK-cell count decrease would contribute to global disease. Fil: Rios, Daniela Alejandra. Gobierno de la Ciudad de Buenos Aires. Hospital General de Niños "Ricardo Gutiérrez"; Argentina. Gobierno de la Ciudad de Buenos Aires. Instituto Multidisciplinario de Investigaciones en Patologías Pediátricas. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto Multidisciplinario de Investigaciones en Patologías Pediátricas; Argentina Fil: Casciato, Paola Cecilia. Italian's Hospital Of Buenos Aires; Argentina Fil: Caldirola, Maria Soledad. Gobierno de la Ciudad de Buenos Aires. Instituto Multidisciplinario de Investigaciones en Patologías Pediátricas. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto Multidisciplinario de Investigaciones en Patologías Pediátricas; Argentina Fil: Gaillard, María Isabel. Gobierno de la Ciudad de Buenos Aires. Instituto Multidisciplinario de Investigaciones en Patologías Pediátricas. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto Multidisciplinario de Investigaciones en Patologías Pediátricas; Argentina Fil: Giadans, Cecilia Graciela. Gobierno de la Ciudad de Buenos Aires. Hospital General de Niños "Ricardo Gutiérrez"; Argentina. Gobierno de la Ciudad de Buenos Aires. Instituto Multidisciplinario de Investigaciones en Patologías Pediátricas. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto Multidisciplinario de Investigaciones en Patologías Pediátricas; Argentina Fil: Ameigeiras, Beatriz. Gobierno de la Ciudad de Buenos Aires. Hospital General de Agudos "Ramos Mejía"; Argentina Fil: de Matteo, Elena Noemí. Gobierno de la Ciudad de Buenos Aires. Instituto Multidisciplinario de Investigaciones en Patologías Pediátricas. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto Multidisciplinario de Investigaciones en Patologías Pediátricas; Argentina Fil: Preciado, María Victoria. Gobierno de la Ciudad de Buenos Aires. Hospital General de Niños "Ricardo Gutiérrez"; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina Fil: Valva, Pamela. Gobierno de la Ciudad de Buenos Aires. Hospital General de Niños "Ricardo Gutiérrez"; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina

Previous studies have established that disturbed lymphocytes are involved in the pathogenesis of Vogt-Koyanagi-Harada (VKH) syndrome. Accordingly, glucocorticoids (GCs), with their well-recognized immune-suppressive function, have been widely used for treatment of VKH patients with acute relapses. However, the systemic response of diverse immune cells to GC therapy in VKH is poorly characterized. To address this issue, we analyzed immune cell subpopulations and their phenotype, as well as cytokine profiles in peripheral blood from VKH patients (n=25) and health controls (HCs, n=21) by flow cytometry and luminex technique, respectively. For 16 patients underwent GC therapy (methylprednisolone, MP), the aforementioned measurements as well as the transcriptome data from patients before and after one-week’s GC therapy were also compared to interrogate the systemic immune response to GC therapy. Lymphocyte composition in the blood was different in VKH patients and HCs. VKH patients had significantly higher numbers of T cells with more activated, polarized and differentiated phenotype, more unswitched memory B cells and monocytes, as compared to HCs. MP treatment resulted in decreased frequencies of T cells and NK cells, inhibited NK cell activation and T cell differentiation, and more profoundly, a marked shift in the distribution of monocyte subsets. Collectively, our findings suggest that advanced activation and differentiation, as well as dysregulated numbers of peripheral lymphocytes are the major immunological features of VKH, and GC therapy with MP not only inhibits T cell activation directly, but also affects monocyte subsets, which might combinatorically result in the inhibition of the pathogenic immune response.

Patients with chronic lung disease (CLD) have an increased risk for severe coronavirus disease-19 (COVID-19) and poor outcomes. Here, we analyze the transcriptomes of 611,398 single cells isolated from healthy and CLD lungs to identify molecular characteristics of lung cells that may account for worse COVID-19 outcomes in patients with chronic lung diseases. We observe a similar cellular distribution and relative expression of SARS-CoV-2 entry factors in control and CLD lungs. CLD AT2 cells express higher levels of genes linked directly to the efficiency of viral replication and the innate immune response. Additionally, we identify basal differences in inflammatory gene expression programs that highlight how CLD alters the inflammatory microenvironment encountered upon viral exposure to the peripheral lung. Our study indicates that CLD is accompanied by changes in cell-type-specific gene expression programs that prime the lung epithelium for and influence the innate and adaptive immune responses to SARS-CoV-2 infection., Patients with chronic lung disease (CLD) have an increased risk for severe coronavirus disease-19 and poor outcomes. Here the authors compare the transcriptomes of single cells isolated from healthy and CLD lungs to identify molecular characteristics of lung cells that may account for worse COVID-19 outcomes in these patients.

Purpose Myositis as a rare manifestation of COVID-19 is only recently being reported. This review examines the current literature on COVID-19-induced myositis focusing on etiopathogenesis, clinical presentations, diagnostic practices, and therapeutic challenges with immunosuppression, and the difficulties experienced by rheumatologists in established myositis in the COVID-19 era. Recent Findings COVID-19 is associated with a viral myositis attributable to direct myocyte invasion or induction of autoimmunity. COVID-19-induced myositis may be varied in presentation, from typical dermatomyositis to rhabdomyolysis, and a paraspinal affliction with back pain. It may or may not present with acute exponential elevations of enzyme markers such as creatine kinase (CK). Virus-mediated muscle inflammation is attributed to ACE2 (angiotensin-converting enzyme) receptor–mediated direct entry and affliction of muscle fibers, leading on to innate and adaptive immune activation. A greater recognition of the stark similarity between anti-MDA5-positive myositis with COVID-19 has thrown researchers into the alley of exploration — finding common etiopathogenic basis as well as therapeutic strategies. For patients with established myositis, chronic care was disrupted during the pandemic with several logistic challenges and treatment dilemmas leading to high flare rates. Teleconsultation bridged the gap while ushering in an era of patient-led care with the digital transition to tools of remote disease assessment. Summary COVID-19 has brought along greater insight into unique manifestations of COVID-19-related myositis, ranging from direct virus-induced muscle disease to triggered autoimmunity and other etiopathogenic links to explore. A remarkable shift in the means of delivering chronic care has led patients and caregivers worldwide to embrace a virtual shift with teleconsultation and opened doorways to a new era of patient-led care.

Since December 2019, Wuhan, China, has experienced an outbreak of coronavirus disease (COVID-19), which is caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Pregnant women are deductively considered to be in immunosuppressive condition for the safety of semi-allograft fetuses, which increases the risk of being infected by the virus. In this review, we analyzed the unique immunological characteristics of pregnant women and reviewed their known outcomes at different trimesters from the perspective of underlying mechanisms that have been studied and speculated so far.

Different emerging viral infections may emerge in different regions of the world and pose a global pandemic threat with high fatality. Clarification of the immunopathogenesis of different emerging viral infections can provide a plan for the crisis management and prevention of emerging infections. This perspective article describes how an emerging viral infection evolves from microbial mutation, zoonotic and/or vector-borne transmission that progresses to a fatal infection due to overt viremia, tissue-specific cytotropic damage or/and immunopathology. We classified immunopathogenesis of common emerging viral infections into 4 categories: 1) deficient immunity with disseminated viremia (e.g., Ebola); 2) pneumocytotropism with/without later hyperinflammation (e.g., COVID-19); 3) augmented immunopathology (e.g., Hanta); and 4) antibody-dependent enhancement of infection with altered immunity (e.g., Dengue). A practical guide to early blocking of viral evasion, limiting viral load and identifying the fatal mechanism of an emerging viral infection is provided to prevent and reduce the transmission, and to do rapid diagnoses followed by the early treatment of virus neutralization for reduction of morbidity and mortality of an emerging viral infection such as COVID-19.

Periodontitis is an oral inflammatory disease in which the polymicrobial synergy and dysbiosis of the subgingival microbiota trigger a deregulated host immune response, that leads to the breakdown of tooth-supporting tissues and finally tooth loss. Periodontitis is characterized by the increased pathogenic activity of T helper type 17 (Th17) lymphocytes and defective immunoregulation mediated by phenotypically unstable T regulatory (Treg), lymphocytes, incapable of resolving the bone-resorbing inflammatory milieu. In this context, the complexity of the immune response orchestrated against the microbial challenge during periodontitis has made the study of its pathogenesis and therapy difficult and limited. Indeed, the ethical limitations that accompany human studies can lead to an insufficient etiopathogenic understanding of the disease and consequently, biased treatment decision-making. Alternatively, animal models allow us to manage these difficulties and give us the opportunity to partially emulate the etiopathogenesis of periodontitis by inoculating periodontopathogenic bacteria or by placing bacteria-accumulating ligatures around the teeth; however, these models still have limited translational application in humans. Accordingly, humanized animal models are able to emulate human-like complex networks of immune responses by engrafting human cells or tissues into specific strains of immunodeficient mice. Their characteristics enable a viable time window for the study of the establishment of a specific human immune response pattern in anin vivosetting and could be exploited for a wider study of the etiopathogenesis and/or treatment of periodontitis. For instance, the antigen-specific response of human dendritic cells against the periodontopathogenPorphyromonas gingivalisfavoring the Th17/Treg response has already been tested in humanized mice models. Hypothetically, the proper emulation of periodontal dysbiosis in a humanized animal could give insights into the subtle molecular characteristics of a human-like local and systemic immune response during periodontitis and support the design of novel immunotherapeutic strategies. Therefore, the aims of this review are: To elucidate how the microbiota-elicited immunopathogenesis of periodontitis can be potentially emulated in humanized mouse models, to highlight their advantages and limitations in comparison with the already available experimental periodontitis non-humanized animal models, and to discuss the potential translational application of using these models for periodontitis immunotherapeutics.

The immunopathogenesis of sarcoidosis remains unclear. This failure in understanding has been clinically impactful, as it has impeded the accurate diagnosis, treatment, and prevention of this disease. Unraveling the mechanisms of sarcoidosis will require input from basic and translational scientists. In order to reach this goal, scientists must have a firm grasp of the clinical aspects of the disease, including its diagnostic criteria, the immunologic defects, clinical presentations, response to therapy, risk factors, and clinical course. This manuscript will provide an overview of the clinical aspects of sarcoidosis that are particularly relevant for the basic and translational scientist. The variable phenotypic expression of the disease will be described, which may be integral in identifying immunologic disease mechanisms that may be relevant to subgroups of sarcoidosis patients. Data concerning treatment and risk factors may yield important insights concerning germane immunologic pathways involved in the development of disease. It is hoped that this manuscript will stimulate communication between scientists and clinicians that will eventually lead to improved care of sarcoidosis patients.

Neuropathic pain (NeP) is commonly encountered in patients with diseases associated with spinal cord damage (e.g., spinal cord injury (SCI) and compressive myelopathy). Recent studies described persistent glial activation and neuronal hyperactivity in SCI, but the pathomechanisms of NeP in chronic compression of the spinal cord remains elusive. The purpose of the present study was to determine the roles of microglia and infiltrating macrophages in NeP. The study was conducted in chimeric spinal hyperostotic mice (ttw/ttw), characterized by chronic progressive compression of the spinal cord as a suitable model of human compressive myelopathy. The severity of spinal cord compression correlated with proportion of activated microglia and hematogenous macrophages. Spinal cord compression was associated with overexpression of mitogen-activated protein kinases (MAPKs) in infiltrating macrophages and reversible blood-spinal cord barrier (BSCB) disruption in the dorsal horns. Our results suggested that chronic neuropathic pain in long-term spinal cord compression correlates with infiltrating macrophages, activated microglial cells and the associated damage of BSCB, together with overexpression of p-38 MAPK and p-ERK1/2 in these cells. Our findings are potentially useful for the design of new therapies to alleviate chronic neuropathic pain associated with compressive myelopathy.

Introduction: Neuromyelitis optica spectrum disorders (NMOSD) are autoimmune diseases of the central nervous system mainly involving the optic nerves and spinal cord. Many advances have been made i...

Severe influenza infection has no effective treatment available. One of the key barriers to developing host-directed therapy is a lack of reliable prognostic factors needed to guide such therapy. Here, we use a network analysis approach to identify host factors associated with severe influenza and fatal outcome. In influenza patients with moderate-to-severe diseases, we uncover a complex landscape of immunological pathways, with the main changes occurring in pathways related to circulating neutrophils. Patients with severe disease display excessive neutrophil extracellular traps formation, neutrophil-inflammation and delayed apoptosis, all of which have been associated with fatal outcome in animal models. Excessive neutrophil activation correlates with worsening oxygenation impairment and predicted fatal outcome (AUROC 0.817–0.898). These findings provide new evidence that neutrophil-dominated host response is associated with poor outcomes. Measuring neutrophil-related changes may improve risk stratification and patient selection, a critical first step in developing host-directed immune therapy., Identification of host factors associated with severe influenza infection could provide insights into treatment options. Here, the authors provide transcriptomic analyses of blood from >100 influenza infected patients and show that changes in circulating neutrophils are associated with severe influenza infection.

Carolina Jasso-Miranda,1,2 Irma Herrera-Camacho,2 Lilian Karem Flores-Mendoza,3 Fabiola Dominguez,1 Veronica Vallejo-Ruiz,1 Gilma Guadalupe Sanchez-Burgos,4 Victoria Pando-Robles,5 Gerardo Santos-Lopez,1 Julio Reyes-Leyva11Laboratory of Immunology and Virology, East Biomedical Research Center, Mexican Institute of Social Security (IMSS), CP 74360 Metepec, Puebla, México; 2Laboratory of Biochemistry and Molecular Biology, Center of Chemistry, Institute of Sciences, Meritorious Autonomous University of Puebla, CP 72570 San Manuel, Puebla, Mexico; 3Department of Chemical, Biologic and Agricultural Sciences, Science and Enginery Division, University of Sonora, CP 85880 Navojoa, Sonora, Mexico; 4Yucatan’s Medical Research Unit, Mexican Institute of Social Security (IMSS), CP 97150 Merida, Yucatan, Mexico; 5Infectious Disease Research Center, National Institute of Public Health, CP 62100 Cuernavaca, Morelos, MexicoBackground: There is a lack of specific antiviral therapy against dengue virus (DENV) in current use. Therefore, a great proportion of dengue cases progress to severe clinical forms due to a complex interplay between virus and host immune response. It has been hypothesized that heterotypic non-neutralizing antibodies enhance DENV infection in phagocytic cells, and this induces an inflammatory response that is involved in the pathogenesis of severe dengue.Purpose: To identify the antiviral and immunomodulatory effects of polyphenols on dengue virus infection.Methods: Human U937-DC-SIGN macrophages were infected with DENV serotypes 2 or 3 in the presence or not of enhancing antibody 4G2. Viral titers and the secretion of tumor necrosis factor-alpha, IL-6, IL-10 and interferon-alpha were analyzed timely.Results: DENV infection alone induced high production of IL-6 and TNF-α, but in the presence of 4G2 antibody, viral titers and TNF-α secretion were potentiated. Based on anti-inflammatory antecedents, the polyphenols curcumin, fisetin, resveratrol, apigenin, quercetin and rutin were tested for antiviral and immunomodulatory properties. Only quercetin and fisetin inhibited DENV-2 and DENV-3 infection in the absence or presence of enhancing antibody (>90%, p

Currently, thyroid-associated ophthalmopathy (TAO) lacks effective treatment due to our lack of clarity in its immunopathogenesis. Orbital fibroblasts play a key role in altering inflammation and immune response in TAO, and are considered as the key target and effector cells in its pathogenesis. The orbit infiltrating CD34+ fibrocytes add on to the process by expressing high levels of autoantigens and inflammatory cytokines, while also differentiating into myofibroblasts or adipocytes. This review focuses on the role of orbital fibroblasts and CD34+ fibrocytes in the pathogenesis of TAO, highlighting the basis of emerging treatments.

Systemic lupus erythematosus (SLE) flares elicit progressive organ damage, leading to disability and early mortality. This study evaluated clinical and immunologic factors associated with impending flare in the Biomarkers of Lupus Disease study. Autoantibodies and 32 soluble mediators were measured by multiplex assays, immune pathway activation by gene expression module scores, and immune cell subset frequencies and activation states by flow cytometry. After providing baseline samples, participants received transient steroids to suppress disease and were followed until flare. Flare occurred early (within 60 days of baseline) in 21 participants and late (90–165 days) in 13. At baseline, compared to the late flare group, the early flare group had differential gene expression in monocyte, T cell, interferon, and inflammation modules, as well as significantly higher frequencies of activated (aCD11b+) neutrophils and monocytes, and activated (CD86hi) naïve B cells. Random forest models showed three subgroups of early flare patients, distinguished by greater baseline frequencies of aCD11b+ monocytes, or CD86hi naïve B cells, or both. Increases in these cell populations were the most accurate biomarkers for early flare in this study. These results suggest that SLE flares may arise from an overlapping spectrum of lymphoid and myeloid mechanisms in different patients.

The article discusses the determining role of immunopathogenesis of the main diseases of the modern man (cancer, atherosclerosis, autoimmune, allergic and infectious diseases). In this regard, the concept of «immune paradigm» is introduced. There is evidence that any pathology is based on the classical immune response to the antigen, whether auto- or xenoantigen, with all stages of its development and parallel changes in the state of immune tolerance: its breakdown in cases of autoimmune and allergic diseases and atherosclerosis; its establishment in cases of cancer and infectious diseases. In the meantime, it is emphasized that the immunopathogenesis is based on insufficient or increased function of immunocompetent regulatory cells with suppressive activity. Here the concept of «immunosuppressive dominant» is introduced. Finally, we discuss the need for fundamental changes in treatment of these diseases, with a focus on molecular and cellular immunotherapy methods and development of integrated approaches to their application.

Psoriatic arthritis is a chronic progressive systemic inflammatory disease of joints and spine, which leads to the development of erosive arthritis, bone resorbtion, multiple enthesitis and spondylitis. Severe clinical course, resistance to therapy, high prevalence of disability, increased mortality of patients determine a need for further study of the disease. Psoriatic arthritis is a multifactorial disease including immune pathogenic factors representing a complex process of interaction between cellular and humoral components of immune system. The most important way of activating epidermal cells and synovial membrane proliferation in psoriatic arthritis is an imbalance of proinflammatory and anti-inflammatory cytokines. It is noted that the features of clinical course in psoriasis are age-dependent. The study of immune response indices in different age groups allows to reveal distinct progression features of the psoriatic pathology.The purpose of this study was to compare concentrations of proinflammatory and anti-inflammatory cytokines, cellular and humoral immunity, and to conduct a comparative analysis in young and adult patients with psoriatic arthritis.The study included a group of patients with psoriatic arthritis (n = 101) who were divided by their age: group 1, from 18 to 44 years (n = 43); group 2, over 44 years (n = 58). The control groups (3 and 4) included virtually healthy people (n = 103) matched for sex and age with the patients. Populational and subpopulation profiling of blood lymphocytes was performed by flow-cytometry using monoclonal antibodies to CD3, CD4, CD8, CD16, CD19 (LLC “Sorbent”, Moscow, Russia). Phagocytic activity of peripheral blood neutrophils was assessed microscopically by uptake of latex particles. Concentrations of IgA, IgM, and IgG immunoglobulins, circulating immune complexes, cytokines (IL-4, IL-6, IL-10, TNFα) in blood serum was determined by enzyme-linked immunosorbent assay. Statistical evaluation of the results obtained was performed using applied “Statistica 6.0” software.In all the age subgroups of patients with psoriatic arthritis, we have revealedstatistically significant differences against controls, i.e., increased relative and absolute number of CD3-CD16+lymphocytes in peripheral blood, higher concentration of CIC-C1q, with decreased concentrations of IgA, IgM, IgG in blood serum. The analysis of the main cellular and humoral indicators of immunity in psoriatic arthritis patients revealed a statistically significant differences for psoriatic arthritis in young and adulthood. E.g., the serum concentration of IL- 10 was statistically significantly lower in psoriatic arthritis at a young age in comparison with adult psoriatic arthritis. Phagocytic number and IgG concentration in serum were statistically significantly lower in adults with psoriatic arthritis adulthood than in young patients.In conclusion, The revealed changes in immunological indices in psoriatic arthritis in young and adult patients indicate to differences against healthy controls, as well as intergroup differences. Previous studies have not revealed statistically any significant differences in immunological parameters between young and adult patients with psoriatic arthritis in, thus suggesting a presence of immune disorders associated with psoriatic pathology, but not with the age of patients. However, changes of immunological reactivity are observed with increasing age of patients with psoriatic arthritis and development of severe clinical forms, and they can be considered as markers of psoriatic disease progression, such as increased concentrations of IL-10 and lower IgG amounts in blood serum, a decreased phagocytic number.

Ankylosing spondylitis (AS) is an inflammatory rheumatoid disease categorized within spondyloarthropathies (SpA) and manifested by chronic spinal arthritis. Several innate and adaptive immune cells and secreted-mediators have been indicated to play a role in AS pathogenesis. Considering the limitations of current therapeutic approaches (NSAIDs, glucocorticoids, DMARDs and biologic drugs), finding new treatments with fewer side effects and high therapeutic potentials are required in AS. Mesenchymal stem cells (MSCs) with considerable immunomodulatory and regenerative properties could be able to attenuate the inflammatory responses and help tissue repair by cell-to-cell contact and secretion of soluble factors. Moreover, MSCs do not express HLA-DR, which renders them a favorable therapeutic choice for transplantation in immune-mediated disorders. In the present review, we describe immunopathogenesis and current treatments restrictions of AS. Afterwards, immunomodulatory properties and applications of MSCs in immune-mediated disorders, as well as recent findings of clinical trials involving mesenchymal stem cell therapy (MSCT) in ankylosing spondylitis, will be discussed in detail. Additional studies are required to investigate several features of MSCT such as cell origin, dosage, administration route and, specifically, the most suitable stage of disease for ideal intervention.

Hermansky-Pudlak Syndrome (HPS) is a rare, genetic, multisystem disorder characterized by oculocutaneous albinism (OCA), bleeding diathesis, immunodeficiency, granulomatous colitis, and pulmonary fibrosis. HPS pulmonary fibrosis (HPS-PF) occurs in 100% of patients with subtype HPS-1 and has a similar presentation to idiopathic pulmonary fibrosis. Upon onset, individuals with HPS-PF have approximately 3 years before experiencing signs of respiratory failure and eventual death. This review aims to summarize current research on HPS along with its associated pulmonary fibrosis and its implications for the development of novel treatments. We will discuss the genetic basis of the disease, its epidemiology, and current therapeutic and clinical management strategies. We continue to review the cellular processes leading to the development of HPS-PF in alveolar epithelial cells, lymphocytes, mast cells, and fibrocytes, along with the molecular mechanisms that contribute to its pathogenesis and may be targeted in the treatment of HPS-PF. Finally, we will discuss emerging new cellular and molecular approaches for studying HPS, including lentiviral-mediated gene transfer, induced pluripotent stem cells (iPSCs), organoid and 3D-modelling, and CRISPR/Cas9-based gene editing approaches.

Sepsis is currently defined as life-threatening organ dysfunction caused by a dysregulated host response to infection. Sepsis may occur secondary to infection anywhere in the body, and its pathogenesis is complex and not yet fully understood. Variations in the host immune response result in diverse clinical manifestations, which complicates clinical recognition and fluid therapy both in humans and veterinary species. Septic shock is a subset of sepsis in which particularly profound circulatory, cellular, and metabolic abnormalities are associated with a greater risk of mortality than with sepsis alone. Although septic shock is a form of distributive shock, septic patients frequently present with hypovolemic and cardiogenic shock as well, further complicating fluid therapy decisions. The goals of this review are to discuss the clinical recognition of sepsis in dogs and cats, the basic mechanisms of its pathogenesis as it affects hemodynamic function, and considerations for fluid therapy. Important pathophysiologic changes, such as cellular interaction, microvascular alterations, damage to the endothelial glycocalyx, hypoalbuminemia, and immune paralysis will be also reviewed. The advantages and disadvantages of treatment with crystalloids, natural and synthetic colloids, and blood products will be discussed. Current recommendations for evaluating fluid responsiveness and the timing of vasopressor therapy will also be considered. Where available, the veterinary literature will be used to guide recommendations.

Introduction: Sarcoidosis is a T-helper cell mediated disease characterized by granulomatous inflammation. We posited that unsupervised clustering of various features in sarcoidosis would establish phenotypes associated with inflammatory activity measured by 18FDG-PET/CT. Our goal was to identify unique features capable of distinguishing clusters and subsequently examine the relationship with FDG avidity to substantiate their potential use as markers for sarcoidosis inflammation.Methods: We performed a retrospective study of a diverse, but primarily African American, cohort of 58 subjects with biopsy proven sarcoidosis followed at the University of Illinois Bernie Mac Sarcoidosis Center and Center for Lung Health who underwent 18FDG-PET/CT scan. Demographic, therapeutic, radiographic, and laboratory data were utilized in unsupervised cluster analysis to identify sarcoidosis phenotypes. The association between clusters, their defining features, and quantitative measurements on 18FDG-PET/CT was determined. The relevance of these features as markers of 18FDG-PET/CT inflammatory activity was also investigated.Results: Clustering determined three distinct phenotypes: (1) a predominantly African American cluster with chronic, quiescent disease, (2) a predominantly African American cluster with elevated conventional inflammatory markers, advanced pulmonary disease and extrathoracic involvement, and (3) a predominantly Caucasian cluster characterized by reduced lymphocyte counts and acute disease. In contrast to the chronic quiescent cluster, Clusters 2 and 3 were defined by significantly greater FDG avidity on 18FDG-PET/CT. Despite similarly increased inflammatory activity on 18FDG-PET/CT, Clusters 2, and 3 differed with regards to extrathoracic FDG avidity and circulating lymphocyte profiles, specifically CD4+ T-cells. Notably, absolute lymphocyte counts and CD4+ T-cell counts were found to predict 18FDG-PET/CT inflammatory activity by receiver operating curve analysis with a 69.2 and 73.42% area under the curve, respectively.Conclusions: Utilizing cluster analysis, three distinct phenotypes of sarcoidosis were identified with significant variation in race, disease chronicity, and serologic markers of inflammation. These phenotypes displayed varying levels of circulating inflammatory cells. Additionally, reduction in lymphocytes, specifically CD4+ T-cells, was significantly related to activity on 18FDG-PET/CT. Though future studies are warranted, these findings suggest that peripheral lymphocyte counts may be considered a determinant of sarcoidosis phenotypes and an indicator of active inflammation on 18FDG-PET/CT.

Graft-versus-host disease is a common complication of hematopoietic stem cell transplantation and the ocular surface is a main target of inflammatory reaction.

Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2) is a novel coronavirus that emerged from Wuhan, China in late 2019 causing coronavirus disease-19 (COVID-19). SARS-CoV-2 infection begins by attaching to angiotensin-converting enzyme 2 receptor (ACE2) via the spike glycoprotein, followed by cleavage by TMPRSS2, revealing the viral fusion domain. Other presumptive receptors for SARS-CoV-2 attachment include CD147, neuropilin-1 (NRP1), and Myeloid C-lectin like receptor (CLR), each of which might play a role in the systemic viral spread. The pathology of SARS-CoV-2 infection ranges from asymptomatic to severe acute respiratory distress syndrome, often displaying a cytokine storm syndrome, which can be life-threatening. Despite progress made, the detailed mechanisms underlying SARS-CoV-2 interaction with the host immune system remain unclear and are an area of very active research. The process’s key players include viral non-structural proteins and open reading frame products, which have been implicated in immune antagonism. The dysregulation of the innate immune system results in reduced adaptive immune responses characterized by rapidly diminishing antibody titers. Several treatment options for COVID-19 are emerging, with immunotherapies, peptide therapies, and nucleic acid vaccines showing promise. This review discusses the advances in the immunopathology of SARS-CoV-2, vaccines and therapies under investigation to counter the effects of this virus, as well as viral variants.

Scientific reports 11(1), 2497 (2021). doi:10.1038/s41598-021-81766-8, Published by Macmillan Publishers Limited, part of Springer Nature, [London]

Type I interferon (IFN) dysregulation is a major contributory factor in the development of several autoimmune diseases, termed type I interferonopathies, and is thought to be the pathogenic link with chronic inflammation in these conditions. Anti-neutrophil cytoplasmic antibody (ANCA)-Associated Vasculitis (AAV) is an autoimmune disease characterised by necrotising inflammation of small blood vessels. The underlying biology of AAV is not well understood, however several studies have noted abnormalities in type I IFN responses. We hypothesised that type I IFN responses are systemically dysregulated in AAV, consistent with features of a type I interferonopathy. To investigate this, we measured the expression of seven interferon regulated genes (IRGs) (ISG15, SIGLEC1, STAT1, RSAD2, IFI27, IFI44L and IFIT1) in peripheral blood samples, as well as three type I IFN regulated proteins (CXCL10, MCP-1 and CCL19) in serum samples from AAV patients, healthy controls and disease controls. We found no difference in type I IFN regulated gene or protein expression between AAV patients and healthy controls. Furthermore, IRG and IFN regulated protein expression did not correlate with clinical measurements of disease activity in AAV patients. Thus, we conclude that systemic type I IFN responses are not key drivers of AAV pathogenesis and AAV should not be considered a type I interferonopathy.