The Two-Faced Cytokine IL-6 in Host Defense and Diseases

Sarilumab Administration in COVID-19 Patients: Literature Review and Considerations

Two years have passed since WHO declared a pandemic state for SARS-CoV-2 infection. COVID-19 pathogenesis consists of a first viral phase responsible for early symptoms followed by an inflammatory phase, cytokine-mediated, responsible for late-onset manifestations up to ARDS. The dysregulated immune response has an outstanding role in the progression of pulmonary damage in COVID-19. IL-6, through the induction of pro-inflammatory chemokines and cytokines, plays a key role in the development and maintenance of inflammation, acting as a pioneer of the hyperinflammatory condition and cytokine storm in severe COVID-19. Therefore, drugs targeting both IL-6 and IL-6 receptors have been evaluated in order to blunt the abnormal SARS-CoV-2-induced cytokine release. Sarilumab, a high-affinity anti-IL-6 receptor antibody, may represent a promising weapon to treat the fearsome hyperinflammatory phase by improving the outcome of patients with moderate-to-severe COVID-19 pneumonia. Further prospective and well-designed clinical studies with larger sample sizes and long-term follow-up are needed to assess the efficacy and the safety of this therapeutic approach to achieve improved outcomes in COVID-19.

Combinations of drug candidate properties affecting development success and discontinuation for five diseases: Lymphoma, non-small cell lung cancer, arthritis, depression, and Alzheimer's disease

The effects of the properties of drug candidates on their successful approval for the treatment of diseases are substantial. However, the success rate of candidates when their properties are combined has not been sufficiently evaluated. We aimed to identify combinations of properties (Target, Action, and Modality) that increased the approval success rate of drug candidates for five diseases as well as to understand the characteristics of discontinued candidates. We calculated the approval success rates by combining the properties of drug candidates developed for five diseases (non-small cell lung cancer [NSCLC], lymphoma, arthritis, depression, and Alzheimer's disease [AD]), using candidates for which clinical development was initiated between 2000 and 2010. We also analyzed the phases and the reasons for the discontinuation of candidates of the five diseases for which development was discontinued. Probable combinations of properties with relatively high success rates for the diseases except for AD were found. These combinations of properties were considered appropriate in light of the pathology of each disease. The percentage of candidates discontinued in phase III for AD was higher than that for the other diseases. The reasons for discontinuation showed different trends between combinations of properties that had high and low approval success rates. As the effects of the properties of candidates on the success rate vary depending on the intended disease, pharmaceutical companies need to consider the probability of success of candidates for individual diseases for more efficient candidate selection. This article is protected by copyright. All rights reserved.

Mannose Receptor-Mediated Carbon Nanotubes as an Antigen Delivery System to Enhance Immune Response Both In Vitro and In Vivo

Carbon nanotubes (CNTs) are carbon allotropes consisting of one, two, or more concentric rolled graphene layers. These can intrinsically regulate immunity by activating the innate immune system. Mannose receptors (MR), a subgroup of the C-type lectin superfamily, are abundantly expressed on macrophages and dendritic cells. These play a crucial role in identifying pathogens, presenting antigens, and maintaining internal environmental stability. Utilizing the specific recognition between mannose and antigen-presenting cells (APC) surface mannose receptors, the antigen-carrying capacity of mannose-modified CNTs can be improved. Accordingly, here, we synthesized the mannose-modified carbon nanotubes (M-MWCNT) and evaluated them as an antigen delivery system through a series of in vitro and in vivo experiments. In vitro, M-MWCNT carrying large amounts of OVA were rapidly phagocytized by macrophages and promoted macrophage proliferation to facilitate cytokines (IL-1β, IL-6) secretion. In vivo, in mice, M-MWCNT induced the maturation of dendritic cells and increased the levels of antigen-specific antibodies (IgG, IgG1, IgG2a, IgG2b), and cytokines (IFN-γ, IL-6). Taken together, M-MWCNT could induce both humoral and cellular immune responses and thereby can be utilized as an efficient antigen-targeted delivery system.

IL-6 Prevents Lung Macrophage Death and Lung Inflammation Injury by Inhibiting GSDME- and GSDMD-Mediated Pyroptosis during Pneumococcal Pneumosepsis

Streptococcus pneumoniae is a leading bacterial cause of a wide range of infections, and pneumococcal pneumosepsis causes high mortality in hosts infected with antibiotic-resistant strains and those who cannot resolve ongoing inflammation. The factors which influence the development and outcome of pneumosepsis are currently unclear. IL-6 is critical for maintaining immune homeostasis, and we determined that this cytokine is also essential for resisting pneumosepsis, as it inhibits macrophage pyroptosis and pyroptosis-related inflammation injury in the lung. IL-6 affected infection outcomes in mice and exerted a protective role, primarily via macrophages. We further found that IL-6 deficiency led to increased lung macrophage death and aggravated lung inflammation, and that exogenous administration of IL-6 protein could decrease macrophage death and alleviate lung tissue inflammation. IL-6 also protected Streptococcus pneumoniae-induced lung macrophage death and lung inflammation injury by inhibiting gasdermin E (GSDME)- and gasdermin D (GSDMD)-mediated pyroptosis. Together, these data reveal a novel mechanism for the development of pneumosepsis and the critical protective role of IL-6. These findings may assist in the early identification and treatment of pneumococcal pneumosepsis.

IMPORTANCE Pneumococcal pneumonia has been a significant cause of morbidity and mortality throughout human history. Failing to control pneumococcal pneumonia and resolve ongoing inflammation in a host can cause sepsis, namely pneumococcal pneumosepsis, and death ensues. Few theories have suggested an optimally therapeutic option for this infectious disease. The interleukin-6 (IL-6, a cytokine featuring pleiotropic activity) theory, proposed here, implies that IL-6 acts as a protector against pneumococcal pneumosepsis. IL-6 prevents lung macrophage death and lung inflammation injury by inhibiting a caspase-3-GSDME-mediated switch from apoptosis to pyroptosis and inhibiting caspase-1-GSDMD-mediated classic pyroptosis during pneumococcal pneumosepsis. Thus, IL-6 is an important determinant for controlling bacterial invasion and a homeostatic coordinator of pneumococcal pneumosepsis. This study clarifies a novel mechanism of occurrence and development of pneumonia and secondary sepsis following a Streptococcus pneumoniae infection. It is important for the early identification and treatment of pneumococcal pneumosepsis.

Immunotherapy of COVID-19: Inside and Beyond IL-6 Signalling

Acting on the cytokine cascade is key to preventing disease progression and death in hospitalised patients with COVID-19. Among anti-cytokine therapies, interleukin (IL)-6 inhibitors have been the most used and studied since the beginning of the pandemic. Going through previous observational studies, subsequent randomised controlled trials, and meta-analyses, we focused on the baseline characteristics of the patients recruited, identifying the most favourable features in the light of positive or negative study outcomes; taking into account the biological significance and predictivity of IL-6 and other biomarkers according to specific thresholds, we ultimately attempted to delineate precise windows for therapeutic intervention. By stimulating scavenger macrophages and T-cell responsivity, IL-6 seems protective against viral replication during asymptomatic infection; still protective on early tissue damage by modulating the release of granzymes and lymphokines in mild-moderate disease; importantly pathogenic in severe disease by inducing the proinflammatory activation of immune and endothelial cells (through trans-signalling and trans-presentation); and again protective in critical disease by exerting homeostatic roles for tissue repair (through cis-signalling), while IL-1 still drives hyperinflammation. IL-6 inhibitors, particularly anti-IL-6R monoclonal antibodies (e.g., tocilizumab, sarilumab), are effective in severe disease, characterised by baseline IL-6 concentrations ranging from 35 to 90 ng/mL (reached in the circulation within 6 days of hospital admission), a ratio of partial pressure arterial oxygen (PaO2) and fraction of inspired oxygen (FiO2) between 100 and 200 mmHg, requirement of high-flow oxygen or non-invasive ventilation, C-reactive protein levels between 120 and 160 mg/L, ferritin levels between 800 and 1600 ng/mL, D-dimer levels between 750 and 3000 ng/mL, and lactate dehydrogenase levels between 350 and 500 U/L. Granulocyte-macrophage colony-stimulating factor inhibitors might have similar windows of opportunity but different age preferences compared to IL-6 inhibitors (over or under 70 years old, respectively). Janus kinase inhibitors (e.g., baricitinib) may also be effective in moderate disease, whereas IL-1 inhibitors (e.g., anakinra) may also be effective in critical disease. Correct use of biologics based on therapeutic windows is essential for successful outcomes and could inform future new trials with more appropriate recruiting criteria.

Biomarkers during COVID-19: Mechanisms of Change and Implications for Patient Outcomes

As the COVID-19 (Coronavirus disease 19) pandemic spreads worldwide, the massive numbers of COVID-19 patients have created a considerable healthcare burden for every country. The clinical spectrum of SARS-CoV-2 infection is broad, ranging from asymptomatic to mild, moderate, severe, and critical. Most COVID-19 patients present with no or mild symptoms, but nearly one-fifth of all patients develop severe or life-threatening complications. In addition to localized respiratory manifestations, severe COVID-19 cases also show extra-pulmonary complications or induce multiorgan failure. Identifying, triaging, and treating patients at risk early is essential and urgent. This article reviews the potential prognostic value of various biomarkers at different clinical spectrum stages of COVID-19 infection and includes information on fundamental prognostic mechanisms as well as potential clinical implications. Biomarkers are measurable biochemical substances used to recognize and indicate disease severity or response to therapeutic interventions. The information they provide is objective and suitable for delivering healthcare providers with a means of stratifying disease state in COVID-19 patients. This, in turn, can be used to help select and guide intervention efforts as well as gauge the efficacy of therapeutic approaches. Here, we review a number of potential biomarkers that may be used to guide treatment, monitor treatment efficacy, and form individualized therapeutic guidance based on patient response. Implementation of the COVID-19 biomarkers discussed here may lead to significantly improved quality of care and patient outcomes for those infected with SARS-CoV-2 worldwide.

Role of Polypeptide Inflammatory Biomarkers in the Diagnosis and Monitoring of COVID-19

The COVID-19 (coronavirus disease 2019) pandemic that took over the world in December 2019 has had everlasting devastating impacts on the lives of people globally. It manifests a huge symptom spectrum ranging from asymptomatic to critically ill patients with an unpredictable outcome. Timely diagnosis and assessment of disease severity is imperative for effective treatment. Possibilities exist that by the time symptoms appear the viral load might increase beyond control. However, it is advisable to get adequately diagnosed as soon as the first symptom appears. There is an immediate requirement of reliable biomarkers of COVID-19 manifesting an early onset for effective clinical management, stratification of high risk patients and ensuring ideal resource allocation. In this review, we attempt to explore and describe important polypeptide inflammatory biomarkers, namely C-reactive protein, Procalcitonin, Ferritin, Lactate Dehydrogenase, Serum amyloid A, Interleukin-6, Tumor necrosis factor-alpha and LIGHT used in the detection and management of COVID-19. Viral pathogenesis and the role of these inflammatory biomarkers is highlighted, based on the evidences available till date. An integrative data monitoring along with their correlation with the natural disease progression is of utmost importance in the management of COVID-19. So further research and in-depth analysis of these biomarkers is warranted in the present scenario.

Recent Advances in the Role of Arid5a in Immune Diseases and Cancer

AT-rich interactive domain 5a (Arid5a) is a nucleic acid binding protein. In this review, we highlight recent advances in the association of Arid5a with inflammation and human diseases. Arid5a is known as a protein that performs dual functions. In in vitro and in vivo studies, it was found that an inflammation-dependent increase in Arid5a expression mediates both transcriptional and post-transcriptional regulatory effects that are implicated in immune regulation and cellular homeostasis. A series of publications demonstrated that inhibiting Arid5a augmented several processes, such as preventing septic shock, experimental autoimmune encephalomyelitis, acute lung injury, invasion and metastasis, immune evasion, epithelial-to-mesenchymal transition, and the M1-like tumor-associated macrophage (TAM) to M2-like TAM transition. In addition, Arid5a controls adipogenesis and obesity in mice to maintain metabolic homeostasis. Taken together, recent progress indicates that Arid5a exhibits multifaceted, both beneficial and detrimental, roles in health and disease and suggest the relevance of Arid5a as a potential therapeutic target.

Immune correlates of Mycobacterium Tuberculosis patients in Zambia stratified by HIV serostatus and level of immunity-a cross-sectional analytical laboratory based study

BACKGROUND

People living with HIV (PLHIV) co-infected with tuberculosis (TB) have a distinct clinical presentation and poorer treatment outcomes compared to HIV-seronegative TB patients. Excluding low CD4 count, innate immune factors associated with TB are not fully elucidated. We, therefore, characterised and compared the expression of IL-6, TNF-α, IFN-γ, and IL-10 in whole blood of treatment naïve TB patients stimulated with heat-killed Mycobacterium tuberculosis stratified by HIV status and the level of CD4 count.

RESULTS

We recruited 39 HIV seropositive and 31 HIV seronegative TB patients. Median (IQR) age was 35(28-42) years and 31(25-36) years respectively, and a majority had pulmonary tuberculosis i.e. 38(95%) and 30(97%), respectively. The two groups were significantly different in the distribution of CD4 count, 563 [465-702.5 cells/mm3] vs 345 [157-483 cell/mm3] in HIV negative vs HIV positive respectively p = <0.001. Post stimulation, the expression of IL-6 in HIV negative TB patients was significantly higher than in the HIV positive 16,757366 [8,827-23,686 pg/ml] vs. 9,508 [5,514-15,008 pg/ml], respectively; p = 0.0360. TNF-α and IFN-γ were highly expressed in HIV negative TB patients compared to the HIV positive though not statistically significant. We only observed higher expression of IL-6 in HIV negative patients in comparison to the HIV positive when stratified by level of CD4 counts as < 500 and ≥ 500 cell/mm3 for both cohorts. 21,953 [8,990-24,206 pg/ml] vs 9,505 [5,400-15,313 pg/ml], p value = 0.0585 in patients with CD4 count < 500 cell/mm3 and 13,168 [7,087-22,584 pg/ml] vs 10,413 [7,397-14,806 pg/ml], p value = 0.3744 for patients with CD4 count of ≥ 500 cell/mm3 respectively. We found a positive pairwise correlation between TNF-α -alpha and IL-6 in both HIV positive and HIV negative patients, r = 0.61 (95% CI 0.36-0.72; p < 0.0001) and r = 0.48 (95% CI 0.15-0.68; p = 0.005) respectively. The IFNγ/IL-10 ratio was higher in HIV negative when compared to HIV positive individuals, 0.052 [0.0-0.28] vs 0.007 [0-0.32] respectively; p = 0.05759. IL-6 independently reduced the probability of TB/HIV, Adjusted odds ratio 0.99, p value 0.007.

CONCLUSIONS

This study suggests that HIV seronegative TB patients have a higher pro-inflammatory response to MTB than HIV seropositive TB patients. Further, it also shows that the level of CD4 influences immunomodulation. The findings suggest that the difference in cytokine expression may be responsible for the distinct patterns of TB presentation between HIV positive and HIV negative patient.

Geraniin inhibits whole blood IFN-γ and IL-6 and promotes IL-1β and IL-8, and stimulates calcium-dependent and sucrose-sensitive erythrocyte death

Correlations between circulating cytokine levels and disease states are well established, and pharmacological modulation of the immune response is thus an important aspect of the assessment of investigational new drugs. Moreover, chemotherapy-related anemia is a major obstacle in cancer treatment. Geraniin (GRN), a tannin extracted from Geranium and other plants, possesses promising antitumor potential. However, the effect of GRN on whole blood (WB) cytokine response and RBC physiology remains unexplored. Heparinized blood from consented, healthy adults was challenged with 100 ng/mL of lipopolysaccharide (LPS) with and without pretreatment with 10 μM of GRN for 24 h at 37 °C, and tumor necrosis factor-α (TNF-α), interferon-γ (IFN-γ), interleukin-1β (IL-1β), IL-6, IL-8, and IL-10 were assayed by ELISA. Moreover, single-cell RBC suspensions were treated with 5-100 μM of GRN for 24 or 48 h at 37 °C and cytotoxicity and canonical eryptotic markers were examined by flow cytometry. It was revealed that GRN significantly attenuated LPS-induced IFN-γ levels, increased IL-1β, decreased IL-6 only in absence of LPS, and aggravated LPS-induced IL-8 while together with LPS significantly diminished IL-10. Furthermore, GRN induced dose-responsive, Ca²⁺-dependent, and sucrose-sensitive hemolysis, along with phosphatidylserine exposure and Ca²⁺ accumulation with no appreciable cell shrinkage or oxidative damage. GRN was also selectively toxic to platelets, significantly delayed reticulocyte maturation, and significantly disrupted leukocyte proportions. In conclusion, GRN regulates the WB cytokine response and promotes premature hemolysis and eryptosis. This study provides insights into the therapeutic utility of GRN in a highly relevant cellular model system.

Tocilizumab drug levels during pregnancy and lactation: A woman who discontinued tocilizumab therapy until the end of the first trimester and resumed it after birth

The demand for tocilizumab is increasing in women who wish to bear children and who have active rheumatoid arthritis. Described here is a woman with rheumatoid arthritis who discontinued her tocilizumab therapy at the end of the first trimester and resumed it after delivery and where tocilizumab levels in maternal serum, infant serum, and the breast milk were measured. Tocilizumab was not detected in maternal serum just before delivery, or in umbilical cord blood or infant serum after birth. Tocilizumab levels in colostrum after intravenous injection were 0.57% of those in serum. Tocilizumab treatment in the first trimester was not associated with a significant drug level in the fetus at delivery and no fetal complications were noted .

Targeting Mediators of Inflammation in Heart Failure: A Short Synthesis of Experimental and Clinical Results

Inflammation has emerged as an important contributor to heart failure (HF) development and progression. Current research data highlight the diversity of immune cells, proteins, and signaling pathways involved in the pathogenesis and perpetuation of heart failure. Chronic inflammation is a major cardiovascular risk factor. Proinflammatory signaling molecules in HF initiate vicious cycles altering mitochondrial function and perturbing calcium homeostasis, therefore affecting myocardial contractility. Specific anti-inflammatory treatment represents a novel approach to prevent and slow HF progression. This review provides an update on the putative roles of inflammatory mediators involved in heart failure (tumor necrosis factor-alpha; interleukin 1, 6, 17, 18, 33) and currently available biological and non-biological therapy options targeting the aforementioned mediators and signaling pathways. We also highlight new treatment approaches based on the latest clinical and experimental research.

Development of type 1 diabetes in a patient treated with anti-interleukin-6 receptor antibody for rheumatoid arthritis

Interleukin‐6 is a pleiotropic cytokine that plays a pathogenic role in type 1 diabetes. Therefore, anti‐interleukin‐6 receptor antibody, tocilizumab, used for the treatment of rheumatoid arthritis, is considered a candidate for immune intervention in type 1 diabetes. Here, we report the case of a 73‐year‐old woman (HLA‐DR9‐DQ3 homozygote) with well‐controlled rheumatoid arthritis who developed type 1 diabetes while receiving tocilizumab treatment. At 57 years‐of‐age, the patient was diagnosed with rheumatoid arthritis, for which she underwent tocilizumab therapy that enabled complete suppression of her joint inflammation. A total of 17 months after starting tocilizumab therapy, she noticed polydipsia, polyuria, general fatigue and weight reduction (−2 kg/month), and was diagnosed with type 1 diabetes with diabetic ketoacidosis based on an arterial pH of 7.26, serum ketone body of 7,437 μmol/L, blood glucose level of 925 mg/dL, glycated hemoglobin of 13.2% and the presence of anti‐islet autoantibodies. This case report shows valuable insight regarding the effect of anti‐interleukin‐6 receptor antibody therapy on type 1 diabetes prevention.

Sympathetic nerve-adipocyte interactions in response to acute stress

Psychological stress predisposes our body to several disorders. Understanding the cellular and molecular mechanisms involved in the physiological responses to psychological stress is essential for the success of therapeutic applications. New studies show, by using in vivo inducible Cre/loxP-mediated approaches in combination with pharmacological blockage, that sympathetic nerves, activated by psychological stress, induce brown adipocytes to produce IL-6. Strikingly, this cytokine promotes gluconeogenesis in hepatocytes, that results in the decline of tolerance to inflammatory organ damage. The comprehension arising from this research will be crucial for the handling of many inflammatory diseases. Here, we review recent advances in our comprehension of the sympathetic nerve-adipocyte axis in the tissue microenvironment.

Systemic effects of IL-6 blockade in rheumatoid arthritis beyond the joints

Interleukin (IL)-6 is produced locally in response to an inflammatory stimulus, and is able to induce systemic manifestations at distance from the site of inflammation. Its unique signaling mechanism, including classical and trans-signaling pathways, leads to a major expansion in the number of cell types responding to IL-6. This pleiotropic cytokine is a key factor in the pathogenesis of rheumatoid arthritis (RA) and is involved in many extra-articular manifestations that accompany the disease. Thus, IL-6 blockade is associated with various biological effects beyond the joints. In this review, the systemic effects of IL-6 in RA comorbidities and the consequences of its blockade will be discussed, including anemia of chronic disease, cardiovascular risks, bone and muscle functions, and neuro-psychological manifestations.

Features of skin wound healing in rats with experimental chronic kidney disease

Chronic kidney disease negatively affects the morphofunctional state of all organs due to hemodynamic and metabolic disorders. Changes in the content of cytokines observed in kidney diseases, which regulate the processes of inflammation and tissue repair, can complicate the course of the wound process. This research aimed to study disorders in the process of skin wound repair due to changes in the dynamics of production of interleukins IL-1β, IL-6, IL-10, IL-4, growth factors bFGF and VEGF in animals with experimental chronic kidney disease. The levels of interleukins and growth factors were determined on the 7th, 14th and 28th days after surgical modeling of wounds in the blood of rats with experimental chronic kidney disease and animals of the control group. To assess the dynamics and quality of wound healing, a semi-quantitative histological analysis was performed. The study showed an increase in the content of pro-inflammatory interleukins in the group of sick rats: on the 7th day the level of IL-1β was 1.19 times higher, and IL-6 – 1.55 times, on the 14th day the level of IL-1β was 1.37 times in comparison with the control group. The maximum increase in the concentration of anti-inflammatory interleukins was noted on the 28th day: IL-4 was 2.10 times higher, IL-10 – 1.39 times higher than in the control group. The content of bFGF and VEGF in animals of the control group reached its maximum on the 7th day, and in animals with chronic kidney disease – on the 15th day after surgery. Semi-quantitative histological analysis showed a decrease in indicators in the group of sick animals: the number of fibroblasts and collagen deposition – on the 7th day, reepithelialization – on the 28th day. A persistent increase in the number of polymorphonuclear leukocytes was also noted at all periods of the experiment: by 1.38, 1.99, and 9.82 times – on the 7th, 14th, and 28th days, respectively. The study showed that the dynamics of the production of interleukins and growth factors were impaired in rats with chronic kidney disease. In the process of damage regeneration in sick animals, pro-inflammatory mechanisms prevailed with the involvement of a large number of immunocompetent cells, as a result, skin wounds took longer to heal.

Microglial Phenotypic Transition: Signaling Pathways and Influencing Modulators Involved in Regulation in Central Nervous System Diseases

Microglia are macrophages that reside in the central nervous system (CNS) and belong to the innate immune system. Moreover, they are crucially involved in CNS development, maturation, and aging; further, they are closely associated with neurons. In normal conditions, microglia remain in a static state. Upon trauma or lesion occurrence, microglia can be activated and subsequently polarized into the pro-inflammatory or anti-inflammatory phenotype. The phenotypic transition is regulated by numerous modulators. This review focus on the literature regarding the modulators and signaling pathways involved in regulating the microglial phenotypic transition, which are rarely mentioned in other reviews. Hence, this review provides molecular insights into the microglial phenotypic transition, which could be a potential therapeutic target for neuroinflammation.

Takayasu's Arteritis Diagnosed in an Adolescent Patient with Crohn's Disease: Management of Biologicals

We report a 14-year-old man with Crohn’s disease (CD) who developed right upper arm pain while being treated with the anti-tumor necrosis factor (TNF)-alpha monoclonal antibody, infliximab. There were no symptoms suggestive of active CD, but the inflammatory response was high, and a contrast-enhanced CT showed the occlusion of the right brachial artery. We diagnosed the patient as having Takayasu’s arteritis (TA) and started treatment with corticosteroids, then tapered off the steroids as the symptoms of TA resolved. Later, TA flared up, and his treatment was changed from infliximab to an anti-IL-6 receptor antibody, tocilizumab. The change to TCZ stabilized TA, but exacerbated CD. It is difficult to control both diseases at the same time, and the choice of biologics for treatment must be carefully considered.

Anti-Inflammatory Effect of Muscle-Derived Interleukin-6 and Its Involvement in Lipid Metabolism

Interleukin (IL)-6 has been studied since its discovery for its role in health and diseases. It is one of the most important pro-inflammatory cytokines. IL-6 was reported as an exacerbating factor in coronavirus disease. In recent years, it has become clear that the function of muscle-derived IL-6 is different from what has been reported so far. Exercise is accompanied by skeletal muscle contraction, during which, several bioactive substances, collectively named myokines, are secreted from the muscles. Many reports have shown that IL-6 is the most abundant myokine. Interestingly, it was indicated that IL-6 plays opposing roles as a myokine and as a pro-inflammatory cytokine. In this review, we discuss why IL-6 has different functions, the signaling mode of hyper-IL-6 via soluble IL-6 receptor (sIL-6R), and the involvement of soluble glycoprotein 130 in the suppressive effect of hyper-IL-6. Furthermore, the involvement of a disintegrin and metalloprotease family molecules in the secretion of sIL-6R is described. One of the functions of muscle-derived IL-6 is lipid metabolism in the liver. However, the differences between the functions of IL-6 as a pro-inflammatory cytokine and the functions of muscle-derived IL-6 are unclear. Although the involvement of myokines in lipid metabolism in adipocytes was previously discussed, little is known about the direct relationship between nonalcoholic fatty liver disease and muscle-derived IL-6. This review is the first to discuss the relationship between the function of IL-6 in diseases and the function of muscle-derived IL-6, focusing on IL-6 signaling and lipid metabolism in the liver.

High-value laboratory testing for hospitalized COVID-19 patients: a review

We present here an evidence-based review of the utility, timing, and indications for laboratory test use in the domains of inflammation, cardiology, hematology, nephrology and co-infection for clinicians managing the care of hospitalized COVID-19 patients. Levels of IL-6, CRP, absolute lymphocyte count, neutrophils and neutrophil-to-lymphocyte ratio obtained upon admission may help predict the severity of COVID-19. Elevated LDH, ferritin, AST, and d-dimer are associated with severe illness and mortality. Elevated cardiac troponin at hospital admission can alert clinicians to patients at risk for cardiac complications. Elevated proBNP may help distinguish a cardiac complication from noncardiac etiologies. Evaluation for co-infection is typically unnecessary in nonsevere cases but is essential in severe COVID-19, intensive care unit patients, and immunocompromised patients.

Bacterial and fungal ventilator associated pneumonia in critically ill COVID-19 patients during the second wave

BACKGROUND

The pandemic of coronavirus disease (COVID-19) has caused huge number of patients admitted to intensive care units (ICUs) in a critical need to mechanical ventilation. Ventilator associated pneumonia (VAP) has been noticed as a common complication in these patients with unfavorable outcomes. The current study aimed to assess bacterial and fungal VAP in COVID-19 patients admitted to ICUs during the second wave and to identify the possible risk factors.

METHODS

Respiratory samples were collected from 197 critically ill COVID-19 patients under mechanical ventilation. Bacterial and fungal superinfections were diagnosed by microbiological cultures with subsequent antimicrobial susceptibility testing of the isolates using available kits.

RESULTS

All specimens 197/197 (100%) were positive for bacterial infections, while fungal elements were detected in 134/197 (68%) of specimens. The most frequently isolated bacteria were pan drug resistant (PDR) Klebsiella pneumoniae (41.1%), followed by multi drug resistant (MDR) Acinetobacter baumannii (27.4%). On the other hand, Candida species represented the most frequently isolated fungi (75.4%) followed by molds including Aspergillus (16.4%) and Mucor (8.2%) species. Possible risk factors for fungal VAP included underlying diabetes mellitus (95% confidence interval [CI] 1.09-3.31; p = 0.02), chest disease (95% CI 1.01-3.32; p = 0.05), hypothyroidism (95% CI 1.01-4.78; p = 0.05), and longer duration of mechanical ventilation (p < 0.001). Furthermore, all patients 134/134 (100%) who developed fungal VAP, were already under treatment with corticosteroids and Tocilizumab.

CONCLUSION

Bacterial and fungal VAP in critically ill COVID-19 patients is a serious problem in the current pandemic. Urgent and strategic steps to keep it under control are compulsory.

Risk Factors Associated with the Clinical Outcomes of COVID-19 and Its Variants in the Context of Cytokine Storm and Therapeutics/Vaccine Development Challenges

The recent appearance of SARS-CoV-2 is responsible for the ongoing coronavirus disease 2019 (COVID-19) pandemic and has brought to light the importance of understanding this highly pathogenic agent to prevent future pandemics. This virus is from the same single-stranded positive-sense RNA family, Coronaviridae, as two other epidemic-causing viruses, SARS-CoV-1 and MERS-CoV. During this pandemic, one crucial focus highlighted by WHO has been to understand the risk factors that may contribute to disease severity and predict COVID-19 outcomes. In doing so, it is imperative to understand the virology of SARS-CoV-2 and the immunological response eliciting the clinical manifestation and progression of COVID-19. In this review, we provide clinical data-based analyses of how multiple risk factors (such as sex, race, HLA genotypes, blood groups, vitamin D deficiency, obesity, smoking, and asthma) contribute to the inflammatory overactivation and cytokine storm (frequently seen in COVID-19 patients) with a focus on the IL-6 pathway. We also draw comparisons to the virulence and pathophysiology of SARS and MERS to establish parallels in immune response and discuss the potential for therapeutic approaches that may limit disease progression in patients with higher risk profiles than others. Moreover, we cover the latest information on approved or upcoming COVID-19 vaccines. This paper also provides perspective on emerging variants and associated opportunistic infections such as black molds and fungus that have added to mortality in some parts of the world, such as India. This compilation of existing COVID-19 studies and data will provide an excellent referencing tool for the research, clinical, and public health communities.

Donor genetic variants in interleukin-6 and interleukin-6 receptor associate with biopsy-proven rejection following kidney transplantation

Rejection after kidney transplantation remains an important cause of allograft failure that markedly impacts morbidity. Cytokines are a major player in rejection, and we, therefore, explored the impact of interleukin-6 (IL6) and IL-6 receptor (IL6R) gene polymorphisms on the occurrence of rejection after renal transplantation. We performed an observational cohort study analyzing both donor and recipient DNA in 1271 renal transplant‐pairs from the University Medical Center Groningen in The Netherlands and associated single nucleotide polymorphisms (SNPs) with biopsy-proven rejection after kidney transplantation. The C-allele of the IL6R SNP (Asp358Ala; rs2228145 A > C, formerly rs8192284) in donor kidneys conferred a reduced risk of rejection following renal transplantation (HR 0.78 per C-allele; 95%-CI 0.67–0.90; P = 0.001). On the other hand, the C-allele of the IL6 SNP (at position-174 in the promoter; rs1800795 G > C) in donor kidneys was associated with an increased risk of rejection for male organ donors (HR per C-allele 1.31; 95%-CI 1.08–1.58; P = 0.0006), but not female organ donors (P = 0.33). In contrast, neither the IL6 nor IL6R SNP in the recipient showed an association with renal transplant rejection. In conclusion, donor IL6 and IL6R genotypes but not recipient genotypes represent an independent prognostic marker for biopsy-proven renal allograft rejection.

30 Years of Biotherapeutics Development-What Have We Learned?

Since the birth of biotechnology, hundreds of biotherapeutics have been developed and approved by the US Food and Drug Administration (FDA) for human use. These novel medicines not only bring significant benefit to patients but also represent precision tools to interrogate human disease biology. Accordingly, much has been learned from the successes and failures of hundreds of high-quality clinical trials. In this review, we discuss general and broadly applicable themes that have emerged from this collective experience. We base our discussion on insights gained from exploring some of the most important target classes, including interleukin-1 (IL-1), tumor necrosis factor α (TNF-α), IL-6, IL-12/23, IL-17, IL-4/13, IL-5, immunoglobulin E (IgE), integrins and B cells. We also describe current challenges and speculate about how emerging technological capabilities may enable the discovery and development of the next generation of biotherapeutics.

Pharmacokinetics and Pharmacodynamic Effects of Nemvaleukin Alfa, a Selective Agonist of the Intermediate-Affinity IL-2 Receptor, in Cynomolgus Monkeys

Nemvaleukin alfa (nemvaleukin, ALKS 4230) is a novel cytokine, created by the fusion of circularly permuted interleukin-2 (IL-2) to the IL-2Rα subunit of the IL-2 receptor (IL-2R) complex, that confers selectivity for the intermediate-affinity IL-2R expressed on CD8⁺ T cells and natural killer (NK) cells. The pharmacokinetics and selective pharmacodynamic properties of nemvaleukin have been demonstrated using in vitro and in vivo mouse models. The pharmacokinetic/pharmacodynamic effects of nemvaleukin on immune cell subtypes were evaluated in cynomolgus monkeys following intravenous (i.v.) and subcutaneous (s.c.) administration to inform dose selection and predict pharmacodynamic effects in humans. Male drug-naïve cynomolgus monkeys (N = 15) were administered either single-dose (i.v. 0.3 mg/kg; s.c. 0.3 mg/kg or 1.0 mg/kg) or repeated-doses (i.v. 0.1 mg/kg on days 1-5 or s.c. 0.5 mg/kg on days 1 and 4) of nemvaleukin. Serial blood samples were collected for pharmacokinetic assessment, immunophenotyping by flow cytometry, and profiling of serum cytokines. Repeat-dose s.c. administration of nemvaleukin with less frequent dosing resulted in total systemic exposure and trough serum concentrations comparable to those seen with i.v. administration, with lower peak serum concentrations. Transient elevation of interferon-γ and IL-6 peaked at 2 and 8 hours after i.v. and s.c. administration, respectively. Selective expansion of immunoprotective central memory, effector memory, and terminal effector CD8⁺ T cells and CD56⁺ NK cells, and minimal expansion of immunosuppressive CD4⁺CD25⁺FoxP3⁺ regulatory T cells was observed following both i.v. and s.c. administration. These data support the ongoing clinical evaluation of i.v. and s.c. nemvaleukin. Significance Statement Administration of the novel interleukin-2 receptor agonist nemvaleukin alfa (nemvaleukin, ALKS 4230) to cynomolgus monkeys resulted in selective expansion of immune effector cells, including CD8⁺ T and NK cells, with minimal effects on immunosuppressive CD4⁺ regulatory T cells, confirming the design of nemvaleukin and highlighting its potential as a cancer immunotherapy. Subcutaneous administration of nemvaleukin achieved systemic exposure and immunostimulatory effects similar to those observed following more frequent intravenous dosing and may represent a practical alternative in a clinical setting.

A Validated Mathematical Model of the Cytokine Release Syndrome in Severe COVID-19

By June 2021, a new contagious disease, the Coronavirus disease 2019 (COVID-19), has infected more than 172 million people worldwide, causing more than 3.7 million deaths. Many aspects related to the interactions of the disease's causative agent, SAR2-CoV-2, and the immune response are not well understood: the multiscale interactions among the various components of the human immune system and the pathogen are very complex. Mathematical and computational tools can help researchers to answer these open questions about the disease. In this work, we present a system of fifteen ordinary differential equations that models the immune response to SARS-CoV-2. The model is used to investigate the hypothesis that the SARS-CoV-2 infects immune cells and, for this reason, induces high-level productions of inflammatory cytokines. Simulation results support this hypothesis and further explain why survivors have lower levels of cytokines levels than non-survivors.

Laboratory and demographic findings among patients with coronavirus disease 2019: A review

Coronavirus disease 2019 (COVID-19) is the third known animal coronavirus, after severe acute respiratory syndrome (SARS) and Middle East respiratory syndrome coronavirus (MERS-CoV). The mean age of the infected patients was estimated to be between 50 and 69 years old. Accordingly, the COVID-19 mortality rate was calculated as 15%. In this regard, the essential component of prevention and planning is knowledge of laboratory and demographic findings among COVID-19 patients; therefore, the present study was conducted to investigate laboratory and demographic findings among these patients worldwide. This systematic review was performed on the articles published in English between January 1, 2019 and May 4, 2020, using MeSH-compliant keywords such as "COVID-19", "Laboratory, coronavirus disease-19 testing", and " demography " in international databases (PubMed, and web of science Scopus). Thereafter, the articles relevant to laboratory and demographic findings among COVID-19 patients were included in the final review. Reviewing the included articles showed changes in the mean lymphocytes count ranged from 0.7 to 39 in hospital or severe cases. Moreover, Leukopenia was not observed in patients with thrombocytopenia. In addition, C-reactive protein (CRP), leukocytes, D-dimer, FDP, FIB, neutrophils, AST, serum creatinine, t-troponin, troponin I, and blood bilirubin levels showed increasing trends in most studies conducted on COVID-19 patients. Notably, the elevated LDH level was more common among children than adults. According to the results of the present study, and by considering the clinical characteristics of COVID-19 patients on the one hand, and considering the changes in laboratory samples such as lymphocytes and other blood markers due to the damaged myocardial, hepatic, and renal tissues on the other hand, it is recommended to confirm the diagnosis of this infection by evaluating the patients' blood samples using other diagnostic methods like lung scan.

Narrowing down the number of potential plant-based probiotic candidates by successive in vitro, technological and in vivo assays

The interest on plant-based fermented food is in raise in Western countries. The aim of this study was to select interleukin (IL)-10 inducing strains for the development of potential probiotic plant-based fermented foods. Departing from a collection of 52 lactic acid bacteria (LAB) strains derived from plant material, in vitro co-culture with murine macrophages allowed us to narrow down the number of candidates to 21 strains able to induce IL-10 secretion. 14 of these strains were able to promote the production of tumour necrosis factor-α too. The capacity to induce IL-6 was used to further reduce the number of strains to 4, from which Lactiplantibacillus plantarum subsp. plantarum LpAv was selected to ferment oat and carrots. L. plantarum LpAv was able to ferment oat and carrots until reaching counts of ca. 10⁸ and 10⁹ cfu/ml. Fermented oat and carrots were orally administered to mice for 10 consecutive days and challenged with a single infective dose of Salmonella enterica serovar. Typhimurium. Counts of L. plantarum LpAv in fermented carrots were 9.23±0.05 cfu/ml and 9.27±0.01 cfu/ml, at day 1 and 10 of the feeding period. Fermented carrots were able to confer enhanced protection (80% of survival) against infection, when compared to control mice (less than 25% of survival). However, L. plantarum LpAv administered as pure culture was not able to confer protection against Salmonella infection. L. plantarum LpAv was selected among 52 plant-derived LAB and it was able to ferment oat and carrots, being only fermented carrots able to confer enhanced protection against Salmonella infection. A succession of in vitro to in vivo tests is proposed as a tool to narrow down the number of candidates when searching for potential novel probiotics from a collection of autochthonous strains.

High serum level of interleukin-6 is linked with dyslipidemia in oral lichen planus

Oral lichen planus (OLP) is a complex chronic inflammatory disorder in which autocytotoxic CD8⁺ T cells, locally present in the affected tissue, induce basal keratinocyte apoptosis, through the release of several cytokines, such as interleukin-6 (IL-6). IL-6 is a proinflammatory cytokine that is related to alterations in lipid metabolism in psoriasis patients. Impaired lipid metabolism together with high serum levels of triglycerides have been found in association with OLP. However, the correlation between serum levels of IL-6 and dyslipidemia has not yet been studied in this disorder. The present study aimed to demonstrate the association between OLP, systemic inflammation through increased release of inflammation mediators such as IL-6 and alteration of lipid metabolism, in order to support the concept of OLP as a marker of systemic inflammation and a potential risk factor of cardiovascular morbidities. For this purpose, we designed a case-control study using a cohort of 18 patients with different clinical forms of OLP compared with 18 control group patients with other oral conditions, to identify a potential correlation between serum levels of IL-6 and serum lipid levels. High plasma serum levels of IL-6 were found to be correlated with cholesterol, high density lipoprotein cholesterol and triglyceride serum levels in the patients with OLP. There was a significant association between erosive and atrophic clinical forms of OLP and the pathological serum values of IL-6 and triglycerides, respectively, making these two parameters good predictive factors of the clinical form of OLP. Further studies of other biomarkers of systemic inflammation using larger cohorts of OLP patients are necessary in order to consider LP as a marker of systemic inflammation and to support the screening of these patients for lipid metabolism changes and treatment with specific antagonists in order to prevent cardiovascular events.

Interplay between interleukin-6 signaling and the vascular endothelium in cytokine storms

Interleukin-6 (IL-6) plays a crucial role in host defense against infection and tissue injuries and is a bioindicator of multiple distinct types of cytokine storms. In this review, we present the current understanding of the diverse roles of IL-6, its receptors, and its signaling during acute severe systemic inflammation. IL-6 directly affects vascular endothelial cells, which produce several types of cytokines and chemokines and activate the coagulation cascade. Endothelial cell dysregulation, characterized by abnormal coagulation and vascular leakage, is a common complication in cytokine storms. Emerging evidence indicates that a humanized anti-IL-6 receptor antibody, tocilizumab, can effectively block IL-6 signaling and has beneficial effects in rheumatoid arthritis, juvenile systemic idiopathic arthritis, and Castleman's disease. Recent work has also demonstrated the beneficial effect of tocilizumab in chimeric antigen receptor T-cell therapy-induced cytokine storms as well as coronavirus disease 2019 (COVID-19). Here, we highlight the distinct contributions of IL-6 signaling to the pathogenesis of several types of cytokine storms and discuss potential therapeutic strategies for the management of cytokine storms, including those associated with sepsis and COVID-19.

Can Resveratrol-Inhaled Formulations Be Considered Potential Adjunct Treatments for COVID-19?

The pandemic caused by severe acute respiratory syndrome coronavirus type 2 (SARS-CoV-2) has led to an extraordinary threat to the global healthcare system. This infection disease, named COVID-19, is characterized by a wide clinical spectrum, ranging from asymptomatic or mild upper respiratory tract illness to severe viral pneumonia with fulminant cytokine storm, which leads to respiratory failure. To improve patient outcomes, both the inhibition of viral replication and of the unwarranted excessive inflammatory response are crucial. Since no specific antiviral drug has been proven effective for the treatment of patients and the only upcoming promising agents are monoclonal antibodies, inexpensive, safe, and widely available treatments are urgently needed. A potential anti-inflammatory molecule to be evaluated, which possesses antiviral activities in several experimental models, is the polyphenol resveratrol. This compound has been shown to inhibit SARS-CoV-2 replication in human primary bronchial epithelial cell cultures and to downregulate several pathogenetic mechanisms involved in COVID-19 severity. The use of resveratrol in clinical practice is limited by the low bioavailability following oral administration, due to the pharmacokinetic and metabolic characteristics of the molecule. Therefore, topical administration through inhaled formulations could allow us to achieve sufficiently high concentrations of the compound in the airways, the entry route of SARS-CoV-2.

Contribution of STAT3 to the pathogenesis of COVID-19

Hyper-inflammatory responses, lymphopenia, unbalanced immune responses, cytokine storm, large viral replication and massive cell death play fundamental roles in the pathogenesis of COVID-19. Extreme production of many kinds of pro-inflammatory cytokines and chemokines occur in severe COVID-19 that called cytokine storm. Signal transducer and activator of transcription-3 (STAT-3) present in the cytoplasm in an inactive form and can be stimulated by a vast range of cytokines, chemokines and growth factors. Thus, STAT-3 can participate in the induction of inflammatory responses during coronavirus infections. STAT-3 can also suppress anti-virus interferon response and induce unbalanced anti-virus adaptive immune response, through influencing Th17-, Th1-, Treg-, and B cell-mediated functions. Furthermore, STAT-3 can contribute to the M2 macrophage polarization, lung fibrosis and thrombosis. Moreover, STAT-3 may be directly targeted by some virus-derived protein and operate as a pro-viral or anti-viral element in a virus-specific process. Here, the possible contribution of STAT-3 to the pathogenesis of COVID-19 was explained, while providing potential approaches to target this transcription factor in an attempt for COVID-19 treatment.

IL-6 signaling mediates the germinal center response, IgM production and nociceptive sensitization in male mice after tibia fracture

BACKGROUND

Up-regulated interleukin 6 (IL-6) signaling, immune system activation, and pronociceptive autoantibodies are characteristic of complex regional pain syndrome (CRPS). IL-6 is known to promote B cell differentiation, thus we hypothesized that IL-6 signaling plays a crucial role in the development of adaptive immune responses and nociceptive sensitization in a murine tibia fracture model of CRPS.

METHODS

Mice deficient in IL-6 expression (IL-6^-/-) or B cell deficient (muMT) underwent tibia fracture and 3 weeks of cast immobilization or sham injury. The deposition of IgM in fractured limbs was followed using Western blotting, and passive serum transfer to muMT fracture mice was used to detect nociception-supporting autoantibodies. Lymph nodes were assessed for hypertrophy, IL-6 expression was measured using qPCR and ELISA, and germinal center formation was evaluated using FACS and immunohistochemistry. The therapeutic effects of exogenous neutralizing anti-IL-6 antibodies were also evaluated in the CRPS fracture model.

RESULTS

Functional IL-6 signaling was required for the post fracture development of nociceptive sensitization, vascular changes, and IgM immune complex deposition in the skin of injured limbs. Passive transfer of sera from wild-type, but not IL-6^-/- fracture mice into muMT fracture mice caused enhanced allodynia and postural unweighting. IL-6^-/- fracture mice displayed reduced popliteal lymphadenopathy after fracture. Germinal center responses were detected in the popliteal lymph nodes of wild-type, but not in IL-6^-/- fracture mice. We observed that IL-6 expression was dramatically enhanced in popliteal lymph node tissue after fracture. Conversely, administration of anti-IL-6 antibodies reduced nociceptive and vascular changes after fracture and inhibited lymphadenopathy.

CONCLUSIONS

Collectively, these data support the hypothesis that IL-6 signaling in the fracture limb of mice is required for germinal center formation, IgM autoantibody production and nociceptive sensitization. Anti-IL-6 therapies might, therefore, reduce pain after limb fracture or in the setting of CRPS.

Neuroimmune reactivity marker expression in rodent models of chemotherapy-induced cognitive impairment: A systematic scoping review

BACKGROUND

Chemotherapy-induced cognitive impairment (CICI) is a debilitating side effect arising from chemotherapy treatments. The condition is characterised by a range of cognitive deficits including impairment to memory, attention, and concentration. Whilst the underlying mechanisms that contribute to CICI remain unclear, neuroinflammation has been suggested as one key contributor.

METHOD

A comprehensive systematic search of EMBASE and Medline via PubMed was conducted to identify studies on neuroimmune reactivity marker expression changes and resulting cognitive changes in preclinical rodent models of CICI.

RESULTS

A total of twenty studies met the eligibility criteria and were included in the scoping review. There was significant heterogeneity in the methodology employed in the included studies. Our findings demonstrate that widespread changes in cytokines, chemokines, microglia reactivity, and astrocyte reactivity are observed in CICI in the brain regions expected to be affected, given the nature of the cognitive impairment observed in CICI.

CONCLUSIONS

Although there was considerable heterogeneity in study design that made comparisons between studies difficult, our findings suggest that neuroinflammation commonly occurs in CICI preclinical rodent models and shows an association with cognitive impairment.

Effect of ligustrazine nanoparticles on Th1/Th2 balance by TLR4/MyD88/NF-κB pathway in rats with postoperative peritoneal adhesion

Background

Postoperative peritoneal adhesion (PPA) is regarded as fibrous bands connecting both injured abdominal wall and organs or adjacent tissues. It is associated with T helper (Th)1 and Th2 differentiation. However, the critical role of the immunopathogenesis of adhesion formation was precisely unknown. The aim of this study was to investigate the effect of a new agent polylactic acid (PLA) nanoparticles loaded with ligustrazine, that is, ligustrazine nanoparticles (LN) on PPA and identify the potential mechanism.

Methods

Twenty-four Sprague–Dawley rats were randomly divided into the sham, model, LN, and sodium hyaluronate (SH) groups. The structure of LN, including entrapment efficiency (EE) and loading capacity (LC), and in vitro drug release were calculated. Adhesions were scored and the Masson's trichrome staining was used to determine the collagen deposition. The expressions of TLR4, MyD88, and NF-κB were measured by qRT-PCR, immunohistochemistry, and western blot assay. Moreover, Th1-related cytokines (IFN-γ, IL-12), Th2-related cytokines (IL-4, IL-6) in the cecum tissue and serum were conducted by ELISA.

Results

LN had good EE, LC, and control-release delivery characters with fairly uniform diameter and spherical morphology. It could effectively prevent adhesion formation after surgery. Besides, it could reduce collagen fibers accumulation, downregulate the expression levels of TLR4, MyD88, and NF-κB, and maintain Th1/Th2 balance.

Conclusions

Ligustrazine nanoparticles had effective effects on Th1/Th2 balance by regulating TLR4/MyD88/NF-κB pathway in PPA rats. It may be served as a promising therapy on postoperative adhesion formation.

Lactobacillus paracasei DTA81, a cholesterol-lowering strain having immunomodulatory activity, reveals gut microbiota regulation capability in BALB/c mice receiving high-fat diet

Aims

In‐vitro/In‐vivo evaluation of cholesterol‐lowering probiotic strain Lactobacillus paracasei DTA81 and the possible connection with the gut microbiota modulation.

Methods and Results

In the present study, strain DTA81 has been evaluated for the possible influence on blood lipid and glucose concentrations, modulation of the immune system, gastrointestinal survivability and modulation of gut microbiota in BALB/c mice receiving a high‐fat diet. After 6 weeks of treatment, a significant reduction of total cholesterol and fasting blood sugar (FBS) among animals treated with L. paracasei DTA81 has been recorded. Comparison of colon tissue levels of different cytokines revealed a significant reduction of the inflammatory cytokine interleukin‐6. The comparison of gut microbiota using the 16S rRNA approach indicated that the treatment with L. paracasei DTA81 significantly increased the taxa Bacteroidetes and Coprococcus. Moreover, the genome of DTA81 was sequenced for the in‐silico assessment, and the analysis indicated the presence of cholesterol assimilation‐related genes as well as the absence of negative traits such as transmissible antibiotic resistance genes, plasmids and prophage regions.

Conclusion

The outcome of this study revealed the in‐vitro and in‐vivo properties of L. paracasei DTA81 and the possible mechanism between consumption of this strain, the abundance of Bacteriodetes/Coprococcus taxa, immunomodulatory activity and the subsequent reduction of cholesterol/FBS in BALB/c mice.

Significance and Impact of the Study

Lactobacillus paracasei DTA81 as a non‐pharmacological potential probiotic supplement can influence metabolic homeostasis in individuals, particularly those adopting high‐fat diets, and it can contribute to reduce coronary heart disease.

Serum ferritin levels in inflammation: a retrospective comparative analysis between COVID-19 and emergency surgical non-COVID-19 patients

BACKGROUND

SARS-CoV-2 infection has spread worldwide, and the pathogenic mechanism is still under investigation. The presence of a huge inflammatory response, defined as "cytokine storm," is being studied in order to understand what might be the prognostic factors implicated in the progression of the infection, with ferritin being one of such markers. The role of ferritin as a marker of inflammation is already known, and whether it changes differently between COVID and non-COVID patients still remains unclear. The aim of this retrospective analysis is to understand whether the inflammatory process in these two types is different.

METHODS

In this retrospective analysis, we compared 17 patients affected by SARS-CoV-2, who had been admitted between February and April 2020 (group A) along with 30 patients admitted for acute surgical disease with SARS-CoV-2 negative swab (group B). A further subgroup of Covid negative patients with leukocytosis was compared to group A.

RESULTS

In group A, the median (interquartile range) serum ferritin was 674 (1284) ng/mL, and it was double the cutoff (300 ng/mL) in 9 out of 17 (52%). The median (IQR) value of ferritin level in the total blood samples of group B was 231, and in the subgroup with leucocytosis, 149 (145). Group A showed a significantly higher ferritin median level compared to the entire group B (two-tailed Mann-Whitney test, p < 0.0001) as well as to the subgroup with leucocytosis (p < 0.0014).

CONCLUSIONS

The role of iron metabolism appears to be directly involved in COVID infection. On the other hand, in the acute inflammation of patients admitted for surgery, and probably in other common phlogistic processes, iron modifications appear to be self-limited. However, our finding suggests the use of ferritin as a marker for COVID infection.

Neurobiology of anesthetic-surgical stress and induced behavioral changes in dogs and cats: A review

The anesthetic-surgical stress response consists of metabolic, neuroendocrine, hemodynamic, immunological, and behavioral adaptations through chemical mediators such as the adrenocorticotropic hormone, growth hormone, antidiuretic hormone, cortisol, aldosterone, angiotensin II, thyroid-stimulating hormone, thyroxine, triiodothyronine, follicle-stimulating hormone, luteinizing hormone, catecholamines, insulin, interleukin (IL)-1, IL-6, tumor necrosis factor-alpha, and prostaglandin E-2. Behavioral changes include adopting the so-called prayer posture, altered facial expressions, hyporexia or anorexia, drowsiness, sleep disorders, restriction of movement, licking or biting the injured area, and vocalizations. Overall, these changes are essential mechanisms to counteract harmful stimuli. However, if uncontrolled surgical stress persists, recovery time may be prolonged, along with increased susceptibility to infections in the post-operative period. This review discusses the neurobiology and most relevant organic responses to pain and anesthetic-surgical stress in dogs and cats. It highlights the role of stress biomarkers and their influence on autonomous and demeanor aspects and emphasizes the importance of understanding and correlating all factors to provide a more accurate assessment of pain and animal welfare in dogs and cats throughout the surgical process.

Effect of interleukin-6, -17, -21, -22, and -23 and STAT3 on signal transduction pathways and their inhibition in autoimmune arthritis

Rheumatic diseases are complex autoimmune diseases which include among others rheumatoid arthritis (RA), juvenile idiopathic arthritis (JIA), and psoriatic arthritis (PsA). These diseases are characterized by prolonged and increased secretion of inflammatory factors, eventually leading to inflammation. This is often accompanied by persistent pain and stiffness in the joint and finally bone destruction and osteoporosis. These diseases can occur at any age, regardless of gender or origin. Autoimmune arthritis is admittedly associated with long-term treatment, and discontinuation of medication is associated with unavoidable relapse. Therefore, it is important to detect the disease at an early stage and apply appropriate preventative measures. During inflammation, pro-inflammatory factors such as interleukins (IL)-6, -17, -21, -22, and -23 are secreted, while anti-inflammatory factors including IL-10 are downregulated. Research conducted over the past several years has focused on inhibiting inflammatory pathways and activating anti-inflammatory factors to improve the quality of life of people with rheumatic diseases. The aim of this paper is to review current knowledge on stimulatory and inhibitory pathways involving the signal transducer and activator of transcription 3 (STAT3). STAT3 has been shown to be one of the crucial factors involved in inflammation and is directly linked with other pro-inflammatory factors and thus is a target of current research on rheumatoid diseases.

[Effect of thoraco-laparoscopic esophagectomy on postoperative immune function of patients with esophageal carcinoma]

OBJECTIVE

To investigate the effect of thoraco-laparoscopic esophagectomy on postoperative immune function of patients with esophageal carcinoma.

METHODS

Eighty-one patients undergoing radical esophagectomy in our hospital between January, 2017 and December, 2019 were enrolled in this study.According to the surgical approach, the patients were divided into endoscopic group (41 cases) and open surgery (3 incisions) group (40 cases).The immunological indicators (CD3+, CD4+, CD8+, and CD4+/CD8+ratio) of the patients were analyzed using double antibody sandwich enzyme-linked immunosorbent assay at 1 day before the surgery and on days 1, 4 and 7 after the surgery.The plasma levels of interleukin 6(IL-6) and cortisol, β-endorphin (β-EP) level, white blood cell count (WBC) and C-reactive protein (CRP) levels of the patients were measured before and on days 1 and 7 after the operation.

RESULTS

No death occurred in either of the group after the operation.On days 4 and 7 after the operation, CD3+, CD4+, CD8+, and CD4+/CD8+ratio were significantly higher in patients undergoing thoracolaparoscopic surgery than in those receiving open surgery (P < 0.05).In both groups, the levels of cortisol, β-EP, WBC, CRP and IL-6 measured on days 1 and 7 postoperatively were significantly different from those before the operation (P < 0.05).At all the indicated postoperative time points, all the measured indicators, with the exception of IL-6 levels on postoperative day 7, which were comparable between the two groups, were significantly higher in the open surgery group than in the endoscopic group (P < 0.05).

CONCLUSIONS

Thoraco-laparoscopic resection of esophageal cancer can reduce postoperative secretion of proinflammatory factors, alleviate inflammatory responses, and promote the recovery of immune functions to accelerate postoperative recovery of the patients.

Differential Binding of Sarilumab and Tocilizumab to IL-6Rα and Effects of Receptor Occupancy on Clinical Parameters

We evaluated interleukin-6 (IL-6) receptor-α subunit (IL-6Rα) signaling inhibition with sarilumab and tocilizumab, the association between IL-6Rα receptor occupancy (RO) and C-reactive protein (CRP), and the potential clinical relevance of any differences. For this, we measured IL-6Rα binding and signaling inhibition with sarilumab and tocilizumab in vitro, simulated soluble IL-6Rα RO over time for approved sarilumab subcutaneous (SC) and tocilizumab intravenous (IV) and SC doses, and assessed associations between calculated RO and CRP reduction, 28-joint Disease Activity Score based on CRP, and 20%/50%/70% improvement in American College of Rheumatology responses from clinical data. Sarilumab binds IL-6Rα in vitro with 15- to 22-fold higher affinity than tocilizumab, and inhibits IL-6-mediated classical and trans signaling via membrane-bound and soluble IL-6Rα. Sarilumab 200 and 150 mg SC every 2 weeks achieved >90% RO after first and second doses, respectively, maintained throughout the treatment period. At steady-state trough, RO was greater with sarilumab 200 mg (98%) and 150 mg SC every 2 weeks (94%), and tocilizumab 162 mg SC weekly (>99%) and 8 mg/kg IV every 4 weeks (99%), vs tocilizumab 162 mg SC every 2 weeks (84%) and 4 mg/kg IV every 4 weeks (60%). Higher RO was associated with greater CRP reduction and 28-joint Disease Activity Score based on CRP reduction, and more sarilumab patients achieving 20%/50%/70% improvement in American College of Rheumatology responses. The greatest reduction in CRP levels was observed with sarilumab (both doses) and tocilizumab 8 mg/kg IV every 4 weeks (reductions proportionally smaller with 4 mg/kg IV every 4 weeks). Higher IL-6Rα binding affinity translated into higher RO with sarilumab vs tocilizumab 4 mg/kg every 4 weeks or 162 mg every 2 weeks; tocilizumab required the higher dose or increased frequency to maintain the same degree of RO and CRP reduction. Higher RO was associated with clinical parameter improvements.

Cytokine release syndrome: inhibition of pro-inflammatory cytokines as a solution for reducing COVID-19 mortality

Coronavirus disease (COVID-19) reached pandemic proportions at the beginning of 2020 and continues to be a worldwide concern. End organ damage and acute respiratory distress syndrome are the leading causes of death in severely or critically ill patients. The elevated cytokine levels in severe patients in comparison with mildly affected patients suggest that cytokine release syndrome (CRS) occurs in the severe form of the disease. In this paper, the significant role of pro-inflammatory cytokines, including IL-1, IL-6, and TNF-alpha, and their mechanism of action in the CRS cascade is explained. Potential therapeutic approaches involving anti-IL-6 and anti-TNF-alpha antibodies to fight COVID-19 and reduce mortality rate in severe cases are also discussed.

Historical overview of the interleukin-6 family cytokine

Interleukin-6 (IL-6) has been identified as a 26-kD secreted protein that stimulates B cells to produce antibodies. Later, IL-6 was revealed to have various functions that overlap with other IL-6 family cytokines and use the common IL-6 signal transducer gp130. IL-6 stimulates cells through multiple pathways, using both membrane and soluble IL-6 receptors. As indicated by the expanding market for IL-6 inhibitors, it has become a primary therapeutic target among IL-6 family cytokines. Here, we revisit the discovery of IL-6; discuss insights regarding the roles of this family of cytokines; and highlight recent advances in our understanding of regulation of IL-6 expression.

Progress in Understanding the IL-6/STAT3 Pathway in Colorectal Cancer

As a pleiotropic cytokine, interleukin-6 (IL-6) not only regulates the cellular immune response, but it also promotes tumor development by activating multiple carcinogenic pathways. IL-6 expression is significantly elevated in colorectal cancer (CRC) and is closely related to CRC development and patient prognosis. In CRC, IL-6 activates signal transducers and activators of transduction-3 (STAT3) to promote tumor initiation and tumor growth. IL-6/STAT3 signalling has a profound effect on tumor-infiltrating immune cells in the tumor immune microenvironment in CRC. Additionally, IL-6/STAT3 pathway activates downstream target genes to protect tumor cells from apoptosis; drive tumor cell proliferation, cell cycle progression, invasion and metastasis; promote tumor angiogenesis; and stimulate drug resistance. Therefore, a thorough understanding of the many effects of the IL-6/STAT3 pathway in CRC is needed, which the present review examines.

Immunity and inflammatory biomarkers in COVID-19: A systematic review

Coronavirus disease 2019 (COVID-19) is a clinical syndrome caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) virus. Patients can be asymptomatic or present respiratory and gastrointestinal symptoms, and even multiple-organ failure which can lead to death. The balance between an effective antiviral response and dysregulated immune response is the key factor determining the severity of COVID-19 progression. A systematic review was performed using the NCBI-PubMed database to find the articles related to COVID-19 immunity and inflammatory response published from 1 December 2019 to 15 April 2020. Haematological, immunological and biochemical parameters were extracted and correlated with disease severity, age and presence of comorbidities. Twelve articles were analysed comprising a total of 1042 hospitalized patients infected with SARS-CoV-2 and 95 different parameters. Total lymphocyte count and levels of CD3+ and CD4+ T cells were decreased in severe and critical cases. Neutrophilia was found in patients who progressed to acute respiratory distress syndrome (ARDS). Interleukin-six (IL-6) was high in mild and severe patients regardless of comorbidities. Erythrocyte sedimentation rate (ESR) and count and C-reactive protein (CRP) levels were increased regardless of disease severity or presence of comorbidities. High levels of D-dimer and lactate dehydrogenase were present in diabetic patients and patients who developed ARDS. Procalcitonin levels were elevated to varying degrees in severe and critical patients. We conclude that the total lymphocyte count, CD3+ and CD4+ T cells are low, especially in severe and critical COVID-19 patients; ESR, CRP and IL-6 were elevated, independent of the severity of disease. Understanding the inflammatory response of COVID-19 patients is essential for the development of better therapeutic and management strategies.

Serenoa repens and Urtica dioica Fixed Combination: In-Vitro Validation of a Therapy for Benign Prostatic Hyperplasia (BPH)

Benign prostatic hyperplasia (BPH) is an age-related chronic disorder, characterized by the hyperproliferation of prostatic epithelial and stromal cells, which drives prostate enlargement. Since BPH aetiology and progression have been associated with the persistence of an inflammatory stimulus, induced both by Nuclear Factor-kappa B (NF-κB) activation and reactive oxygen species (ROS) production, the inhibition of these pathways could result in a good tool for its clinical treatment. This study aimed to evaluate the antioxidant and anti-inflammatory activity of a combined formulation of Serenoa repens and Urtica dioica (SR/UD) in an in vitro human model of BPH. The results confirmed both the antioxidant and the anti-inflammatory effects of SR/UD. In fact, SR/UD simultaneously reduced ROS production, NF-κB translocation inside the nucleus, and, consequently, interleukin 6 (IL-6) and interleukin 8 (IL-8) production. Furthermore, the effect of SR/UD was also tested in a human androgen-independent prostate cell model, PC3. SR/UD did not show any significant antioxidant and anti-inflammatory effect, but was able to reduce NF-κB translocation. Taken together, these results suggested a promising role of SR/UD in BPH and BPH-linked disorder prevention.

Relationship between IL-6 and COVID-19: to be considered during treatment

The detection and control of pro-inflammatory response is crucial in the early stages of viral infection. Coronavirus disease 2019 (COVID-19) is an emerging viral disease of global concern and optimal treatment has yet to be determined. Unknown response of treatment of COVID-19 is important during patient monitoring. IL-6 is one of the key cytokines after activated macrophages. Therefore, control of systemic IL-6 levels in SARS-CoV-2 infected patients may be a parameter for COVID-19 disease. This review is focused on the induction of IL-6 after viral infections as a target molecule for monitoring cellular response.

Tocilizumab-induced Leukoencephalopathy with a Reversible Clinical Course

Tocilizumab (TCZ; Actemra/RoActemra) is an anti-interleukin (IL)-6 receptor antibody for the treatment of rheumatoid arthritis (RA) and other autoimmune diseases and cytokine storms. The present case is a 63-year-old female well-controlled RA patient, who presented with a progressive cognitive impairment after 34 months of TCZ administration. Brain magnetic resonance imaging (MRI) showed leukencephalopathy with a lactic acid peak in magnetic resonance spectroscopy (MRS), a decreased blood flow in single photon emission computed tomography (SPECT), and a decreased accumulation in fluorodeoxyglucose positron emission tomography (FDG-PET). The discontinuation of TCZ improved her cognitive function and brain MRI findings at 3 months after drug cessation. The present case suggests that TCZ may sometimes cause leukoencephalopathy after long-term administration, and thus the early discontinuation of TCZ is recommended to achieve a good prognosis.