IL-6 drives T cell death to participate in lymphopenia in COVID-19

R-ketorolac ameliorates cancer-associated cachexia and prolongs survival of tumour-bearing mice

BACKGROUND

Cancer-associated cachexia (CAC) is a debilitating syndrome associated with poor quality of life and reduced life expectancy of cancer patients. CAC is characterized by unintended body weight reduction due to muscle and adipose tissue loss. A major hallmark of CAC is systemic inflammation. Several non-steroidal anti-inflammatory drugs (NSAIDs) have been suggested for CAC treatment, yet no single medication has proven reliable. R-ketorolac (RK) is the R-enantiomer of a commonly used NSAID. The effect of RK on CAC has not yet been evaluated.

METHODS

Ten- to 11-week-old mice were inoculated with C26 or CHX207 cancer cells or vehicle control (phosphate-buffered saline [PBS]). After cachexia onset, 2 mg/kg RK or PBS was administered daily by oral gavage. Body weight, food intake and tumour size were continuously measured. At study endpoints, blood was drawn, mice were sacrificed and tissues were excised. Immune cell abundance was analysed using a Cytek® Aurora spectral flow cytometer. Cyclooxygenase (COX) activity was determined in lung homogenates using a fluorometric kit. Muscle tissues were analysed for mRNA and protein expression by quantitative real-time PCR and western blotting analysis, respectively. Muscle fibre size was determined on histological slides after haematoxylin/eosin staining.

RESULTS

Ten-day survival rate of C26-bearing animals was 10% while RK treatment resulted in a 100% survival rate (P = 0.0009). Chemotherapy resulted in a 10% survival rate 14 days after treatment initiation, but all mice survived upon co-medication with RK and cyclophosphamide (P = 0.0001). Increased survival was associated with a protection from body weight loss in C26 (-0.61 ± 1.82 vs. -4.48 ± 2.0 g, P = 0.0004) and CHX207 (-0.49 ± 0.33 vs. -2.49 ± 0.93 g, P = 0.0003) tumour-bearing mice treated with RK, compared with untreated mice. RK ameliorated musculus quadriceps (-1.7 ± 7.1% vs. -27.8 ± 8.3%, P = 0.0007) and gonadal white adipose tissue (-18.8 ± 49% vs. -69 ± 15.6%, P = 0.094) loss in tumour-bearing mice, compared with untreated mice. Mechanistically, RK reduced circulating interleukin-6 (IL-6) concentrations from 334 ± 151 to 164 ± 123 pg/mL (P = 0.047) in C26 and from 93 ± 39 to 35 ± 6 pg/mL (P = 0.0053) in CHX207 tumour-bearing mice. Moreover, RK protected mice from cancer-induced T-lymphopenia (+1.8 ± 42% vs. -49.2 ± 12.1% in treated vs. untreated mice, respectively). RK was ineffective in ameliorating CAC in thymus-deficient nude mice, indicating that the beneficial effect of RK depends on T-cells.

CONCLUSIONS

RK improved T-lymphopenia and decreased systemic IL-6 concentrations, resulting in alleviation of cachexia and increased survival of cachexigenic tumour-bearing mice, even under chemotherapy and independent of COX inhibition. Considering its potential, we propose that the use of RK should be investigated in patients suffering from CAC.

Severe COVID-19 and long COVID are associated with high expression of STING, cGAS and IFN-α

The cGAS-STING pathway appears to contribute to dysregulated inflammation during coronavirus disease 2019 (COVID-19); however, inflammatory factors related to long COVID are still being investigated. In the present study, we evaluated the association of cGAS and STING gene expression levels and plasma IFN-α, TNF-α and IL-6 levels with COVID-19 severity in acute infection and long COVID, based on analysis of blood samples from 148 individuals, 87 with acute COVID-19 and 61 in the post-COVID-19 period. Quantification of gene expression was performed by real-time PCR, and cytokine levels were quantified by ELISA and flow cytometry. In acute COVID-19, cGAS, STING, IFN-α, TNF-α, and IL-6 levels were higher in patients with severe disease than in those with nonsevere manifestations (p < 0.05). Long COVID was associated with elevated cGAS, STING and IFN-α levels (p < 0.05). Activation of the cGAS-STING pathway may contribute to an intense systemic inflammatory state in severe COVID-19 and, after infection resolution, induce an autoinflammatory disease in some tissues, resulting in long COVID.

Unveiling COVID-19 Secrets: Harnessing Cytokines as Powerful Biomarkers for Diagnosis and Predicting Severity

Introduction

In coronavirus disease (COVID-19), inflammation takes center stage, with a cascade of cytokines released, contributing to both inflammation and lung damage. The objective of this study is to identify biomarkers for diagnosing and predicting the severity of COVID-19.

Materials and Methods

Cytokine levels were determined in the serum from venous blood samples collected from 100 patients with COVID-19 and 50 healthy controls. COVID-19 patients classified based on the Modified Early Warning (MEWS) score. Cytokine concentrations were determined with a multiplex ELISA kit (Bio-Plex Pro™ Human Cytokine Screening Panel).

Results

The concentrations of all analyzed cytokines were elevated in the serum of COVID-19 patients relative to the control group, but no significant differences were observed in interleukin-9 (IL-9) and IL-12 p70 levels. In addition, the concentrations of IL-1α, IL-1β, IL-1ra, IL-2Rα, IL-6, IL-12 p40, IL-18, and tumor necrosis factor alpha (TNFα) were significantly higher in symptomatic patients with accompanying pneumonia without respiratory failure (stage 2) than in asymptomatic/mildly symptomatic patients (stage 1).

Conclusion

The study revealed that IL-1ra, IL-2Rα, IL-6, IL-8, IL-12 p40, IL-16, and IL-18 levels serve as potential diagnostic biomarkers in COVID-19 patients. Furthermore, elevated IL-1α levels proved to be valuable in assessing the severity of COVID-19.

Differentially Expressed Inflammatory Cell Death-Related Genes and the Serum Levels of IL-6 are Determinants for Severity of Coronaviruses Diseases-2019 (COVID-19)

Background

Inflammatory cell death, PANoptosis, has been suggested to orchestrate the lymphocyte decrement among coronavirus disease-2019 (COVID-19) patients. The main aim of this study was to examine the differences in the expression of key genes related to inflammatory cell death and their correlation with lymphopenia in the mild and severe types of COVID-19 patients.

Materials and Methods

Eighty-eight patients (36 to 60 years old) with mild (n = 44) and severe (n = 44) types of COVID-19 were enrolled. The expression of key genes related to apoptosis (FAS-associated death domain protein, FADD), pyroptosis (ASC (apoptosis-associated speck-like protein containing caspase activation and recruitment domains (CARD)), the adapter protein ASC binds directly to caspase-1 and is critical for caspase-1 activation in response to a broad range of stimuli), and necroptosis (mixed lineage kinase domain-like, MLKL) genes were examined by reverse transcription-quantitative polymerase chain reaction (RT-qPCR) assay, and compared between the groups. The serum levels of interleukin (IL)-6 were measured by enzyme-linked immunosorbent assay (ELISA) assay.

Results

A major increase in the expression of FADD, ASC, and MLKL-related genes in the severe type of patients was compared to the mild type of patients. The serum levels of IL-6 similarly indicated a significant increase in the severe type of the patients. A significant negative correlation was detected between the three genes' expression and the levels of IL-6 with the lymphocyte counts in both types of COVID-19 patients.

Conclusion

Overall, the main regulated cell-death pathways are likely to be involved in lymphopenia in COVID-19 patients, and the expression levels of these genes could potentially predict the patients' outcome.

The immune paradox of SARS-CoV-2: Lymphocytopenia and autoimmunity evoking features in COVID-19 and possible treatment modalities

SARS-CoV-2 causes multiorgan damage to vital organs and tissue that are known to be due to a combination of tissue tropisms and cytokine-mediated damage that it can incite in COVID-19. The effects of SARS-Co-2 on the lymphocytes and therefore on the immune response have attracted attention recently in COVID-19 to understand its effects in causing a chronic state of ongoing infection with Long-COVID. The associated lymphopaenia and autoimmune disease state, which is an apparent paradox, needs to be researched to dissect possible mechanisms underlying this state. This paper attempts to unravel the aforesaid immune paradox effects of SARS-CoV-2 on the lymphocytes and discusses appropriate treatment modalities with antiviral drugs and nutraceuticals which could prove virucidal in SARS-CoV-2 seeding monocytes and lymphocytes in patients with COVID-19 and Long-COVID. Importantly it proposes a new in vitro treatment modality of immune regulating cells that can help patients fight the lymphopaenia associated with COVID-19 and Long-COVID.