Targeting cytokine storm as the potential anti-viral therapy: Implications in regulating SARS-CoV-2 pathogenicity

Age-related immune response disparities between adults and children with severe COVID-19: a case-control study in China

Background

Elucidation of immune response differences is critical for uncovering underlying mechanisms and developing potential intervention measures among adults and children with COVID-19.

Methods

In this retrospective study, we analyzed serum biochemical markers and cytokine profiles among adults and children with COVID-19 in the First People's Hospital of Chenzhou in Hunan, China from 1 December 2022 to 13 February 2023. A case-control study was conducted using propensity score matching (PSM) to mitigate possible confounding factors.

Results

The significant differences observed included lymphocyte exhaustion, an increased neutrophil-to-lymphocyte (NEU/LYM) ratio, high levels of C-reactive protein (CRP), and a cytokine storm, characterized by high levels of Th1 proinflammatory cytokines, including interleukin 1β (IL-1β), IL-6, IL-8, interferon type I (IFN-γ), and tumor necrosis factor (TNF-α) in the lung among severe adult COVID-19 patients. Additionally, systemic immune responses were observed in children with COVID-19.

Conclusion

Significant differences in immune responses between adults and children with COVID-19 highlight the different mechanisms and potential intervention measures of COVID-19.

Diosmetin-7-O-β-D-glucopyranoside from Pogostemonis Herba alleviated SARS-CoV-2-induced pneumonia by reshaping macrophage polarization and limiting viral replication

ETHNOPHARMACOLOGICAL RELEVANCE

Viral pneumonia is the leading cause of death after SARS-CoV-2 infection. Despite effective at early stage, long-term treatment with glucocorticoids can lead to a variety of adverse effects and limited benefits. The Chinese traditional herb Pogostemonis Herba is the aerial part of Pogostemon Cablin (Blanco) Benth., which has potent antiviral, antibacterial, anti-inflammatory, and anticancer effects. It was used widely for treating various throat and respiratory diseases, including COVID-19, viral infection, cough, allergic asthma, acute lung injury and lung cancer.

AIM OF THE STUDY

To investigate the antiviral and anti-inflammatory effects of chemical compounds from Pogostemonis Herba in SARS-CoV-2-infected hACE2-overexpressing mouse macrophage RAW264.7 cells and hACE2 transgenic mice.

MATERIALS AND METHODS

The hACE2-overexpressing RAW264.7 cells were exposed with SARS-CoV-2. The cell viability was detected by CCK8 assay and cell apoptotic rate was by flow cytometric assay. The expressions of macrophage M1 phenotype markers (TNF-α and IL-6) and M2 markers (IL-10 and Arg-1) as well as the viral loads were detected by qPCR. The mice were inoculated intranasally with SARS-CoV-2 omicron variant to induce viral pneumonia. The levels of macrophages, neutrophils, and T cells in the lung tissues of infected mice were analyzed by full spectrum flow cytometry. The expressions of key proteins were detected by Western blot assay.

RESULTS

Diosmetin-7-O-β-D-glucopyranoside (DG) presented the strongest anti-SARS-CoV-2 activity. Intervention with DG at the concentrations of 0.625-2.5 μM not only reduced the viral replication, cell apoptosis, and the productions of inflammatory cytokines (IL-6 and TNF-α) in SARS-CoV-2-infected RAW264.7 cells, but also reversed macrophage polarity from M1 to M2 phenotype. Furthermore, treatment with DG (25-100 mg/kg) alleviated acute lung injury, and reduced macrophage infiltration in SARS-COV-2-infected mice. Mechanistically, DG inhibited SARS-COV-2 gene expression and HK3 translation via targeting YTHDF1, resulting in the inactivation of glycolysis-mediated NF-κB pathway.

CONCLUSIONS

DG exerted the potent antiviral and anti-inflammatory activities. It reduced pneumonia in SARS-COV-2-infected mice via inhibiting the viral replication and accelerating M2 macrophage polarization via targeting YTHDF1, indicating its potential for COVID-19 treatment.

Surveying haemoperfusion impact on COVID-19 from machine learning using Shapley values

BACKGROUND

Haemoperfusion (HP) is an innovative extracorporeal therapy that utilizes special cartridges to filter the blood, effectively removing pro-inflammatory cytokines, toxins, and pathogens in COVID-19 patients. This retrospective cohort study aimed to assess the clinical benefits of HP for severe COVID-19 cases using Shapley values for machine learning models.

METHODS

The research involved 578 inpatients (≥ 20 years old) admitted to Baqiyatallah hospital (Tehran, Iran). The control group (359 patients) received standard treatment, including high doses of corticosteroids (a single 500 mg methylprednisolone pulse, followed by 250 mg for 2 days), categorized as regimen (I). On the other hand, the HP group (219 patients) received regimen II, consisting of the same corticosteroid treatment (regimen I) along with haemoperfusion using Cytosorb H300. The frequency of haemoperfusion sessions varied based on the type of lung involvement determined by chest CT scans. In addition, the value function v defines the Shapley value of the i th feature for the query point x , where the input matrix features represent individual characteristics, drugs, and history and clinical conditions of the patient.

RESULTS

Our data showed a favorable clinical response in the HP group compared to the control group. Notably, one-to-three sessions of HP using the CytoSorb® 300 cartridge led to reduced ventilation requirements and mortality rates in severe COVID-19 patients. Shapley values were calculated to evaluate the contribution of haemoperfusion among other factors, such as side effects, medications, and individual characteristics, to COVID-19 patient outcomes. In addition, there is a significant difference between the two groups among the treatments and medications used remdesivir, adalimumab, tocilizumab, favipiravir, Interferon beta-1a, enoxaparin prophylaxis, enoxaparin full dose, heparin prophylaxis, and heparin full dose (P < 0.05). It seems that haemoperfusion has a positive impact on the reduction of inflammation markers and renal functional such as ferritin and creatinine, respectively, as well as D-dimer and WBC levels in the HP group were significantly lower than the control group.

CONCLUSION

The findings indicated that haemoperfusion played a crucial role in predicting patient survival, making it a significant feature in classifying patients' prognoses.

Microplastics dysregulate innate immunity in the SARS-CoV-2 infected lung

Introduction

Global microplastic (MP) pollution is now well recognized, with humans and animals consuming and inhaling MPs on a daily basis, with a growing body of concern surrounding the potential impacts on human health.

Methods

Using a mouse model of mild COVID-19, we describe herein the effects of azide-free 1 μm polystyrene MP beads, co-delivered into lungs with a SARS-CoV-2 omicron BA.5 inoculum. The effect of MPs on the host response to SARS-CoV-2 infection was analysed using histopathology and RNA-Seq at 2 and 6 days post-infection (dpi).

Results

Although infection reduced clearance of MPs from the lung, virus titres and viral RNA levels were not significantly affected by MPs, and overt MP-associated clinical or histopathological changes were not observed. However, RNA-Seq of infected lungs revealed that MP exposure suppressed innate immune responses at 2 dpi and increased pro-inflammatory signatures at 6 dpi. The cytokine profile at 6 dpi showed a significant correlation with the 'cytokine release syndrome' signature observed in some COVID-19 patients.

Discussion

The findings are consistent with the recent finding that MPs can inhibit phagocytosis of apoptotic cells via binding of Tim4. They also add to a growing body of literature suggesting that MPs can dysregulate inflammatory processes in specific disease settings.

Elevated level of circulating calprotectin correlates with severity and high mortality in patients with COVID-19

BACKGROUND

Patients with coronavirus disease-2019 (COVID-19) are characterized by hyperinflammation. Calprotectin (S100A8/S100A9) is a calcium- and zinc-binding protein mainly secreted by neutrophilic granulocytes or macrophages and has been suggested to be correlated with the severity and prognosis of COVID-19.

AIM

To thoroughly evaluate the diagnostic and prognostic utility of calprotectin in patients with COVID-19 by analyzing relevant studies.

METHODS

PubMed, Web of Science, and Cochrane Library were comprehensively searched from inception to August 1, 2023 to retrieve studies about the application of calprotectin in COVID-19. Useful data such as the level of calprotectin in different groups and the diagnostic efficacy of this biomarker for severe COVID-19 were extracted and aggregated by using Stata 16.0 software.

RESULTS

Fifteen studies were brought into this meta-analysis. First, the pooled standardized mean differences (SMDs) were used to estimate the differences in the levels of circulating calprotectin between patients with severe and non-severe COVID-19. The results showed an overall estimate of 1.84 (95% confidence interval [CI]: 1.09-2.60). Diagnostic information was extracted from 11 studies, and the pooled sensitivity and specificity of calprotectin for diagnosing severe COVID-19 were 0.75 (95% CI: 0.64-0.84) and 0.88 (95% CI: 0.79-0.94), respectively. The AUC was 0.89 and the pooled DOR was 18.44 (95% CI: 9.07-37.51). Furthermore, there was a strong correlation between elevated levels of circulating calprotectin and a higher risk of mortality outcomes in COVID-19 patients (odds ratio: 8.60, 95% CI: 2.17-34.12; p < 0.1).

CONCLUSION

This meta-analysis showed that calprotectin was elevated in patients with severe COVID-19, and this atypical inflammatory cytokine might serve as a useful biomarker to distinguish the severity of COVID-19 and predict the prognosis.

The injured monocyte: The link to chronic critical illness and mortality following injury

BACKGROUND

This study aimed to understand the altered innate immune response in severely injured patients leading to chronic critical illness (CCI). Specifically, it focused on characterizing the monocyte populations and their correlation with CCI development and long-term complications.

METHODS

Over a 3-year period, we monitored patients with severe injuries for up to 1-year postinjury. Chronic critical illness was defined as an ICU stay exceeding 14 days with persistent organ failure. Blood samples were collected on Days 1 and 5 for monocyte phenotypic expression analysis using cytometry by time flight. The monocyte subpopulations studied were classical (CL), intermediate (INT), and nonclassical (NC), along with cell surface receptor expression and activation.

RESULTS

Out of 80 enrolled patients, 26 (32.5%) developed CCI. Patients with CCI had more severe injuries (Injury Severity Score, 32.4 + 5.2 vs. 29.6 + 4.1, p = 0.01) and received a higher number of red blood cells (8.9 + 4.1 vs. 4.7 + 3.8 units, p < 0.01) compared with those without CCI. In patients with CCI, the NC monocytes were significantly reduced by over twofold early, and significantly increased later, compared with those without CCI. Moreover, significant changes in intracellular cytokine expression and cell receptors were observed within each monocyte subpopulation in patients with CCI, indicating an increased proinflammatory phenotype but decreased phagocytic capacity and antigen presentation. The development of CCI and the presence of this unique monocyte phenotype were associated with a significantly increased risk of infection, discharge to a long-term care facility, and 1-year mortality of 27%.

CONCLUSION

Development of CCI following severe injury is associated with significant long-term morbidity and unacceptably high mortality. The altered NC phenotype with reduced phagocytic capacity and antigen presentation in patients developing CCI after severe injury is appears partially responsible. Early identification of this unique phenotype may help predict and treat patients at risk for CCI, leading to improved outcomes.

LEVEL OF EVIDENCE

Prognostic and Epidemiological; Level III.