Cytokine storm and targeted therapy in hemophagocytic lymphohistiocytosis

The lncRNA LINC02446 promotes tumor progression and HLH occurrence by regulating the expression of KLRs and IL-10 in EBV-NK-LPDs

INTRODUCTION

Refractory Epstein-Barr virus-associated NK-cell lymphoproliferative diseases (EBV-NK-LPDs) are prone to hemophagocytic lymphohistiocytosis (HLH) with short survival and poor prognosis. Although various therapies have been used to relieve the symptoms, hematopoietic stem cell transplantation is considered the only potentially therapeutic approach. There is an urgent need to explore the pathogenesis of EBV-NK-LPDs and develop an effective better treatment.

METHODS

Here, we investigated long non-coding RNA (lncRNA) profile using high-throughput RNA sequencing data (n = 6, healthy donors; n = 5, infectious mononucleosis; n = 10, chronic active Epstein-Barr virus disease (CAEBV)-NK; n = 7, CAEBV-T) and screened out LINC02446, whose upregulation was further validated by quantitative real-time polymerase chain reaction in EBV-NK-LPDs. We further explored the correlation between LINC02446 and the clinical characteristics of patients with EBV-NK-LPDs. Then, based on sequencing data, we performed in vitro experiments to investigate the function and mechanism of LINC02446 in EBV-NK-LPDs.

RESULTS

LINC02446 was specifically highly expressed in NK cells of EBV-NK-LPDs patients. EBV-NK-LPDs patients with high expression of LINC02446 showed higher EBV-DNA copy number and ferritin levels, as well as a higher incidence of HLH. LINC02446 was closely related to the KLRs family and LINC02446 could regulate the expression of KLRs genes. In addition, LINC02446 positively regulated the expression of IL-10 in EBV-NK-LPDs cell lines, which revealed that LINC02446 may promote HLH by upregulating IL-10 in EBV-NK-LPDs.

CONCLUSIONS

This is the first study that LINC02446 regulates the expression of KLRs family and IL-10 in EBV-NK-LPDs, resulting in lymphoma progression and HLH occurrence, showing its potential as a therapeutic target for EBV-NK-LPDs.

Ruxolitinib-based regimen in children with autoimmune disease or autoinflammatory disease-related haemophagocytic lymphohistiocytosis

For autoimmune disease (AD) and autoinflammatory disease (AID)-related haemophagocytic lymphohistiocytosis (HLH) (AD/AID-HLH), there is still a lack of standardized treatment. Glucocorticoids (GCs) are the main treatment currently; however, 37.9% to 61% of patients fail to achieve effective control of HLH, making it urgent to find novel treatment strategies. We conducted a retrospective, single-centre study examining ruxolitinib (RUX)-based regimen in children with AD/AID-HLH. Patients were first treated with RUX monotherapy, and additional treatments including methylprednisolone and etoposide were added sequentially when the disease could not be controlled. The study included 26 patients with a median follow-up of 23.9 months, of whom 15 had prior treatments. The overall response rate at week 8 with the RUX-based regimen was 96.2%, with 92.3% attaining complete response (CR) and 3.9% attaining partial response. The 2-year overall survival rate was 96.2% (95% CI, 80.4% to 99.9%). During RUX monotherapy, 46.1% of patients achieved CR as the best response, with a median first response time to RUX of 2 days. Additionally, 53.8% of patients required additional GCs and 23.1% required etoposide chemotherapy. All observed adverse events were manageable and acceptable. Overall, our study supports the efficacy and safety of the RUX-based regimen in children with AD/AID-HLH.

A predictive model for Epstein-Barr virus-associated hemophagocytic lymphohistiocytosis

BACKGROUND

Epstein-Barr virus-associated hemophagocytic lymphohistiocytosis (EBV-HLH) is a severe hyperinflammatory disorder induced by overactivation of macrophages and T cells. This study aims to identify the risk factors for the progression from infectious mononucleosis (EBV-IM) to EBV-HLH, by analyzing the laboratory parameters of patients with EBV-IM and EBV-HLH and constructing a clinical prediction model. The outcome of this study carries important clinical value for early diagnosis and treatment of EBV-HLH.

METHODS

A retrospective analysis was conducted on 60 patients diagnosed with EBV-HLH and 221 patients diagnosed with EBV-IM at our hospital between November 2018 and January 2024. Participants were randomly assigned to derivation and internal validation cohorts in a 7:3 ratio. LASSO regression and logistic regression analyses were employed to identify risk factors and construct the nomogram.

RESULTS

Ferritin (OR, 213.139; 95% CI, 8.604-5279.703; P=0.001), CD3-CD16+CD56+% (OR, 0.011; 95% CI, 0-0.467; P=0.011), anti-EBV-NA-IgG (OR, 57.370; 95%CI, 2.976-1106.049; P=0.007), IL-6 (OR, 71.505; 95%CI, 2.118-2414.288; P=0.017), IL-10 (OR, 213.139; 95% CI, 8.604-5279.703; P=0.001) were identified as independent predictors of EBV-HLH. The prediction model demonstrated excellent discriminatory capability evidenced by an AUC of 0.997 (95% CI,0.993-1.000). When visualized using a nomogram, the ROC curves for the derivation and validation cohorts exhibited AUCs of 0.997 and 0.993, respectively. These results suggested that the model was highly stable and accurate. Furthermore, calibration curves and clinical decision curves indicated that the model possessed good calibration and offered significant clinical benefits.

CONCLUSIONS

The nomogram, which was based on these five predictors, exhibited robust predictive value and stability, thereby can be used to aid clinicians in the early detection of EBV-HLH.

Hemophagocytic lymphohistiocytosis: current treatment advances, emerging targeted therapy and underlying mechanisms

Hemophagocytic lymphohistiocytosis (HLH) is a rapidly progressing, life-threatening syndrome characterized by excessive immune activation, often presenting as a complex cytokine storm. This hyperactive immune response can lead to multi-organ failure and systemic damage, resulting in an extremely short survival period if left untreated. Over the past decades, although HLH has garnered increasing attention from researchers, there have been few advancements in its treatment. The cytokine storm plays a crucial role in the treatment of HLH. Investigating the detailed mechanisms behind cytokine storms offers insights into targeted therapeutic approaches, potentially aiding in early intervention and improving the clinical outcome of HLH patients. To date, there is only one targeted therapy, emapalumab targeting interferon-γ, that has gained approval for primary HLH. This review aims to summarize the current treatment advances, emerging targeted therapeutics and underlying mechanisms of HLH, highlighting its newly discovered targets potentially involved in cytokine storms, which are expected to drive the development of novel treatments and offer fresh perspectives for future studies. Besides, multi-targeted combination therapy may be essential for disease control, but further trials are required to determine the optimal treatment mode for HLH.

Into the storm: the imbalance in the yin-yang immune response as the commonality of cytokine storm syndromes

There is a continuous cycle of activation and contraction in the immune response against pathogens and other threats to human health in life. This intrinsic yin-yang of the immune response ensures that inflammatory processes can be appropriately controlled once that threat has been resolved, preventing unnecessary tissue and organ damage. Various factors may contribute to a state of perpetual immune activation, leading to a failure to undergo immune contraction and development of cytokine storm syndromes. A literature review was performed to consider how the trajectory of the immune response in certain individuals leads to cytokine storm, hyperinflammation, and multiorgan damage seen in cytokine storm syndromes. The goal of this review is to evaluate how underlying factors contribute to cytokine storm syndromes, as well as the symptomatology, pathology, and long-term implications of these conditions. Although the recognition of cytokine storm syndromes allows for universal treatment with steroids, this therapy shows limitations for symptom resolution and survival. By identifying cytokine storm syndromes as a continuum of disease, this will allow for a thorough evaluation of disease pathogenesis, consideration of targeted therapies, and eventual restoration of the balance in the yin-yang immune response.

Acute kidney injury in critical care: complications of hemophagocytic lymphohistiocytosis

Hemophagocytic lymphohistiocytosis (HLH) is an immune dysfunction characterized by an exaggerated and pathological inflammatory response, potentially leading to systemic inflammatory reactions and multiple-organ failure, including renal involvement. HLH can be classified as primary or secondary, with primary HLH associated with genetic mutations affecting cell degranulation capacity, and secondary HLH often linked to infections, tumors, and autoimmune diseases. The pathogenesis of HLH is not fully understood, but primary HLH is typically driven by genetic defects, whereas secondary HLH involves the activation of CD8+ T cells and macrophages, leading to the release of inflammatory cytokines and systemic inflammatory response syndrome (SIRS). The clinical presentation of HLH includes non-specific manifestations, making it challenging to differentiate from severe sepsis, particularly secondary HLH due to infections. Shared features include prolonged fever, hepatosplenomegaly, hematopenia, hepatic dysfunction, hypertriglyceridemia, and hypofibrinogenemia, along with histiocytosis and hemophagocytosis. However, distinctive markers like dual hemocytopenia, hypertriglyceridemia, hypofibrinogenemia, and elevated sCD25 levels may aid in differentiating HLH from sepsis. Indeed, no singular biomarker effectively distinguishes between hemophagocytic lymphohistiocytosis and infection. However, research on combined biomarkers provides insights into the differential diagnosis. Renal impairment is frequently encountered in both HLH and sepsis. It can result from a systemic inflammatory response triggered by an influx of inflammatory mediators, from direct damage caused by these factors, or as a consequence of the primary disease process. For instance, macrophage infiltration of the kidney can lead to structural damage affecting various renal components, precipitating disease. Presently, tubular necrosis remains the predominant form of renal involvement in HLH-associated acute kidney injury (HLH-AKI). However, histopathological changes may also encompass interstitial inflammation, glomerular abnormalities, microscopic lesions, and thrombotic microangiopathy. Treatment approaches for HLH and sepsis diverge significantly. HLH is primarily managed with repeated chemotherapy to eliminate immune-activating stimuli and suppress hypercellularity. The treatment approach for sepsis primarily focuses on anti-infective therapy and intensive symptomatic supportive care. Renal function significantly influences clinical decision-making, particularly regarding the selection of chemotherapy and antibiotic dosages, which can profoundly impact patient prognosis. Conversely, renal function recovery is a complex process influenced by factors such as disease severity, timely diagnosis, and the intensity of treatment. A crucial aspect in managing HLH-AKI is the timely diagnosis, which plays a pivotal role in reversing renal impairment and creating a therapeutic window for intervention, may have opportunity to improve patient prognosis. Understanding the clinical characteristics, underlying causes, biomarkers, immunopathogenesis, and treatment options for hemophagocytic lymphohistiocytosis associated with acute kidney injury (HLH-AKI) is crucial for improving patient prognosis.

The impact of immunosuppression on the mortality and hospitalization of Monkeypox: a systematic review and meta-analysis of the 2022 outbreak

BACKGROUND

Limited data is available regarding the severity and mortality of Mpox in individuals with immunocompromised conditions. Therefore, we performed this meta-analysis to understand the impact of HIV- or non-HIV-associated immunosuppression on the severity of Mpox requiring hospitalization and mortality.

METHODS

A thorough literature search was performed from 2022 up to January 2024. The results were presented as odds ratios (ORs). We only included patients who required hospitalization for severity rather than isolation.

RESULTS

A total of 34 studies were included in this analysis. Our analysis did not find a significant difference in the hospitalization risk between HIV-positive individuals and those who were HIV-negative (OR = 1.03; P = 0.85; 7 studies; CD4 count of fewer than 200 cells/µL was less than 0.5% across all studies). Patients with a CD4 count lower than 200 cells/µL or an unsuppressed RNA viral load (> 200 copies/ml) had a significantly higher hospitalization risk (OR = 5.3, P < 0.001) and (OR = 3, P < 0.001), respectively. Most of the reported deaths were reported in patients with HIV with CD4 counts below 200 cells/µL, with some fatal cases occurring in non-HIV immunosuppressed patients, particularly organ transplant recipients. Based on the autopsy findings, Mpox was confirmed in multiple organs, particularly the digestive tract, lung, and testes. Furthermore, some studies documented cases of death that were suspected to be related to hemophagocytic lymphohistiocytosis (HLH) and immune reconstitution inflammatory syndrome (IRIS). Most of the death reports showed concomitant non-Mpox infections at the time of hospitalization and death CONCLUSIONS: Our finding shows that Mpox acts as an opportunistic pathogen in immunocompromised individuals. These individuals should be prioritized for early care and closely monitored for signs of deteriorating clinical conditions. Clinical manifestations and autopsy findings strongly suggest Mpox dissemination to multiple organs, particularly the digestive tract, and lungs. However, the presence of concomitant non-Mpox infections complicates the assessment of the attribution of Mpox to death. Caution should be exercised when interpreting data suggesting poorer outcomes in individuals with non-HIV immunosuppression, as current evidence is scarce and further research is needed.

Single-Cell Transcriptomic Analysis of Epstein-Barr Virus-Associated Hemophagocytic Lymphohistiocytosis

Epstein-Barr virus (EBV) infection can lead to infectious mononucleosis (EBV-IM) and, more rarely, EBV-associated hemophagocytic lymphohistiocytosis (EBV-HLH), which is characterized by a life-threatening hyperinflammatory cytokine storm with immune dysregulation. Interferon-gamma (IFNγ) has been identified as a critical mediator for primary HLH; however, the detailed role of IFNγ and other cytokines in EBV-HLH is not fully understood. In this study, we used single-cell RNA sequencing to characterize the immune landscape of EBV-HLH and compared it with EBV-IM. Three pediatric patients with EBV-HLH with different backgrounds, one with X-linked lymphoproliferative syndrome type 1 (XLP1), two with chronic active EBV disease (CAEBV), and two patients with EBV-IM were enrolled. The TUBA1B + STMN1 + CD8 + T cell cluster, a responsive proliferating cluster with rich mRNA detection, was explicitly observed in EBV-IM, and the upregulation of SH2D1A-the gene responsible for XLP1-was localized in this cluster. This proliferative cluster was scarcely observed in EBV-HLH cases. In EBV-HLH cases with CAEBV, upregulation of LAG3 was observed in EBV-infected cells, which may be associated with an impaired response by CD8 + T cells. Additionally, genes involved in type I interferon (IFN) signaling were commonly upregulated in each cell fraction of EBV-HLH, and activation of type II IFN signaling was observed in CD4 + T cells, natural killer cells, and monocytes but not in CD8 + T cells in EBV-HLH. In conclusion, impaired responsive proliferation of CD8 + T cells and upregulation of type I IFN signaling were commonly observed in EBV-HLH cases, regardless of the patients' background, indicating the key features of EBV-HLH.

Secondary hemophagocytic syndrome in an acquired immunodeficiency syndrome and Alpha-thalassemia patient infected with Talaromyces marneffei: A case report and literature review

Hemophagocytic lymphohistiocytosis (HLH) is a life-threatening disease characterized by a hyperinflammatory syndrome and impairment of multiple organ systems. Talaromycosis marneffei (TSM) is an opportunistic infection mostly found in immunosuppressed populations, such as those with acquired immunodeficiency syndrome (AIDS), and is prevalent in southern China. However, HLH secondary to TSM is extremely rare and has only been reported in isolated cases. A 30-year-old patient with recurrent high fever and progressive cytopenia was diagnosed with HLH secondary to disseminated TSM with AIDS and Alpha-thalassemia. The patient remained in sustained remission without recurrence after effective treatment with antifungals and glucocorticoids.

The anti-inflammatory effect of metformin: The molecular targets

Metformin is an anti-diabetic drug. Metformin mainly inhibits gluconeogenesis in the liver and reduces blood sugar. In addition to the anti-diabetic effects, many studies have revealed that metformin has anti-inflammatory effects. Various molecules were suggested to be the target of the metformin's anti-inflammatory effects. However, the conclusion is not clear. Metformin is related to a number of molecules and the identification of the main target in anti-inflammatory effects leads to the understanding of inflammation and metformin. In this article, I discuss each suggested molecule, involved mechanisms, and their relationship with various diseases.

Prognostic Factors of Adult Hemophagocytic Lymphohistiocytosis and Clinical Utility of HLH-2004 Diagnostic Criteria and HScore: A Real-World Multicenter Study from Thailand

INTRODUCTION

Adult hemophagocytic lymphohistiocytosis (HLH) is a rare disease with a dismal prognosis. Early diagnosis and prompt management are necessary for improved outcomes.

METHODS

This multicenter retrospective study investigated the etiologies, survival, and prognostic factors of HLH, including the utility of HLH-2004 criteria and HScore in real-life clinical practice.

RESULTS

A total of 147 HLH patients were identified by using a combination of hemophagocytosis identification in bone marrow and the HLH-related international classification disease-10. A total of 116 (78.9%) patients fulfilled the HLH diagnosis by HScore, while 91 (61.9%) patients fulfilled 5 of 8 HLH-2004 criteria. In Thailand, the clinical application of HLH-2004 criteria needed to be reduced from 8 to 6 due to a lack of sCD25 and natural killer cell activity tests. Using the adapted HLH-2004 with a cutoff value of 4 resulted in 132 (89.9%) cases meeting the diagnostic criteria. Among these 132 confirmed HLH patients by using adapted HLH-2004, HLH was triggered by infection (29.5%), autoimmune disease (12.9%), malignancy (40.9%), and unknown cause (16.7%). Median overall survival of HLH patients was extremely short (67 days). Ferritin >6,000 μg/L, HLH from infection, malignancy, and unknown etiology were demonstrated as independent prognostic factors for inferior survival (hazard ratio [HR] 2.47; 95% confidence interval [CI] 1.39-4.37, HR 4.69; 95% CI 1.38-15.92, HR 6.09; 95% CI 1.84-20.14, and HR 6.02; 95% CI 1.64-22.05, respectively).

CONCLUSION

Ferritin is a helpful biomarker for HLH diagnosis and prognostic prediction. Autoimmune disease-triggered HLH has favorable outcomes. Future prospective study is required to verify the use of the adapted HLH-2004 criteria.

The signature and predictive value of immune parameters in patients with secondary hemophagocytic lymphohistiocytosis

BACKGROUND

Secondary hemophagocytic lymphohistiocytosis (sHLH) is a rare but fatal clinical syndrome, characterized by severe immune dysfunction and overwhelming inflammatory response. However, the host immune signature and also its role in predicting the clinical outcome are not fully described.

OBJECTIVE

The present study aims to investigate the host immune status of sHLH patients in the early stage of the disease, including lymphocyte subsets, phenotypes and cytokines, and also to explore its clinical value in prognosis.

METHODS

Sixty-four patients with sHLH admitted to a tertiary hospital in central China between 2018 and 2022 were enrolled, of which 21 were deceased. The subsets and phenotypes of lymphocytes, and the levels of cytokines in serum were analyzed.

RESULTS

In patients with sHLH, the percentages of total T cells, CD8+ T cells, HLA-DR+ T cells, HLA-DR+CD8+ T cells, CD45RO+CD4+ T cells, and the levels of IL-1β, IL-2R, IL-6, IL-8, IL-10 and TNF-α were significantly increased, while the percentages of CD4+ T cells, NK cells, CD45RA+CD4+ T cells, CD45RA+ regulatory T (Treg) cells, the counts of total T cells, total B cells, CD4+ T cells, CD8+ T cells, NK cells, and the ratio of CD4+ T/CD8+ T cells were significantly decreased, compared with healthy controls (HC). In addition, dysregulation of host immune response and high inflammatory status were more obvious in deceased patients than that of survivors. Kaplan-Meier survival analysis and multivariate logistic regression analysis demonstrated that lower levels of CD4+ T cells count and CD28+CD4+ T cells percentage, but higher levels of NK cells percentage and IL-1β were poor prognostic indicators of sHLH.

CONCLUSION

The evaluation of immunological markers has critical value for selecting prognostic markers and potential treatment target among adults with sHLH.

An analysis of reported cases of hemophagocytic lymphohistiocytosis (HLH) after COVID-19 vaccination

Although COVID-19 vaccines are an effective public health tool to combat the global pandemic, serious adverse events, such as hemophagocytic lymphohistiocytosis (HLH), caused by them are a concern. In this systematic review, cases of HLH reported after COVID-19 vaccination have been examined to understand the relationship between the two and propose effective therapeutic strategies. Furthermore, ruxolitinib's potential as a cytokine inhibitor and its affinity for CD25 were initially assessed through molecular docking, aiming to aid targeted HLH therapy. PubMed and Web of Science databases were searched for published individual case reports on the occurrence of HLH after the administration of any COVID-19 vaccine. A total of 17 articles (25 patients) were included in this qualitative analysis. Furthermore, molecular docking was employed to investigate the therapeutic potential of ruxolitinib for HLH after COVID-19 vaccination. The mean age of patients who developed HLH after COVID-19 vaccination was 48.1 years. Most HLH episodes occurred after the BNT162b2 mRNA COVID-19 vaccination (14/25 cases) and to an extent after the ChAdOx1 nCov-19 vaccination (5/25 cases). Almost all affected patients received steroid and antibiotic therapy. Three patients died despite treatment because of esophagus rupture, neutropenic fever, bacteroides bacteremia, refractory shock, and encephalopathy and shock. Visual docking results of IL-2 Rα and ruxolitinib using the Discovery Studio 2019 Client software yielded a model score of 119.879. The findings highlight the importance of considering and identifying the adverse effects of vaccination and the possibility of using ruxolitinib for treating HLH after COVID-19 vaccination.

Ehrlichia-Induced Hemophagocytic Lymphohistiocytosis (HLH) With No Response to Doxycycline Treatment

Hemophagocytic lymphohistiocytosis (HLH) is a rare, life-threatening condition characterized by the persistent activation of antigen-presenting cells and multisystemic inflammation. Ehrlichiosis is a tick-born infection that primarily infects the white blood cells and can present with a variety of symptoms, including fever, fatigue, and multisystemic complications. Here, we present a 58-year-old female hospitalized for a urinary tract infection. Her hospital course was complicated by HLH, which was later discovered to be precipitated by an Ehrlichia chaffeensis infection. The patient did not respond to the doxycycline treatment, developed multiorgan failure, and passed away after a few weeks of treatment trials.

Interplay of host and viral factors in inflammatory pathway mediated cytokine storm during RNA virus infection

RNA viruses always have been a serious concern for human health by causing several outbreaks, often pandemics. The excessive mortality and deaths associated with the outbreaks caused by these viruses were due to the excessive induction of pro-inflammatory cytokines leading to cytokine storm. Cytokines are important for cell-to-cell communication to maintain cell homeostasis. Disturbances of this homeostasis can lead to intricate chain reactions resulting in a massive release of cytokines. This could lead to a severe self-reinforcement of several feedback processes, which could eventually cause systemic harm, multiple organ failure, or death. Multiple inflammation-associated pathways were involved in the cytokine production and its regulation. Different RNA viruses induce these pathways through the interplay with their viral factors and host proteins and miRNAs regulating these pathways. This review will discuss the interplay of host proteins and miRNAs that can play an important role in the regulation of cytokine storm and the possible therapeutic potential of these molecules for the treatment and the challenges associated with the clinical translation.

Anaplasmosis-Induced Hemophagocytic Lymphohistiocytosis: A Case Report and Review of the Literature

Cases of anaplasmosis have increased steadily and are appearing in states where it is less common. While symptoms are usually mild, in rare cases it can cause hemophagocytic lymphohistiocytosis. Here, we present a case of polymerase chain reaction-confirmed Anaplasma phagocytophilum with morulae on peripheral blood smear associated with biopsy-proven hemophagocytic lymphohistiocytosis.

BPOZ-2 is a negative regulator of the NLPR3 inflammasome contributing to SARS-CoV-2-induced hyperinflammation

Introduction

Inflammation play important roles in the initiation and progression of acute lung injury (ALI), acute respiratory distress syndrome (ARDS), septic shock, clotting dysfunction, or even death associated with SARS-CoV-2 infection. However, the pathogenic mechanisms underlying SARS-CoV-2-induced hyperinflammation are still largely unknown.

Methods

The animal model of septic shock and ALI was established after LPS intraperitoneal injection or intratracheal instillation. Bone marrow-derived macrophages (BMDMs) from WT and BPOZ-2 KO mouse strains were harvested from the femurs and tibias of mice. Immunohistology staining, ELISA assay, coimmunoprecipitation, and immunoblot analysis were used to detect the histopathological changes of lung tissues and the expression of inflammatory factors and protein interaction.

Results and conclusions

We show a distinct mechanism by which the SARS-CoV-2 N (SARS-2-N) protein targets Bood POZ-containing gene type 2 (BPOZ-2), a scaffold protein for the E3 ubiquitin ligase Cullin 3 that we identified as a negative regulator of inflammatory responses, to promote NLRP3 inflammasome activation. We first demonstrated that BPOZ-2 knockout (BPOZ-2 KO) mice were more susceptible to lipopolysaccharide (LPS)-induced septic shock and ALI and showed increased serum IL-1β levels. In addition, BMDMs isolated from BPOZ-2 KO mice showed increased IL-1β production in response to NLRP3 stimuli. Mechanistically, BPOZ-2 interacted with NLRP3 and mediated its degradation by recruiting Cullin 3. In particular, the expression of BPOZ-2 was significantly reduced in lung tissues from mice infected with SARS-CoV-2 and in cells overexpressing SARS-2-N. Importantly, proinflammatory responses triggered by the SARS-2-N were significantly blocked by BPOZ-2 reintroduction. Thus, we concluded that BPOZ-2 is a negative regulator of the NLPR3 inflammasome that likely contributes to SARS-CoV-2-induced hyperinflammation.