Platelets mediate the clearance of senescent red blood cells by forming prophagocytic platelet-cell complexes.

ABSTRACT: In humans, ∼0.1% to 0.3% of circulating red blood cells (RBCs) are present as platelet-RBC (P-RBC) complexes, and it is 1% to 2% in mice. Excessive P-RBC complexes are found in diseases that compromise RBC health (eg, sickle cell disease and malaria) and contribute to pathogenesis. However, the physiological role of P-RBC complexes in healthy blood is unknown. As a result of damage accumulated over their lifetime, RBCs nearing senescence exhibit physiological and molecular changes akin to those in platelet-binding RBCs in sickle cell disease and malaria. Therefore, we hypothesized that RBCs nearing senescence are targets for platelet binding and P-RBC formation. Confirming this hypothesis, pulse-chase labeling studies in mice revealed an approximately tenfold increase in P-RBC complexes in the most chronologically aged RBC population compared with younger cells. When reintroduced into mice, these complexes were selectively cleared from the bloodstream (in preference to platelet-free RBC) through the reticuloendothelial system and erythrophagocytes in the spleen. As a corollary, patients without a spleen had higher levels of complexes in their bloodstream. When the platelet supply was artificially reduced in mice, fewer RBC complexes were formed, fewer erythrophagocytes were generated, and more senescent RBCs remained in circulation. Similar imbalances in complex levels and senescent RBC burden were observed in humans with immune thrombocytopenia (ITP). These findings indicate that platelets are important for binding and clearing senescent RBCs, and disruptions in platelet count or complex formation and clearance may negatively affect RBC homeostasis and may contribute to the known risk of thrombosis in ITP and after splenectomy.

Clostridium perfringens virulence factors are nonredundant activators of the NLRP3 inflammasome.

Inflammasome signaling is a central pillar of innate immunity triggering inflammation and cell death in response to microbes and danger signals. Here, we show that two virulence factors from the human bacterial pathogen Clostridium perfringens are nonredundant activators of the NLRP3 inflammasome in mice and humans. C. perfringens lecithinase (also known as phospolipase C) and C. perfringens perfringolysin O induce distinct mechanisms of activation. Lecithinase enters LAMP1+ vesicular structures and induces lysosomal membrane destabilization. Furthermore, lecithinase induces the release of the inflammasome-dependent cytokines IL-1ß and IL-18, and the induction of cell death independently of the pore-forming proteins gasdermin D, MLKL and the cell death effector protein ninjurin-1 or NINJ1. We also show that lecithinase triggers inflammation via the NLRP3 inflammasome in vivo and that pharmacological blockade of NLRP3 using MCC950 partially prevents lecithinase-induced lethality. Together, these findings reveal that lecithinase activates an alternative pathway to induce inflammation during C. perfringens infection and that this mode of action can be similarly exploited for sensing by a single inflammasome.

Agricultural Waste Management by Production of Second-Generation Bioethanol from Sugarcane Bagasse Using Indigenous Yeast Strain.

In the wake of rapid industrialization and burgeoning transportation networks, the escalating demand for fossil fuels has accelerated the depletion of finite energy reservoirs, necessitating urgent exploration of sustainable alternatives. To address this, current research is focusing on renewable fuels like second-generation bioethanol from agricultural waste such as sugarcane bagasse. This approach not only circumvents the contentious issue of food-fuel conflicts associated with biofuels but also tackles agricultural waste management. In the present study indigenous yeast strain, Clavispora lusitaniae QG1 (MN592676), was isolated from rotten grapes to ferment xylose sugars present in the hemicellulose content of sugarcane bagasse. To liberate the xylose sugars, dilute acid pretreatment was performed. The highest reducing sugars yield was 1.2% obtained at a temperature of 121 °C for 15 min, a solid-to-liquid ratio of 1:25 (% w/v), and an acid concentration of 1% dilute acid H2SO4 that was significantly higher (P < 0.001) yield obtained under similar conditions at 100 °C for 1 h. The isolated strain was statistically optimized for fermentation process by Plackett-Burman design to achieve the highest ethanol yield. Liberated xylose sugars were completely utilized by Clavispora lusitaniae QG1 (MN592676) and gave 100% ethanol yield. This study optimizes both fermentation process and pretreatment of sugarcane bagasse to maximize bioethanol yield and demonstrates the ability of isolated strain to effectively utilize xylose as a carbon source. The desirable characteristics depicted by strain Clavispora lusitaniae shows its promising utilization in management of industrial waste like sugarcane bagasse by its conversion into renewable biofuels like bioethanol.

A Dual-Antigen Enzyme-Linked Immunosorbent Assay Allows the Assessment of Severe Acute Respiratory Syndrome Coronavirus 2 Antibody Seroprevalence in a Low-Transmission Setting.

Estimates of seroprevalence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) antibodies have been hampered by inadequate assay sensitivity and specificity. Using an enzyme-linked immunosorbent assay-based approach that combines data about immunoglobulin G responses to both the nucleocapsid and spike receptor binding domain antigens, we show that excellent sensitivity and specificity can be achieved. We used this assay to assess the frequency of virus-specific antibodies in a cohort of elective surgery patients in Australia and estimated seroprevalence in Australia to be 0.28% (95% Confidence Interval, 0-1.15%). These data confirm the low level of transmission of SARS-CoV-2 in Australia before July 2020 and validate the specificity of our assay.

Physicochemical, antioxidant and enzymes activities of grape fruit peel and pomace enriched functional drinks.

Experiment was conducted to determine the proximate, minerals, antioxidant capacities and enzymes activities of grape fruit peel and grape fruit pomace along with sensorial evaluation of functional drinks. In this milieu, values of grapefruit peel and pomace powder for moisture, fat, crude protein, carbohydrate, crude fiber, ash, and NFE were recorded as 10.85±1.34,8.9±0.08 , 9.27±0.03, 7.69±0.02, 60.22±2.32, 50.33±2.1, 6.13±0.02, 6.13±0.01, 2.97±0.01 ,2.16±0.01 ,10.56±1.97, 24.97±2.4, respectively whilst in time intervals highest TPC for peel (118.66±8.9) mg/g was observed in 60 min followed by (102.33±7.6) mg/g at 90 min and (82.02±5.5) mg/g at 30 min respectively Whereas, the recorded TPC for pomace at 30, 60 and 90 minute were (112.73±9.1) mg/g has observed in 60 min followed by (97.21±7.9) mg/g at 90 min and (84.55±5.8) mg/g at 30 min respectively. Among the time intervals highest flavonoids contents of peel were at 60 min 52.3±1.9% followed by 52.51±1.7% at 90 min and minimum 50.72±1.4% at 30 min. The highest ABTS value was observed for peel content 248.33±5.6 λg/ml in ethanol extract followed by methanolic extract 212.11±4.4 λg/ml least in water extract 152.5±3.2 λg/ml. The means reviewed FRAP activity highest value for ethanol in peel and pomace were (92.66±5.3 µg/ml Fe2+/g) & (82.47±4.2 µg/ml Fe2+/g) followed by methanol (86.33±4.1 µg/ml Fe2+/g) & (76.83±3.4 µg/ml Fe2+/g) and least in water (66.46±2.2 µg ml Fe2+/g) &(54.24±2.1 µg/ml Fe2+/g) respectively. The color acceptability varied significant effect between 7.49 to 7.55 in T0 to T3. Likewise, storage imparted more significant decline from 7.72 to 7.30 at 0th to 60th days, respectively. The flavor scores were 7.59, 7.41, 7.26 and 7.53 in T0, T1, T2 and T3 respectively. The overall acceptability of drink was significantly increase from initiation (0th) day to termination (60th) day as 7.68 to 6.9.

Association of Factor V Leiden G1691A and Prothrombin gene G20210A mutations with adverse pregnancy outcomes.

OBJECTIVE: To determine the association of Factor V Leiden / prothrombin gene mutation in Pakistani women with adverse pregnancy outcomes. METHOD: The prospective study was conducted at the Aga Khan University Hospital, Karachi, from January 1 to December 31, 2016, and comprised females > 40 years having history of two or more foetal losses with no apparent aetiology. Restriction fragment length polymorphism- Polymerase chain reaction was performed using MnlI and HindIII restriction enzymes for factor V Leiden G1691A and prothrombin gene mutation G20210A. Females with two or more consecutive normal pregnancies were enrolled as the control group. Data was analysed using SPSS 19. RESULTS: Of the 172 participants with a mean age of 29.3±5.9 years (range: 19-38 years). 86(50%) each were healthy controls and those with recurrent pregnancy loss. There were 238 livebirths among the controls compared to 13 in the other group. Factor V Leiden G1691A was identified in 2(2.3%) women, and prothrombin gene mutation G20210A in 1(1.2%) woman in the patient group, while no mutation was identified in the control group. CONCLUSIONS: The prevalence of Factor V Leiden / prothrombin gene mutation in women with recurrent pregnancy loss was found to be very low.

The molecular basis of immune-based platelet disorders.

Platelets have a predominant role in haemostasis, the maintenance of blood volume and emerging roles as innate immune cells, in wound healing and in inflammatory responses. Platelets express receptors that are important for platelet adhesion, aggregation, participation in inflammatory responses, and for triggering degranulation and enhancing thrombin generation. They carry a cargo of granules bearing enzymes, adhesion molecules, growth factors and cytokines, and have the ability to generate reactive oxygen species. The platelet is at the frontline of a host of cellular responses to invading pathogens, injury, and infection. Perhaps because of this intrinsic responsibility of a platelet to rapidly respond to thrombotic, pathological and immunological factors as part of their infantry role; platelets are susceptible to targeted attack by the adaptive immune system. Such attacks are often transitory but result in aberrant platelet activation as well as significant loss of platelet numbers and platelet function, paradoxically leading to elevated risks of both thrombosis and bleeding. Here, we discuss the main molecular events underlying immune-based platelet disorders with specific focus on events occurring at the platelet surface leading to activation and clearance.

Better get moving on laboratory quality assurance.

PURPOSE: With recent advances in laboratory hematology automation, emphasis is now on quality assurance processes as they are indispensable for generating reliable and accurate test results. It is therefore imperative to acquire efficient measures for recognizing laboratory malfunctions and errors to improve patient safety. The paper aims to discuss these issues. DESIGN/METHODOLOGY/APPROACH: Moving algorithm is a quality control process that monitors analyzer performance from historical records through a continuous process, which does not require additional expenditure, and can serve as an additional support to the laboratory quality control program. FINDINGS: The authors describe an important quality assurance tool, which can be easily applied in any laboratory setting, especially in cost-constrained areas where running commercial controls throughout every shift may not be a feasible option. ORIGINALITY/VALUE: The authors focus on clinical laboratory quality control measures for providing reliable test results. The moving average appears to be a reasonable and applicable choice for vigilantly monitoring each result.

Pharmaceutical quality evaluation of different glimepiride brands marketed in Karachi (Pakistan): In pursuance to global issue of availability and affordability of quality medicines.

Availability of economical quality medicines is always required for chronic disease management. Price differences among multiple brands of a product do not essentially displays low quality for the more affordable brand, however in a few occurrences it appears. Glimepiride, an oral anti-diabetic drug, is produced by several national and multinational industries in Pakistan with considerable cost variation. The study aimed to evaluate the quality and economy of various Glimepiride brands available in Karachi, specifically of public sector hospitals. For this, eight glimepiride brands were collected and analyzed for the pharmaceutical quality using physical parameters, disintegration test, dissolution profile, spectrophotometric assay and content uniformity. Pharmacoeconomic assessment was also carried out such as availability, affordability and price variation. A profound discrepancy was observed among the prices of selected brands. All of the products found to be equivalent to the reference product except G5, the most inexpensive and highest consumed product of a public sector hospital. Study concludes that products with higher quality and lesser price can be used as a substitute to the costly brands while availability of a substandard product looks for consideration of pertinent authorities to assure the distribution of quality medicines.

Performance evaluation of a coagulation laboratory using Sigma metrics.

Purpose Two-thirds of medical decisions are based on laboratory test results. Therefore, laboratories should practice strict quality control (QC) measures. Traditional QC processes may not accurately reflect the magnitude of errors in clinical laboratories. Six Sigma is a statistical tool which provides opportunity to assess performance at the highest level of excellence. The purpose of this paper is to evaluate performance of the coagulation laboratory utilizing Sigma metrics as the highest level of quality. Design/methodology/approach Quality indicators of the coagulation laboratory from January 1, 2009, to December 31, 2015, were evaluated. These QIs were categorized into pre-analytical, analytical and post-analytical. Relative frequencies of errors were calculated and converted to Sigma scale to determine the extent of control over each process. The Sigma level of 4 was considered optimal performance. Findings During the study period, a total of 474,655 specimens were received and 890,535 analyses were performed. These include 831,760 (93.4 percent) routine and 58,775 (6.6 percent) special tests. Stat reporting was requested for 166,921 (18.7 percent). Of 7,535,146 total opportunities (sum of the total opportunities for all indicators), a total of 4,005 errors were detected. There were 2,350 (58.7 percent) pre-analytical, 11 (0.3 percent) analytical and 1,644 (41 percent) post-analytical errors. Average Sigma value obtained was 4.8 with 12 (80 percent) indicators achieving a Sigma value of 4. Three (20 percent) low-performance indicators were: unacceptable proficiency testing (3.8), failure to inform critical results (3.6) and delays in stat reporting (3.9). Practical implications This study shows that a small number of errors can decrease Sigma value to below acceptability limits. If clinical laboratories start using Sigma metrics for monitoring their performance, they can identify gaps in their performance more readily and hence can improve their performance and patient safety. Social implications This study provides an opportunity for the laboratorians to choose and set world-class goals while assessing their performance. Originality/value To the best of the authors' knowledge and belief, this study is the first of its kind that has utilized Sigma metrics as a QC tool for monitoring performance of a coagulation laboratory.

Utilization of microalgae for agricultural runoff remediation and sustainable biofuel production through an integrated biorefinery approach.

Generally wastewater such agricultural runoff is considered a nuisance; however, it could be harnessed as a potential source of nutrients like nitrates and phosphates in integrated biorefinery context. In the current study, microalgae Chlorella sp. S5 was used for bioremediation of agricultural runoff and the leftover algal biomass was used as a potential source for production of biofuels in an integrated biorefinery context. The microalgae Chlorella sp. S5 was cultivated on Blue Green (BG 11) medium and a comprehensive optimization of different parameters including phosphates, nitrates, and pH was carried out to acquire maximum algal biomass enriched with high lipids content. Dry biomass was quantified using the solvent extraction technique, while the identification of nitrates and phosphates in agricultural runoff was carried out using commercial kits. The algal extracted lipids (oils) were employed in enzymatic trans-esterification for biodiesel production using whole-cell biomass of Bacillus subtilis Q4 MZ841642. The resultant fatty acid methyl esters (FAMEs) were analyzed using Fourier transform infrared (FTIR) spectroscopy and gas chromatography coupled with mass spectrometry (GC-MS). Subsequently, both the intact algal biomass and its lipid-depleted algal biomass were used for biogas production within a batch anaerobic digestion setup. Interestingly, Chlorella sp. S5 demonstrated a substantial reduction of 95% in nitrate and 91% in phosphate from agricultural runoff. The biodiesel derived from algal biomass exhibited a noteworthy total FAME content of 98.2%, meeting the quality standards set by American Society for Testing and Materials (ASTM) and European union (EU) standards. Furthermore, the biomethane yields obtained from whole biomass and lipid-depleted biomass were 330.34 NmL/g VSadded and 364.34 NmL/g VSadded, respectively. In conclusion, the findings underscore the potent utility of Chlorella sp. S5 as a multi-faceted resource, proficiently employed in a sequential cascade for treating agricultural runoff, producing biodiesel, and generating biogas within the integrated biorefinery concept.

Waldenström Macroglobulinaemia lymphoma patients have impaired platelet and coagulation function.

Clinical features in patients with the B-cell lymphoma, Waldenström Macroglobulinaemia (WM), include cytopenias, IgM-mediated hyperviscosity, fatigue, bleeding and bruising. Therapeutics such as Bruton's tyrosine kinase inhibitors (BTKis) exacerbate bleeding risk. Abnormal haemostasis arising from platelet dysfunction, altered coagulation or vascular impairment have not been investigated in WM patients. To evaluate haemostatic dysfunction in samples from WM patients. Whole blood (WB) samples were collected from 14 WM patients not receiving therapy, 5 patients receiving BTKis and 15 healthy donors (HDs). Platelet receptor levels and reticulation were measured by flow cytometry, plasma thrombin generation ± platelets by FRET assay, WB clotting potential by rotational thromboelastometry (ROTEM), and plasma soluble glycoprotein VI (sGPVI) and serum thrombopoietin (TPO) by ELISA. Donor platelet spreading, aggregation and ability to accelerate thrombin generation in the presence of WM-derived IgM were assessed. WM platelet receptor levels, responses to physiological agonists and plasma sGPVI were within normal ranges. WM platelets had reduced reticulation (p=0.0012) while serum TPO levels were increased (p=0.0040). WM plasma displayed slower thrombin generation (p=0.0080) and WM platelets contributed less to endogenous thrombin potential (ETP, p=0.0312). HD plasma or platelets incubated with IgM (50-60 mg/mL) displayed reduced spreading (p=0.0002), aggregation (p<0.0001) and ETP (p=0.0081). Alterations to thrombin potential and WB coagulation were detected in WM samples. WM IgM significantly impaired haemostasis in vitro. Platelet and coagulation properties are disturbed in well-managed WM patients.

Synthesis and initial in vitro biological evaluation of two new zinc-chelating compounds: comparison with TPEN and PAC-1.

The lipophilic, cell-penetrating zinc chelator N,N,N',N',-tetrakis(2-pyridylmethyl) ethylenediamine (TPEN, 1) and the zinc chelating procaspase-activating compound PAC-1 (2) both have been reported to induce apoptosis in various cell types. The relationship between apoptosis-inducing ability and zinc affinity (Kd), have been investigated with two new model compounds, ZnA-DPA (3) and ZnA-Pyr (4), and compared to that of TPEN and PAC-1. The zinc-chelating o-hydroxybenzylidene moiety in PAC-1 was replaced with a 2,2'-dipicoylamine (DPA) unit (ZnA-DPA, 3) and a 4-pyridoxyl unit (ZnA-Pyr, 4), rendering an order of zinc affinity TPEN>ZnA-Pyr>ZnA-DPA>PAC-1. The compounds were incubated with the rat pheochromocytoma cell line PC12 and cell death was measured in combination with ZnSO4, a caspase-3 inhibitor, or a ROS scavenger. The model compounds ZnA-DPA (3) and ZnA-Pyr (4) induced cell death at higher concentrations as compared to PAC-1 and TPEN, reflecting differences in lipophilicity and thereby cell-penetrating ability. Addition of ZnSO4 reduced cell death induced by ZnA-Pyr (4) more than for ZnA-DPA (3). The ability to induce cell death could be reversed for all compounds using a caspase-3-inhibitor, and most so for TPEN (1) and ZnA-Pyr (4). Reactive oxygen species (ROS), as monitored using dihydro-rhodamine (DHR), were involved in cell death induced by all compounds. These results indicate that the Zn-chelators ZnA-DPA (3) and ZnA-Pyr (4) exercise their apoptosis-inducing effect by mechanisms similar to TPEN (1) and PAC-1 (2), by chelation of zinc, caspase-3 activation, and ROS production.

A neutral comparative analysis of additive, multiplicative, and mixed quantitative randomized response models.

In survey sampling, the randomized response technique is a useful tool to collect reliable data in many fields including sociology, education, economics, and psychology etc. Over the past few decades, many variants of quantitative randomized response models have been developed by researchers. The existing literature on randomized response models lacks a neutral comparative study of different models to help the practitioners choose the appropriate model for a given practical problem. In most of the existing studies, the authors tend to show only the favorable results by hiding the cases where their suggested models are inferior to the existing models. This approach often leads to biased comparisons which may badly misguide the practitioners when choosing a randomized response model for a practical problem at hand. This paper attempts a neutral comparison of six existing quantitative randomized response models using separate as well as joint measures of respondent-privacy and model-efficiency. The findings suggest that one model may perform better than the other model in terms of efficiency but may perform worse when other metrics of model quality are taken into account. The current study guides practitioners in choosing the right model for a given problem under a particular situation.

Paediatric Thrombosis: A Five-Year Experience From A Tertiary Care Center Of Pakistan.

BACKGROUND: Advances in imaging techniques and longer survival of chronic medical conditions contribute to the increase in paediatric thrombosis. We aim to determine the incidence, underlying risk factors, management and clinical outcome of paediatric thrombosis at a multidisciplinary facility of Pakistan. METHODS: A retrospectively analysis of the medical records of patients in the paediatric age group admitted at the Aga Khan University hospital from January 2013-September 2018 was performed. Site of thrombosis, associated risks factors, management options and outcome of thrombotic event were evaluated. RESULTS: Of the 22,320 paediatric hospitalization, 35 paediatric patients were diagnosed with thrombosis (15 cases per 10,000 admissions). The median age of the study group was 15 years and twenty patients (57%) were male. The commonest site of thrombosis was in lower limb venous 11 (31%), followed by upper limb venous thrombosis 6 (17%), abdominal vein thrombosis 7 (20%), cerebral venous thrombosis 5 (14%), pulmonary embolism and arterial thrombosis 3(9% each). Eighty three percent had underlying clinical condition including central venous catheter [CVC] (26%), malignancy and infection (14% each), antiphospholipid antibody syndrome (9%), inherited thrombophilia (9%), congenital heart disease (6%), while thrombotic thrombocytopenic purpura and autoimmune disorder (3% each). Twelve (34%) patients were treated with heparin only, 8 (23%) received heparin followed by warfarin while warfarin as a single agent was given in 2 (5.7%) patients. One patient died of pulmonary embolism while 9 (25%) had persistence or recurrence of thrombosis. CONCLUSIONS: Incidence of paediatric thrombosis was 0.15%. CVC placement was the most common associated risk factor. Warfarin and heparin both were found to be safe anticoagulation option. Recurrence rate was found to be high.

Different Shapes Of Megakaryocytes In Essential Thrombocythemia.

Essential thrombocytopenia is the myeloproliferative neoplasm associated with the JAK2/CALR/MPL mutation. It is characterized by an increase in thrombocytes and abnormal megakaryocytes. WHO established the diagnostic criteria for diagnosing the myeloproliferative disorder, which is the combination of molecular, clinical, and histological findings. The appearance of megakaryocytes on bone marrow biopsy is the distinguishing feature to identify myeloproliferative neoplasm, and this short review would like to emphasize the presentation of megakaryocytes in bone marrow biopsy.

Cryoprecipitate as an alternative to platelet transfusion in thrombocytopenia.

Platelet transfusions are not always available for bleeding in severe thrombocytopenia, as storage outside of major centers is limited by their short shelf-life. Data are lacking to support alternative available blood products; however, additional fibrinogen has been shown to enhance clot formation in vitro. To test the hypothesis that cryoprecipitate supplementation could improve clot formation in severe thrombocytopenia, eight hematological malignancy patients with platelet counts under 10 × 109/L each had 10 units of apheresis cryoprecipitate transfused prior to planned prophylactic platelet transfusions. The primary endpoint of thromboelastometry amplitude at 20 min increased by a mean of 5.1 mm (p < 0.01) following cryoprecipitate transfusion despite persisting thrombocytopenia. Thromboelastometry clotting times reduced by a mean of 7.8 s (p < 0.05) and alpha angle increased by a mean of 10.6° (p < 0.01). These results are consistent with cryoprecipitate enhancing the strength of the fibrin/platelet meshwork within the forming thrombus. While platelet transfusion remains the standard of care, where platelet supplies are limited, these data provide a rationale for the use of cryoprecipitate to obtain hemostasis in bleeding thrombocytopenic patients.

Clostridium septicum α-toxin activates the NLRP3 inflammasome by engaging GPI-anchored proteins.

Clostridium species are a group of Gram-positive bacteria that cause diseases in humans, such as food poisoning, botulism, and tetanus. Here, we analyzed 10 different Clostridium species and identified that Clostridium septicum, a pathogen that causes sepsis and gas gangrene, activates the mammalian cytosolic inflammasome complex in mice and humans. Mechanistically, we demonstrate that α-toxin secreted by C. septicum binds to glycosylphosphatidylinositol (GPI)-anchored proteins on the host plasma membrane, oligomerizing and forming a membrane pore that is permissive to efflux of magnesium and potassium ions. Efflux of these cytosolic ions triggers the activation of the innate immune sensor NLRP3, inducing activation of caspase-1 and gasdermin D, secretion of the proinflammatory cytokines interleukin-1ß and interleukin-18, pyroptosis, and plasma membrane rupture via ninjurin-1. Furthermore, α-toxin of C. septicum induces rapid inflammasome-mediated lethality in mice and pharmacological inhibition of the NLRP3 inflammasome using MCC950 prevents C. septicum-induced lethality. Overall, our results reveal that cytosolic innate sensing of α-toxin is central to the recognition of C. septicum infection and that therapeutic blockade of the inflammasome pathway may prevent sepsis and death caused by toxin-producing pathogens.