AIM2 Research Articles

Absent in Melanoma 2 Gene Associated Periodontitis and Coronary Heart Disease

Aims To study the association between AIM2 gene polymorphisms and the tendency for periodontal infection and coronary heart disease, and to determine whether males or females are more susceptible to these diseases. Additionally, we examined its association with the features of periodontal disease. Methods 140 patients were enrolled in this study, and those who took part were divided into four groups as follows: healthy (c), periodontal disease (P), coronary heart disease with intact periodontium (AS-C), and coronary heart disease with periodontal disease (AS-P). Information on entrants, including age, sex, body mass index, and indicators of periodontal disease severity, was documented. Blood samples were collected, and AIM2 gene polymorphisms were evaluated by polymerase chain reaction test, gel phase, and sequences. Results Genetic analysis of AIM2 G/T (rs2793845) revealed a high frequency of the (T) allele and (GT and TT) genotypes that were detected in the periodontal disease and coronary heart disease groups in males. The Hardy-Weinberg equilibrium of alleles and genotypes did not differ significantly between the study groups. Gene polymorphisms were also significantly correlated with indicators of periodontal disease severity. Conclusion High frequenting of (T) alleles and (GT, TT) genotypes in AIM2 single nucleotide polymorphisms (SNP) were associated with an increased tendency to develop periodontal disease and coronary heart disease. It can be supposed that it has a causative function in the pathophysiology of both disorders, and the validity of SNP as a potential genomic factor for the risk of both disorders in Iraqi males.

Tachol1 QTL on mouse chromosome 1 is responsible for hypercholesterolemia and diet-induced obesity.

Hypercholesterolemia raises the risk for cardiovascular complications and overall health. Hypercholesterolemia is common, affecting 10% of the general population of the US, and heritable. Most individuals with hypercholesterolemia have a polygenic predisposition to the condition. Previously we identified a quantitative trait locus, Tachol1, linked to hypercholesterolemia on mouse chromosome 1 (Chr1) in a cross between C57BL/6J (B6) and TALLYHO/JngJ (TH) mice, a polygenic model for human obesity, type 2 diabetes and hyperlipidemia. Subsequently, using congenic mice that carry a TH-derived genomic segment of Chr1 on a B6 background, we demonstrated that the distal segment of Chr1, where Tachol1 maps, is necessary to cause hypercholesterolemia, as well as diet-induced obesity. In this study, we generated overlapping subcongenic lines to the distal segment of congenic region and characterized subcongenic mice carrying the smallest TH region of Tachol1, ~ 16.2Mb in size (B6.TH-Chr1-16.2Mb). Both male and female B6.TH-Chr1-16.2Mb mice showed a significantly increased plasma total cholesterol levels compared to B6 on both chow and high fat (HF) diet. B6.TH-Chr1-16.2Mb mice also had greater fat mass than B6 on HF diet, without increasing food intake. The gene and protein expression levels of absent in melanoma 2 (Aim2) gene were significantly upregulated in B6.TH-Chr1-16.2Mb mice compared to B6. In summary, we confirmed the effect of Tachol1 on hypercholesterolemia and diet-induced obesity using subcongenic analysis.

Dental Pulp Stem Cells Modulate Inflammasome Pathway and Collagen Deposition of Dermal Fibroblasts.

Fibrosis is a pathological condition consisting of a delayed deposition and remodeling of the extracellular matrix (ECM) by fibroblasts. This deregulation is mostly triggered by a chronic stimulus mediated by pro-inflammatory cytokines, such as TNF-α and IL-1, which activate fibroblasts. Due to their anti-inflammatory and immunosuppressive potential, dental pulp stem cells (DPSCs) could affect fibrotic processes. This study aims to clarify if DPSCs can affect fibroblast activation and modulate collagen deposition. We set up a transwell co-culture system, where DPSCs were seeded above the monolayer of fibroblasts and stimulated with LPS or a combination of TNF-α and IL-1β and quantified a set of genes involved in inflammasome activation or ECM deposition. Cytokines-stimulated co-cultured fibroblasts, compared to unstimulated ones, showed a significant increase in the expression of IL-1β, IL-6, NAIP, AIM2, CASP1, FN1, and TGF-β genes. At the protein level, IL-1β and IL-6 release as well as FN1 were increased in stimulated, co-cultured fibroblasts. Moreover, we found a significant increase of MMP-9 production, suggesting a role of DPSCs in ECM remodeling. Our data seem to suggest a crosstalk between cultured fibroblasts and DPSCs, which seems to modulate genes involved in inflammasome activation, ECM deposition, wound healing, and fibrosis.

The association between CCR5, NLRC4, and AIM2 gene polymorphisms and susceptibility to tuberculosis in the Iraqi population

Abstract. Khaleel B, Al-Alwani HRS, Asmar A. 2024. The association between CCR5, NLRC4, and AIM2 gene polymorphisms and susceptibility to tuberculosis in the Iraqi population. Biodiversitas 25: 1022-1029. In immunological reactions against Mycobacterium tuberculosis, chemokines and their receptors, including CXCR3, CCR5, and RANTES, play an important role in the migration and activation of cells. The inflammasome is a multiprotein complex that serves as a master regulator of inflammation. Genetic polymorphisms contribute to individual phenotypic differences, such as disease risk and drug response. The current study was done to find the polymorphism in the CCR5, NLRC4, and AIM2 genes in our population and to look into how this polymorphism is linked to getting tuberculosis. Seventy-five tuberculosis patients participated in this study, while the control group comprised twenty-five control healthy individuals. We took two milliliters of blood from the patients and the control group and placed them in an Ethylenediaminetetraacetic acid (EDTA tube), or DNA extraction. Real-time PCR was used to find changes in the genes for CCR5 (rs2227010, rs2734648, rs1799987, rs1799988, rs1800023, rs1800024), NLRC4 (C-rs479333), and AIM2 (CC-rs1103577). Some genotypes were more common in the patient group, including SNPs CCR5 (rs2227010, rs2734648, rs1799988, rs1800023, rs1800024), NLRC4 C-rs479333, and AIM2 CC-rs1103577. However, by using Two-Two cross table the genotype of SNP CCR5-rs1799987 was not significantly different between the patient and the controls. Patients also had a lot of certain alleles for the SNPs CCR5 (rs2227010, rs1799988, rs1800023, rs1800024) and NLRC4 (rs479333). However, the alleles for the SNPs CCR5 (rs2734648, rs1799987) and AIM2 CC (rs1103577) were not very different between patients and controls. This study concludes that a polymorphism in various SNPs of the CCR5, NLRC4, and AIM2 genes may be a risk factor for tuberculosis.

Membrane inflammasome activation by choriodecidual Ureaplasma parvum infection without intra-amniotic infection in a Non-Human Primate model†.

Intrauterine infection is a significant cause of neonatal morbidity and mortality. Ureaplasma parvum is a microorganism commonly isolated from cases of preterm birth and preterm premature rupture of membranes (pPROM). However, the mechanisms of early stage ascending reproductive tract infection remain poorly understood. To examine inflammation in fetal (chorioamnionic) membranes we utilized a non-human primate (NHP) model of choriodecidual U. parvum infection. Eight chronically catheterized pregnant rhesus macaques underwent maternal-fetal catheterization surgery at ~105-112 days gestation and choriodecidual inoculation with U. parvum (105 CFU/mL, n =4) or sterile media (controls; n = 4) starting at 115-119 days, repeated at 5-day intervals until C-section at 136-140 days (term=167 days). The average inoculation to delivery interval was 21 days, and Ureaplasma infection of the amniotic fluid (AF) was undetectable in all animals. Choriodecidual Ureaplasma infection resulted in increased fetal membrane expression of MMP-9 and PTGS2, but did not result in preterm labor or increased concentrations of AF pro-inflammatory cytokines. However, membrane expression of inflammasome sensors, NLRP3, NLRC4, AIM2, and NOD2, and adaptor ASC (PYCARD) gene expression were significantly increased. Gene expression of IL-1β, IL-18, IL-18R1 , CASPASE-1, and pro-CASPASE-1 protein increased with Ureaplasma infection. Downstream inflammatory genes MYD88 and NFκB (Nuclear factor kappa-light-chain-enhancer of activated B cells) were also significantly upregulated. These results demonstrate that choriodecidualUreaplasma infection, can cause activation of inflammasome complexes and pathways associated with pPROM and preterm labor prior to microbes being detectable in the AF.

Characterization of two transcriptomic subtypes of marker-null large cell carcinoma of the lung suggests different origin and potential new therapeutic perspectives

Pulmonary large cell carcinoma (LCC) is an undifferentiated neoplasm lacking morphological, histochemical, and immunohistochemical features of small cell lung cancer, adenocarcinoma (ADC), or squamous cell carcinoma (SCC). The available molecular information on this rare disease is limited. This study aimed to provide an integrated molecular overview of 16 cases evaluating the mutational asset of 409 genes and the transcriptomic profiles of 20,815 genes. Our data showed that TP53 was the most frequently inactivated gene (15/16; 93.7%) followed by RB1 (5/16; 31.3%) and KEAP1 (4/16; 25%), while CRKL and MYB genes were each amplified in 4/16 (25%) cases and MYC in 3/16 (18.8%) cases; transcriptomic analysis identified two molecular subtypes including a Pure-LCC and an adenocarcinoma like-LCC (ADLike-LCC) characterized by different activated pathways and cell of origin. In the Pure-LCC group, POU2F3 and FOXI1 were distinctive overexpressed markers. A tuft cell-like profile and the enrichment of a replication stress signature, particularly involving ATR, was related to this profile. Differently, the ADLike-LCC were characterized by an alveolar-cell transcriptomic profile and association with AIM2 inflammasome complex signature. In conclusion, our study split the histological marker-null LCC into two different transcriptomic entities, with POU2F3, FOXI1, and AIM2 genes as differential expression markers that might be probed by immunohistochemistry for the differential diagnosis between Pure-LCC and ADLike-LCC. Finally, the identification of several signatures linked to replication stress in Pure-LCC and inflammasome complex in ADLike-LCC could be useful for designing new potential therapeutic approaches for these subtypes.

Association Between AIM2 and Pycard Genes Polymorphisms and Susceptibility to Periodontitis with Coronary Heart Disease.

Numerous genetic variations in inflammasome components are linked to prevalent disorders in the general population, including periodontitis and cardiovascular illness. Polymorphisms in the genes play a critical in the initiation and development of inflammatory diseases. The limited study on AIM2 gene variation associated with inflammatory disease and no study of PYCARD gene variation associated with inflammatory disease. This case-control study was to examine the association between the single nucleotide polymorphism of AIM2 and Pycard genes with susceptibility to periodontitis with and without coronary heart disease, to determine interleuken-18 and gasdermin D levels in the saliva of periodontitis with and without coronary heart disease patients, as well as their correlation with salivary interleuken-18 and gasdermin D levels and clinical periodontal parameters. The present study recruited 120 participants: 30 were healthy subjects (control, C), 30 had generalized periodontitis (P), 30 had atherosclerosis coronary heart disease with clinically healthy periodontium (AS-C), and 30 had atherosclerosis coronary heart disease with generalized periodontitis (AS-P). All individuals' demographic data recorded, saliva and blood samples collected, then periodontal characteristics were detailed. These parameters include plaque index, bleeding on probing, probing pocket depth, and clinical attachment loss. AIM2 and Pycard gene polymorphisms were analyzed by polymerase chain reaction assay, electrophoresis and sequencing. An enzyme-linked immunosorbent assay (ELISA) was conducted to determine the level of interleuken-18 and gasdermin D in their saliva. The study result of high frequency (T) in single-nucleotide polymorphisms. The high genotypes distribution of GT and TT genotypes in the AIM2 gene and the CT and TT genotypes in the Pycard gene were detected in the periodontitis, atherosclerosis coronary heart disease with healthy periodontium and atherosclerosis coronary heart disease with generalized periodontitis groups as compared to control group. Elevation of salivary interleuken-18 and gasdermin D levels in three patients' groups compared to healthy controls. Both these single-nucleotide polymorphisms also significantly correlated with higher salivary interleuken-18 and gasdermin D levels and worse clinical indices of periodontitis. Single-nucleotide polymorphisms in the AIM2 and Pycard genes are associated with an increased risk of developing periodontitis with and/or without coronary heart disease. Elevation of salivary interleuken-18 and gasdermin D levels associated and impacted on periodontitis with and/or without coronary heart disease. These single-nucleotide polymorphisms may provide evidence for a genetic role in the pathogenesis of periodontitis with and without atherosclerosis coronary heart disease.

Genetic modification of inflammation- and clonal hematopoiesis-associated cardiovascular risk.

Clonal hematopoiesis of indeterminate potential (CHIP) is associated with an increased risk of cardiovascular diseases (CVDs), putatively via inflammasome activation. We pursued an inflammatory gene modifier scan for CHIP-associated CVD risk among 424,651 UK Biobank participants. We identified CHIP using whole-exome sequencing data of blood DNA and modeled as a composite, considering all driver genes together, as well as separately for common drivers (DNMT3A, TET2, ASXL1, and JAK2). We developed predicted gene expression scores for 26 inflammasome-related genes and assessed how they modify CHIP-associated CVD risk. We identified IL1RAP as a potential key molecule for CHIP-associated CVD risk across genes and increased AIM2 gene expression leading to heightened JAK2- and ASXL1-associated CVD risk. We show that CRISPR-induced Asxl1-mutated murine macrophages had a particularly heightened inflammatory response to AIM2 agonism, associated with an increased DNA damage response, as well as increased IL-10 secretion, mirroring a CVD-protective effect of IL10 expression in ASXL1 CHIP. Our study supports the role of inflammasomes in CHIP-associated CVD and provides evidence to support gene-specific strategies to address CHIP-associated CVD risk.

Elevated expression of the AIM2 gene in response to Helicobacter pylori along with the decrease of NLRC4 inflammasome is associated with peptic ulcer development.

Helicobacter Pylori (H. Pylori) cause peptic ulcer disease (PUD), but the inflammasome's role in PUD is not well understood. Therefore this study has investigated inflammasome compartment expression and IL-1β production in gastritis (G) and peptic ulcer disease. This study was based on gene expression of inflammasome compartments on stomach biopsies of 50 patients with PUD as cases and 50 individuals with gastritis as controls. The expression of NLRC4, ASC, IL-18, and serum IL-1β decreased in the PUD group compared to the control group. AIM2 gene expression increased, and NLRP12 gene expression decreased in H. pylori-seropositive positive (HP+ ) individuals compared to H. pylori-seronegative (HP- ) individuals. The G-HP+ subjects had higher serum IL-1β and AIM2 gene expression than G-HP- subjects but lower NLRP3 and NLRP12 gene expression. The PUD-HP+ had lower serum IL-1β, but higher AIM2 and IL-18 expression than PUD-HP- . The PUD-HP- patients had decreased IL-18 expression than G-HP- group. The PUD-HP+ had lower serum IL-1β and NLRC4 expression than G-HP+, while NLRP1 and NLRP3 were higher in expression in PUD-HP+ . The expression of caspase-1, NLRP3 and NAIP were correlated with IL-1β and IL-18. In conclusion, a decrease in NLRC4, IL-18, ASC genes, and IL-1β levels in PUD patients compared to gastritis may act in the development of PUD. H. pylori caused AIM2 induction and reduced NLRP12, indicating their contribution to bacterial responses. Decreased NLRC4 expression and IL-1β protein, together with enhanced NLRP1, and NLRP3 expression, promotes H. pylori to develop peptic ulcers.

Impact of nsSNPs in human AIM2 and IFI16 gene: a comprehensive in silico analysis

AIM2 and IFI16 are the most studied members of AIM2-like receptors (ALRs) in humans and share a common N-Terminal PYD domain and C-terminal HIN domain. The HIN domain binds to dsDNA in response to the invasion of bacterial and viral DNA, and the PYD domain directs apoptosis-associated speck-like protein via protein–protein interactions. Hence, activation of AIM2 and IFI16 is crucial for protection against pathogenic assaults, and any genetic variation in these inflammasomes can dysregulate the human immune system. In this study, different computational tools were used to identify the most deleterious and disease-causing non-synonymous single nucleotide polymorphisms (nsSNPs) in AIM2 and IFI16 proteins. Molecular dynamic simulation was performed for the top damaging nsSNPs to study single amino acid substitution-induced structural alterations in AIM2 and IFI16. The observed results suggest that the variants G13V, C304R, G266R, and G266D for AIM2, and G13E and C356F are deleterious and affect structural integrity. We hope that the suggested deleterious nsSNPs and structural dynamics of AIM2 and IFI16 variants will guide future research to better understand the function of these variants with large-scale studies and may assist in fresher therapeutics focusing on these polymorphisms. Communicated by Ramaswamy H. Sarma

The cytosolic DNA sensor AIM2 promotes Helicobacter-induced gastric pathology via the inflammasome.

Helicobacter pylori (H. pylori) infection can trigger chronic gastric inflammation perpetuated by overactivation of the innate immune system, leading to a cascade of precancerous lesions culminating in gastric cancer. However, key regulators of innate immunity that promote H. pylori-induced gastric pathology remain ill-defined. The innate immune cytosolic DNA sensor absent in melanoma 2 (AIM2) contributes to the pathogenesis of numerous autoimmune and chronic inflammatory diseases, as well as cancers including gastric cancer. We therefore investigated whether AIM2 contributed to the pathogenesis of Helicobacter-induced gastric disease. Here, we reveal that AIM2 messenger RNA and protein expression levels are elevated in H. pylori-positive versus H. pylori-negative human gastric biopsies. Similarly, chronic Helicobacter felis infection in wild-type mice augmented Aim2 gene expression levels compared with uninfected controls. Notably, gastric inflammation and hyperplasia were less severe in H. felis-infected Aim2-/- versus wild-type mice, evidenced by reductions in gastric immune cell infiltrates, mucosal thickness and proinflammatory cytokine and chemokine release. In addition, H. felis-driven proliferation and apoptosis in both gastric epithelial and immune cells were largely attenuated in Aim2-/- stomachs. These observations in Aim2-/- mouse stomachs correlated with decreased levels of inflammasome activity (caspase-1 cleavage) and the mature inflammasome effector cytokine, interleukin-1β. Taken together, this work uncovers a pathogenic role for the AIM2 inflammasome in Helicobacter-induced gastric disease, and furthers our understanding of the host immune response to a common pathogen and the complex and varying roles of AIM2 at different stages of cancerous and precancerous gastric disease.

Autoinflammation in Syndromic Hidradenitis Suppurativa: The Role of AIM2.

AIM2 is a key cytoplasmatic pathogen-sensor that detects foreign DNA from viruses and bacteria; it can also recognize damaged or anomalous presence of DNA, promoting inflammasome assembly and activation with the secretion of IL-1β, thus sustaining a chronic inflammatory state, potentially leading to the onset of autoinflammatory skin diseases. Given the implication of the IL-1β pathway in the pathogenesis of syndromic hidradenitis suppurativa (HS), an autoinflammatory immune-mediated skin condition, the potential involvement of AIM2 was investigated. Sequencing of the whole coding region of the AIM2 gene, comprising 5'- and 3' UTR and a region upstream of the first exon of ~800 bp was performed in twelve syndromic HS patients. Six out of twelve syndromic HS patients carried a heterozygous variant c.-208 A ≥ C (rs41264459), located on the promoter region of the AIM2 gene, with a minor allele frequency of 0.25, which is much higher than that reported in 1000 G and GnomAD (0.075 and 0.094, respectively). The same variant was found at a lower allelic frequency in sporadic HS and isolated pyoderma gangrenosum (PG) (0.125 and 0.065, respectively). Our data suggest that this variant might play a role in susceptibility to develop syndromic forms of HS but not to progress to sporadic HS and PG. Furthermore, epigenetic and/or somatic variations could affect AIM2 expression leading to different, context-dependent responses.

A Targeted Epigenetic Clock for the Prediction of Biological Age.

Epigenetic clocks were initially developed to track chronological age, but accumulating evidence indicates that they can also predict biological age. They are usually based on the analysis of DNA methylation by genome-wide methods, but targeted approaches, based on the assessment of a small number of CpG sites, are advisable in several settings. In this study, we developed a targeted epigenetic clock purposely optimized for the measurement of biological age. The clock includes six genomic regions mapping in ELOVL2, NHLRC1, AIM2, EDARADD, SIRT7 and TFAP2E genes, selected from a re-analysis of existing microarray data, whose DNA methylation is measured by EpiTYPER assay. In healthy subjects (n = 278), epigenetic age calculated using the targeted clock was highly correlated with chronological age (Spearman correlation = 0.89). Most importantly, and in agreement with previous results from genome-wide clocks, epigenetic age was significantly higher and lower than expected in models of increased (persons with Down syndrome, n = 62) and decreased (centenarians, n = 106; centenarians' offspring, n = 143; nutritional intervention in elderly, n = 233) biological age, respectively. These results support the potential of our targeted epigenetic clock as a new marker of biological age and open its evaluation in large cohorts to further promote the assessment of biological age in healthcare practice.

Association between expression of ZBP1, AIM2, and MDA5 genes and severity of COVID-19.

Antiviral and inflammatory responses following the detection of the virus genome by nucleic acid sensors play a vital role in the pathogenesis and outcome of diseases. In this study, we investigated the ZBP1, AIM2, and MDA5 expression levels in COVID-19 patients with different intensities of the disease. 75 quantitative Real-Time PCR (qRT-PCR)-confirmed COVID-19 patients were included consecutively and divided into 3 groups of mild, severe, and critical based on the severity of the disease. Also, 25 healthy volunteer subjects were included. PBMCs were collected from the whole blood, and RNA was extracted using commercial kit. The expression of ZBP1, AIM2, and MDA5 genes was investigated using qRT-PCR technique. The mean age of the patients and healthy volunteers was 52.73±13.78 and 49.120±12.490, respectively. In each group, 13 out of 25 participants were male. The expression levels of ZBP1 (P=0.001), AIM2 (P=0.001), and MDA5 (P= 0.003) transcript were significantly higher in COVID-19 patients than the control group. The results also revealed that the expression levels of ZBP1, AIM2, and MDA5 were significantly higher in the critical and severe COVID-19 patients compared to those with mild disease (P<0.05). Moreover, regarding the gender, the expression levels of AIM2 and MDA5 were significantly elevated in male severe (P=0.04 and P=0.003, respectively) and critical (P=0.005 and P=0.0004, respectively) patients than the female ones. The results indicated that ZBP1, AIM2, and MDA5 genes might have an important role in the severity of COVID-19 disease. Moreover, the severity of COVID-19 disease in male and female patients might be related to AIM2, and MDA5 expression levels. More studies are recommended to be conducted to clarify this issue.

A novel probiotic strain exerts therapeutic effects on mouse model of multiple sclerosis by altering the expression of inflammasome and IDO genes and modulation of T helper cytokine profile.

Multiple sclerosis is an inflammatory demyelinating disease that commences to neuronal cell destruction. Recently, a promising evidence of synergic effects of combined supplementation with vitamin D and probiotics in modulating the gut microbiota and metabolome is emerging. Bacillus Coagulans IBRC-M10791 as a novel strain was chosen, prevention and treatment impacts of regular administered were studied in Cuprizone-induced C57bl/6 mouse of demyelination. The mice were divided into six groups and received a daily dose of cuprizone or probiotics. To investigate the effect of probiotic, the IDO-1, CYP27B1, NLRP1, NLRP3, and AIM2 expression were estimated by Real-Time PCR, and IL-4, IL-17, IFN-gamma, and TGF-beta cytokines were measured by ELISA. The results showed that there was significant decrease in IL-17 and IFN-γ and modulatory effects on IL-4 and TGF-β. On the other hand, we demonstrated that there are significant decrease for expression of IDO-1, CYP27b1, NLRP1, NLRP3 and AIM2 genes in prevention and treatment groups compared to cuprizone group. Also, a significant enhancement in rate of remyelination and alternations proved by LFB staining and Y-Maze test. In conclusion, our study provides insight into how the therapeutic effect of the chosen strain of probiotic was correlated with the modulation of the level of inflammatory and anti-inflammatory cytokines. Further, we demonstrated that the expression of genes related to Tryptophan, Vitamin D and Inflammasome pathways could be affected by B.coagulans. Our study could be beneficial to provide a novel Co-therapeutic strategy for Multiple sclerosis.

Neutrophil Extracellular Traps Augmented Alveolar Macrophage Pyroptosis via AIM2 Inflammasome Activation in LPS-Induced ALI/ARDS.

BackgroundUncontrollable inflammation is a critical feature of gram-negative bacterial pneumonia-induced acute respiratory distress syndrome (ARDS). Both neutrophils and alveolar macrophages participate in inflammation, but how their interaction augments inflammation and triggers ARDS is unclear. The authors hypothesize that neutrophil extracellular traps (NETs), which are formed during neutrophil NETosis, partly cause alveolar macrophage pyroptosis and worsen the severity of ARDS.MethodsThe authors first analysed whether NETs and caspase-1 are involved in clinical cases of ARDS. Then, the authors employed a lipopolysaccharide (LPS)-induced ARDS model to investigate whether targeting NETs or alveolar macrophages is protective. The AIM2 sensor can bind to DNA to promote AIM2 inflammasome activation, so the authors studied whether degradation of NET DNA or silencing of the AIM2 gene could protect alveolar macrophages from pyroptosis in vitro.ResultsAnalysis of aspirate supernatants from ARDS patients showed that NET and caspase-1 levels were correlated with the severity of ARDS and that the levels of NETs and caspase-1 were higher in nonsurvivors than in survivors. In vivo, the NET level and proportion of pyroptotic alveolar macrophages in bronchoalveolar lavage fluid (BALF) were obviously higher in LPS-challenged mice than in control mice 24 h after injury. Administration of DNase I (a NET DNA-degrading agent) and BB-Cl-amidine (a NET formation inhibitor) alleviated alveolar macrophage pyroptosis, and Ac-YVAD-cmk (a pyroptosis inhibitor) attenuated NET levels in BALF and neutrophil infiltration in alveoli. All treatments markedly attenuated the severity of ARDS. Notably, LPS causes NETs to induce alveolar macrophage pyroptosis, and degradation of NET DNA or silencing of the AIM2 gene protected against alveolar macrophage pyroptosis.ConclusionThese findings shed light on the proinflammatory role of NETs in mediating the neutrophil–alveolar macrophage interaction, which influences the progression of ARDS.

A systemic inflammatory response primes blood monocytes in cutaneous leishmaniasis

Abstract Cutaneous leishmaniasis is a localized infection controlled by CD4+ T cells that produce IFN-y within lesions. Phagocytic cells recruited to lesions are exposed to IFN-y which triggers their ability to kill the intracellular parasites. To determine what systemic responses are occurring that might influence the disease, we performed RNA sequencing (RNA-seq) on the blood of 50 L. braziliensis-infected patients, as well as 14 healthy controls. Genes reflecting Interferon downstream activation such as GBP1-6, STAT1, IDO1, AIM2, BATF2, SOCS1 and FCGR-related genes, were upregulated in patients and functional enrichment analysis identified a transcriptional type II Interferon-stimulated gene (ISG) signature as the dominant response. An increase in monocytes and macrophages in the blood, estimated from our RNA-seq dataset, was positively correlated with this type II ISG signature. Consistent with this result, patients had circulating IFN-y in their serum. Monocytes in the bone marrow and circulating in the blood of mice infected with leishmania exhibited increased expression of Class II, further supporting the premise that there is a systemic response to infection. Together, these results suggest that there is a mechanism to limit systemic spread of the parasites, as well as enhance parasite control by pre-activating cells prior to lesion entry.

Analysis of inflammasomes and CYP27B1 genes in cuprizone demyelinated C57BL/6 mice and evaluation of Th1 and Th2 patterns after oral administration of Lactobacillus casei strain T2 (IBRC-M10783)

Multiple sclerosis is characterized by the destruction of myelin in the CNS. Various factors including genetics, epigenetics, and environmental factors are involved in the development of the disease. There is evidence that changes in the gut microbiome profile are associated with immune-related diseases such as MS. Probiotics can alter the composition of the gut microbiota on the mucosal surfaces by differentiating naive T cells into Th1, Th2, Th17, and Treg cells. Female C57BL/6 mice were divided into 6 groups (n = 7): Normal group, cuprizone group (gavage of cuprizone for 4 weeks), Probiotic group (gavage of probiotic for 4 weeks), Treatment1 group (Probiotic for 4 weeks and then cuprizone for 4 weeks), treatment2 group (cuprizone for 4 weeks and then probiotic for 4 weeks) and treatment3 group (cuprizone for 4 weeks and then probiotic for 4 weeks with vitamin D3). Then the expression of NLRP-1, NLRP-3, AIM2, and CYP27B1 genes were evaluated using Real-Time PCR, and serum levels of IFN-γ and IL-4 were also measured by ELISA.The results showed a significant decrease in the expression of inflammasome and CYP27B1 genes in the probiotic-treated groups compared to the cuprizone group. Also, the comparison between probiotic-treated groups and cuprizone group showed a significant decrease in the amount of IFN-γ and IL-4. Due to reduced expression of the inflammasome genes as well as the decrease in IFN-γ levels as an inflammatory cytokine, it appears that L. casei may be effective in the healing process of demyelinated mice.

Common Features of the DNA Methylation Landscape of Human Naïve and Memory CD4, CD8 T Cells and B Cells

Epigenetic mechanisms including DNA methylation are critical drivers of immune cell lineage differentiation and activation. However, there has been limited coordinated investigation of common pathways in distinct cell types for immunological processes such as immune memory. Further, it remains unclear if the genesis of memory in both CD4 and CD8 lineages proceeds via a linear course of differentiation or progresses in a circular ‘on-off-on’ sequence, which is epigenetically driven. Here, we scanned genome-wide differences in DNA methylation among CD4 and CD8 naive and memory cells states and combined this data with similar data on naive and memory B cell states. Our findings, overall, are consistent with the literature describing the DNA methylome as a major driver of individual central and effector T cell memory states as well as in memory B cells. We observed unusually large differences in DNA methylation in thousands of CpG sites in hundreds of genes associated with the development of memory in each lineage, contributing considerably to our knowledge of the loci regulated during lymphocyte memory generation. Our data similarly describe considerable overlap in genes with altered DNA methylation in the T cell lineage, with primarily a loss of DNA methylation in over 125,000 CpGs significantly associated with the generation of central memory in both CD4 and CD8 cells Furthermore, our analyses revealed specific CpG dinucleotides in both CD4 and CD8 cells whose methylation pattern is consistent with the circular model of memory generation. Finally, as evidence of common pathways in the generation of immune memory we highlight 22 gene loci, including several within the promoter region of the AIM2 gene, with dramatically altered DNA methylation in all three memory lineages.

Differential expression of the inflammasome complex genes in systemic lupus erythematosus.

Systemic lupus erythematosus (SLE) is a complex autoimmune disorder involving heterogeneous clinical manifestations and numerous susceptibility genes. Several findings evidence the critical role of inflammasomes in the predisposition to autoimmune diseases and in SLE. We investigated whether inflammasome polymorphins could affect susceptibility to develop and/or severity SLE. Moreover, differences in inflammasome activation in peripheral blood were also evaluated in SLE patients and controls. The distribution of 13 SNPs in eight inflammasome genes was evaluated. To assess inflammasome priming in peripheral blood monocytes of SLE and controls, differential expression of selected inflammasome genes and IL-1ß production was analyzed in resting condition as well as after LPS and ATP stimulation. Results showed that the gain-of-function variant rs10754558 (NLRP3) was significantly more frequent in SLE patients with nephritis, reinforcing the concept of a key role of NLRP3 inflammasome not only in SLE but also especially in kidney disease. SLE monocytes in resting condition showed a higher level of IL-1ß expression and produced higher levels of IL-1ß when stimulated with LPS+ATP comparing to controls. The stimulation induced a significant expression of NLRP1, AIM2, CASP1, and IL1B genes, suggesting that the NLRP1 inflammasome is responsible for the IL-1ß production observed in monocytes. These data emphasized once more the important contribution of inflammasome in SLE-associated inflammation.