NOD2 Research Articles

The CARD9 Gene in Koalas (Phascolarctos cinereus): Does It Play a Role in the Cryptococcus-Koala Interaction?

Cryptococcus is a genus of fungal pathogens that can infect and cause disease in a range of host species and is particularly prominent in koalas (Phascolarctos cinerus). Like other host species, koalas display a range of outcomes upon exposure to environmental Cryptococcus, from external nasal colonization to asymptomatic invasive infection and, in rare cases, severe clinical disease resulting in death. Host factors contributing to these varied outcomes are poorly understood. Due to their close relationship with eucalypt trees (a key environmental niche for Cryptococcus gattii) and suspected continual exposure to the pathogen, koalas provide a unique opportunity to examine host susceptibility in natural infections. Caspase recruitment domain-containing protein 9 (CARD9) is a key intracellular signaling protein in the fungal innate immune response. Humans with mutations in CARD9 succumb to several different severe and chronic fungal infections. This study is the first to sequence and explore CARD9 variation in multiple koalas using Sanger sequencing. Four CARD9 exons were successfully sequenced in 22 koalas from a New South Wales, Australia population. We found minimal variation between koalas across all four exons, an observation that was also made when CARD9 sequences were compared between koalas and six other species, including humans and mice. Ten single-nucleotide polymorphisms (SNP) were identified in this study and explored in the context of cryptococcal exposure outcomes. While we did not find any significant association with variation in cryptococcal outcomes, we found a high degree of conservation between species at several SNP loci that requires further investigation. The findings from this study lay the groundwork for further investigations of CARD9 and Cryptococcus both in koalas and other species, and highlight several considerations for future studies.

A phase I, first-in-human study of ONO-7018 in patients with relapsed/refractory non-Hodgkin lymphoma or chronic lymphocytic leukemia.

TPS7083 Background: Mucosa-associated lymphoid tissue lymphoma translocation protein 1 (MALT1) is a key component of the caspase recruitment domain-containing protein 11 (CARD 11)-B-cell lymphoma/leukemia 10 (BCL 10)-MALT1 signalosome complex, which activates nuclear factor-kappaB (NF-κB) signaling in response to B-cell–receptor or T-cell–receptor stimulation. Activation of NF-κB signaling promotes survival and proliferation of B-cell lymphoma and T-cell lymphoma. ONO-7018 is an oral, potent, and selective MALT1 inhibitor that has demonstrated preclinical efficacy in several lymphoma models (Morishita D, et al. Blood. 2020). Therefore, ONO-7018 has therapeutic potential for non-Hodgkin lymphoma (NHL) and chronic lymphocytic leukemia (CLL). This study aims to determine the maximum tolerated dose (MTD) and to evaluate the safety, tolerability, pharmacokinetics, pharmacodynamics, and efficacy of ONO-7018 as monotherapy in patients with relapsed or refractory NHL or CLL. Methods: This Phase I, first-in-human, open-label, multicenter study will be done in two parts, a dose-escalation phase (part 1) and a dose-expansion phase (part 2). An estimated 54 eligible patients will be enrolled. Patients must be adults with relapsed/refractory NHL or CLL with measurable disease; all acute toxic effects of prior antitumor therapy should be grade ≤1; have Eastern Cooperative Oncology Group performance status 0 to 2; and have adequate bone marrow, renal, and hepatic function. Exclusion criteria include history of other lymphoid malignancy, central nervous system involvement, active autoimmune disease, systemic and active infection, serious or uncontrolled medical disorder, and patient inability to swallow tablets. ONO-7018 will be administered orally. In part 1, patients will be assigned to a dose level cohort (≤4 dose levels: DL1-DL4) using a 3+3 dose-escalation design. In part 2, patients will be given the recommended dose level from part 1, following safety review. The primary endpoints include dose-limiting toxicity, MTD, and treatment-emergent adverse events. Secondary endpoints include pharmacokinetics, objective response rate, duration of response, progression-free survival, and overall survival. The study began February 13, 2023, and is currently recruiting; part 1 is ongoing. Clinical trial information: NCT05515406 .

Polo-like kinase 1 (PLK1) is a novel CARD14-binding protein in keratinocytes

Caspase recruitment domain (CARD)-containing protein 14 (CARD14) is an intracellular protein that mediates nuclear factor-kappa B (NF-ĸB) signaling and proinflammatory gene expression in skin keratinocytes. Several hyperactivating CARD14 mutations have been associated with psoriasis and other inflammatory skin diseases. CARD14-induced NF-ĸB signaling is dependent on the formation of a CARD14-BCL10-MALT1 (CBM) signaling complex, but upstream receptors and molecular mechanisms that activate and regulate CARD14 signaling are still largely unclear. Using unbiased affinity purification and mass spectrometry (AP-MS) screening, we discover polo-like kinase 1 (PLK1) as a novel CARD14-binding protein. CARD14-PLK1 binding is independent of the CARD14 CARD domain but involves a consensus phospho-dependent PLK1-binding motif in the CARD14 linker region (LR). Expression of the psoriasis-associated CARD14(E138A) variant in human keratinocytes induces the recruitment of PLK1 to CARD14-containing signalosomes in interphase cells, but does not affect the specific location of PLK1 in mitotic cells. Finally, disruption of the PLK1-binding motif in CARD14(E138A) increases CARD14-induced proinflammatory signaling and gene expression. Together, our data identify PLK1 as a novel CARD14-binding protein and indicate a negative regulatory role for PLK1 in CARD14 signaling.

Role and molecular mechanism of NOD2 in chronic non-communicable diseases.

Nucleotide-binding oligomerization domain containing 2 (NOD2), located in the cell cytoplasm, is a pattern recognition receptor belonging to the innate immune receptor family. It mediates the innate immune response by identifying conserved sequences in bacterial peptide glycans and plays an essential role in maintaining immune system homeostasis. Gene mutations of NOD2 lead to the development of autoimmune diseases such as Crohn's disease and Blau syndrome. Recently, NOD2 has been shown to be associated with the pathogenesis of diabetes, cardiac-cerebral diseases, and cancers. However, the function of NOD2 in these non-communicable diseases (CNCDs) is not well summarized in reviews. Our report mainly discusses the primary function and molecular mechanism of NOD2 as well as its potential clinical significance in CNCDs.

Increased susceptibility to Mycobacterium avium complex infection in miniature Schnauzer dogs caused by a codon deletion in CARD9

Mammals are generally resistant to Mycobacterium avium complex (MAC) infections. We report here on a primary immunodeficiency disorder causing increased susceptibility to MAC infections in a canine breed. Adult Miniature Schnauzers developing progressive systemic MAC infections were related to a common founder, and pedigree analysis was consistent with an autosomal recessive trait. A genome-wide association study and homozygosity mapping using 8 infected, 9 non-infected relatives, and 160 control Miniature Schnauzers detected an associated region on chromosome 9. Whole genome sequencing of 2 MAC-infected dogs identified a codon deletion in the CARD9 gene (c.493_495del; p.Lys165del). Genotyping of Miniature Schnauzers revealed the presence of this mutant CARD9 allele worldwide, and all tested MAC-infected dogs were homozygous mutants. Peripheral blood mononuclear cells from a dog homozygous for the CARD9 variant exhibited a dysfunctional CARD9 protein with impaired TNF-α production upon stimulation with the fungal polysaccharide β-glucan that activates the CARD9-coupled C-type lectin receptor, Dectin-1. While CARD9-deficient knockout mice are susceptible to experimental challenges by fungi and mycobacteria, Miniature Schnauzer dogs with systemic MAC susceptibility represent the first spontaneous animal model of CARD9 deficiency, which will help to further elucidate host defense mechanisms against mycobacteria and fungi and assess potential therapies for animals and humans.

Innate phase production of IFN-γ by memory and effector T cells expressing early activation marker CD69 during infection with Cryptococcus deneoformans in the lungs.

Cryptococcus deneoformans is a yeast-type fungus that causes fatal meningoencephalitis in immunocompromised patients and evades phagocytic cell elimination through an escape mechanism. Memory T (Tm) cells play a central role in preventing the reactivation of this fungal pathogen. Among these cells, tissue-resident memory T (TRM) cells quickly respond to locally invaded pathogens. This study analyzes the kinetics of effector T (Teff) cells and Tm cells in the lungs after cryptococcal infection. Emphasis is placed on the kinetics and cytokine expression of TRM cells in the early phase of infection. CD4+ Tm cells exhibited a rapid increase by day 3, peaked at day 7, and then either maintained their levels or exhibited a slight decrease until day 56. In contrast, CD8+ Tm cells reached their peak on day 3 and thereafter decreased up to day 56 post-infection. These Tm cells were predominantly composed of CD69+ TRM cells and CD69+ CD103+ TRM cells. Disruption of the CARD9 gene resulted in reduced accumulation of these TRM cells and diminished interferon (IFN) -γ expression in TRM cells. TRM cells were derived from T cells with T cell receptors non-specific to ovalbumin in OT-II mice during cryptococcal infection. In addition, TRM cells exhibited varied behavior in different tissues. These results underscore the importance of T cells, which produce IFN-γ in the lungs during the early stage of infection, in providing early protection against cryptococcal infection through CARD9 signaling.

Uncommon Variants in FLG2 and NOD2 Are Associated with Atopic Dermatitis in the Ethiopian Population

Loss-of-function variants in the filaggrin gene (FLG) have been identified as the strongest cause of susceptibility to atopic dermatitis (AD) in Europeans and Asians. However, very little is known about the genetic etiology behind AD in African populations, where the prevalence of AD is notably high. We sought to investigate the genetic origins of AD by performing whole-genome sequencing in an Ethiopian family with 12 individuals and several affected in different generations. We identified two variants within FLG2 (D13Y) and NOD2 (A918S) genes co-segregating with AD in the affected individuals. Further genotyping analyses in both Ethiopian and Swedish AD cases and controls revealed a significant association with the FLG2 variant (D13Y, p < 0.0013) only in the Ethiopian cohort. However, the NOD2 variant (A918S) did not show any association in our Ethiopian cohort. Instead, two previously recognized NOD2 variants (A849V, p < 0.0085, and G908R, p < 0.0036) were significantly associated with AD in our Ethiopian cohort. Our study indicates that the FLG2 and NOD2 genes might be important in the etiology of AD in Ethiopians. Additional genetic and functional studies are needed to confirm the role of these genes and the associated variants into the development of AD.

Functional characterization of NOD1 from golden pompano Trachinotus ovatus

Fish rely on innate immune system for immunity, and nucleotide-binding oligomerization domain-like receptors (NLRs) are a vital group of receptor for recognition. In the present study, NOD1 gene was cloned and characterized from golden pompano Trachinotus ovatus, a commercially important aquaculture fish species. The ORF of T. ovatus NOD1 was 2820 bp long, encoding 939 amino acid residues with a highly conserved domains containing CARD-NACHT-LRRs. Phylogenetic analysis revealed that the T. ovatus NOD1 clustered with those of fish and separated from those of birds and mammals. T. ovatus NOD1 has wide tissue distribution with the highest expression in gills. Bacterial challenges (Streptococcus agalactiae and Vibrio alginolyticus) significantly up-regulated the expression of NOD1 with different response time. The results of T. ovatus NOD1 ligand recognition and signaling pathway analysis revealed that T. ovatus NOD1 could recognize iE-DAP at the concentration of ≧ 100 ng/mL and able to activate NF-κB signaling pathway. This study confirmed that NOD1 play a crucial role in the innate immunity of T. ovatus. The findings of this study improve our understanding on the immune function of NOD1 in teleost, especially T. ovatus.

A Systemic Review and Meta-analysis on Natural Resistance-associated Macrophage Protein 1 (3'-Untranslated Region) and Nucleotide-binding Oligomerization Domain-2 (rs8057341) Polymorphisms and Leprosy Susceptibility in Asian and Caucasian Populations.

The current meta-analysis aims to explore the potential correlation between natural resistance-associated macrophage protein 1 (NRAMP1) (3'-Untranslated region [3'-UTR]) and nucleotide-binding oligomerization domain-2 (NOD2 [rs8057341]) gene polymorphisms and their association with leprosy susceptibility in both Asian and Caucasian populations. Datas were retrieved from case control studies with NOD 2 and NRAMP 1 gene polymorphism associated with leprosy disease. Leprosy emerges as a particularly distinctive ailment among women on a global scale. The NRAMP1 (3'-UTR) and NOD2 (rs8057341) genetic variations play a crucial role in the progression of leprosy. A systematic review of relevant case-control studies was conducted across several databases, including ScienceDirect, PubMed, Google Scholar, and Embase. Utilizing MetaGenyo and Review Manager 5.4 Version, statistical analyses were carried out. Nine case-control studies totaling 3281 controls and 3062 leprosy patients are included in the research, with the objective of examining the potential association between NRAMP1 (3'-UTR) and NOD2 (rs8057341) gene polymorphisms and leprosy risk. The review methodology was registered in PROSPERO (ID520883). The findings reveal a robust association between NRAMP1 (3'-UTR) and NOD2 (rs8057341) gene polymorphisms and leprosy risk across various genetic models. Although the funnel plot analysis did not identify publication bias, bolstering these findings and elucidating potential gene-gene and gene-environment interactions require further comprehensive epidemiological research. This study identified a strong correlation between polymorphisms in the NOD2 (rs8057341) genes and susceptibility to leprosy across two genetic models. Further comprehensive epidemiological investigations are warranted to validate these findings and explore potential interactions between these genes and environmental factors.

Abstract 6986: Oncogenic CARD11 enhances marginal zone B cell survival by potentiating the non-canonical NF-κB pathway

Abstract Dysregulation of antigen receptor-mediated signaling contributes to the oncogenesis of lymphoid malignancies. The activated B cell-like (ABC) subtype of Diffuse Large B cell Lymphoma (DLBCL) is characterized by receptor-independent constitutive activation of the canonical nuclear factor-kappaB (NF-κB) pathway, which is essential for the proliferation and survival of tumor cells. Caspase recruitment domain-containing protein 11 (CARD11) is a scaffolding protein that regulates B and T cell receptor signaling to canonical NF-κB activation downstream for adaptive immune response. Oncogenic gain-of-function (GOF) CARD11 mutations bypass normal pathway regulation and result in a hyperactive CARD11 that signals constitutively. Although present in ~10% of human ABC-DLBCL biopsies, we do not have a complete mechanistic understanding of how CARD11 GOF mutations drive abnormal B cell proliferation to cause lymphoma. We generated a mouse expressing the DLBCL-associated GOF mutation C49Y from the endogenous CARD11 locus. GOF CARD11 was sufficient to specifically drive B cell expansion in the mice with no significant effect on CD4+ or CD8+ T cells or NK cells. Quantification of splenic lymphocytes revealed that CARD11C49Y/C49Y mice had ~5-fold more splenic B cells when compared to CARD11+/+ mice and ~13-fold more marginal zone (MZ) B cells. CARD11C49Y/C49Y MZ B cells proliferated and survived much better than CARD11+/+ following stimulation with αIgM and importantly exhibited significant survivability prior to stimulation. Bulk mRNA sequencing revealed genes uniquely dysregulated in CARD11C49Y/C49Y MZ B cells including those associated with non-canonical NF-κB pathway signaling. CARD11C49Y/C49Y MZ B cells exhibited elevated levels of the p100 precursor NF-kB subunit leading to enhanced production of nuclear p52 following BAFF treatment. CARD11C49Y/C49Y MZ B cells also exhibited elevated levels of TRAF2, TRAF3 and cIAP1/2, components of a complex that degrades the NIK kinase that is responsible in normal cells for inducing p100 processing. Our results reveal an unexpected ability of CARD11 GOF mutants to potentiate the non-canonical NF-κB pathway through p100 accumulation, which likely contributes to the dysregulated B cell expansion observed in DLBCL cases that harbor CARD11 GOF variants. Citation Format: Anushka Ghosh, Joel Pomerantz. Oncogenic CARD11 enhances marginal zone B cell survival by potentiating the non-canonical NF-κB pathway [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 6986.

Membrane-associated RING-CH 7 inhibits stem-like capacities of bladder cancer cells by interacting with nucleotide-binding oligomerization domain containing 1

BackgroundCancer stem-like capacities are major factors contributing to unfavorable prognosis. However, the associated molecular mechanisms underlying cancer stem-like cells (CSCs) maintain remain unclear. This study aimed to investigate the role of the ubiquitin E3 ligase membrane-associated RING-CH 7 (MARCH7) in bladder cancer cell CSCs.MethodsMale BALB/c nude mice aged 4–5 weeks were utilized to generate bladder xenograft model. The expression levels of MARCHs were checked in online databases and our collected bladder tumors by quantitative real-time PCR (q-PCR) and immunohistochemistry (IHC). Next, we evaluated the stem-like capacities of bladder cancer cells with knockdown or overexpression of MARCH7 by assessing their spheroid-forming ability and spheroid size. Additionally, we conducted proliferation, colony formation, and transwell assays to validate the effects of MARCH7 on bladder cancer CSCs. The detailed molecular mechanism of MARCH7/NOD1 was validated by immunoprecipitation, dual luciferase, and in vitro ubiquitination assays. Co-immunoprecipitation experiments revealed that nucleotide-binding oligomerization domain-containing 1 (NOD1) is a substrate of MARCH7.ResultsWe found that MARCH7 interacts with NOD1, leading to the ubiquitin–proteasome degradation of NOD1. Furthermore, our data suggest that NOD1 significantly enhances stem-like capacities such as proliferation and invasion abilities. The overexpressed MARCH7 counteracts the effects of NOD1 on bladder cancer CSCs in both in vivo and in vitro models.ConclusionOur findings indicate that MARCH7 functions as a tumor suppressor and inhibits the stem-like capacities of bladder tumor cells by promoting the ubiquitin–proteasome degradation of NOD1. Targeting the MARCH7/NOD1 pathway could be a promising therapeutic strategy for bladder cancer patients.

Deverji's disease after COVID-19: Case report

Deverji's disease is a rare idiopathic skin disease characterized by keratinization disorder and manifested in follicular hyperkeratosis, orange-red peeling plaques, palmar-plantar keratodermia with the possible development of erythroderma. The etiopathogenesis of this dermatosis is still unknown. There are such possible trigger factors as traumatization, ultraviolet radiation, taking certain medications, autoimmune and oncological diseases, bacterial or viral infection, vaccination. The presence of familial cases is due to a mutation in the CARD14 gene. Diagnosis of the disease is based on characteristic clinical symptoms. The histological picture has no pathognomonic features; however, a biopsy is necessary for differential diagnosis with other papulosquamous dermatoses. Treatment of Deverji's disease remains a difficult task, since the disease pathogenesis has not been fully studied.&#x0D; The article describes a clinical case of Deverji's disease manifestation in a 64-year-old woman who had suffered COVID-19 infection twice. She was admitted to the Department of Dermatology and Venerology (Sechenov University) with complaints of skin rashes on her face, trunk, upper and lower extremities, accompanied by severe itching. The absence of any distinctive clinical and histological changes, the torpidity of the skin process and resistance to the therapy made it difficult to make a diagnosis. After the emergence of characteristic clinical symptoms (palmar-plantar keratodermia, salmon-tinged rashes with islands of healthy skin), as well as the results of repeated histological examination (alternating areas of ortho- and parakeratosis; uneven granular layer; vacuolization of basal cells; uneven broad acantholytic strands; loosened dermo-epidermal junction; small perivascular lymph-macrophage infiltrates) Deverji's disease was diagnosed.&#x0D; The use of standard therapies (systemic glucocorticosteroid therapy, methotrexate, topical therapy) did not give any results, and therefore it was decided to initiate the netakimab. After 5 injections, the first positive results were obtained in the form of the color paling and a decrease in the number of rashes, palmar-plantar keratodermia regression and improvement of the patient psychoemotional state. After 11 injections, almost complete remission was achieved, and treatment was continued until all symptoms disappeared completely.&#x0D; The article provides a literature review of the etiopathogenesis, clinical manifestations and treatment methods of Deverji's disease. The described clinical case is the fifth example in the world of the Deverji's disease manifestation after a COVID-19 infection, and is also the first case of the IL-17 inhibitor netakimab successful use for the disease treatment.

CARD9 mutations in patients with fungal infections: An update from the last 5 years.

Autosomal recessive deficiency in the caspase recruitment domain-containing protein 9 (CARD9) is a congenital immunological condition that leads to susceptibility to mucocutaneous and invasive fungal infections. There is growing incidence of fungal infections in patients with CARD9 deficiency, a phenomenon that is increasingly recognised. This study aimed to assess the frequency, geographic distribution and nature of mutations in patients with CARD9 deficiency, based on published papers in the literature until March 2023. We swiftly conducted a study to pinpoint every documented instance of fungal infections arising from CARD9 deficiency. We selected case reports from the databases of PubMed, Embase, Scopus and Google Scholar spanning the period from October 2009 to March 2023. We analysed 90 cases of fungal infections and identified 32 mutations in the CARD9 gene. Notably, the homozygous (HMZ) p.Q295X (c.883C > T) mutation was associated with an increased risk of candidiasis. In contrast, the HMZ p.Q289X (c.865C > T) mutation is linked to a higher risk of dermatophytosis. We observed differences in the geographical distribution of these mutations. The primary mutations found in African patients differ from those in Asian patients. Specifically, Asian patients exhibit a broader spectrum of CARD9 mutations than African patients. The diversity of mutations observed in the 90 cases revealed 32 distinct variations, emphasising the unique genetic alterations in the CARD9 gene associated with specific geographical areas and the corresponding prevalence of fungal infections.

Role of CARD9 in Cell- and Organ-Specific Immune Responses in Various Infections.

The caspase recruitment domain-containing protein 9 (CARD9) is an intracellular adaptor protein that is abundantly expressed in cells of the myeloid lineage, such as neutrophils, macrophages, and dendritic cells. CARD9 plays a critical role in host immunity against infections caused by fungi, bacteria, and viruses. A CARD9 deficiency impairs the production of inflammatory cytokines and chemokines as well as migration and infiltration, thereby increasing susceptibility to infections. However, CARD9 signaling varies depending on the pathogen causing the infection. Furthermore, different studies have reported altered CARD9-mediated signaling even with the same pathogen. Therefore, this review focuses on and elucidates the current literature on varied CARD9 signaling in response to various infectious stimuli in humans and experimental mice models.

Identifying functional dysregulation of NOD2 variant Q902K in patients with Yao syndrome

Background and objectivesThe study investigated the pathogenesis of Yao syndrome (YAOS), a rare systemic autoinflammatory disease associated with the nucleotide-binding oligomerization domain containing 2 (NOD2) gene variants.MethodsRNA sequencing analyses were used to detect transcriptomic profile changes. Immunoblot and immunohistochemistry were used to examine the NOD2-mediated inflammatory signaling pathways and ELISA was used to detect cytokines.ResultsTranscriptome analysis of YAOS revealed NOD-like receptor signaling pathway enrichment. Compared with HCs, P-RIP2, p-p65, p-p38, p-ERK, and p-JNK notably increased in PBMCs of a patient with YAOS. P-RIP2, p-p65, and p-p38 elevated in small intestinal mucosa tissues. P-p65 and p-p38 in synovial tissues from YAOS were higher than those in patients with rheumatoid arthritis (RA) and osteoarthritis (OA). Serum interleukin (IL)-6 level along with tumor necrosis factor (TNF)-α and IL-6 secreted from PBMCs were markedly higher in patients with YAOS in comparison to healthy controls (HCs). The supernatants of synovial cells from a patient with YAOS showed substantially higher IL-1β and IL-6 levels than those of RA and OA. Canakinumab therapy of a Q902K heterozygous patient with YAOS resulted in notable clinical improvement.ConclusionOverproduction of pro-inflammatory cytokines and the hyperactivation of NOD2-mediated signaling pathways were found in the NOD2 variant Q902K patient with YAOS. NOD2-RIP2-MAPK pathway might play a pivotal role in the pathogenesis of YAOS. These results provide new perspectives for targeted therapies in YAOS.

A60 INVESTIGATING THE ROLE OF NUCLEOTIDE-BINDING OLIGOMERIZATION DOMAIN (NOD) PROTEINS DURING BACTERIAL INFECTIONS IN INTESTINAL EPITHELIAL CELLS

Abstract Background Inflammatory bowel disease (IBD) is a collection of conditions that result in the inflammation of the gastrointestinal tract causing diarrhea, abdominal pain, weight loss, nausea, and vomiting. With its prevalence a whopping 0.6% in Canada, there is a need to understand the targets of therapy for the disease. Crohn’s disease, which is one of the two main conditions implicated in IBD, is most often associated with polymorphisms in the NOD2 gene. NOD2 is integral to the innate immune system of mammals, and functions as a pattern recognition receptor within the cytosol of cells. It detects conserved bacterial peptidoglycans to elicit an anti-microbial response by activating the nuclear factor kappa B pathway. NOD proteins also tackle infections upon bacterial recognition by recruitment of autophagy proteins allowing for the degradation of invading bacteria. Given their roles in bacterial clearance, it is unsurprising that mice deficient for NOD1 or NOD2 show increased susceptibility to pathogens, which is also what is thought to occur with Crohn's disease patients. Aims Although NOD1 and NOD2 have been well characterized in immune cells, little research has been done to interrogate their role during bacterial dysbiosis in intestinal epithelial cells. This research aims to elucidate the global signaling landscape that these proteins modulate in intestinal epithelial cells post-infection. We hypothesize that NOD1 and NOD2 play a critical role in host defense against intracellular bacterial pathogens in intestinal epithelial cells. Methods Intestinal crypts were harvested from WT, Nlrc4-/-, and Nlrc4-/- Ripk2-/- C57BL/6 mice to generate primary ileal organoids. Organoids infected with Shigella flexneri were harvested for protein and RNA. Downstream western blot, qPCR, Immunohistochemistry, and CFU analyses were performed to ensure the efficacy of the infection. Results Upon Shigella flexneri infection, CFU counts were only able to be recorded in a non-pyroptotic background (Nlrc4-/-). When examining the organoids by Immunohistochemistry, Shigella was well visualized in the Nlrc4-/- enteroids and was absent in WT controls 4 hours post-infection. Additionally, an increase in pro-inflammatory and stress genes was seen only in Nlrc4-/- organoids compared to WT controls. Finally, Nlrc4-/- Ripk2-/- organoids experience higher bacterial loads by CFU analysis compared to Nlrc4-/-Ripk2+/+ organoids. Conclusions Our research has shown that NOD1 and NOD2 deficiencies in primary mouse epithelial cells have increased bacteria loads compared to WTs upon infections showcasing a novel epithelial-intrinsic role for NOD1 and NOD2. This new insight into an epithelium-intrinsic role may be a step towards understanding the mechanism behind NOD2-associated Crohn's disease pathogenesis. Funding Agencies CIHRCrohn's and Colitis Canada

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.

P1193 NOD2 and Beyond: Unmasking Tobacco-Induced Epigenetic Changes in Crohn's Disease

Abstract Background Smoking has been shown to have a very negative impact on Crohn's disease (CD). Indeed, this harmful habit induces the early onset of the disease and doubles the risk of postoperative recurrence. This research project involves a thorough analysis of omics data, with a primary focus on DNA methylation, one of the most prevalent epigenetic modifications. Our hypothesis is that tobacco-induced alterations in gene methylation pattern of subcutaneous adipose tissue (SAT), particularly within key pathways, contribute to a more adverse disease profile in smokers. Methods A comprehensive epigenome-wide analysis was conducted using the Illumina EPIC/450k array to investigate subcutaneous adipose tissue in patients with CD, encompassing both smokers and non-smokers. Utilizing tools such as dmpfinder and Bumphunter (minfi), differentially methylated positions (DMPs) and regions (DMRs) were identified. Additionally, gene expression analysis for key genes was performed to establish correlations between methylation and subsequent gene expression, not only in SAT but also in other fat depots such as visceral adipose tissue (VAT) or peripheral blood mononuclear cells (PBMCs). Results A distinctive DNA methylation pattern in the SAT of smokers compared to non-smoker CD patients was identified (Fig. 1A). Over 27,270 DMPs associated with significant biological processes related to DNA damage, inflammation, or immunity were uncovered (Fig. 1B-C). Additionally, more than 13,000 DMRs located in the promoter region were identified (Fig. 1C). The relationship between methylation levels in the promoter regions and subsequent gene expression on SAT was validated for selected genes. Specifically, NOD2 exhibited higher DNA methylation in the promoter region among smokers compared to non-smokers CD patients (p value=0.04), resulting in reduced NOD2 gene expression on SAT (p value=0.04) (Fig.1D). Consistent results were observed in other tissues such as VAT and PBMCs (Fig. 1E). Finally, we observe the implication of NOD2 in pathways related to immune response, inflammation or apoptosis and a trend indicating that lower NOD2 expression is associated with higher levels of C-reactive protein (CRP)(Fig. 1F). Conclusion Our study reveals that smoking produces DNA methylation changes on SAT of CD patients and affects the expression of several key genes involved in the pathogeny of CD. Particularly, our results unveil a new link between tobacco-smoking and lower NOD2 expression and associate this to an elevated levels of PCR, paving the way for a fresh perspective in exploring disease prognosis.

Association between non-coding transcript variant polymorphisms (rs3135499, rs3135500) of the NOD2 gene and the propensity to rheumatoid arthritis in the Iraqi population

AimThe objective of this study was to explore how the existence of two particular SNPs located in potential binding sites for microRNAs in the 3′- UTR region of the NOD2 gene could impact the susceptibility to rheumatoid arthritis (RA) among the Iraqi population. BackgroundRheumatoid arthritis (RA) is a chronic autoimmune condition that predominantly affects the joints. In RA, the immune system erroneously attacks the tissue surrounding the joints, resulting in stiffness, inflammation, pain, and mobility restrictions, particularly in areas such as the wrists, spine, knees, ankles, and feet. While numerous genes in the human genome play a part in the development of RA, specific genetic regions within these genes may have a noteworthy influence on both the initiation and progression of RA and this influence may extend to other inflammatory conditions as well. MethodIn a case-control study, genomic DNA (gDNA) was isolated from the peripheral blood of 200 individuals. These participants were categorized into two groups: one comprising 100 individuals diagnosed with rheumatoid arthritis, and the other composed of 100 healthy individuals who served as the control group. Various laboratory parameters and anthropometric data, such as age, gender, body mass index (BMI), levels of anti-cyclic citrullinated peptide (anti-CCP), and rheumatoid factor (RF), were assessed. Subsequently, all samples were genotyped for two specific polymorphisms located within the NOD2 gene (rs3135499 and rs3135500) using rhAmp-polymerase chain reaction technology. Finally, the collected data underwent analysis using a range of statistical methods. ResultsThe results indicated a substantial correlation between the risk of developing rheumatoid arthritis (RA) and the allele frequencies of the rs3135500G > A polymorphism, specifically [G vs A; Odds Ratio (OR) = 1.76; 95% Confidence Interval (CI) (1.8 – –2.6); p < 0.005], as well as the genotypes [GG vs GA + AA; OR = 2.4; 95% CI (1.15–2.2), p < 0.001], [GA vs GG; OR = 0.1; 95% CI (0.33–0.4), p < 0.001], and [AA vs GG; OR = 0.08; 95% CI (0.02–0.37), p < 0.001]. Conversely, the rs3135499 A > C polymorphism did not exhibit significant variations, except for [CC vs AA+AC; OR = 2.7; 95% CI (1.3–5.73), p < 0.009], and [AC vs AA; OR = 2.95; 95% CI (0.87–10.02), p < 0.03] after adjusting for factors like gender, age, BMI, smoking status, and family history. It's worth noting that markers such as anti-CCP, RF, and CRP produced positive results exclusively among RA patients. Additionally, parameters like BMI, ESR, WBCs, and Urea exhibited significant differences between the RA group and the healthy control group (p < 0.02, p < 0.0001, p < 0.002, and p < 0.01, respectively). Furthermore, there was a strong linkage observed between the rs3135500G > A and rs3135499A > C polymorphism of the NOD2 gene in patients (D′ = 0.85). ConclusionOur findings indicate an association between rheumatoid arthritis (RA) and the rs3135500 G/A polymorphism situated in the 3′-UTR of the NOD2 gene, particularly in the presence of the A allele. Additionally, the AA haplotype model was associated with an increased susceptibility to RA within the genetic region of NOD2.

Comprehensive clinical phenotype, genotype and therapy in Yao syndrome.

Yao syndrome (YAOS) is formerly called nucleotide-binding oligomerization domain containing 2 (NOD2)-associated autoinflammatory disease.We report a large cohort of YAOS. We conducted a retrospective analysis of a cohort of adult patients with systemic autoinflammatory diseases (SAIDs). All patients underwent testing for a periodic fever syndrome gene panel. A total of 194 patients carried NOD2 variants, 152 patients were diagnosed with YAOS, and 42 had mixed autoinflammatory diseases with combined variants in NOD2 and other SAID-associated genes. Demographic, clinical and molecular data were summaried. In sub-group analysis of the 194 patients, individual patients were often identified to carry two or more variants that usually included IVS8 + 158/R702W, IVS8 + 158/L1007fs, IVS8 + 158/V955I, IVS8 + 158/other, or NOD2/variants in other SAID genes. Ninety-nine patients carried single variants. Taken together, these variants contribute to the disease in combination or individually. This largest cohort has provided comprehensive clinical and genotyping data in YAOS. Variants in the NOD2 gene can give rise to a spectrum from inflammatory bowel disease to autoinflammatory disease.This report further raises awareness of the underdiagnosed disease in the medical community.