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1.
EMBO Mol Med ; 2024 Jul 08.
Article in English | MEDLINE | ID: mdl-38977927

ABSTRACT

In humans, blood Classical CD14+ monocytes contribute to host defense by secreting large amounts of pro-inflammatory cytokines. Their aberrant activity causes hyper-inflammation and life-threatening cytokine storms, while dysfunctional monocytes are associated with 'immunoparalysis', a state of immune hypo responsiveness and reduced pro-inflammatory gene expression, predisposing individuals to opportunistic infections. Understanding how monocyte functions are regulated is critical to prevent these harmful outcomes. We reveal platelets' vital role in the pro-inflammatory cytokine responses of human monocytes. Naturally low platelet counts in patients with immune thrombocytopenia or removal of platelets from healthy monocytes result in monocyte immunoparalysis, marked by impaired cytokine response to immune challenge and weakened host defense transcriptional programs. Remarkably, supplementing monocytes with fresh platelets reverses these conditions. We discovered that platelets serve as reservoirs of key cytokine transcription regulators, such as NF-κB and MAPK p38, and pinpointed the enrichment of platelet NF-κB2 in human monocytes by proteomics. Platelets proportionally restore impaired cytokine production in human monocytes lacking MAPK p38α, NF-κB p65, and NF-κB2. We uncovered a vesicle-mediated platelet-monocyte-propagation of inflammatory transcription regulators, positioning platelets as central checkpoints in monocyte inflammation.

2.
Cancers (Basel) ; 16(12)2024 Jun 12.
Article in English | MEDLINE | ID: mdl-38927906

ABSTRACT

Volatile organic compounds (VOCs) are an increasingly meaningful method for the early detection of various types of cancers, including lung cancer, through non-invasive methods. Traditional cancer detection techniques such as biopsies, imaging, and blood tests, though effective, often involve invasive procedures or are costly, time consuming, and painful. Recent advancements in technology have led to the exploration of VOC detection as a promising non-invasive and comfortable alternative. VOCs are organic chemicals that have a high vapor pressure at room temperature, making them readily detectable in breath, urine, and skin. The present study leverages artificial intelligence (AI) and machine learning algorithms to enhance classification accuracy and efficiency in detecting lung cancer through VOC analysis collected from exhaled breath air. Unlike other studies that primarily focus on identifying specific compounds, this study takes an agnostic approach, maximizing detection efficiency over the identification of specific compounds focusing on the overall compositional profiles and their differences across groups of patients. The results reported hereby uphold the potential of AI-driven techniques in revolutionizing early cancer detection methodologies towards their implementation in a clinical setting.

3.
Nat Rev Rheumatol ; 2024 Jun 17.
Article in English | MEDLINE | ID: mdl-38886559

ABSTRACT

Kawasaki disease, a systemic vasculitis that affects young children and can result in coronary artery aneurysms, is the leading cause of acquired heart disease among children. A hallmark of Kawasaki disease is increased blood platelet counts and platelet activation, which is associated with an increased risk of developing resistance to intravenous immunoglobulin and coronary artery aneurysms. Platelets and their releasate, including granules, microparticles, microRNAs and transcription factors, can influence innate immunity, enhance inflammation and contribute to vascular remodelling. Growing evidence indicates that platelets also interact with immune and non-immune cells to regulate inflammation. Platelets boost NLRP3 inflammasome activation and IL-1ß production by human immune cells by releasing soluble mediators. Activated platelets form aggregates with leukocytes, such as monocytes and neutrophils, enhancing numerous functions of these cells and promoting thrombosis and inflammation. Leukocyte-platelet aggregates are increased in children with Kawasaki disease during the acute phase of the disease and can be used as biomarkers for disease severity. Here we review the role of platelets in Kawasaki disease and discuss progress in understanding the immune-effector role of platelets in amplifying inflammation related to Kawasaki disease vasculitis and therapeutic strategies targeting platelets or platelet-derived molecules.

4.
Plant Biol (Stuttg) ; 2024 Jun 17.
Article in English | MEDLINE | ID: mdl-38886872

ABSTRACT

In Mediterranean regions, severe summers are becoming more common, leading to restrictions to vine productivity and yield quality, requiring sustainable practices to support this sector. We assessed the behaviour of three red grapevine varieties from the Douro Region to examine their tolerance to summer climate stress from the perspective that the less common varieties may have potential for increased use in a climate change scenario. Leaf and fruit biochemical profile, antioxidant activity and fruit colorimetric parameters were assessed at different phenological stages in Aragonez (AR), Tinto Cão (TC) and Touriga Nacional (TN) grape varieties. All three varieties exhibit significant variability in phenological timing, influenced by genetic and environmental factors. Photosynthetic pigment strategies differed among varieties. Chlorophyll content in AR was high to cope with high radiation, while TN displaying a balanced approach, and TC had lower pigment levels, with higher levels of phenolics, antioxidants, and soluble sugars, particularly during stress. The variations in berry biochemical profile highlight the distinct characteristics of the varieties. TC and TN show potential for coping with climate change, having elevated total acidity, while AR has larger and heavier berries with distinct coloration. These findings reinforce the need to study the behaviour of different varieties in each Terroir, to understand their diverse strategies to deal with summer climate stress. This will help in selecting the most suitable variety for these conditions under vineyard management in the Douro Region.

5.
bioRxiv ; 2024 Feb 12.
Article in English | MEDLINE | ID: mdl-38405743

ABSTRACT

A hallmark of CRISPR immunity is the acquisition of short viral DNA sequences, known as spacers, that are transcribed into guide RNAs to recognize complementary sequences. The staphylococcal type III-A CRISPR-Cas system uses guide RNAs to locate viral transcripts and start a response that displays two mechanisms of immunity. When immunity is triggered by an early-expressed phage RNA, degradation of viral ssDNA can cure the host from infection. In contrast, when the RNA guide targets a late-expressed transcript, defense requires the activity of Csm6, a non-specific RNase. Here we show that Csm6 triggers a growth arrest of the host that provides immunity at the population level which hinders viral propagation to allow the replication of non-infected cells. We demonstrate that this mechanism leads to defense against not only the target phage but also other viruses present in the population that fail to replicate in the arrested cells. On the other hand, dormancy limits the acquisition and retention of spacers that trigger it. We found that the ssDNase activity of type III-A systems is required for the re-growth of a subset of the arrested cells, presumably through the degradation of the phage DNA, ending target transcription and inactivating the immune response. Altogether, our work reveals a built-in mechanism within type III-A CRISPR-Cas systems that allows the exit from dormancy needed for the subsistence of spacers that provide broad-spectrum immunity.

6.
Br J Pharmacol ; 181(8): 1308-1323, 2024 Apr.
Article in English | MEDLINE | ID: mdl-37990806

ABSTRACT

BACKGROUND AND PURPOSE: Sepsis-surviving adult individuals commonly develop immunosuppression and increased susceptibility to secondary infections, an outcome mediated by the axis IL-33/ILC2s/M2 macrophages/Tregs. Nonetheless, the long-term immune consequences of paediatric sepsis are indeterminate. We sought to investigate the role of age in the genesis of immunosuppression following sepsis. EXPERIMENTAL APPROACH: Here, we compared the frequency of Tregs, the activation of the IL-33/ILC2s axis in M2 macrophages and the DNA methylation of epithelial lung cells from post-septic infant and adult mice. Likewise, sepsis-surviving mice were inoculated intranasally with Pseudomonas aeruginosa or by subcutaneous inoculation of the B16 melanoma cell line. Finally, blood samples from sepsis-surviving patients were collected and the concentration of IL-33 and Tregs frequency were assessed. KEY RESULTS: In contrast to 6-week-old mice, 2-week-old mice were resistant to secondary infection and did not show impairment in tumour controls upon melanoma challenge. Mechanistically, increased IL-33 levels, Tregs expansion, and activation of ILC2s and M2-macrophages were observed in 6-week-old but not 2-week-old post-septic mice. Moreover, impaired IL-33 production in 2-week-old post-septic mice was associated with increased DNA methylation in lung epithelial cells. Notably, IL-33 treatment boosted the expansion of Tregs and induced immunosuppression in 2-week-old mice. Clinically, adults but not paediatric post-septic patients exhibited higher counts of Tregs and seral IL-33 levels. CONCLUSION AND IMPLICATIONS: These findings demonstrate a crucial and age-dependent role for IL-33 in post-sepsis immunosuppression. Thus, a better understanding of this process may lead to differential treatments for adult and paediatric sepsis.


Subject(s)
Interleukin-33 , Sepsis , Humans , Mice , Animals , Child , Immunity, Innate , Lymphocytes/metabolism , Lymphocytes/pathology , Immunosuppression Therapy
7.
bioRxiv ; 2023 Oct 10.
Article in English | MEDLINE | ID: mdl-37873082

ABSTRACT

Immunoglobulin A (IgA) is the most abundant antibody isotype produced across mammals and plays a specialized role in mucosal homeostasis 1 . Constantly secreted into the lumen of the intestine, IgA binds commensal microbiota to regulate their colonization and function 2,3 , with unclear implications for health. IgA deficiency is common in humans but is difficult to study due to its complex etiology and comorbidities 4-8 . Using genetically and environmentally controlled mice, here we show that IgA-deficient animals have a baseline alteration in the colon epithelium that increases susceptibility to multiple models of colorectal cancer. Transcriptome, imaging, and flow cytometry-based analyses revealed that, in the absence of IgA, colonic epithelial cells induce antibacterial factors and accelerate cell cycling in response to the microbiota. Oral treatment with IgA was sufficient to suppress aberrant epithelial proliferation independently of bacterial binding, suggesting that IgA provides a feedback signal to epithelial cells in parallel with its known roles in microbiome shaping. In a primary colonic organoid culture system, IgA directly suppresses epithelial growth. Conversely, the susceptibility of IgA-deficient mice to colorectal cancer was reversed by Notch inhibition to suppress the absorptive colonocyte developmental program, or by inhibition of the cytokine MIF, the receptor for which was upregulated in stem cells of IgA-deficient animals. These studies demonstrate a homeostatic function for IgA in tempering physiological epithelial responses to microbiota to maintain mucosal health.

8.
Aorta (Stamford) ; 11(3): 107-111, 2023 Jun.
Article in English | MEDLINE | ID: mdl-37619567

ABSTRACT

BACKGROUND: Incisional hernia (IH) is an important surgical complication that has several ways of prevention, including modifications in the surgical technique of the initial procedure. Its incidence can reach 69% in high-risk patients and long-term follow-up. Of the risky procedures, open abdominal aortic aneurysmectomy is the one with the highest risk. Ways to reduce this morbid complication were suggested, and prophylactic mesh rises as an important tool to prevent recurrence. METHODS: A retrospective cohort study review of medical records of patients undergoing vascular surgery for abdominal aortoiliac aneurysm (AAA) or vascular bypass surgery due to aortoiliac occlusive disease. We identified 193 patients treated between 2010 and 2020. We further performed a one-to-nine matching analysis between the use of prophylactic mesh and control groups, based on estimated propensity scores for each patient. RESULTS: Prophylactic mesh group had a 18% lower risk of IH, compared with the control group (relative risk: 0.82; 95% confidence interval [CI] = 0.74-0.93). The difference in IH rates between the groups compared was 2.6% (95% CI: -19.8 to 25.5). From the perspective of the number needed to treat, it would be necessary to use prophylactic mesh in 39 (95% CI: 35-44) patients to avoid one IH in this population. CONCLUSION: Use of prophylactic mesh in the repair of AAA significantly reduces the incidence of IH in nearly one in five cases. Our data suggest that there is benefit in the use of prophylactic mesh in open aneurysmectomy surgery regarding postoperative IH development.

9.
Front Pediatr ; 11: 1205971, 2023.
Article in English | MEDLINE | ID: mdl-37539009

ABSTRACT

Introduction: Low cardiac output syndrome (LCOS) is a significant cause of morbidity and the leading cause of mortality after pediatric cardiac surgery. Levosimendan has been shown safe and effective in pediatrics to treat LCOS. We aimed to review our local strategy with preoperative prophylactic Levosimendan infusion to minimize LCOS after heart surgery in identified high-risk patients. Methods: Retrospective monocentric study. As there is no reliable cardiac output measurement in children, we recorded hemodynamic parameters as surrogates of cardiac output after extracorporeal circulation through an electronic patient survey system at different time points. Results: Seventy-two children received Levosimendan before surgery between 2010 and 2019. As expected, most patients were newborns and infants with prolonged open-heart surgeries. Median cardiopulmonary bypass time was 182 [137-234] min, and aortic clamping time was 95 [64-126] min. The postoperative hemodynamic parameters, vasoactive-inotropic score, and urine output remained stable throughout the first 48 h. Only a tiny portion of the patients had combined surrogate markers of LCOS with a maximal median arterial lactate of 2.6 [1.9-3.5] mmol/L during the first six postoperative hours, which then progressively normalized. The median arterio-venous difference in oxygen saturation was 31 [23-38] % between 12 and 18 h post-surgery and gradually decreased. The median venous-to-arterial CO2 difference was the highest at 10 [7-12] mmHg between 12 and 18 h post-surgery. Nine patients (13%) required extracorporeal membrane oxygenation. No patient required dialysis or hemofiltration. Mortality was 0%. Conclusion: Before congenital heart surgery, preoperative prophylactic administration of Levosimendan seems effective and safe for decreasing occurrence and duration of LCOS in high-risk children.

10.
Methods Mol Biol ; 2696: 73-92, 2023.
Article in English | MEDLINE | ID: mdl-37578716

ABSTRACT

Inflammasomes are crucial sentinels of the innate immune system that sense clues of infection, cellular stress, or metabolic imbalances. Upon activation, the inflammasome sensor (e.g., NLRP3) recruits the adaptor protein apoptosis-associated speck-like protein containing a CARD (ASC). ASC rapidly oligomerizes to form a micron-sized structure termed "ASC speck." These are crucial for the activation of caspase-1 and downstream inflammatory signals released following a specific form of lytic cell death called pyroptosis. Hence, due to their considerably large size, ASC specks can be easily visualized by microscopy as a simple upstream readout for inflammasome activation. Here, we provide three detailed protocols for imaging ASC specks: (1) live-cell imaging of macrophage cell lines expressing a fluorescent protein fusion form of ASC, (2) imaging of human primary cells using immunofluorescence staining of endogenous ASC, and (3) visualization and quantification of specks on a single-cell level using imaging flow cytometry.


Subject(s)
CARD Signaling Adaptor Proteins , Inflammasomes , Humans , Inflammasomes/metabolism , CARD Signaling Adaptor Proteins/metabolism , Apoptosis , Caspase 1/metabolism , Microscopy, Confocal , Fluorescent Antibody Technique , NLR Family, Pyrin Domain-Containing 3 Protein/metabolism
11.
JCI Insight ; 8(14)2023 07 24.
Article in English | MEDLINE | ID: mdl-37279077

ABSTRACT

Kawasaki disease (KD) is the leading cause of acquired heart disease among children. Increased platelet counts and activation are observed during the course of KD, and elevated platelet counts are associated with higher risks of developing intravenous immunoglobulin resistance and coronary artery aneurysms. However, the role of platelets in KD pathogenesis remains unclear. Here, we analyzed transcriptomics data generated from the whole blood of patients with KD and discovered changes in the expression of platelet-related genes during acute KD. In the Lactobacillus casei cell wall extract (LCWE) murine model of KD vasculitis, LCWE injection increased platelet counts and the formation of monocyte-platelet aggregates (MPAs), upregulated the concentration of soluble P-selectin, and increased circulating thrombopoietin and interleukin 6 (IL-6). Furthermore, platelet counts correlated with the severity of cardiovascular inflammation. Genetic depletion of platelets (Mpl-/- mice) or treatment with an anti-CD42b antibody significantly reduced LCWE-induced cardiovascular lesions. Furthermore, in the mouse model, platelets promoted vascular inflammation via the formation of MPAs, which likely amplified IL-1B production. Altogether, our results indicate that platelet activation exacerbates the development of cardiovascular lesions in a murine model of KD vasculitis. These findings enhance our understanding of KD vasculitis pathogenesis and highlight MPAs, which are known to enhance IL-1B production, as a potential therapeutic target for this disorder.


Subject(s)
Mucocutaneous Lymph Node Syndrome , Vasculitis , Animals , Mice , Mucocutaneous Lymph Node Syndrome/genetics , Mucocutaneous Lymph Node Syndrome/drug therapy , Blood Platelets/metabolism , Disease Models, Animal , Inflammation
12.
Front Pediatr ; 11: 1137841, 2023.
Article in English | MEDLINE | ID: mdl-37020652

ABSTRACT

Introduction: The aim of this national prospective surveillance study was to compare the clinical presentation, laboratory findings, treatment, and coronary artery outcome in patients with incomplete and complete Kawasaki disease (KD). Methods: Between March 2013 and February 2019, children with a diagnosis of complete and incomplete KD were reported by the Swiss Paediatric Surveillance Unit and prospectively enrolled. Clinical data, laboratory values, treatment, and echocardiographic features were collected at diagnosis and 1 year of follow-up. Data were compared between children with complete or incomplete KD. Results: A total of 351 questionnaires were registered from children with a diagnosis of KD. Of them, 219 (62.4%) children had complete KD, and 132 (37.6%) children had incomplete KD. Children with incomplete KD were younger and had a longer-lasting fever; however, there were no differences in the level of C-reactive protein. All but four children received intravenous immunoglobulin treatment, whereas 14% of children were treated with corticosteroids. Children with incomplete KD were more often treated with corticosteroids than children with incomplete KD (p = 0.01). At diagnosis, 39 (11.1%) patients had only coronary artery dilation and 57 (16.2%) had at least one coronary artery aneurysm. There were no differences in coronary artery involvement between the two groups. At follow-up, 273 of 294 (92.8%) patients had no coronary artery involvement, with no difference between the two groups (p = 0.609). The overall incidence of coronary artery aneurysms at diagnosis was 16.2%. At follow-up, most coronary artery aneurysms had regressed, and coronary artery aneurysms were present in only 5.8% of the patients. Coronary artery aneurysms were slightly more frequent in patients with incomplete KD at follow-up (p = 0.039) but not at diagnosis (p = 0.208). Conclusion: Although the clinical presentation in children with incomplete and complete KD differs, the absence of coronary artery involvement does not. The use of corticosteroids appears to be preventive against the development of coronary artery aneurysms in these patients. However, the results of this study suggest a lower rate of coronary artery aneurysm regression in patients with incomplete KD. Further studies on a larger scale are needed to assess the risk of non-regression of coronary artery aneurysms in this particular group of patients.

13.
Anaesth Rep ; 11(1): e12217, 2023.
Article in English | MEDLINE | ID: mdl-36875790

ABSTRACT

A child with early failure of a Fontan circulation was listed for cardiac transplantation and then developed a subhepatic abscess. Surgical drainage was deemed necessary after the failure of an attempted percutaneous procedure. Following a multidisciplinary discussion, a laparoscopic technique was chosen to optimise postoperative recovery. To our knowledge, the literature does not describe any case of laparoscopic surgery in a patient with a failing Fontan circulation. This case report highlights the physiological variations involved with this management strategy, discusses the implications and risks, and offers some recommendations.

14.
Sensors (Basel) ; 23(4)2023 Feb 17.
Article in English | MEDLINE | ID: mdl-36850872

ABSTRACT

Currently, few experimental methods exist that enable the mechanical characterization of adhesives under high strain rates. One such method is the Split Hopkinson Bar (SHB) test. The mechanical characterization of adhesives is performed using different specimen configurations, such as Single Lap Joint (SLJ) specimens. A gripping system, attached to the bars through threading, was conceived to enable the testing of SLJs. An optimization study for selecting the best thread was performed, analyzing the thread type, the nominal diameter, and the thread pitch. Afterwards, the gripping system geometry was numerically evaluated. The optimal threaded connection for the specimen consists of a trapezoidal thread with a 14 mm diameter and a 2 mm thread pitch. To validate the gripping system, the load-displacement (P-δ) curve of an SLJ, which was simulated as if it were tested on the SHB apparatus, was compared with an analogous curve from a validated drop-weight test numerical model.

15.
Front Immunol ; 13: 1007080, 2022.
Article in English | MEDLINE | ID: mdl-36451809

ABSTRACT

Efficient mouse models to study SARS-CoV-2 infection are critical for the development and assessment of vaccines and therapeutic approaches to mitigate the current pandemic and prevent reemergence of COVID-19. While the first generation of mouse models allowed SARS-CoV-2 infection and pathogenesis, they relied on ectopic expression and non-physiological levels of human angiotensin-converting enzyme 2 (hACE2). Here we generated a mouse model carrying the minimal set of modifications necessary for productive infection with multiple strains of SARS-CoV-2. Substitution of only three amino acids in the otherwise native mouse Ace2 locus (Ace2 TripleMutant or Ace2™), was sufficient to render mice susceptible to both SARS-CoV-2 strains USA-WA1/2020 and B.1.1.529 (Omicron). Infected Ace2™ mice exhibited weight loss and lung damage and inflammation, similar to COVID-19 patients. Previous exposure to USA-WA1/2020 or mRNA vaccination generated memory B cells that participated in plasmablast responses during breakthrough B.1.1.529 infection. Thus, the Ace2™ mouse replicates human disease after SARS-CoV-2 infection and provides a tool to study immune responses to sequential infections in mice.


Subject(s)
COVID-19 , SARS-CoV-2 , Humans , Mice , Animals , Angiotensin-Converting Enzyme 2/genetics , Disease Models, Animal , Pandemics
16.
Nature ; 610(7932): 547-554, 2022 10.
Article in English | MEDLINE | ID: mdl-36198790

ABSTRACT

Loss of Paneth cells and their antimicrobial granules compromises the intestinal epithelial barrier and is associated with Crohn's disease, a major type of inflammatory bowel disease1-7. Non-classical lymphoid cells, broadly referred to as intraepithelial lymphocytes (IELs), intercalate the intestinal epithelium8,9. This anatomical position has implicated them as first-line defenders in resistance to infections, but their role in inflammatory disease pathogenesis requires clarification. The identification of mediators that coordinate crosstalk between specific IEL and epithelial subsets could provide insight into intestinal barrier mechanisms in health and disease. Here we show that the subset of IELs that express γ and δ T cell receptor subunits (γδ IELs) promotes the viability of Paneth cells deficient in the Crohn's disease susceptibility gene ATG16L1. Using an ex vivo lymphocyte-epithelium co-culture system, we identified apoptosis inhibitor 5 (API5) as a Paneth cell-protective factor secreted by γδ IELs. In the Atg16l1-mutant mouse model, viral infection induced a loss of Paneth cells and enhanced susceptibility to intestinal injury by inhibiting the secretion of API5 from γδ IELs. Therapeutic administration of recombinant API5 protected Paneth cells in vivo in mice and ex vivo in human organoids with the ATG16L1 risk allele. Thus, we identify API5 as a protective γδ IEL effector that masks genetic susceptibility to Paneth cell death.


Subject(s)
Apoptosis Regulatory Proteins , Crohn Disease , Genetic Predisposition to Disease , Intraepithelial Lymphocytes , Nuclear Proteins , Paneth Cells , Animals , Humans , Mice , Apoptosis Regulatory Proteins/metabolism , Cell Death , Crohn Disease/genetics , Crohn Disease/metabolism , Crohn Disease/pathology , Genetic Predisposition to Disease/genetics , Intestinal Mucosa/pathology , Nuclear Proteins/metabolism , Paneth Cells/pathology , Receptors, Antigen, T-Cell/immunology , Receptors, Antigen, T-Cell/metabolism , Intraepithelial Lymphocytes/immunology , Intraepithelial Lymphocytes/metabolism , Cell Survival , Organoids , Alleles
17.
Science ; 377(6606): 660-666, 2022 08 05.
Article in English | MEDLINE | ID: mdl-35926021

ABSTRACT

The microbiome contributes to the development and maturation of the immune system. In response to commensal bacteria, intestinal CD4+ T lymphocytes differentiate into functional subtypes with regulatory or effector functions. The development of small intestine intraepithelial lymphocytes that coexpress CD4 and CD8αα homodimers (CD4IELs) depends on the microbiota. However, the identity of the microbial antigens recognized by CD4+ T cells that can differentiate into CD4IELs remains unknown. We identified ß-hexosaminidase, a conserved enzyme across commensals of the Bacteroidetes phylum, as a driver of CD4IEL differentiation. In a mouse model of colitis, ß-hexosaminidase-specific lymphocytes protected against intestinal inflammation. Thus, T cells of a single specificity can recognize a variety of abundant commensals and elicit a regulatory immune response at the intestinal mucosa.


Subject(s)
Bacteroidetes , CD4-Positive T-Lymphocytes , Colitis , Intestinal Mucosa , beta-N-Acetylhexosaminidases , Animals , Bacteroidetes/enzymology , Bacteroidetes/immunology , CD4-Positive T-Lymphocytes/immunology , CD8 Antigens/immunology , Colitis/immunology , Colitis/microbiology , Disease Models, Animal , Intestinal Mucosa/immunology , Intestinal Mucosa/microbiology , Mice , Mice, Inbred C57BL , beta-N-Acetylhexosaminidases/immunology
18.
Science ; 377(6603): 276-284, 2022 07 15.
Article in English | MEDLINE | ID: mdl-35857588

ABSTRACT

γδ T cells represent a substantial fraction of intestinal lymphocytes at homeostasis, but they also constitute a major lymphocyte population infiltrating colorectal cancers (CRCs); however, their temporal contribution to CRC development or progression remains unclear. Using human CRC samples and murine CRC models, we found that most γδ T cells in premalignant or nontumor colons exhibit cytotoxic markers, whereas tumor-infiltrating γδ T cells express a protumorigenic profile. These contrasting T cell profiles were associated with distinct T cell receptor (TCR)-Vγδ gene usage in both humans and mice. Longitudinal intersectional genetics and antibody-dependent strategies targeting murine γδ T cells enriched in the epithelium at steady state led to heightened tumor development, whereas targeting γδ subsets that accumulate during CRC resulted in reduced tumor growth. Our results uncover temporal pro- and antitumor roles for γδ T cell subsets.


Subject(s)
Colorectal Neoplasms , Cytotoxicity, Immunologic , Intestines , Intraepithelial Lymphocytes , Receptors, Antigen, T-Cell, gamma-delta , Animals , Colorectal Neoplasms/immunology , Colorectal Neoplasms/pathology , Humans , Intestines/immunology , Intraepithelial Lymphocytes/immunology , Mice , Receptors, Antigen, T-Cell, gamma-delta/genetics , Receptors, Antigen, T-Cell, gamma-delta/physiology
19.
EMBO Mol Med ; 14(6): e15415, 2022 06 08.
Article in English | MEDLINE | ID: mdl-35438238

ABSTRACT

Inflammasomes sense intracellular clues of infection, damage, or metabolic imbalances. Activated inflammasome sensors polymerize the adaptor ASC into micron-sized "specks" to maximize caspase-1 activation and the maturation of IL-1 cytokines. Caspase-1 also drives pyroptosis, a lytic cell death characterized by leakage of intracellular content to the extracellular space. ASC specks are released among cytosolic content, and accumulate in tissues of patients with chronic inflammation. However, if extracellular ASC specks contribute to disease, or are merely inert remnants of cell death remains unknown. Here, we show that camelid-derived nanobodies against ASC (VHHASC ) target and disassemble post-pyroptotic inflammasomes, neutralizing their prionoid, and inflammatory functions. Notably, pyroptosis-driven membrane perforation and exposure of ASC specks to the extracellular environment allowed VHHASC to target inflammasomes while preserving pre-pyroptotic IL-1ß release, essential to host defense. Systemically administrated mouse-specific VHHASC attenuated inflammation and clinical gout, and antigen-induced arthritis disease. Hence, VHHASC neutralized post-pyroptotic inflammasomes revealing a previously unappreciated role for these complexes in disease. VHHASC are the first biologicals that disassemble pre-formed inflammasomes while preserving their functions in host defense.


Subject(s)
Inflammasomes , Single-Domain Antibodies , Animals , CARD Signaling Adaptor Proteins/metabolism , Caspase 1/metabolism , Humans , Inflammasomes/metabolism , Inflammation/metabolism , Mice , NLR Family, Pyrin Domain-Containing 3 Protein/metabolism , Pyroptosis
20.
Cell Mol Immunol ; 19(7): 777-790, 2022 07.
Article in English | MEDLINE | ID: mdl-35468944

ABSTRACT

The food colorant Red 40 is an environmental risk factor for colitis development in mice with increased expression of interleukin (IL)-23. This immune response is mediated by CD4+ T cells, but mechanistic insights into how these CD4+ T cells trigger and perpetuate colitis have remained elusive. Here, using single-cell transcriptomic analysis, we found that several CD4+ T-cell subsets are present in the intestines of colitic mice, including an interferon (IFN)-γ-producing subset. In vivo challenge of primed mice with Red 40 promoted rapid activation of CD4+ T cells and caused marked intestinal epithelial cell (IEC) apoptosis that was attenuated by depletion of CD4+ cells and blockade of IFN-γ. Ex vivo experiments showed that intestinal CD4+ T cells from colitic mice directly promoted apoptosis of IECs and intestinal enteroids. CD4+ T cell-mediated cytotoxicity was contact-dependent and required FasL, which promoted caspase-dependent cell death in target IECs. Genetic ablation of IFN-γ constrained IL-23- and Red 40-induced colitis development, and blockade of IFN-γ inhibited epithelial cell death in vivo. These results advance the understanding of the mechanisms regulating colitis development caused by IL-23 and food colorants and identify IFN-γ+ cytotoxic CD4+ T cells as a new potential therapeutic target for colitis.


Subject(s)
CD4-Positive T-Lymphocytes , Colitis , Food Coloring Agents , Interleukin-23 , Animals , CD4-Positive T-Lymphocytes/immunology , Colitis/chemically induced , Colitis/immunology , Food Coloring Agents/adverse effects , Interferon-gamma/metabolism , Interleukin-23/adverse effects , Mice , Mice, Inbred C57BL
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