Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 180
Filter
Add more filters











Publication year range
2.
Sci Immunol ; 9(97): eadn0178, 2024 Jul 12.
Article in English | MEDLINE | ID: mdl-38996010

ABSTRACT

Virus-induced cell death is a key contributor to COVID-19 pathology. Cell death induced by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is well studied in myeloid cells but less in its primary host cell type, angiotensin-converting enzyme 2 (ACE2)-expressing human airway epithelia (HAE). SARS-CoV-2 induces apoptosis, necroptosis, and pyroptosis in HAE organotypic cultures. Single-cell and limiting-dilution analysis revealed that necroptosis is the primary cell death event in infected cells, whereas uninfected bystanders undergo apoptosis, and pyroptosis occurs later during infection. Mechanistically, necroptosis is induced by viral Z-RNA binding to Z-DNA-binding protein 1 (ZBP1) in HAE and lung tissues from patients with COVID-19. The Delta (B.1.617.2) variant, which causes more severe disease than Omicron (B1.1.529) in humans, is associated with orders of magnitude-greater Z-RNA/ZBP1 interactions, necroptosis, and disease severity in animal models. Thus, Delta induces robust ZBP1-mediated necroptosis and more disease severity.


Subject(s)
COVID-19 , Necroptosis , Pyroptosis , RNA-Binding Proteins , Respiratory Mucosa , SARS-CoV-2 , Humans , SARS-CoV-2/immunology , COVID-19/immunology , COVID-19/pathology , Necroptosis/immunology , Animals , Respiratory Mucosa/virology , Respiratory Mucosa/immunology , Respiratory Mucosa/pathology , RNA-Binding Proteins/metabolism , RNA-Binding Proteins/genetics , Mice , Cell Death/immunology , Angiotensin-Converting Enzyme 2/metabolism , Angiotensin-Converting Enzyme 2/genetics , Apoptosis/immunology
4.
Nat Nanotechnol ; 19(6): 856-866, 2024 Jun.
Article in English | MEDLINE | ID: mdl-38480836

ABSTRACT

The efficacy of STING (stimulator of interferon genes) agonists is due to various factors, primarily inefficient intracellular delivery, low/lack of endogenous STING expression in many tumours, and a complex balance between tumour control and progression. Here we report a universal STING mimic (uniSTING) based on a polymeric architecture. UniSTING activates STING signalling in a range of mouse and human cell types, independent of endogenous STING expression, and selectively stimulates tumour control IRF3/IFN-I pathways, but not tumour progression NF-κB pathways. Intratumoural or systemic injection of uniSTING-mRNA via lipid nanoparticles (LNPs) results in potent antitumour efficacy across established and advanced metastatic tumour models, including triple-negative breast cancer, lung cancer, melanoma and orthotopic/metastatic liver malignancies. Furthermore, uniSTING displays an effective antitumour response superior to 2'3'-cGAMP and ADU-S100. By favouring IRF3/IFN-I activity over the proinflammatory NF-κB signalling pathway, uniSTING promotes dendritic cell maturation and antigen-specific CD8+ T-cell responses. Extracellular vesicles released from uniSTING-treated tumour cells further sensitize dendritic cells via exosome-containing miRNAs that reduced the immunosuppressive Wnt2b, and a combination of LNP-uniSTING-mRNA with α-Wnt2b antibodies synergistically inhibits tumour growth and prolongs animal survival. Collectively, these results demonstrate the LNP-mediated delivery of uniSTING-mRNA as a strategy to overcome the current STING therapeutic barriers, particularly for the treatment of multiple cancer types in which STING is downregulated or absent.


Subject(s)
Membrane Proteins , Signal Transduction , Animals , Humans , Membrane Proteins/metabolism , Membrane Proteins/genetics , Signal Transduction/drug effects , Mice , Cell Line, Tumor , Interferon Regulatory Factor-3/metabolism , Nanoparticles/chemistry , Neoplasms/drug therapy , Neoplasms/immunology , Neoplasms/metabolism , Female , RNA, Messenger/genetics , RNA, Messenger/metabolism , NF-kappa B/metabolism , Mice, Inbred C57BL , Liposomes
5.
J Med Virol ; 96(3): e29504, 2024 Mar.
Article in English | MEDLINE | ID: mdl-38445794

ABSTRACT

While most NOD-like receptors (NLRs) are predominately expressed by innate immune cells, NLRC3, an inhibitory NLR of immune signaling, exhibits the highest expression in lymphocytes. The role of NLRC3 or any NLRs in B lymphocytes is completely unknown. Gammaherpesviruses, including human Epstein-Barr virus (EBV) and murine gammaherpesvirus 68 (MHV-68), establish latent infection in B lymphocytes, which requires elevated NF-κB. This study shows that during latent EBV infection of human B cells, viral-encoded latent membrane protein 1 (LMP1) decreases NLRC3 transcript. LMP1-induced-NF-κB activation suppresses the promoter activity of NLRC3 via p65 binding to the promoter. Conversely, NLRC3 inhibits NF-κB activation by promoting the degradation of LMP1 in a proteasome-dependent manner. In vivo, MHV-68 infection reduces Nlrc3 transcripts in splenocytes, and Nlrc3-deficient mice show greater viral latency than controls. These results reveal a bidirectional regulatory circuit in B lymphocytes, where viral latent protein LMP1 reduces NLRC3 expression, while NLRC3 disrupts gammaherpesvirus latency, which is an important step for tumorigenesis.


Subject(s)
Epstein-Barr Virus Infections , Virus Latency , Animals , Humans , Mice , Herpesvirus 4, Human/genetics , NF-kappa B , B-Lymphocytes , Intercellular Signaling Peptides and Proteins
6.
Cell Rep ; 43(3): 113852, 2024 Mar 26.
Article in English | MEDLINE | ID: mdl-38427558

ABSTRACT

The NLRP3 inflammasome is essential for caspase-1 activation and the release of interleukin (IL)-1ß, IL-18, and gasdermin-D in myeloid cells. However, research on species-specific NLRP3's physiological impact is limited. We engineer mice with the human NLRP3 gene, driven by either the human or mouse promoter, via syntenic replacement at the mouse Nlrp3 locus. Both promoters facilitate hNLRP3 expression in myeloid cells, but the mouse promoter responds more robustly to LPS. Investigating the disease impact of differential NLRP3 regulation, we introduce the D305N gain-of-function mutation into both humanized lines. Chronic inflammation is evident with both promoters; however, CNS outcomes vary significantly. Despite poor response to LPS, the human promoter results in D305N-associated aseptic meningitis, mirroring human pathology. The mouse promoter, although leading to increased CNS expression post-LPS, does not induce meningitis in D305N mutants. Therefore, human-like NLRP3 expression may be crucial for accurate modeling of its role in disease pathogenesis.


Subject(s)
Hereditary Autoinflammatory Diseases , NLR Family, Pyrin Domain-Containing 3 Protein , Humans , Animals , Mice , NLR Family, Pyrin Domain-Containing 3 Protein/genetics , NLR Family, Pyrin Domain-Containing 3 Protein/metabolism , Lipopolysaccharides/pharmacology , Inflammasomes/metabolism , Inflammation , Syndrome , Interleukin-1beta/metabolism , Caspase 1/metabolism
7.
Int J Pharm ; 652: 123836, 2024 Mar 05.
Article in English | MEDLINE | ID: mdl-38266940

ABSTRACT

The most common influenza vaccines are inactivated viruses produced in chicken eggs, which is a time-consuming production method with variable efficacy due to mismatches of the vaccine strains to the dominant circulating strains. Subunit-based vaccines provide faster production times in comparison to the traditional egg-produced vaccines but often require the use of an adjuvant to elicit a highly protective immune response. However, the current FDA approved adjuvant for influenza vaccines (MF59) elicits a primarily helper T-cell type 2 (Th2)-biased humoral immune response. Adjuvants that can stimulate a Th1 cellular response are correlated to have more robust protection against influenza. The cyclic dinucleotide cGAMP has been shown to provide a potent Th1 response but requires the use of a delivery vehicle to best initiate its signalling pathway in the cytosol. Herein, acetalated dextran (Ace-DEX) was used as the polymer to fabricate microparticles (MPs) via double-emulsion, electrospray, and spray drying methods to encapsulate cGAMP. This study compared each fabrication method's ability to encapsulate and retain the hydrophilic adjuvant cGAMP. We compared their therapeutic efficacy to Addavax, an MF59-like adjuvant, and cGAMP Ace-DEX MPs provided a stronger Th1 response in vaccinated BALB/c mice. Furthermore, we compared Ace-DEX MPs to spray dried MPs composed from a commonly used polymer for drug delivery, poly(lactic-co-glycolic acid) (PLGA). We observed that all Ace-DEX MPs elicited similar humoral and cellular responses to the PLGA MPs. Overall, the results shown here indicate Ace-DEX can perform similarly to PLGA as a polymer for drug delivery and that spray drying can provide an efficient way to produce MPs to encapsulate cGAMP and stimulate the immune system.


Subject(s)
Influenza Vaccines , Influenza, Human , Squalene , Animals , Mice , Humans , Dextrans , Polysorbates , Vaccines, Subunit , Adjuvants, Immunologic , Adjuvants, Pharmaceutic
8.
Nat Biomed Eng ; 2023 Dec 04.
Article in English | MEDLINE | ID: mdl-38049469

ABSTRACT

As a chronic autoinflammatory condition, ulcerative colitis is often managed via systemic immunosuppressants. Here we show, in three mouse models of established ulcerative colitis, that a subcutaneously injected colon-specific immunosuppressive niche consisting of colon epithelial cells, decellularized colon extracellular matrix and nanofibres functionalized with programmed death-ligand 1, CD86, a peptide mimic of transforming growth factor-beta 1, and the immunosuppressive small-molecule leflunomide, induced intestinal immunotolerance and reduced inflammation in the animals' lower gastrointestinal tract. The bioengineered colon-specific niche triggered autoreactive T cell anergy and polarized pro-inflammatory macrophages via multiple immunosuppressive pathways, and prevented the infiltration of immune cells into the colon's lamina propria, promoting the recovery of epithelial damage. The bioengineered niche also prevented colitis-associated colorectal cancer and eliminated immune-related colitis triggered by kinase inhibitors and immune checkpoint blockade.

9.
Nat Biotechnol ; 2023 Sep 25.
Article in English | MEDLINE | ID: mdl-37749267

ABSTRACT

Increasing evidence implicates the tumor microbiota as a factor that can influence cancer progression. In patients with colorectal cancer (CRC), we found that pre-resection antibiotics targeting anaerobic bacteria substantially improved disease-free survival by 25.5%. For mouse studies, we designed an antibiotic silver-tinidazole complex encapsulated in liposomes (LipoAgTNZ) to eliminate tumor-associated bacteria in the primary tumor and liver metastases without causing gut microbiome dysbiosis. Mouse CRC models colonized by tumor-promoting bacteria (Fusobacterium nucleatum spp.) or probiotics (Escherichia coli Nissle spp.) responded to LipoAgTNZ therapy, which enabled more than 70% long-term survival in two F. nucleatum-infected CRC models. The antibiotic treatment generated microbial neoantigens that elicited anti-tumor CD8+ T cells. Heterologous and homologous bacterial epitopes contributed to the immunogenicity, priming T cells to recognize both infected and uninfected tumors. Our strategy targets tumor-associated bacteria to elicit anti-tumoral immunity, paving the way for microbiome-immunotherapy interventions.

10.
Cell ; 186(11): 2288-2312, 2023 05 25.
Article in English | MEDLINE | ID: mdl-37236155

ABSTRACT

Inflammasomes are critical sentinels of the innate immune system that respond to threats to the host through recognition of distinct molecules, known as pathogen- or damage-associated molecular patterns (PAMPs/DAMPs), or disruptions of cellular homeostasis, referred to as homeostasis-altering molecular processes (HAMPs) or effector-triggered immunity (ETI). Several distinct proteins nucleate inflammasomes, including NLRP1, CARD8, NLRP3, NLRP6, NLRC4/NAIP, AIM2, pyrin, and caspases-4/-5/-11. This diverse array of sensors strengthens the inflammasome response through redundancy and plasticity. Here, we present an overview of these pathways, outlining the mechanisms of inflammasome formation, subcellular regulation, and pyroptosis, and discuss the wide-reaching effects of inflammasomes in human disease.


Subject(s)
Inflammasomes , Humans , Apoptosis Regulatory Proteins/metabolism , CARD Signaling Adaptor Proteins/metabolism , Caspases/metabolism , Cell Death , Inflammasomes/metabolism , Neoplasm Proteins/metabolism , NLR Family, Pyrin Domain-Containing 3 Protein/metabolism , Pyroptosis
SELECTION OF CITATIONS
SEARCH DETAIL