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Nature Communications Jun 2024Porcine deltacoronavirus (PDCoV) is an emerging enteric pathogen that has recently been detected in humans. Despite this zoonotic concern, the antigenic structure of...
Porcine deltacoronavirus (PDCoV) is an emerging enteric pathogen that has recently been detected in humans. Despite this zoonotic concern, the antigenic structure of PDCoV remains unknown. The virus relies on its spike (S) protein for cell entry, making it a prime target for neutralizing antibodies. Here, we generate and characterize a set of neutralizing antibodies targeting the S protein, shedding light on PDCoV S interdomain crosstalk and its vulnerable sites. Among the four identified antibodies, one targets the S1A domain, causing local and long-range conformational changes, resulting in partial exposure of the S1B domain. The other antibodies bind the S1B domain, disrupting binding to aminopeptidase N (APN), the entry receptor for PDCoV. Notably, the epitopes of these S1B-targeting antibodies are concealed in the prefusion S trimer conformation, highlighting the necessity for conformational changes for effective antibody binding. The binding footprint of one S1B binder entirely overlaps with APN-interacting residues and thus targets a highly conserved epitope. These findings provide structural insights into the humoral immune response against the PDCoV S protein, potentially guiding vaccine and therapeutic development for this zoonotic pathogen.
Topics: Spike Glycoprotein, Coronavirus; Animals; Antibodies, Neutralizing; Swine; Antibodies, Viral; Epitopes; Humans; Deltacoronavirus; CD13 Antigens; Coronavirus Infections; Protein Domains; Protein Binding; Swine Diseases; HEK293 Cells
PubMed: 38909062
DOI: 10.1038/s41467-024-49693-0 -
Nature Communications Jun 2024During primary varicella zoster virus (VZV) infection, infected lymphocytes drive primary viremia, causing systemic dissemination throughout the host, including the...
During primary varicella zoster virus (VZV) infection, infected lymphocytes drive primary viremia, causing systemic dissemination throughout the host, including the skin. This results in cytokine expression, including interferons (IFNs), which partly limit infection. VZV also spreads from skin keratinocytes to lymphocytes prior to secondary viremia. It is not clear how VZV achieves this while evading the cytokine response. Here, we show that VZV glycoprotein C (gC) binds IFN-γ and modifies its activity, increasing the expression of a subset of IFN-stimulated genes (ISGs), including intercellular adhesion molecule 1 (ICAM1), chemokines and immunomodulatory genes. The higher ICAM1 protein level at the plasma membrane of keratinocytes facilitates lymphocyte function-associated antigen 1-dependent T cell adhesion and expression of gC during infection increases VZV spread to peripheral blood mononuclear cells. This constitutes the discovery of a strategy to modulate IFN-γ activity, upregulating a subset of ISGs, promoting enhanced lymphocyte adhesion and virus spread.
Topics: Humans; Interferon-gamma; Cell Adhesion; T-Lymphocytes; Intercellular Adhesion Molecule-1; Keratinocytes; Herpesvirus 3, Human; Varicella Zoster Virus Infection; Leukocytes, Mononuclear; Viral Envelope Proteins; Lymphocyte Function-Associated Antigen-1
PubMed: 38909022
DOI: 10.1038/s41467-024-49657-4 -
Biomedicine & Pharmacotherapy =... Jun 2024The induction of immunological tolerance is a promising strategy for managing autoimmune diseases, allergies, and transplant rejection. Tregitopes, a class of peptides,... (Review)
Review
The induction of immunological tolerance is a promising strategy for managing autoimmune diseases, allergies, and transplant rejection. Tregitopes, a class of peptides, have emerged as potential agents for this purpose. They activate regulatory T cells, which are pivotal in reducing inflammation and promoting tolerance, by binding to MHC II molecules and facilitating their processing and presentation to Treg cells, thereby encouraging their proliferation. Moreover, Tregitopes influence the phenotype of antigen-presenting cells by attenuating the expression of CD80, CD86, and MHC class II while enhancing ILT3, resulting in the inhibition of NF-kappa B signaling pathways. Various techniques, including in vitro and in silico methods, are applied to identify Tregitope candidates. Currently, Tregitopes play a vital role in balancing immune activation and tolerance in clinical applications such as Pompe disease, diabetes-related antigens, and the prevention of spontaneous abortions in autoimmune diseases. Similarly, Tregitopes can induce antigen-specific regulatory T cells. Their anti-inflammatory effects are significant in conditions such as autoimmune encephalomyelitis, inflammatory bowel disease, and Guillain-Barré syndrome. Additionally, Tregitopes have been leveraged to enhance vaccine design and efficacy. Recent advancements in understanding the potential benefits and drawbacks of IVIG and the discovery of the function and mechanism of Tregitopes have introduced Tregitopes as a popular option for immune system modulation. It is expected that they will bring about a significant revolution in the management and treatment of autoimmune and immunological diseases. This article is a comprehensive review of Tregitopes, concluding with the potential of these epitopes as a therapeutic avenue for immunological disorders.
PubMed: 38908205
DOI: 10.1016/j.biopha.2024.116983 -
Cell Communication and Signaling : CCS Jun 2024Triple-negative breast cancer (TNBC) is recognized as the most aggressive and immunologically infiltrated subtype of breast cancer. A high circulating...
BACKGROUND
Triple-negative breast cancer (TNBC) is recognized as the most aggressive and immunologically infiltrated subtype of breast cancer. A high circulating neutrophil-to-lymphocyte ratio (NLR) is strongly linked to a poor prognosis among patients with breast cancer, emphasizing the critical role of neutrophils. Although the involvement of neutrophils in tumor metastasis is well documented, their interactions with primary tumors and tumor cells are not yet fully understood.
METHODS
Clinical data were analyzed to investigate the role of neutrophils in breast cancer. In vivo mouse model and in vitro co-culture system were used for mechanism researches. Blocking experiments were further performed to identify therapeutic agents against TNBC.
RESULTS
TNBC cells secreted GM-CSF to sustain the survival of mature neutrophils and upregulated CD11b expression. Through CD11b, neutrophils specifically binded to ICAM1 on TNBC cells, facilitating adhesion. Transcriptomic sequencing combined with human and murine functional experiments revealed that neutrophils, through direct CD11b-ICAM1 interactions, activated the MAPK signaling pathway in TNBC cells, thereby enhancing tumor cell invasion and migration. Atorvastatin effectively inhibited ICAM1 expression in tumor cells, and tumor cells with ICAM1 knockout or treated with atorvastatin were unresponsive to neutrophil activation. The MAPK pathway and MMP9 expression were significantly inhibited in the tumor tissues of TNBC patients treated with atorvastatin.
CONCLUSIONS
Targeting CD11b-ICAM1 with atorvastatin represented a potential clinical approach to reduce the malignant characteristics of TNBC.
Topics: Triple Negative Breast Neoplasms; Neutrophils; Humans; Animals; CD11b Antigen; Female; Intercellular Adhesion Molecule-1; Mice; Cell Adhesion; Cell Line, Tumor; Disease Progression; Cell Movement
PubMed: 38907234
DOI: 10.1186/s12964-024-01716-5 -
Polish Journal of Microbiology Jun 2024Interferon-alpha (IFN-α) is a first-line drug for treating chronic hepatitis B (CHB). Guanylate-binding protein 1 (GBP1) is one of the interferon-stimulating factors,...
Interferon-alpha (IFN-α) is a first-line drug for treating chronic hepatitis B (CHB). Guanylate-binding protein 1 (GBP1) is one of the interferon-stimulating factors, which participates in the innate immunity of the host and plays an antiviral and antibacterial role. In this study, we explored how GBP1 is involved in IFN-α antiviral activity against HBV. Before being gathered, HepG2-NTCP and HepG2 2.15 cells were transfected with the wild-type hGBP1 plasmid or si-GBP1, respectively, and followed by stimulation with Peg-IFNα-2b. We systematically explored the role of GBP1 in regulating HBV infection in cell models. Additionally, we also examined GBP1 levels in CHB patients. GBP1 activity increased, and its half-life was prolonged after HBV infection. Overexpression of GBP1 inhibited the production of HBsAg and HBeAg, as well as HBs protein and HBV total RNA levels, whereas silencing of GBP1 inhibited its ability to block viral infections. Interestingly, overexpressing GBP1 co-treatment with Peg-IFNα-2b further increased the antiviral effect of IFN-α, while GBP1 silencing co-treatment with Peg-IFNα-2b partly restored its inhibitory effect on HBV. Mechanistically, GBP1 mediates the anti-HBV response of Peg-IFNα-2b by targeting HBs. Analysis of clinical samples revealed that GBP1 was elevated in CHB patients and increased with Peg-IFNα-2b treatment, while GBP1 showed good stability in the interferon response group. Our study demonstrates that GBP1 inhibits HBV replication and promotes HBsAg clearance. It is possible to achieve antiviral effects through the regulation of IFN-α induced immune responses in response to HBV.
Topics: Humans; Interferon-alpha; Hepatitis B virus; Antiviral Agents; GTP-Binding Proteins; Hep G2 Cells; Hepatitis B, Chronic; Male; Hepatitis B Surface Antigens; Female; Adult; Virus Replication; Hepatitis B
PubMed: 38905278
DOI: 10.33073/pjm-2024-021 -
International Journal of Biological... 2024Renal fibrosis is the common pathway in the progression of chronic kidney disease (CKD). Acyloxyacyl hydrolase (AOAH) is expressed in various phagocytes and is highly...
Renal fibrosis is the common pathway in the progression of chronic kidney disease (CKD). Acyloxyacyl hydrolase (AOAH) is expressed in various phagocytes and is highly expressed in proximal tubular epithelial cells (PTECs). Research shows that AOAH plays a critical role in infections and chronic inflammatory diseases, although its role in kidney injury is unknown. Here, we found that AOAH deletion led to exacerbated kidney injury and fibrosis after folic acid (FA) administration, which was reversed by overexpression of in kidneys. ScRNA-seq revealed that mice exhibited increased subpopulation of CD74 PTECs, though the percentage of total PTECs were decreased compared to WT mice after FA treatment. Additionally, exacerbated kidney injury and fibrosis seen in mice was attenuated via administration of methyl ester of (S, R)-3-(4-hydroxyphenyl)-4,5-dihydro-5-isoxazole acetic acid (ISO-1), an inhibitor of macrophage inhibition factor (MIF) and CD74 binding. Finally, AOAH expression was found positively correlated with estimated glomerular filtration rate while negatively correlated with the degree of renal fibrosis in kidneys of CKD patients. Thus, our work indicates that AOAH protects against kidney injury and fibrosis by inhibiting renal tubular epithelial cells CD74 signaling pathways. Targeting kidney AOAH represents a promising strategy to prevent renal fibrosis progression.
Topics: Animals; Mice; Macrophages; Carboxylic Ester Hydrolases; Humans; Antigens, Differentiation, B-Lymphocyte; Renal Insufficiency, Chronic; Mice, Inbred C57BL; Male; Histocompatibility Antigens Class II; Folic Acid; Kidney Tubules; Fibrosis; Mice, Knockout; Epithelial Cells
PubMed: 38904010
DOI: 10.7150/ijbs.91237 -
Frontiers in Immunology 2024Cancer-associated fibroblasts (CAFs) are the primary stromal cells found in tumor microenvironment, and display high plasticity and heterogeneity. By using single-cell...
BACKGROUND
Cancer-associated fibroblasts (CAFs) are the primary stromal cells found in tumor microenvironment, and display high plasticity and heterogeneity. By using single-cell RNA-seq technology, researchers have identified various subpopulations of CAFs, particularly highlighting a recently identified subpopulation termed antigen-presenting CAFs (apCAFs), which are largely unknown.
METHODS
We collected datasets from public databases for 9 different solid tumor types to analyze the role of apCAFs in the tumor microenvironment.
RESULTS
Our data revealed that apCAFs, likely originating mainly from normal fibroblast, are commonly found in different solid tumor types and generally are associated with anti-tumor effects. apCAFs may be associated with the activation of CD4+ effector T cells and potentially promote the survival of CD4+ effector T cells through the expression of C1Q molecules. Moreover, apCAFs exhibited highly enrichment of transcription factors RUNX3 and IKZF1, along with increased glycolytic metabolism.
CONCLUSIONS
Taken together, these findings offer novel insights into a deeper understanding of apCAFs and the potential therapeutic implications for apCAFs targeted immunotherapy in cancer.
Topics: Tumor Microenvironment; Cancer-Associated Fibroblasts; Humans; Single-Cell Analysis; Neoplasms; Gene Expression Regulation, Neoplastic; Gene Expression Profiling; Core Binding Factor Alpha 3 Subunit; Transcriptome
PubMed: 38903527
DOI: 10.3389/fimmu.2024.1372432 -
Biology Direct Jun 2024Prior research has highlighted the involvement of a transcriptional complex comprising C-terminal binding protein 2 (CtBP2), histone acetyltransferase p300, and nuclear...
BACKGROUND
Prior research has highlighted the involvement of a transcriptional complex comprising C-terminal binding protein 2 (CtBP2), histone acetyltransferase p300, and nuclear factor kappa B (NF-κB) in the transactivation of proinflammatory cytokine genes, contributing to inflammation in mice with acute respiratory distress syndrome (ARDS). Nonetheless, it remains uncertain whether the therapeutic targeting of the CtBP2-p300-NF-κB complex holds potential for ARDS suppression.
METHODS
An ARDS mouse model was established using lipopolysaccharide (LPS) exposure. RNA-Sequencing (RNA-Seq) was performed on ARDS mice and LPS-treated cells with CtBP2, p300, and p65 knockdown. Small molecules inhibiting the CtBP2-p300 interaction were identified through AlphaScreen. Gene and protein expression levels were quantified using RT-qPCR and immunoblots. Tissue damage was assessed via histological staining.
KEY FINDINGS
We elucidated the specific role of the CtBP2-p300-NF-κB complex in proinflammatory gene regulation. RNA-seq analysis in LPS-challenged ARDS mice and LPS-treated CtBP2-knockdown (CtBP2), p300, and p65 cells revealed its significant impact on proinflammatory genes with minimal effects on other NF-κB targets. Commercial inhibitors for CtBP2, p300, or NF-κB exhibited moderate cytotoxicity in vitro and in vivo, affecting both proinflammatory genes and other targets. We identified a potent inhibitor, PNSC928, for the CtBP2-p300 interaction using AlphaScreen. PNSC928 treatment hindered the assembly of the CtBP2-p300-NF-κB complex, substantially downregulating proinflammatory cytokine gene expression without observable cytotoxicity in normal cells. In vivo administration of PNSC928 significantly reduced CtBP2-driven proinflammatory gene expression in ARDS mice, alleviating inflammation and lung injury, ultimately improving ARDS prognosis.
CONCLUSION
Our results position PNSC928 as a promising therapeutic candidate to specifically target the CtBP2-p300 interaction and mitigate inflammation in ARDS management.
Topics: Animals; Mice; Respiratory Distress Syndrome; Inflammation; Alcohol Oxidoreductases; E1A-Associated p300 Protein; Co-Repressor Proteins; Male; Lipopolysaccharides; Mice, Inbred C57BL; Disease Models, Animal; p300-CBP Transcription Factors; NF-kappa B
PubMed: 38902802
DOI: 10.1186/s13062-024-00491-0 -
Multimodal HLA-I genotype regulation by human cytomegalovirus US10 and resulting surface patterning.ELife Jun 2024Human leucocyte antigen class I (HLA-I) molecules play a central role for both NK and T-cell responses that prevent serious human cytomegalovirus (HCMV) disease. To...
Human leucocyte antigen class I (HLA-I) molecules play a central role for both NK and T-cell responses that prevent serious human cytomegalovirus (HCMV) disease. To create opportunities for viral spread, several HCMV-encoded immunoevasins employ diverse strategies to target HLA-I. Among these, the glycoprotein US10 is so far insufficiently studied. While it was reported that US10 interferes with HLA-G expression, its ability to manipulate classical HLA-I antigen presentation remains unknown. In this study, we demonstrate that US10 recognizes and binds to all HLA-I (HLA-A, -B, -C, -E, -G) heavy chains. Additionally, impaired recruitment of HLA-I to the peptide loading complex was observed. Notably, the associated effects varied significantly dependending on HLA-I genotype and allotype: (i) HLA-A molecules evaded downregulation by US10, (ii) tapasin-dependent HLA-B molecules showed impaired maturation and cell surface expression, and (iii) βm-assembled HLA-C, in particular HLA-C*05:01 and -C*12:03, and HLA-G were strongly retained in complex with US10 in the endoplasmic reticulum. These genotype-specific effects on HLA-I were confirmed through unbiased HLA-I ligandome analyses. Furthermore, in HCMV-infected fibroblasts inhibition of overlapping US10 and US11 transcription had little effect on HLA-A, but induced HLA-B antigen presentation. Thus, the US10-mediated impact on HLA-I results in multiple geno- and allotypic effects in a so far unparalleled and multimodal manner.
Topics: Humans; Cytomegalovirus; Histocompatibility Antigens Class I; Genotype; Viral Proteins; Protein Binding; Host-Pathogen Interactions; Gene Expression Regulation; Antigen Presentation
PubMed: 38900146
DOI: 10.7554/eLife.85560 -
MAbs 2024Over the past two decades, therapeutic antibodies have emerged as a rapidly expanding domain within the field of biologics. tools that can streamline the process of...
Over the past two decades, therapeutic antibodies have emerged as a rapidly expanding domain within the field of biologics. tools that can streamline the process of antibody discovery and optimization are critical to support a pipeline that is growing more numerous and complex every year. High-quality structural information remains critical for the antibody optimization process, but antibody-antigen complex structures are often unavailable and antibody docking methods are still unreliable. In this study, DeepAb, a deep learning model for predicting antibody Fv structure directly from sequence, was used in conjunction with single-point experimental deep mutational scanning (DMS) enrichment data to design 200 potentially optimized variants of an anti-hen egg lysozyme (HEL) antibody. We sought to determine whether DeepAb-designed variants containing combinations of beneficial mutations from the DMS exhibit enhanced thermostability and whether this optimization affected their developability profile. The 200 variants were produced through a robust high-throughput method and tested for thermal and colloidal stability (T, T, T), affinity (K) relative to the parental antibody, and for developability parameters (nonspecific binding, aggregation propensity, self-association). Of the designed clones, 91% and 94% exhibited increased thermal and colloidal stability and affinity, respectively. Of these, 10% showed a significantly increased affinity for HEL (5- to 21-fold increase) and thermostability (>2.5C increase in T), with most clones retaining the favorable developability profile of the parental antibody. Additional tests suggest that these methods would enrich for binding affinity even without first collecting experimental DMS measurements. These data open the possibility of antibody optimization without the need to predict the antibody-antigen interface, which is notoriously difficult in the absence of crystal structures.
Topics: Muramidase; Antibody Affinity; Protein Stability; Humans; Antigens; Animals; Computer Simulation
PubMed: 38899735
DOI: 10.1080/19420862.2024.2362775