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Proceedings of the National Academy of... Sep 2021Cell surface receptors are critical for cell signaling and constitute a quarter of all human genes. Despite their importance and abundance, receptor interaction networks...
Cell surface receptors are critical for cell signaling and constitute a quarter of all human genes. Despite their importance and abundance, receptor interaction networks remain understudied because of difficulties associated with maintaining membrane proteins in their native conformation and their typically weak interactions. To overcome these challenges, we developed an extracellular vesicle-based method for membrane protein display that enables purification-free and high-throughput detection of receptor-ligand interactions in membranes. We demonstrate that this platform is broadly applicable to a variety of membrane proteins, enabling enhanced detection of extracellular interactions over a wide range of binding affinities. We were able to recapitulate and expand the interactome for prominent members of the B7 family of immunoregulatory proteins such as PD-L1/CD274 and B7-H3/CD276. Moreover, when applied to the orphan cancer-associated fibroblast protein, LRRC15, we identified a membrane-dependent interaction with the tumor stroma marker TEM1/CD248. Furthermore, this platform enabled profiling of cellular receptors for target-expressing as well as endogenous extracellular vesicles. Overall, this study presents a sensitive and easy to use screening platform that bypasses membrane protein purification and enables characterization of interactomes for any cell surface-expressed target of interest in its native state.
Topics: Antigens, CD; Antigens, Neoplasm; B7 Antigens; B7-H1 Antigen; HEK293 Cells; Humans; Membrane Proteins; Protein Interaction Domains and Motifs
PubMed: 34531301
DOI: 10.1073/pnas.2025451118 -
Current Opinion in Organ Transplantation Oct 2023De novo HLA-DQ antibodies are the most frequently observed after solid-organ allotransplantation; and are associated with the worse adverse graft outcomes compared with... (Review)
Review
PURPOSE OF REVIEW
De novo HLA-DQ antibodies are the most frequently observed after solid-organ allotransplantation; and are associated with the worse adverse graft outcomes compared with all other HLA antibodies. However, the biological explanation for this observation is not yet known. Herein, we examine unique characteristics of alloimmunity directed specifically against HLA-DQ molecules.
RECENT FINDINGS
While investigators attempted to decipher functional properties of HLA class II antigens that may explain their immunogenicity and pathogenicity, most early studies focused on the more expressed molecule - HLA-DR. We here summarize up-to-date literature documenting specific features of HLA-DQ, as compared to other class II HLA antigens. Structural and cell-surface expression differences have been noted on various cell types. Some evidence suggests variations in antigen-presenting function and intracellular activation pathways after antigen/antibody interaction.
SUMMARY
The clinical effects of donor-recipient incompatibility at HLA-DQ, the risk of generating de novo antibodies leading to rejection, and the inferior graft outcomes indicate increased immunogenicity and pathogenicity that is unique to this HLA antigen. Clearly, knowledge generated for HLA-DR cannot be applied interchangeably. Deeper understanding of features unique to HLA-DQ may support the generation of targeted preventive-therapeutic strategies and ultimately improve solid-organ transplant outcomes.
Topics: Humans; Kidney Transplantation; Isoantibodies; HLA-DQ Antigens; Histocompatibility Testing; HLA-DR Antigens; Graft Rejection
PubMed: 37219535
DOI: 10.1097/MOT.0000000000001079 -
European Journal of Nuclear Medicine... Feb 2022Without a standard test for pancreatic carcinomas, this highly lethal disease is normally diagnosed at its advanced stage, leading to a low survival rate of patients....
PURPOSE
Without a standard test for pancreatic carcinomas, this highly lethal disease is normally diagnosed at its advanced stage, leading to a low survival rate of patients. Trophoblast cell-surface antigen 2 (Trop-2), a transmembrane glycoprotein, is associated with cell proliferation and highly expressed in most of solid epithelial tumors, including pancreatic cancer. A non-invasive method of imaging Trop-2 would greatly benefit clinical diagnosis and monitoring of pancreatic cancer. In the current study, Zr-labeled anti-Trop-2 antibody (AF650) was recruited for the systemic evaluation of Trop-2 as an immunoPET target for pancreatic cancer imaging.
METHODS
AF650 was conjugated with desferrioxamine (DFO) and then radiolabeled with Zr. Trop-2 expression levels were determined in three pancreatic cancer cell lines (BxPC-3, MIA PaCa-2, and AsPC-1) via western blot, flow cytometry, saturation binding assay, and immunofluorescence staining. The targeting capacity of Zr-DFO-AF650 was evaluated in mouse models with subcutaneous xenograft of pancreatic cancers via PET imaging and bio-distribution studies. In addition, a Trop-2-positive orthotopic cancer model was recruited for further validating the targeting specificity of Zr-DFO-AF650.
RESULTS
BxPC-3 cells expressed high levels of Trop-2, while AsPC-1 and MIA PaCa-2 cells expressed low levels of Trop-2. Additionally, Zr-DFO-AF650 exhibited high specificity to Trop-2 in BxPC-3 cells (K = 22.34 ± 2.509 nM). In subcutaneous xenograft models, about 28.8 ± 7.63%ID/g tracer accumulated in the BxPC-3 tumors at 120 h post injection, which was much higher than those reaching MIA PaCa-2 (6.76 ± 2.08%ID/g) and AsPC-1 (3.51 ± 0.69%ID/g) tumors (n = 4). More importantly, Zr-DFO-AF650 could efficiently distinguish primary tumors in the orthotopic BxPC-3 cancer model, showing high correlation between PET imaging and bio-distribution and sensitivity.
CONCLUSIONS
Zr-DFO-AF650 can be effectively used to detect pancreatic cancer via Trop-2-mediated immunoPET in vivo, clearly revealing the great potential of Trop-2-based non-invasive imaging in pancreatic cancer detection and treatment monitoring.
Topics: Animals; Antigens, Surface; Cell Line, Tumor; Humans; Mice; Mice, Nude; Pancreatic Neoplasms; Positron-Emission Tomography; Trophoblasts; Zirconium
PubMed: 34519889
DOI: 10.1007/s00259-021-05563-1 -
Immunology Letters Jul 2022Neutrophils are the most abundant cells of the immune system and key in combating infections through phagocytosis, reactive oxygen species, neutrophil extracellular...
Neutrophils are the most abundant cells of the immune system and key in combating infections through phagocytosis, reactive oxygen species, neutrophil extracellular traps, and secretion of cytokines and antimicrobial peptides. Beyond this, they may influence the adaptive immune response by modulating CD4 T cell responses. In response to cytokines, mainly GM-CSF, but also IFN-γ and TNF-α, neutrophils express major histocompatibility complex class II molecules on their surface. However, to function as antigen-presenting cells for CD4 T cells, more requirements need to be fulfilled, like antigen internalization, processing into fragments containing T cell epitopes, and their presentation on the cell surface together with costimulatory molecules. Here, studies investigating the key features of antigen-presentation by neutrophils are summarized and discussed. Together, they provide evidence for a potential of neutrophils to specifically activate antigen-experienced CD4 T cells.
Topics: Antigen Presentation; Antigen-Presenting Cells; CD4-Positive T-Lymphocytes; Cytokines; Histocompatibility Antigens Class II; Neutrophils
PubMed: 35577002
DOI: 10.1016/j.imlet.2022.04.007 -
Frontiers in Immunology 2023Trophoblast cell surface antigen 2 (Trop2) exhibits limited expression in normal tissues but is over-expressed across various solid tumors. The effectiveness of... (Review)
Review
Trophoblast cell surface antigen 2 (Trop2) exhibits limited expression in normal tissues but is over-expressed across various solid tumors. The effectiveness of anti-Trop2 antibody-drug conjugate (ADC) in managing breast cancer validates Trop2 as a promising therapeutic target for cancer treatment. However, excessive toxicity and a low response rate of ADCs pose ongoing challenges. Safer and more effective strategies should be developed for Trop2-positive cancers. The dynamic structural attributes and the oligomeric assembly of Trop2 present formidable obstacles to the progression of innovative targeted therapeutics. In this review, we summarize recent advancements in understanding Trop2's structure and provide an overview of the epitope characteristics of Trop2-targeted agents. Furthermore, we discuss the correlation between anti-Trop2 agents' epitopes and their respective functions, particularly emphasizing their efficacy and specificity in targeted therapies.
Topics: Humans; Antigens, Neoplasm; Cell Adhesion Molecules; Neoplasms; Immunoconjugates
PubMed: 38179054
DOI: 10.3389/fimmu.2023.1332489 -
Reviews in Endocrine & Metabolic... Jun 2022TWEAK (tumor necrosis factor-like weak inducer of apoptosis) is a member of the TNF superfamily that controls a multitude of cellular events including proliferation,... (Review)
Review
TWEAK (tumor necrosis factor-like weak inducer of apoptosis) is a member of the TNF superfamily that controls a multitude of cellular events including proliferation, migration, differentiation, apoptosis, angiogenesis, and inflammation. TWEAK control of these events is via an expanding list of intracellular signalling pathways which include NF-κB, ERK/MAPK, Notch, EGFR and AP-1. Two receptors have been identified for TWEAK - Fn14, which targets the membrane bound form of TWEAK, and CD163, which scavenges the soluble form of TWEAK. TWEAK appears to elicit specific events based on the receptor to which it binds, tissue type in which it is expressed, specific extrinsic conditions, and the presence of other cytokines. TWEAK signalling is protective in healthy tissues, but in chronic inflammatory states become detrimental to the tissue. Consistent data show a role for the TWEAK/FN14/CD163 axis in metabolic disease, chronic autoimmune diseases, and acute ischaemic stroke. Low circulating concentrations of soluble TWEAK are predictive of poor cardiovascular outcomes in those with and without diabetes. This review details the current understanding of the TWEAK/Fn14/CD163 axis as one of the chief regulators of immune signalling and its cell-specific role in metabolic disease development and progression.
Topics: Antigens, CD; Antigens, Differentiation, Myelomonocytic; Brain Ischemia; Cytokine TWEAK; Humans; Inflammation; Metabolic Diseases; Receptors, Cell Surface; Receptors, Tumor Necrosis Factor; Stroke; TWEAK Receptor; Tumor Necrosis Factors
PubMed: 34542797
DOI: 10.1007/s11154-021-09688-4 -
Journal of Translational Medicine Oct 2023Chimeric antigen receptor NK (CAR-NK) cell therapy is one of the most promising immunotherapies. Although it has shown a significant therapeutic effect in hematologic...
BACKGROUND
Chimeric antigen receptor NK (CAR-NK) cell therapy is one of the most promising immunotherapies. Although it has shown a significant therapeutic effect in hematologic malignancies, few successes have been obtained in solid tumors including esophageal squamous cell carcinoma (ESCC). The major reasons are lack of specific cell surface antigens and complex tumor microenvironment. Here we identify CD22, a well-known tumor surface marker in hematologic malignancies, is expressed in ESCC, possibly serving as a potential target of CAR-NK cell therapy.
METHODS
The expression of 13 tumor cell surface antigens used clinically was analyzed in patients from The Cancer Genome Atlas (TCGA) database. Also, mRNA expression were detected in 2 ESCC cell lines and 2 patients samples by qCPR. Then according to Venn diagram, CD22 was selected for further investigation. Following this, the expression of CD22 by immunofluorescence (IF) in ESCC cell lines and by immunohistochemistry (IHC) in 87 cases of human ESCC samples was detected respectively. On the basis of H-score results, the correlation between CD22 expression and clinical parameters was analyzed. As a proof, the efficacy of CD22-targeted CAR-NK cells against ESCC cell lines was performed by a real-time cell analyzer (RTCA) platform.
RESULTS
KYSE-140 and KYSE-150 cell lines displayed surface expression of CD22. IHC showed an 80.46% (70/87) positive rate in ESCC patient samples. Among these, cell membranous expression of CD22 was observed in 27.59% (24/87) patient samples. Through chi-square test, expression of CD22 in ESCC was associated with lymph node metastasis while it was no related to the depth of tumor invasion and clinical stage. Engineered CD22-targeted CAR-NK cells exhibited inhibitory growth capability against ESCC cell lines (p < 0.0001).
CONCLUSIONS
CD22 is a potential tumor surface antigen capable of being targeted by CAR-NK cells in ESCC. And potential therapeutics for ESCC may be developed based on immune cells expressing anti-CD22 CAR. The study also indicates that CD22 CAR-NK cells could be used in other cancers and more in vivo experiments are needed.
Topics: Humans; Esophageal Squamous Cell Carcinoma; Esophageal Neoplasms; Carcinoma, Squamous Cell; Biomarkers, Tumor; Killer Cells, Natural; Hematologic Neoplasms; Antigens, Surface; Cell- and Tissue-Based Therapy; Cell Line, Tumor; Tumor Microenvironment; Sialic Acid Binding Ig-like Lectin 2
PubMed: 37817249
DOI: 10.1186/s12967-023-04409-8 -
Neuro-oncology Jun 2021Immunotherapy with chimeric antigen receptor (CAR) T cells is actively being explored for pediatric brain tumors in preclinical models and early phase clinical studies....
BACKGROUND
Immunotherapy with chimeric antigen receptor (CAR) T cells is actively being explored for pediatric brain tumors in preclinical models and early phase clinical studies. At present, it is unclear which CAR target antigens are consistently expressed across different pediatric brain tumor types. In addition, the extent of HLA class I expression is unknown, which is critical for tumor recognition by conventional αβTCR T cells.
METHODS
We profiled 49 low- and high-grade pediatric brain tumor patient-derived orthotopic xenografts (PDOX) by flow analysis for the expression of 5 CAR targets (B7-H3, GD2, IL-13Rα2, EphA2, and HER2), and HLA class I. In addition, we generated B7-H3-CAR T cells and evaluated their antitumor activity in vitro and in vivo.
RESULTS
We established an expression hierarchy for the analyzed antigens (B7-H3 = GD2 >> IL-13Rα2 > HER2 = EphA2) and demonstrated that antigen expression is heterogenous. All high-grade gliomas expressed HLA class I, but only 57.1% of other tumor subtypes had detectable expression. We then selected B7-H3 as a target for CAR T-cell therapy. B7-H3-CAR T cells recognized tumor cells in an antigen-dependent fashion. Local or systemic administration of B7-H3-CAR T cells induced tumor regression in PDOX and immunocompetent murine glioma models resulting in a significant survival advantage.
CONCLUSIONS
Our study highlights the importance of studying target antigen and HLA class I expression in PDOX samples for the future design of immunotherapies. In addition, our results support active preclinical and clinical exploration of B7-H3-targeted CAR T-cell therapies for a broad spectrum of pediatric brain tumors.
Topics: Animals; Antigens, Surface; B7 Antigens; Brain Neoplasms; Child; Humans; Mice; Receptors, Chimeric Antigen; T-Lymphocytes; Xenograft Model Antitumor Assays
PubMed: 33320196
DOI: 10.1093/neuonc/noaa278 -
International Journal of Molecular... Dec 2023Cancer management still requires more potent and safer treatments, of which immunomodulatory receptors on the lymphocyte surface have started to show promise in new... (Review)
Review
Cancer management still requires more potent and safer treatments, of which immunomodulatory receptors on the lymphocyte surface have started to show promise in new cancer immunotherapies (e.g., CTLA-4 and PD-1). CD6 is a signal-transducing transmembrane receptor, mainly expressed by all T cells and some B and NK cell subsets, whose endogenous ligands (CD166/ALCAM, CD318/CDCP-1, Galectins 1 and 3) are overexpressed by malignant cells of different lineages. This places CD6 as a potential target for novel therapies against haematological and non-haematological malignancies. Recent experimental evidence for the role of CD6 in cancer immunotherapies is summarised in this review, dealing with diverse and innovative strategies from the classical use of monoclonal antibodies to soluble recombinant decoys or the adoptive transfer of immune cells engineered with chimeric antigen receptors.
Topics: Activated-Leukocyte Cell Adhesion Molecule; Antigens, CD; Antigens, Differentiation, T-Lymphocyte; Immunotherapy; Neoplasms; T-Lymphocytes
PubMed: 38139340
DOI: 10.3390/ijms242417510 -
International Journal of Molecular... Apr 2022Infectious diseases are a burden for aquaculture. Antigen processing and presentation (APP) to the immune effector cells that fight pathogens is key in the adaptive... (Review)
Review
Infectious diseases are a burden for aquaculture. Antigen processing and presentation (APP) to the immune effector cells that fight pathogens is key in the adaptive immune response. At the core of the adaptive immunity that appeared in lower vertebrates during evolution are the variable genes encoding the major histocompatibility complex (MHC). MHC class I molecules mainly present peptides processed in the cytosol by the proteasome and transported to the cell surface of all cells through secretory compartments. Professional antigen-presenting cells (pAPC) also express MHC class II molecules, which normally present peptides processed from exogenous antigens through lysosomal pathways. Autophagy is an intracellular self-degradation process that is conserved in all eukaryotes and is induced by starvation to contribute to cellular homeostasis. Self-digestion during autophagy mainly occurs by the fusion of autophagosomes, which engulf portions of cytosol and fuse with lysosomes (macroautophagy) or assisted by chaperones (chaperone-mediated autophagy, CMA) that deliver proteins to lysosomes. Thus, during self-degradation, antigens can be processed to be presented by the MHC to immune effector cells, thus, linking autophagy to APP. This review is focused on the essential components of the APP that are conserved in teleost fish and the increasing evidence related to the modulation of APP and autophagy during pathogen infection.
Topics: Adaptive Immunity; Animals; Antigen Presentation; Antigens; Autophagy; Histocompatibility Antigens; Histocompatibility Antigens Class II; Lysosomes; Peptides
PubMed: 35563287
DOI: 10.3390/ijms23094899