Capsaicinoids (CPCs) is a special ingredient with pungent smell in condiments, which can also be used as an exogenetic marker for kitchen waste oil. Development of immunoassay for CPCs remains a challenging due to relatively difficult preparation of the broad-spectrum antibody (Ab). In this work, a broad-spectrum polyclonal antibody (pAb) which can simultaneously recognize capsaicin (CPC), dihydrocapsaicin (DCPC), nordihydrocapsaicin (NDCPC), and N-vanillylnonanamide (N-V) is produced, and a non-enzyme immunoassay (NISA) based on this Ab, dendritic mesoporous silica nanomaterials (DMSNs), polydopamine (PDA), and high catalytic efficiency of Pt nanoparticles to prepare signal probe (DMSNs@PDA@Pt) is established.
View Article and Find Full Text PDFA novel peroxidase-like nanozyme has been constructed by decorating two-dimensional TiCT nanosheets (TiCT NSs) with gold nanoparticles (AuNPs) to develop a colorimetric and photothermal dual-mode immunosensor. The TiCT/AuNPs nanocomposite-catalyzed 3,3',5,5'-tetramethylbenzidine (TMB)-HO reaction system produces the one-electron oxidation product of TMB (oxTMB), which exhibits color change and strong near-infrared (NIR) laser-driven photothermal effect at 808 nm laser irradiation. Given these characteristics, the developed immunosensor achieves ultrasensitive dual-mode detection of zearalenone (ZEN) by measuring colorimetric and photothermal signals with a microplate reader and a portable infrared thermometer, respectively.
View Article and Find Full Text PDFSpectrochim Acta A Mol Biomol Spectrosc
December 2023
Common typical β-agonists mainly include ractopamine (RAC), salbutamol (SAL), and clenbuterol (CLB). In view of the harm to human health causes by the ingestion of animal derived food containing β-agonists, and a series of regulations have been issued to restrict the usage of β-agonists as growth promoters. In this work, a fluorescence immunoassay is developed for the simultaneous detection of typical β-agonists based on blue-green upconversion nanoparticles (UCNPs) combine with magnetic separation.
View Article and Find Full Text PDFPreventing the protein-protein interaction of the cellular chromatin binding protein Lens Epithelium-Derived Growth Factor (LEDGF) and human immunodeficiency virus (HIV) integrase is an important possible strategy for anti-viral treatment for AIDS. We have used Intracellular Antibody Capture technology to isolate a single VH antibody domain that binds to LEDGF. The crystal structure of the LEDGF-VH complex reveals that the single domain antibody mimics the effect of binding of HIV integrase to LEDGF which is crucial for HIV propagation.
View Article and Find Full Text PDFHIV-1 traffics through dendritic cells (DCs) en route to establishing a productive infection in T lymphocytes but fails to induce an innate immune response. Within DC endosomes, HIV-1 somehow evades detection by the pattern-recognition receptor (PRR) Toll-like receptor 8 (TLR8). Using a phosphoproteomic approach, we identified a robust and diverse signaling cascade triggered by HIV-1 upon entry into human DCs.
View Article and Find Full Text PDFGenetically modified T cells to recognize tumor-associated antigens by transgenic TCRs or chimeric antigen receptors (CAR) have been successfully applied in clinical trials. However, the disadvantages of either TCR mismatching or the requirement of a surface tumor antigen limit their wider applications in adoptive T cell therapy. A TCR-like chimeric receptor, specific for the melanoma-related gp100/HLA-A2 complex was created by joining a TCR-like antibody GPA7 with the endodomains of CD28 and CD3-ζ chain.
View Article and Find Full Text PDFImmune responses at the intestinal mucosa must allow for host protection whilst simultaneously avoiding inappropriate inflammation. Although much work has focused on the innate immune functionality of hematopoietic immune cells, non-hematopoietic cell populations - including epithelial and stromal cells - are now recognized as playing a key role in innate defense at this site. In this study we examined the innate immune capacity of primary human intestinal stromal cells (iSCs).
View Article and Find Full Text PDFThe efficacy of immunotherapy based on natural killer (NK) cells is hampered by intrinsic non-specific cytotoxicity and insufficient activation of NK cells. Here, we confer the T-cell receptor-like (TCR-like) specificity on NK cells, taking advantage of both the innate and adaptive immune arms of the immune response to generate enhanced anti-melanoma activity. The TCR-like antibody (Ab) GPA7 was selected against melanoma-associated gp100/human leukocyte antigen (HLA)-A2 complex and then fused to intracellular domain of CD3-ζ chain.
View Article and Find Full Text PDFNOD2 is an intracellular sensor that contributes to immune defense and inflammation. Here we investigated whether NOD2 mediates its effects through control of microRNAs (miRNAs). miR-29 expression was upregulated in human dendritic cells (DCs) in response to NOD2 signals, and miR-29 regulated the expression of multiple immune mediators.
View Article and Find Full Text PDFNovel strains of influenza A viruses (IAVs) have emerged with high infectivity and/or pathogenicity in recent years, causing worldwide concern. T cells are correlated with protection in humans through cross-reactive immunity against heterosubtypes of IAV. However, the different hierarchical roles of IAV-derived epitopes with distinct levels of polymorphism in the cross-reactive T-cell responses against IAV remain elusive.
View Article and Find Full Text PDFConventional Y-shaped antibodies have been widely used in research, diagnostics and therapeutics. Their large size result in disadvantages in certain applications, which makes production difficult. Different parts of an antibody have been used to replace the whole antibody to make it smaller.
View Article and Find Full Text PDFTuberculosis causes serious health problem for the world population. Antigenic peptides selected by pathogen-specific cytotoxic T lymphocytes (CTLs) are presented by major histocompatibility complex (MHC; or human leukocyte antigen [HLA] in humans) molecules, and HLA-A restricted responses may be of interest for vaccine development and the understanding of cellular immunity. A series of peptides derived from the 10-KDa culture filtrate protein (CFP10) and the 6 kDa early secretory antigenic target (ESAT-6) in the Mycobacterium tuberculosis (Mtb) have been screened and a CTL epitope restricted by the human leukocyte antigen HLA-A24, a common HLA allele in Asian people, has been identified.
View Article and Find Full Text PDFAntibodies (Abs) have been engineered into small antigen-binding fragments and rebuilt into multivalent high-avidity molecules for improving in vivo pharmacokinetics and efficacy in clinical use. To increase the avidity of a T-cell receptor-like single-domain Ab (sdAb) specific for HLA-A2 complex, we fused the sdAb to a coiled-coil peptide derived from human cartilage oligomeric matrix protein (COMP48) to make an sdAb multimer, termed combody. The combody improved the binding avidity of sdAb significantly, whereas the specificity for the targeted cells was retained.
View Article and Find Full Text PDFThe magnitude of CTL-mediated immunity response is highly dependent on the density of antigenic peptide-MHC I complexes at the cell surface. In this study, we adopt a novel strategy to promote the surface level of specific peptide-MHC I complexes. The strategy combines the inhibition of transporter associated with antigen processing (TAP) with the delivery of specific peptide into endoplasmic reticulum directly without the help of TAP.
View Article and Find Full Text PDFHLA-B27 can form beta-2 microglobulin (beta2m)-associated heterotrimers (HLA-B27) and beta2m-free homodimers (B27(2)). Here, we study the role of complexed peptide in the interaction of these forms of B27 with the killer cell immunoglobulin (Ig)-like receptors KIR3DL1 and KIR3DL2 and with Ig-like transcripts LILRB1 and LILRB2. HLA-B27 tetramers complexed with three of five different naturally processed self peptides and three of seven pathogen-derived epitopes bound to KIR3DL1-expressing transfectants and NK cells.
View Article and Find Full Text PDFThe strong association of HLA B27 with spondyloarthropathies contrasts strikingly with most autoimmune diseases, which are HLA class II associated and thought to be mediated by CD4+ T lymphocytes. By introducing a human-derived HLA B27-restricted TCR into HLA B27 transgenic mice, we have obtained a functional TCR transgenic model, GRb, dependent on HLA B27 for response. Surprisingly, HLA B27 supported CD4+ as well as CD8+ T cell responses in vivo and in vitro.
View Article and Find Full Text PDFObjective: HLA-B27 is capable of forming in vitro a heavy-chain homodimer structure lacking beta(2)-microglobulin. We undertook this study to ascertain if patients with spondylarthritis express beta(2)-microglobulin-free HLA-B27 heavy chains in the form of homodimers and receptors for HLA-B27 homodimers.
Methods: Expression of HLA-B27 heavy chains by mononuclear cells was analyzed by fluorescence-activated cell sorter staining, Western blotting with the monoclonal antibody HC-10, and 2-dimensional isoelectric focusing.