PubMed · 2415805
The source did not provide an abstract. Follow the original record for more information.
Explore connections, maps & timelines
C Nava. [Haptens].. https://pubmed.ncbi.nlm.nih.gov/2415805/
Cite the original work for its findings. Save a collection to share your selection of sources.
KEEP EXPLORING
Aspergillus ochraceus contaminates agricultural products and produces nephrotoxic, carcinogenic ochratoxin A (OTA), posing severe food safety hazards. A dual-signal lateral flow immunochromatographic assay (dLFIA) based on ZrO₂@C nanoprobes was established for quantitative detection of A. ochraceus biomass. A novel monoclonal antibody (mAb 4B4) was prepared as the capture antibody to immobilize A. ochraceus mycelial lysate antigen on the test line, and a rabbit polyclonal antibody (pAb G2801) as the detection antibody to modify ZrO₂@C composites (synthesized via UiO-66 pyrolysis) into 200 nm colorimetric/photothermal nanoprobes. This dLFIA achieved limits of detection of 0.164 μg/mL (colorimetric) and 0.517 μg/mL (photothermal). This efficient and reliable method allows quantitative analysis of A. ochraceus biomass, which is suitable for routine monitoring of fungal contamination in agro-food matrices.
During the process of lymphocyte recirculation, lymphocytes bind via L-selectin to sulfated sialyl-Lewisx (sLex)-containing carbohydrate ligands expressed on the surface of high endothelial venules (HEV). We have examined the expression of sLex on HEV using a panel of mAbs specific for sLex and sLex-related structures, and have examined the function of different sLex-bearing structures using an in vitro assay of lymphocyte rolling on HEV. We report that three sLex mAbs, 2F3, 2H5, and CSLEX-1, previously noted to bind with high affinity to glycolipid-linked sLex, vary in their ability to stain HEV in different lymphoid tissues and bind differentially to O-linked versus N-linked sLex on glycoproteins. Treatment of tissue sections with neuraminidase abolished staining with all three mAbs but slightly increased staining with MECA-79, a mAb to a sulfation-dependent HEV-associated carbohydrate determinant. Treatment of tissue sections with O-sialoglycoprotease under conditions that removed the vast majority of MECA-79 staining, only partially reduced staining with the 2F3 and 2H5 mAbs. Using a novel rolling assay in which cells bind under flow to HEV of frozen tissue sections, we demonstrate that a pool of O-sialoglycoprotease-resistant molecules is present on HEV that is sufficient for attachment and rolling of lymphocytes via L-selectin. This interaction is not inhibited by the mAb MECA-79. Furthermore, MECA-79 mAb blocks binding to untreated sections by only 30%, whereas the sLex mAb 2H5 blocks binding by approximately 60% and a combination of MECA-79 and 2H5 mAb blocks binding by 75%. We conclude that a pool of O-glycoprotease-resistant sLex-like L-selectin ligands exist on human HEV that is distinct from the mucin-associated moieties recognized by MECA-79 mAb. We postulate that these ligands may participate in lymphocyte binding to HEV.
The use of antisense oligodeoxyribonucleotides (ODN) is a potential method to switch off gene expression. The poor cellular uptake of ODN in primary cells still is a limiting factor that may contribute to the lack of functional efficacy. Various forms of cationic lipids have been developed for efficient delivery of nucleic acids into different cell types. We examined the two cationic lipids DOTAP and DOSPER to improve uptake of ODN into primary human hematopoietic cells. Using a radiolabeled 23-mer, ODN uptake into blood-derived mononuclear cells could be increased 42- to 93-fold by DOTAP and 440- to 1,025-fold by DOSPER compared with application of ODN alone. DOTAP was also effective for delivery of ODN into leukocytes within whole blood, which may resemble more closely the in vivo conditions. As assessed by fluorescein isothiocyanate-conjugated ODN both cationic lipids enhanced cytoplasmic accumulation of ODN in endosome/lysosome-like structures with a partial shift of fluorescence to the whole cytoplasm and the nucleus following an incubation of 24 hours. ODN uptake by cationic lipids into different hematopoietic cell subsets was examined by dual-color immunofluorescence analysis with subset-specific monoclonal antibodies. We found a cell type-dependent delivery of ODN with greatest uptake in monocytes and smallest uptake in T cells. CD34+ cells, B cells, and granulocytes took up ODN at an intermediate level. Uptake of ODN into isolated CD34+ cells could be increased 100- to 240-fold using cationic lipids compared with application of ODN alone. Stimulation of CD34+ cells by interleukin-3 (IL-3), IL-6, and stem cell factor did not significantly improve cationic lipid-mediated ODN delivery. Sequence-specific antisense effects in clonogenic assays could be shown by transfection of bcr-abl oncogene-directed antisense ODN into primary cells of patients with chronic myelogenous leukemia using this established protocol. In conclusion, cationic lipids may be useful tools for delivery of antisense ODN into primary hematopoietic cells. These studies provide a basis for clinical protocols in the treatment of hematopoietic cells in patients with hematologic malignancies and viral diseases by antisense ODN.