Expression of B7 costimulatory molecule in cultured human epidermal Langerhans cells is regulated at the mRNA level
| Autor: | Rossella Manfredini, Giampiero Girolomoni, Andrea Cossarizza, Alberto Giannetti, Valentina Zacchi, Sergio Ferrari, Giovanna Zambruno |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 1994 |
| Předmět: |
medicine.drug_class
Immunoelectron microscopy Antigen presentation CD-80 Molecular Sequence Data Fluorescent Antibody Technique Dermatology Biology Monoclonal antibody Biochemistry Polymerase Chain Reaction accessory molecules Dispase medicine Humans Langerhans cells dendritic cells RNA Messenger Antigen-presenting cell Microscopy Immunoelectron Molecular Biology Cell potency Cells Cultured In Situ Hybridization Base Sequence gene expression Antibodies Monoclonal Cell Biology Dendritic cell Flow Cytometry Molecular biology Endocytosis Cell biology Up-Regulation antigen presentation Gene Expression Regulation Langerhans Cells B7-1 Antigen CD80 |
| Zdroj: | Scopus-Elsevier |
| Popis: | Langerhans cells (LC) belong to the dendritic cell lineage and are the principal antigen-presenting cells of squamous epithelia. Snort-term cultured LC (cLC) exhibit a marked augmented capacity to stimulate allogeneic T cells and acquire the ability to activate naive T cells, probably in relation to enhanced expression of accessory signals. In this study, we evaluated the expression of B7 costimulatory molecule (CD80) in human freshly isolated (fLC) and cLC at both the protein and mRNA level. Staining of frozen skin sections did not reveal any epidermal dendritic cell reactive with either of two different anti-B7 monoclonal antibodies. fLC in suspension did not exhibit any B7 staining as evaluated by two-color flow-cytometry analysis and immunoelectron microscopy. In contrast, LC that were cultured for 24–72 h displayed strong surface B7 reactivity with a characteristic patchy pattern. Treatment with dispase and trypsin did not reduce B7 staining of cLC. Following warming to 37 °C, cLC tagged with anti-B7 monoclonal antibody and gold-conjugated secondary antibody could internalize surface B7 by using the organelles of receptor-mediated endocytosis. B7 mRNA, detected by the reverse-transcriptase polymerase chain reaction technique, was expressed at a low level in purified (>90% HLA-DR + ) fLC but not in LC-depleted epidermal cells, and was markedly upregulated in purified cLC. The results indicate that 1) fLC do not express B7 protein on their surface, but acquire B7 during culture, 2) surface B7 is not sensitive to trypsin, 3) B7 expression is regulated primarily at the mRNA level, and 4) membrane B7 can be internalized within cLC. B7 molecule on CLC may be relebant to their increased antigen-presenting cell potency and ability to stimulate naive T lymphocytes. |
| Databáze: | OpenAIRE |
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