Phagocytosis of antigens by Langerhans cells
<p>Mature dendritic cells (DC) isolated from lymphoid tissues initiate antigen-specific T-dependent responses even though they are non-phagocytic and weakly pinocytic, whereas Langerhans cells (LC; immature DC) can process protein antigens but are poorly immunostimulatory. Thus antigens may b...
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| Format: | Thesis |
| Language: | English |
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1992
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| _version_ | 1817932186542669824 |
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| author | Reis e Sousa, C Reis e Sousa, Caetano |
| author2 | Austyn, J |
| author_facet | Austyn, J Reis e Sousa, C Reis e Sousa, Caetano |
| author_sort | Reis e Sousa, C |
| collection | OXFORD |
| description | <p>Mature dendritic cells (DC) isolated from lymphoid tissues initiate antigen-specific T-dependent responses even though they are non-phagocytic and weakly pinocytic, whereas Langerhans cells (LC; immature DC) can process protein antigens but are poorly immunostimulatory. Thus antigens may be acquired by cells of this lineage at an immature stage but, to our knowledge, there have been no studies on the phagocytic capacity of these cells <em>in vitro</em>.</p> <p>Using a newly-developed flow cytometric assay to measure the association between fluorescent markers and LC in epidermal cell cultures, and light and electron microscopy, we have observed phagocytosis of a variety of particles by freshly-isolated LC. The cells readily phagocytosed zymosan, heat-killed <em>S. cerevisiae</em>, bacteria (<em>S. aureus</em> and <em>C. parvum</em>) and fluorescent latex beads, but were unable to take up IgG- or complement-coated sheep erythrocytes, as opposed to MØ. Similarly, many freshly-isolated splenic DC had some phagocytic activity. However, the capacity of both LC and splenic DC to phagocytose zymosan, bacteria and fluorescent latex beads was markedly decreased after maturation in culture, consistently with the fact that mature DC are poorly phagocytic.</p> <p>Zymosan binding and uptake were much greater in fresh LC from C57BL/6 compared to BALB/c mice, and the loss of phagocytic capacity for zymosan during maturation followed different kinetics in the two strains. Two receptors mediating uptake of zymosan in LC were identified based on the effect of different inhibitors. Both of these receptors, recognising mannose and β-glucan residues, appear to be differentially regulated in the two mouse strains and during culture of LC.</p> <p>Our findings support the notion that DC are capable of acquiring particulate antigens for presentation at an immature stage, through recognition units for carbohydrate determinants common to a variety of potentially pathogenic organisms.</p> |
| first_indexed | 2024-03-06T19:37:07Z |
| format | Thesis |
| id | oxford-uuid:1f69e0f0-1d08-4c2f-aa02-216231100f14 |
| institution | University of Oxford |
| language | English |
| last_indexed | 2024-12-09T03:33:55Z |
| publishDate | 1992 |
| record_format | dspace |
| spelling | oxford-uuid:1f69e0f0-1d08-4c2f-aa02-216231100f142024-12-01T17:28:49ZPhagocytosis of antigens by Langerhans cellsThesishttp://purl.org/coar/resource_type/c_db06uuid:1f69e0f0-1d08-4c2f-aa02-216231100f14Langerhans cellsPhagocytosisAntigens, Immune responseDendritic cellsEnglishPolonsky Theses Digitisation Project1992Reis e Sousa, CReis e Sousa, CaetanoAustyn, JAustyn, J<p>Mature dendritic cells (DC) isolated from lymphoid tissues initiate antigen-specific T-dependent responses even though they are non-phagocytic and weakly pinocytic, whereas Langerhans cells (LC; immature DC) can process protein antigens but are poorly immunostimulatory. Thus antigens may be acquired by cells of this lineage at an immature stage but, to our knowledge, there have been no studies on the phagocytic capacity of these cells <em>in vitro</em>.</p> <p>Using a newly-developed flow cytometric assay to measure the association between fluorescent markers and LC in epidermal cell cultures, and light and electron microscopy, we have observed phagocytosis of a variety of particles by freshly-isolated LC. The cells readily phagocytosed zymosan, heat-killed <em>S. cerevisiae</em>, bacteria (<em>S. aureus</em> and <em>C. parvum</em>) and fluorescent latex beads, but were unable to take up IgG- or complement-coated sheep erythrocytes, as opposed to MØ. Similarly, many freshly-isolated splenic DC had some phagocytic activity. However, the capacity of both LC and splenic DC to phagocytose zymosan, bacteria and fluorescent latex beads was markedly decreased after maturation in culture, consistently with the fact that mature DC are poorly phagocytic.</p> <p>Zymosan binding and uptake were much greater in fresh LC from C57BL/6 compared to BALB/c mice, and the loss of phagocytic capacity for zymosan during maturation followed different kinetics in the two strains. Two receptors mediating uptake of zymosan in LC were identified based on the effect of different inhibitors. Both of these receptors, recognising mannose and β-glucan residues, appear to be differentially regulated in the two mouse strains and during culture of LC.</p> <p>Our findings support the notion that DC are capable of acquiring particulate antigens for presentation at an immature stage, through recognition units for carbohydrate determinants common to a variety of potentially pathogenic organisms.</p> |
| spellingShingle | Langerhans cells Phagocytosis Antigens, Immune response Dendritic cells Reis e Sousa, C Reis e Sousa, Caetano Phagocytosis of antigens by Langerhans cells |
| title | Phagocytosis of antigens by Langerhans cells |
| title_full | Phagocytosis of antigens by Langerhans cells |
| title_fullStr | Phagocytosis of antigens by Langerhans cells |
| title_full_unstemmed | Phagocytosis of antigens by Langerhans cells |
| title_short | Phagocytosis of antigens by Langerhans cells |
| title_sort | phagocytosis of antigens by langerhans cells |
| topic | Langerhans cells Phagocytosis Antigens, Immune response Dendritic cells |
| work_keys_str_mv | AT reisesousac phagocytosisofantigensbylangerhanscells AT reisesousacaetano phagocytosisofantigensbylangerhanscells |