Processing of exogenous heat-aggregated (denatured) and particulate (native) hepatitis B surface antigen for class I-restricted epitope presentation
| Autor: | Schirmbeck, R., Bohm, W., Melber, K., Reimann, J. |
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| Rok vydání: | 1995 |
| Předmět: | |
| Zdroj: | Scopus-Elsevier |
| ISSN: | 1550-6606 0022-1767 |
| DOI: | 10.4049/jimmunol.155.10.4676 |
| Popis: | Many cell types efficiently present an epitope of the hepatitis B surface Ag (HBsAg) to murine class I-restricted CTL following an in vitro pulse with native 22-nm HBsAg particles. Processing of exogenous HBsAg particles required its cytochalasin B-insensitive uptake and acid proteolysis in an endocytic compartment, was insensitive to brefeldin A and cycloheximide, and did not involve regurgitation of antigenic peptides. In contrast, after an in vitro pulse of cells with exogenous, heat-denatured 1-micron HBsAg aggregates, only macrophages (but not other cell types tested) presented the Ld-restricted HBsAg epitope efficiently to CTL. Processing of exogenous HBsAg aggregates required its cytochalasin B-sensitive uptake, was insensitive to brefeldin A, and involved regurgitation of antigenic peptides. Processing of the two different, exogenous HBsAg preparations for class I-restricted epitope presentation thus involved alternative pathways: an "endocytic pathway" for native 22-nm particles, and a "phagocytic pathway" for denatured 1-microns aggregates. Both HBsAg preparations displayed different immunogenicity for class I-restricted CTL in vivo when delivered without adjuvants: native HBsAg particles were of high immunogenicity, and denatured HBsAg aggregates were of low immunogenicity. Class I-restricted CTL are thus primed in vivo after "endocytic processing" of native HBsAg particles as well as "phagocytic processing" of denatured HBsAg aggregates. |
| Databáze: | OpenAIRE |
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