1. Vesicles bearing MHC class II molecules mediate transfer of antigen from antigen-presenting cells to CD4<SUP>+</SUP> T cells
- Author
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Arnold, Paula Y. and Mannie, Mark D.
- Abstract
Previous studies have provided evidence that myelin basic protein (MBP)-specific rat T cells acquire antigen via transfer of preformed peptide / MHC class II complexes from splenic antigen-presenting cells (APC). The purpose of the present study was to determine how T cells acquire peptide / MHC class II complexes from APC in vitro. Our results show that a MHC class II+ T cell line, R1-trans, released MHC class II-bearing vesicles that directly stimulated MBP-specific CD4+ T cells. Vesicles expressing complexes of MHC class II and MBP were also specifically cytotoxic to MBP-specific T cells. Surviving T cells acquired MHC class II / antigen complexes from these vesicles by a mechanism that did not require protein synthesis but depended on specific TCR interactions with peptide/self MHC complexes. Furthermore, MBP / MHC class II-bearing vesicles enabled T cells to present MBP to other T cell responders. These studies provide evidence that APC release vesicles expressing preformed peptide / MHC class II complexes that interact with clonotypic TCR, allowing MHC class II acquisition by T cells. Vesicular transport of antigen / MHC class II complexes from professional APC to T cells may represent an important mechanism of communication among cells of the immune system.
- Published
- 1999
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