## Abstract T cell receptor‐transgenic F5 mice were used to assess primary CD8^+^ T cell responses to a modified virus Ankara (MVA)‐vectored vaccine in the absence of CD4^+^ T cell help. Naive, CD8‐enriched, CFSE‐labelled F5 cells were transferred into normal or CD4^+^ cell‐depleted mice and the mi
CD4 T cell help is required for primary CD8 T cell responses to vesicular antigen delivered to dendritic cells in vivo
✍ Scribed by Karine Serre; Laurent Giraudo; Carole Siret; Lee Leserman; Patrick Machy
- Publisher
- John Wiley and Sons
- Year
- 2006
- Tongue
- English
- Weight
- 553 KB
- Volume
- 36
- Category
- Article
- ISSN
- 0014-2980
No coin nor oath required. For personal study only.
✦ Synopsis
Abstract
Insight into the mechanisms by which dendritic cells (DC) present exogenous antigen to T cells is of major importance in the design of vaccines. We examined the effectiveness of free antigen as well as antigen with lipopolysaccharide, emulsified in complete Freund's adjuvant, and antigen encapsulated in liposomes in activating adoptively transferred antigen‐specific CD4 and CD8 T cells. When contained in liposomes, 100‐ to 1000‐fold lower antigen amounts were as efficient in inducing proliferation and effector functions of CD4 and CD8 T cells in draining lymph nodes as other antigen forms. CD11c^+^/CD11b^+^/CD205^mod^/CD8α^–^ DC that captured liposomes were activated and presented this form of antigen in an MHC class I‐ and class II‐restricted manner. CD4 T cells differentiated into Th1 and Th2 effector cells. Primary expansion and cytotoxic activity of CD8 T cells were CD4 T cell‐dependent and required the transporter associated with antigen processing (TAP). Finally, adoptively transferred CD4 and CD8 T cells were not deleted after primary immunization and rapidly responded to a secondary immunization with antigen‐containing liposomes. In conclusion, encapsulation of antigen in liposomes is an efficient way of delivering antigen to DC for priming of both CD4 and CD8 T cell responses. Importantly, primary CD8 T cell responses were CD4 T cell‐dependent.
📜 SIMILAR VOLUMES
## Abstract Naturally occurring CD4^+^ regulatory T cells can be identified on the basis of expression of CD25 and suppression of T cell responses __in vitro__ after TCR triggering. Here, we demonstrate that a CD134^+^ subset of CD4^+^CD25^+^ T cells in naive rats suppresses antigen‐specific T cell