RESUMO
The activation of CD8(+) T-cells requires the uptake of exogenous polypeptide antigens and proteolytic processing of these antigens to octamer or nonamer peptides, which are loaded on MHC-I complexes and presented to the T-cell. By using an azide as a bioorthogonal protecting group rather than as a ligation handle, masked antigens were generated-antigens that are not recognized by their cognate T-cell unless they are deprotected on the cell using a Staudinger reduction.
Assuntos
Apresentação de Antígeno/imunologia , Antígenos/química , Antígenos/imunologia , Azidas/química , Apresentação Cruzada/imunologia , Células Dendríticas/química , Células Dendríticas/imunologia , Linfócitos T CD8-Positivos/citologia , Linfócitos T CD8-Positivos/imunologia , Células Dendríticas/citologia , Antígenos de Histocompatibilidade Classe I/química , Antígenos de Histocompatibilidade Classe I/imunologia , Humanos , Propriedades de SuperfícieRESUMO
Activation of a cytotoxic T-cell is a complex multistep process, and tools to study the molecular events and their dynamics that result in T-cell activation in situ and in vivo are scarce. Here, we report the design and use of conditional epitopes for time-controlled T-cell activation in vivo. We show that trans-cyclooctene-protected SIINFEKL (with the lysine amine masked) is unable to elicit the T-cell response characteristic for the free SIINFEKL epitope. Epitope uncaging by means of an inverse-electron demand Diels-Alder (IEDDA) event restored T-cell activation and provided temporal control of T-cell proliferation in vivo.