CD4^(+)T cells integrate well-defined signals from the T-cell receptor(TCR)(signal 1)and a host of costimulatory molecules(signal 2)to initiate clonal expansion and differentiation into diverse functional T helper(Th)...CD4^(+)T cells integrate well-defined signals from the T-cell receptor(TCR)(signal 1)and a host of costimulatory molecules(signal 2)to initiate clonal expansion and differentiation into diverse functional T helper(Th)subsets.However,our ability to guide the expansion of context-appropriate Th subsets by deploying these signals in vaccination remains limited.Using cell-based vaccines,we selectively amplified signal 1 by exclusive presentation of an optimized peptide:MHC II(pMHC II)complex in the absence of classic costimulation.Contrary to expectations,amplified signal 1 alone was strongly immunogenic and selectively expanded highaffinity TCR clonotypes,despite delivering intense TCR signals.In contrast to natural infection or standard vaccines,amplified signal 1,presented by a variety of professional and nonprofessional antigen-presenting cells(APCs),induced exclusively polyfunctional Th1 effector and memory cells,which protected against retroviral infection and tumor challenge,and expanded tumor-reactive CD4^(+)T cells otherwise rendered unresponsive in tumor-bearing hosts.Together,our findings uncover a default Th1 response to ample signal 1 and offer a means to selectively prime such protective responses by vaccination.展开更多
基金supported by the Francis Crick Institute(FC001099)which receives its core funding from Cancer Research UK,the UK Medical Research Council,and the Wellcome Trust.
文摘CD4^(+)T cells integrate well-defined signals from the T-cell receptor(TCR)(signal 1)and a host of costimulatory molecules(signal 2)to initiate clonal expansion and differentiation into diverse functional T helper(Th)subsets.However,our ability to guide the expansion of context-appropriate Th subsets by deploying these signals in vaccination remains limited.Using cell-based vaccines,we selectively amplified signal 1 by exclusive presentation of an optimized peptide:MHC II(pMHC II)complex in the absence of classic costimulation.Contrary to expectations,amplified signal 1 alone was strongly immunogenic and selectively expanded highaffinity TCR clonotypes,despite delivering intense TCR signals.In contrast to natural infection or standard vaccines,amplified signal 1,presented by a variety of professional and nonprofessional antigen-presenting cells(APCs),induced exclusively polyfunctional Th1 effector and memory cells,which protected against retroviral infection and tumor challenge,and expanded tumor-reactive CD4^(+)T cells otherwise rendered unresponsive in tumor-bearing hosts.Together,our findings uncover a default Th1 response to ample signal 1 and offer a means to selectively prime such protective responses by vaccination.
