CD40 on APCs is needed for optimal programming, maintenance, and recall of CD8+ T cell memory even in the absence of CD4+ T cell help.

T Cell Help + Cd4 T Cell Memory Even in the Absence of + Cd8 Programming, Maintenance, and Recall of Cd40 on Apcs Is Needed for Optimal

CD40-CD40 ligand interaction between dendritic cells and CD8+ T cells is needed to stimulate maximal T cell responses in the absence of CD4+ T cell help.

Stimulation of CD40 on APCs through CD40L expressed on helper CD4+ T cells activates and "licenses" the APCs to prime CD8+ T cell responses. Although other stimuli, such as TLR agonists, can also activate APCs, it is unclear to what extent they can replace the signals provided by CD40-CD40L interactions. In this study, we used an adoptive transfer system to re-examine the role of CD40 in the pr...

T Cell Help + CD 4 T Cell Memory Even in the Absence of + CD 8 Programming , Maintenance , and Recall of CD 40 on APCs Is Needed for Optimal Rock

CD40-deficient, Influenza-specific CD8 Memory T Cells Develop and Function Normally in a CD40-sufficient Environment

Two models have been proposed to explain the requirement for CD40 signaling in CD8 T cell responses. The first model suggests that CD4 T cells activate antigen-presenting cells (APCs) through CD40 signaling (APC licensing). In turn, licensed APCs are able to prime naive CD8 T cells. The second model suggests that CD154-expressing CD4 T cells activate CD40-bearing CD8 T cells directly. Although ...

Direct CD4 help provision following interaction of memory CD4 and CD8 T cells with distinct antigen-presenting dendritic cells.

Accumulating evidence suggests that CD4 help is needed at the memory stage to mount effective secondary CD8 T cell responses. In this paper, we report that memory CD4 T cells can provide efficient help to memory CD8 T cells after interaction of the two lymphocytes with distinct dendritic cells. Provision of help to CD8 T cells required direct cell-cell contact and involved both IL-2 and CD40 li...