Dendritic cell–mediated T-cell activation pathways (DC-T cell activation)

Dendritic cell–mediated T-cell activation pathways represent the fundamental process by which the innate immune system initiates and shapes adaptive immunity. Dendritic cells (DCs) act as professional antigen-presenting cells that capture pathogens or tumor antigens, process them, and present them via Major Histocompatibility Complex (MHC) molecules to T-cell receptors (TCRs) (Worbs et al., 2017). This interaction, known as Signal 1, is necessary but insufficient for full activation; it requires Signal 2, provided by costimulatory molecules like CD80 and CD86 on DCs binding to CD28 on T-cells (Gardner et al., 2020). Additionally, Signal 3 involves the secretion of polarizing cytokines such as IL-12 or IL-6, which dictate the differentiation of T-cells into specific effector subsets like Th1 or Th17 (Hilligan & Ronchese, 2020). In cancer, these pathways are often hijacked or suppressed by the tumor microenvironment, leading to T-cell exhaustion, while in autoimmune diseases, they are inappropriately activated against self-antigens (Wylie et al., 2019). Therapeutic interventions like checkpoint inhibitors (e.g., anti-PD-1, anti-CTLA-4) and costimulation blockers (e.g., Abatacept) target specific nodes within these pathways to either restore anti-tumor immunity or suppress pathological inflammation (Mellman et al., 2011).

Other names

Dendritic cell-T cell crosstalkAntigen presentation and T-cell primingDendritic cell-T cell synapseDC-T cell interaction pathway

Modulation of the immunological synapse through the blockade or activation of costimulatory and coinhibitory receptors (e.g., CTLA-4, PD-1) and MHC-TCR interactions.