The immune battlefield: The impact of inflammatory cytokines on CD8⁺ T-cell immunity - Fig 1

<p><b>A.</b> CD8⁺ T-cell basics: upon integrating the 3 signals needed for activation (1, TCR; 2, costimulation; 3, cytokines), a naïve antigen-specific CD8⁺ T cell clonally expands, acquires effector functions to kill invading pathogen, and then undergoes numerical contraction, developing into long-lived protective memory antigen-specific CD8⁺ T cells. <b>B</b>. Memory CD8⁺ T-cell exposure to proinflammatory cytokines (i.e., IL-12, IL-15, IFN-I) enhances their function, allowing them to counteract and neutralize pathogen risk. <b>C.</b> Virus-mediated inhibition of IFN-I production leads to dysfunctional CD8⁺ T-cell responses and pathogen persistence. <b>D</b>. Transient IL-10 does not impair functional CD8⁺ T-cell responses, allowing pathogen control and clearance. Sustained IL-10 production leads to CD8⁺ T-cell dysfunction and pathogen persistence. <b>E</b>. Inflammation influences memory CD8⁺ T-cell generation, impacting vaccine development and protective immunity. IFN, interferon; IL, interleukin; MPEC, memory precursor effector cell; SLEC, short-lived effector cell; TCR, T-cell receptor.