Fig. 5

Inhibition of antigen-specific activation of T cells by IL-1Ra. (A) Correlation analyses between IL1RN mRNA level and seven immunogenic gene programs associated with PDA. Each immunogenic program consists of different number of signature genes (labeled in parenthesis). Correlation coefficients are labeled under the gene programs. Treg: regulatory T cells. APCs: antigen-presenting cells. (B) The flowchart of testing inhibitory effects of IL-1Ra on IL-1β or antigen (Pep.)-induced interferon (IFN)-γ secretion by the splenocytes collected from OT-1 mice (OT-1 splenocytes). Pep.: an OT-1 peptide (SIYRYGGL) specific for activating CD8⁺ T cells of OT-1 mice. (C) IL-1Ra protein inhibits IL-1β-induced IFN-γ secretion by OT-1 splenocytes. OT-1 splenocytes were treated with the combination of recombinant IL-1Ra (100 ng/ml) and IL-1β (1 ng/ml) for 18 h. IFN-γ-positive colonies were monitored by an ELISPOT assay and images were processed by ImageJ software (boxes). Student’s t-test was performed (right). (D) IL-1Ra inhibits antigen-induced IFN-γ secretion. IFN-γ secretion at different time points (3 h, 6 h, and 18 h) in OT-1 splenocytes following a combination of 0.1 ng/ml OT-1 peptide (Pep.) and 100 ng/ml IL-1Ra treatment. OT-1 splenocytes without OT-1 peptide treatment served as negative control (no Pep.). Right: ELISPOT images were processed and quantified. Student’s t-test was performed. (E) IL-1Ra inhibits CD8⁺ T cell activation by dendritic cells. Left: CD8⁺ T cells were enriched from ovalbumin (OVA)-immunized mice and incubated with OVA-pulsed DC2.4 dendritic cells (DC2.4/OVA), followed by detection of IFN-γ secretion. Middle: IFN-γ secretion in a mixture of CD8⁺-T cell and DC2.4/OVA in response to different concentration of IL-1Ra. Immune cells without IL-1Ra treatment serve as a negative control. Right: ELISPOT images were processed and quantified. Student’s t-test was performed. * p < 0.05. ** p < 0.01. *** p < 0.001. **** p < 0.0001