Stressors that exhibit immunosuppression might act by different mechanisms, i.e. alter the number of cells involved in the immune response, the ability of the cells to produce cytokines, chemokines, antibodies or growth factors, the composition of the subpopulations of cells present at the site of the response, or the function of the cells. This Adverse Outcome Pathway (AOP) describes how impairment of the signaling receptor IL-1R1 in T cells can lead to impaired T cell activation and antibody production, leading to increased susceptibility to infection. The AOP focuses on the blocking of binding of IL-1 to IL-1R1, leading to the Inhibition of Nuclear factor kappa B (NF-kB). This AOP is referred to as AOP 277 in the Collaborative Adverse Outcome Pathway Wiki (AOP-Wiki).