Characterization of Innate and Adaptive Immune Responses in PYNOD-Deficient Mice

PYNOD (also called NLRP10) is a member of the nucleotide-binding domain and leucine-rich repeat containing family. Many members of this family play important roles in the activation and/or regulation of immune and inflammatory responses. We previously showed that PYNOD inhibits the IL-1β secretion in response to microbial infection in PYNOD-transgenic mice. In this study, we generated PYNOD-knockout (KO) mice and further investigated PYNOD's role in the innate and adaptive immune responses. Similar to wild-type macrophages, PYNOD-KO macrophages produced IL-1β and induced pyroptosis, a caspase-1-dependent programmed cell death, in response to various inflammasome activators and microbial infection. In addition, the PYNOD deficiency did not significantly affect the proliferation or cytokine production of T cells, the delayed-type hypersensitivity responses, the anti-tumor immunity, the Ag-specific Ab production, the cytotoxicity of NK cells, or the maturation, Ag-presenting capacity, or elicited migration of dendritic cells. Furthermore, the steady-state skin self-antigen transport to regional lymph nodes was not impaired in PYNOD-KO mice, suggesting that PYNOD is dispensable for steady-state dendritic cell migration. These results suggested that PYNOD is dispensable for the regulation of innate and adaptive immune responses in mice, unless PYNOD's expression is highly induced under certain conditions.