Innate lymphoid cells: parallel checkpoints and coordinate interactions with T cells

• The phenotypic and functional parallels between ILC and T cell subsets establish common immune checkpoints.
• Complementarity and redundancy between ILCs and T cells ensures immune protection.
• The immune function of ILCs are revealed in conditions of deficiencies of adaptive immunity.

Protection of epithelial and mucosal surfaces is required for survival. The recent discovery of a diverse array of innate lymphoid cells that lie immediately beneath these surfaces has unexpectedly uncovered an entire defense system distinct from the adaptive system essential to protect these barriers. This multilayered design provides a robust system through coupling of two highly complementary networks to ensure immune protection. Here, we discuss the similarities in the hardwiring and diversification of innate lymphoid cells and T cells during mammalian immune responses.