Tissue residency of innate lymphoid cells in lymphoid and nonlymphoid organs

Abstract

Innate lymphoid cells (ILC) contribute to barrier immunity, tissue homeostasis, and immune regulation at various anatomical sites throughout the body. How ILCs maintain their presence in lymphoid and peripheral tissues is currently unknown. We found that in the lymphoid and non-lymphoid organs of adult mice, ILC are tissue-resident cells that were maintained and expanded locally under physiologic conditions, upon systemic perturbation of immune homeostasis, and during acute helminth infection. However, at later time points post-infection, cells from hematogenous sources helped to partially replenish the pool of resident ILCs. Thus, ILC are maintained by self-renewal in broadly different microenvironments and physiological settings. Such an extreme “sedentary” lifestyle is consistent with the proposed roles of ILCs as sentinels and local keepers of tissue function.

Natural killer cell memory in infection, inflammation and cancer

“…In response to systemic viral infection, memory NK cells distributed through the whole body might efficiently mediate viral control. Using parabiosis experiments, it was recently reported that not only ILCs but also subsets of NK cells carrying markers of conventional NK cells are tissue resident in different organs including the small intestine, lung and salivary gland 70 . It will be important to further dissect and characterize NK cell subsets in different organs, to understand their relationship to conventional NK cells and ILCs and to unravel their unique functionality and memory potential during disease.…”

Functional and phenotypic heterogeneity of group 3 innate lymphoid cells

“…ILC3 have a long half‐life in tissues and lymph nodes and are largely replenished locally within the tissue 30, 52. Surprisingly, ILC3 can maintain their phenotype and function even in the absence of ROR γ t expression and persist for a significant length of time 53.…”

Plasticity of Myeloid Cells during Oral Barrier Wound Healing and the Development of Bisphosphonate-related Osteonecrosis of the Jaw

“…The highly active renewal capability of skin epidermis and intestinal epithelium affords rapid repopulation and recovery of barrier tissue continuity, and a repertoire of adaptive and innate immunity plays an essential role in the maintenance of barrier function and homeostatic relationship with microbes (3,4). Barrier tissues maintain resident memory T cells (5,6), innate lymphoid cells (7), and macrophages (8), which are highly specialized and capable of proliferating locally without contributions from distantly localized precursor cell populations. Infections and injuries to barrier tissues immediately activate the tissue-resident cells initiating the immune cascade.…”