The immune system is pivotal for not only fighting against various infections but also regulating the homeostasis of numerous tissues and organs. Our research group focuses on the role of natural helper (NH) cells, a new innate lymphocyte that we recently identified, in the regulation of inflammation and tissue homeostasis.
NH cells are a member of type 2 innate lymphoid cells (Group 2 innate lymphoid cell; ILC2), which are distinct from previously known lymphocytes such as T cells, B cells, and NK cells. NH cells are localized in fat-associated lymphoid clusters “FALC” and express c-Kit, Sca-1 but are negative for lineage markers, which are expressed on various hematopoietic cells.
NH cells also express several cytokine receptors such as IL-2R, IL-7R, IL-25R and IL-33R. IL-25 and IL-33 are known to induce type 2 immune responses during helminth infection and allergic inflammation. NH cells produce large amounts of IL-5 and IL-13 in response to a combination of IL-2 + IL-25 or IL-33 alone and induce eosinophilia and goblet cell hyperplasia that not only attacks the worm but also exacerbates allergic symptoms.
While some functions of NH cells are relatively well described, the role of NH cells in other diseases associated with IL-25 and IL-33 remain unclear. NH cells are localized in FALC, but the functional and developmental characteristics of FALC in adipose tissue and the role of NH cells in the homeostatic regulation of adipose tissue are largely unknown. Furthermore, the mechanism and specific cellular markers involved in their developmental pathway remain to be elucidated.
We are excited to investigate the functions of NH cells and hope to work with those who are interested in the role of innate immune cells in the regulation of homeostasis in our bodies.