In: Biology
What are the characteristics of innate lymphocyte cells?
Innate lymphocyte cells (ILCs) are recently discovered type of lymphocytes originating from lymphoid lineage but is a part of the innate immune system. ILCs can orchestrate immune response to invading pathogens through cytokine signals released from the tissue because unlike T and B lymphocytes, ILCs do not express antigen recognition receptors as such their activation and expansion is not directed by antigen but rather by cytokines.Before ILCs, natural killer cells(NK cells) were the only innate cells able to respond to cytokines released by antigen presenting cells(APCs) but unlike ILCs, NK cells are cytotoxic and can initiate the immune response against virus and tumours. Based on cell surface markers and cytokine expression profiles ILCs can be categorised as ILC1, ILC2 and ILC3. ILC3 are shown to interact with dendritic cells to maintain the epithelial barrier and with macrophages to establish tolerance towards commensal microbiota. In addition, ILCs maintain tissue homeostasis and integrity. Failure of ILC activation has been linked to several inflammatory and autoimmune disorders in human.