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Basics of Allergy
Published in Pudupakkam K Vedanthan, Harold S Nelson, Shripad N Agashe, PA Mahesh, Rohit Katial, Textbook of Allergy for the Clinician, 2021
Rafeul Alam, Dipa K Sheth, Magdalena M Gorska
Recent studies have identified a distinct population of innate lymphoid cells (Klose and Artis 2016, Mjosberg et al. 2011). These ILCs are analogous to T helper cells in their function. ILC1, ILC2 and ILC3 have a cytokine profile that is similar to that of Th1, Th2 and Th17. Although their frequency is low compared to T helper cells, ILCs produce much higher quantities of effector cytokines (e.g., IL5 and IL13 production by ILC2s) and significantly contribute to the pathogenesis of inflammatory diseases and host defense.
Innate lymphoid cells
Published in Phillip D. Smith, Richard S. Blumberg, Thomas T. MacDonald, Principles of Mucosal Immunology, 2020
Innate lymphoid cells (ILCs) have recently come to the forefront of mucosal immunology, being recognized as prompt effectors against infection and injury, and as orchestrators of immune responses. While it was understood that such orchestration was controlled by antigen-presenting cells (APCs)—dendritic cells (DCs), macrophages, and B cells—and helper T (TH) cells, it came as a surprise that ILCs function like TH cells early in the unfolding of an immune response.
Immunologic responses to various forms of allergen immunotherapy
Published in Richard F. Lockey, Dennis K. Ledford, Allergens and Allergen Immunotherapy, 2020
Umit Murat Sahiner, Mohamed H. Shamji, Sakura Sato, Ozge Soyer, Stephen J. Till, Motohiro Ebisawa, Mübeccel Akdis, Stephen R. Durham
Innate lymphoid cells (ILCs) are defined as a novel subset of lymphoid cells that lack antigen-specific receptors and are divided into three different subgroups. ILC2s are under the control of transcription factor GATA-3, and once activated by epithelium-derived IL-25, IL-33, and thymic stromal lymphopoietin (TSLP), they produce type 2 cytokines IL-4, IL-5, and IL-13 [5,6]. ILC2s represent an important alternative source of type 2 cytokines and are likely to increase and maintain the local allergic inflammation. Recently, the role of ILC2s is defined in several diseases, such as allergic airway inflammation [7,8], allergic rhinitis [9], atopic dermatitis [10], and eosinophilic esophagitis [11].
Impact of aging on immune function in the pathogenesis of pulmonary diseases: potential for therapeutic targets
Published in Expert Review of Respiratory Medicine, 2023
Sadiya Bi Shaikh, Chiara Goracci, Ariel Tjitropranoto, Irfan Rahman
Studies have shown that the maturation of the respiratory immune system in the postnatal environment depends on the type and abundance of antigen exposure to the host [19]. The lung microbiota helps in the development, induction, homeostasis, and tolerance of the respiratory immune system [20]. Numerous modifications take place in the pulmonary aging environment that influences the function of the innate immune system and host defenses against lung infections. One of the examples is the mucociliary barrier, which is a major defense against the pathogens in the bronchioles and the upper respiratory of the lung, both of which supply a physical barrier against a broad range of debris and microbes on top of the airways [17]. Studies have demonstrated a reductionmucociliary clearance in aged individuals donating to microbial invasion of the alveoli and lower airways [17,21,22]. The lung residential epithelial cells, innate lymphoid cells (ILCs), alveolar macrophages (AMs), and other pulmonary immune cells are vital to maintaining a stable state in the lungs [20]. Nevertheless, the capacity of these immune cells to identify different airway allergens and pathogens leads to the activation of inflammatory alterations in the lungs. There are some situations under which these lung inflammatory alterations are gentle and self-resolving, but during a respiratory condition such as acute lung injury (ALI) or sepsis, these pulmonary changes may show harmful effects on the host depending on the severity of the inflammatory innate immune response [18].
Preliminary Report on Interleukin-22, GM-CSF, and IL-17F in the Pathogenesis of Acute Anterior Uveitis
Published in Ocular Immunology and Inflammation, 2021
Jerry Chien-Chieh Huang, Matthew Schleisman, Dongseok Choi, Claire Mitchell, Lindsey Watson, Mark Asquith, James T. Rosenbaum
The immune system is often conceptualized as having two arms, an innate component and an acquired or adaptive component. The latter contributors, primarily T and B lymphocytes, can undergo somatic gene rearrangements to make highly targeted immune responses. But the immune system also includes additional cells that have the light microscopic appearance of lymphocytes, but these lymphoid cells have limited or no ability to make gene rearrangements. These cells are often called innate lymphoid cells. Examples include natural killer cells (NKs), mucosal associated immune T cells (MAITs), and ILCs (innate lymphoid cells) which have been subdivided into ILC-1, 2, and 3 on the basis of the primary cytokines each produces. Natural killer cells express killer immunoglobulin-like receptor (KIR), polymorphic receptors which interact with major histocompatibility complex (MHC) class I. HLA B27 can dimerize on the cell surface and thus activate KIR.7 This has helped lead to a recognition that NK cells could contribute to HLA B27-related diseases such as ankylosing spondylitis.8 Much less is known about MAIT cells or ILC subsets in spondyloarthritis, except for a small number of studies now implicating ILC-3 cells.9,10 We are unaware of prior studies which have sought to investigate a role for MAIT cells or ILCs in the pathogenesis of acute anterior uveitis.
An update on the role of chronic rhinosinusitis with nasal polyps as a co-morbidity in severe asthma
Published in Expert Review of Respiratory Medicine, 2020
Riccardo Castagnoli, Amelia Licari, Ilaria Brambilla, Mariangela Tosca, Giorgio Ciprandi, Gian Luigi Marseglia
Recently, novel insights into the pathophysiological role of innate immunity in CRSwNP and asthma have been provided by identifying a group of innate immune cells known as innate-lymphoid cells (ILCs). Reacting to ‘danger signals,’ ILCs produce a wide variety of cytokines able to influence immune responses [71,72]. After stimulation by epithelial cells-derived cytokines IL-25, IL-33, and thymic stromal lymphopoietin (TSLP), activated group 2 ILCs (ILC2 cells) produce high amounts of the IL-5 and IL-13 [73]. ILC2 cells are highly represented in NP tissues [74], thus indicating an essential role in activating type 2 inflammation in CRSwNP. Interestingly, a higher expression of Th2-driven cytokines (IL-4, IL-5, IL-9, and IL-13), TSLP, IL-25, and IL-33, as well as higher ILC2 cells, was observed in nasal tissues of severe asthmatic subjects with comorbid CRSwNP receiving nasal surgery [75]. After surgery, Lee et al. observed a significant improvement of asthma control and lung function parameters in these subjects, thus suggesting that an ILC2-induced and upregulated activity of Th2-related cytokines in asthmatics with CRSwNP may contribute to a recalcitrant status of asthma control [75].