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Interleukin-8
Published in Jason Kelley, Cytokines of the Lung, 2022
Robert M. Strieter, Theodore J. Standiford, Mark W. Rolfe, Steven L. Kunkel
The ability of a cytokine to influence the production of another cytokine is important in immunoregulation. Interleukin-4 (IL-4), also known as B-cell growth factor or B-cell stimulation factor-1, possesses several properties related to lymphocyte activation, proliferation, and differentiation. However, it exerts significant suppressive activity on monocytes. Interleukin-4, in a dose-dependent fashion, inhibits the production of monocyte-derived IL-1, TNF, and IL-6 (Hart et al., 1989; Donnelly et al., 1990; Lee et al., 1990). Recently, our laboratory has shown that IL-4, in a dose-dependent manner, can suppress LPS-induced monocyte-derived IL-8 (Standiford et al., 1990b). In addition, this inhibitory effect was substantial, even if IL-4 was delayed 1 h poststimulation with LPS. Moreover, the suppressive effect of IL-4 was abrogated in the presence of a protein synthesis inhibitor (cycloheximide). These data suggested that IL-4’s inhibitory effects were mediated through the generation of a de novo protein intermediate. Although monocyte-derived cytokines appear to be significantly influenced by IL-4, the production of endothelial cell- and fibroblast-derived IL-8 is not inhibited in the presence of IL-4 (Standiford et al., 1990c). In the setting of newly recruited monocytes, IL-4 can exert powerful regulatory effects in modulating monocyte-derived cytokines.
Programmed Death 1 Receptor (PD-1)-mediated Immunomodulatory Effects in Pancreatic Cancer
Published in Surinder K. Batra, Moorthy P. Ponnusamy, Gene Regulation and Therapeutics for Cancer, 2021
Ashu Shah, Catherine Orzechowski, Maneesh Jain
Tumor cells exploit intrinsic mechanisms of immune evasion which include reduced antigen presentation, increased expression of immunosuppressive molecules such as PD-L1 and accumulation of antigen specific Tregs in the tumor microenvironment resulting in immunosuppression [18]. The immune system is characterized by its ability to distinguish between normal cells in the body and tumor cells through the expression of costimulatory and coinhibitory molecules on immune cells called immune checkpoints. These immune checkpoint molecules play a key role in immunoregulation and immune homeostasis through on-off switch mechanisms and protect the host against autoimmunity. However, tumor cells use these checkpoint molecules to protect themselves from an attack by the immune system. One such checkpoint protein, PD-1, is a coinhibitory receptor which is present on conventional T cells in conjunction with other costimulatory and co-inhibitory molecules and is an important regulator of T cell activation. PD-1 operates as off switch to limit T cell activation by interacting with its ligand, PD-L1, present on normal cells. Under inflammatory conditions like cancer, receptor PD-1 overexpression on T cells is congruent with upregulation of its ligand PD-L1 on antigen presenting cells (APC) and tumor cells [19]. The interaction between PD-1 receptor and its ligand PD-L1 leads to suppressed T cell activation and proliferation which promotes an immunosuppressed condition in the inflammatory microenvironment.
Mesenchymal Stem Cells from Dental Tissues
Published in Vincenzo Guarino, Marco Antonio Alvarez-Pérez, Current Advances in Oral and Craniofacial Tissue Engineering, 2020
Febe Carolina Vázquez Vázquez, Jael Adrián Vergara-Lope Núñez, Juan José Montesinos, Patricia González-Alva
Subsequent studies have shown that MSCs can mediate immunosuppression in animal and human models. There are two main aspects regarding the immunoregulation of MSCs; the first one involves the immunosuppressive effects of allogeneic MSCs. The second one includes the effects of inflammatory cytokines on MSCs activity and differentiation (Grinnemo et al. 2004).
Metabolomics approach of Symphyotrichum squamatum ethanol extract and its nano-Ag formulation protective effect on gastric ulcer via bio-chemical and pathological analyses
Published in Biomarkers, 2023
Heba A. Hassan, Iriny M. Ayoub, Tamer I. M. Ragab, Sherif M. Afifi, Abd El-Nasser G. El-Gendy, Abdel Razik H. Farrag, Ahmed M. Abd-ELGawad, Mohamed Farag, Abdelsamed Elshamy, Naglaa M. Ammar
Secondary metabolites profiling of SSEE revealed the presence of several compounds, mainly phenolics and terpenoids. Phenolics were documented as significant scavengers of the free radicals along with their antiinflammatiory effects (El-Newary et al.2021). Phenolic compounds were reported to act as protectors against most models of gastric ulcers in rats. This action might be mediated via several mechanisms such as i) cytoprotection, ii) antioxidants including the increasing of SOD and CAT activity as well as GSH levels, iii) immunoregulation by increasing of anti-inflammatory cytokines, and iv) anti-H. pylori (Serafim et al.2020). Terpenes, including sesqui-, di- and tri units, were reported to have the potentialities for inhibition and/or stimulation of i) gastric juice secretion (Chioma et al.2009), ii) mucosal production and defense (Siqueira et al.2012), iv) pepsin and H+-K+-ATPase activities (Lakshmi et al.2010). Also, terpenes were found to have the capabilities to protect the gastroduodenal mucosa, increase PGE2 level (Jain and Surana 2009), and eliminate free radicals with enhancement of ulcer blood circulation (Kim et al.2005). Some triterpenes were stated to increase the levels of TAC, MDA along with the down-regulation of caspase-3 activity (Elshamy et al.2020).
Research progress on antiviral constituents in traditional Chinese medicines and their mechanisms of action
Published in Pharmaceutical Biology, 2022
Pathogeneses of many viral diseases are dominated by the pathological impairment of immune response resulting from the direct viral invasion and damaged tissues (Yang et al. 2021). Immune response is classified into specific and non-specific. The physiological significance of immune response to organisms is threefold: defense, homeostasis, and surveillance (Herich et al. 2019). Defense means to prevent viruses from invading and to clear them away timely. Homeostasis means sustaining the dynamic equilibrium of immunity, where the damaged or necrotic cells resulting from virus infection are eliminated by immunity. As for surveillance, it aims to detect diseased cells in the body at any time and to remove them timely. Coordination and effectiveness of these three functions are reliant on precise immunoregulation, while viral infection often leads to immune dysfunction. TCM is composed of many ingredients and often plays a role through various mechanisms, which not only targets at the virus, but also the host's immune response and produces a synergistic effect (Ding, Zeng, et al. 2017; Zhang, Morris-Natschke, et al. 2020).
Probiotics for the prevention of atopic dermatitis in infants from different geographic regions: a systematic review and Meta-analysis
Published in Journal of Dermatological Treatment, 2022
Lifeng Chen, Yongshan Ni, Xingdong Wu, Guixia Chen
Some studies have shown that probiotic intake during pregnancy and early infancy can be a major measure for the prevention of AD (11,38). This preventive effect may be mediated by early colonization of beneficial bacteria such as LGG. It is known that the early gut microbiota is important for forming the immune system and establishing The cell balance (39). Probiotics can reduce the severity of AD by inhibiting T helper cell type 2 (Th2)-mediated responses and increasing the Th1/Th2 ratio (40); by inhibiting Th2 cell responses, cytokines such as IL-4, IL-5, IL-6 and IL-13 are no longer released (41), INF-γ is reduced (cytokines released by Th1 cells), phagocytosis is promoted, and serum IgA is increased. Probiotics can also stimulate the secretion of IL-10 and transformation of growth factor-β (TGF-β) (42). Probiotics can reduce proinflammatory cytokines, IL-4, IL-6, tumor necrosis factor-α (TNF-α), INF-γ, and high-sensitivity C-reactive protein (hsCRP) (43) by increasing the expression of IL-10 and Treg-related cytokines. To demonstrate the effectiveness of probiotics, a new mechanism that inhibits the differentiation of mature dendritic cells and converts naive T cells into Th2 was proposed (44). Immunoregulation reduces the susceptibility of inflammatory and allergic factors to regulate the skin axis of the gut. Probiotics also regulate brain function, including stress response of gut axis (45).