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Introduction to basic immunology and vaccine design
Published in Amine Kamen, Laura Cervera, Bioprocessing of Viral Vaccines, 2023
Alaka Mullick, Shantoshini Dash
As shown in Figure 3.3, upon recognition of a foreign organism, cells of the innate immune system secrete small molecules called cytokines to send a danger signal to the other elements of the immune system. These molecules are responsible for the communication between different cell types, stimulating certain functions, repressing others, thereby orchestrating a coordinated response to the external threat. A subset of cytokines called chemokines can induce chemotactic activity, recruiting various cell types to the site of infection. The recruited cell type also secretes cytokines and chemokines, thereby amplifying the response [3]. It is important to note that, in addition to the cells of the innate immune system, other cell types such as epithelial cells, endothelial cells, and fibroblasts also express PRRs and thus can also contribute to the inflammatory response by producing cytokines.
Immune System Imaging
Published in Margarida M. Barroso, Xavier Intes, In Vivo, 2020
Michael J. Hickey, M. Ursula Norman
Leukocyte migration is typically driven by interaction of chemokines with leukocyte-expressed chemokine receptors. In the cortex, chemokine expression is relatively low and uniform with CCL25 and CXCL12 contributing to DN thymocyte accumulation at the SCZ (Plotkin et al., 2003; Bunting et al., 2011; Dzhagalov and Phee, 2012). In the medulla, both the CCR4 ligands (CCL17, CCL22) and the CCR7 ligands (CCL19, CCL21) are highly expressed by medullary DCs, setting up a chemotactic gradient to attract cells expressing the appropriate receptors. After positive selection, thymocytes upregulate CCR4 and CCR7 allowing these cells to migrate into the medulla in response to this chemotactic gradient (Misslitz et al., 2006; Petrie and Zuniga-Pflucker, 2007). 2PM studies show that this migration is blocked by an inhibitor of chemokine receptor signaling. Similarly, positively selected thymocytes deficient in CCR7 showed reduced entry into the medulla following positive selection (Kurobe et al., 2006; Ehrlich et al., 2009), while CCR4 deficiency also reduced the ability of postpositive selection DP and SP CD4 thymocytes to accumulate in the medulla and to interact with medullary DCs (Hu et al., 2015). Together these observations support a role for chemokine-driven migration in these responses.
Nanostructured Biointerfaces
Published in Šeila Selimovic, Nanopatterning and Nanoscale Devices for Biological Applications, 2017
Jean Paul Allain, Monica Echeverry-Rendón, Juan Jose Pavón, Sandra L. Arias
In the process of recognizing the presence of a biomaterial, the body activates different molecules such as mitogens, chemoattractants, cytokines, growth factors, and other bioactive molecules that can modulate the activity of macrophages, along with the proliferation and activation of other cell populations in the inflammatory and wound-healing responses, which are identified by the presence of mononuclear cells such as monocytes and lymphocytes, at the biomaterial implant site. Chemokines are cytokines that are chemoattractants. They coordinate cellular migration in inflammation to produce an efficient and effective process of wound healing and are involved in other processes such as hematopoiesis, angiogenesis, and cellular differentiation. The production of cytoquines such as interleukin-4 and interleukin-13 plays a significant role in the reaction of the body after exposure to a foreign agent [32,33].
Genetic variants affecting chemical mediated skin immunotoxicity
Published in Journal of Toxicology and Environmental Health, Part B, 2022
Isisdoris Rodrigues de Souza, Patrícia Savio de Araujo-Souza, Daniela Morais Leme
The ROS-mediated damages induced in the skin may be sensed by the pattern recognition receptors (TLRs and NLRs) present in keratinocytes (Biswas 2016). These pattern recognition receptors then initiate a signal transduction pathway, activating genes through the action of transcription factors, such as nuclear factor kappa B (NF-ĸB). NF-κB is intrinsically related to the activation of genes related to production of antioxidant enzymes, as well as genes of inflammatory cytokines and chemokines (Corsini et al. 2013; Tabas and Glass 2013). Chemokines act as chemoattractants to guide the migration of several immune cells mainly leukocytes, but also lymphocytes, DCs and NK cells. Chemokines also promote angiogenesis and are involved in the maturation, differentiation and activation of lymphocytes and DCs, which may facilitate skin sensitization. Excessive chemokine activation and synthesis are hallmarks of psoriasis and AD (Nedoszytko et al. 2014).
Environmental chemicals and adverse pregnancy outcomes: Placenta as a target and possible driver of pre- and postnatal effects
Published in Critical Reviews in Environmental Science and Technology, 2023
Jing Li, Adrian Covaci, Da Chen
Cytokines and chemokines regulate and determine the immune responses and control immune cell trafficking and the cellular arrangement of immune organs. Excessive or insufficient production of cytokines may significantly contribute to the immune responses (Borish et al., 2003). Dysregulated placental immune responses have been linked with preeclampsia and metabolic disease. Therefore, the interference with cytokines and chemokines could elevate the risk of APOs via further triggering of immune responses. However, the underlying modes of action have not been sufficiently explored.