The Role of Biomaterials and Scaffolds on Immune Responses in Regenerative Medicine: Macrophage Phenotype Modulation by Biomaterial Properties and Scaffold Architectures

2021 ◽  
Author(s):  
Ezgi Antmen ◽  
Nihal Engin Vrana ◽  
Vasif Hasirci

Scaffolds are an integral part of the regenerative medicine field. The contact of biomaterials with tissue, as was clearly observed over the years, induces immune reactions in a material and...

2005 ◽  
Vol 53 (6) ◽  
pp. 689-698 ◽  
Author(s):  
Julián F. Hillyer ◽  
Bruce M. Christensen

Mosquitoes mount strong humoral and cellular immune responses against foreign organisms. Two components of the mosquito immune response that have received much attention are the phenoloxidase cascade that leads to melanization and antimicrobial peptides. The purpose of the current study was to use immunocytochemistry and transmission electron microscopy to identify the location of the melanization rate-limiting enzyme phenoloxidase and the antimicrobial peptide defensin in innate immune reactions against Escherichia coli and Micrococcus luteus by the mosquito Aedes aegypti. Our results show that both phenoloxidase and defensin are present at the sites of melanin biosynthesis in immune reactions against bacteria. Furthermore, both proteins are often present inside the same melanotic capsules. When hemocytes were analyzed, phenoloxidase was present in the cytosol of oenocytoids, but no significant amounts of defensin were detected inside any hemocytes. In summary, these data show that phenoloxidase and defensin colocalize in melanization reactions against bacteria and argue for further studies into the potential role of defensin in phenoloxidase-based melanization innate immune responses in mosquitoes.


2020 ◽  
Vol 21 (4) ◽  
pp. 1393 ◽  
Author(s):  
Sylwia Wrotek ◽  
Justyna Sobocińska ◽  
Henryk M. Kozłowski ◽  
Małgorzata Pawlikowska ◽  
Tomasz Jędrzejewski ◽  
...  

Glutathione is one of the most important and potent antioxidants. The development of pharmacological compounds that can either increase or decrease glutathione concentrations has allowed investigation into the role of glutathione in various biological processes, including immune responses. Recent findings have shown that glutathione not only affects certain factors involved in immunological processes but also modifies complex immune reactions such as fever. Until recently, it was not known why some patients do not develop fever during infection. Data suggest that fever induction is associated with oxidative stress; therefore, antioxidants such as glutathione can reduce pyrexia. Surprisingly, new studies have shown that low glutathione levels can also inhibit fever. In this review, we focus on recent advances in this area, with an emphasis on the role of glutathione in immune responses accompanied by fever. We describe evidence showing that disturbed glutathione homeostasis may be responsible for the lack of fever during infections. We also discuss the biological significance of the antipyretic effects produced by pharmacological glutathione modulators.


2020 ◽  
Vol 11 (SPL1) ◽  
pp. 546-549
Author(s):  
Shweta Dadarao Parwe ◽  
Milind Abhimanyu Nisargandha ◽  
Rishikesh Thakre

Hitherto, there is no proper line of treatment for the new (nCOVID19). The development of unique antiviral drugs has taken precedence. Therapeutic antibodies () will be a significantly beneficial agent against nCOVID-19. Here the host immune responses to new discussed in this review provide strategy and further treatment and understanding of clinical interventions against nCOVID-19. Plasma therapy uses the antibodies found in the blood of people recovering (or convalesced) from an infection to treat infected patients. When an infection occurs, the body begins producing proteins specially made to kill the germ, called antibodies. Those antibodies coat specifically plasma in the blood of survivors, the yellow transparent liquid blood portion for months or even years. research assesses plasma use from Convalescent patients of infected with nCOVID-19 as a possible preventive treatment. But it is not yet recommended as a line of treatment, and it is used as a clinical trial in the new in Indian population.


2021 ◽  
Author(s):  
Fabrice Cognasse ◽  
Kathryn Hally ◽  
Sebastien Fauteux-Daniel ◽  
Marie-Ange Eyraud ◽  
Charles-Antoine Arthaud ◽  
...  

AbstractAside from their canonical role in hemostasis, it is increasingly recognized that platelets have inflammatory functions and can regulate both adaptive and innate immune responses. The main topic this review aims to cover is the proinflammatory effects and side effects of platelet transfusion. Platelets prepared for transfusion are subject to stress injury upon collection, preparation, and storage. With these types of stress, they undergo morphologic, metabolic, and functional modulations which are likely to induce platelet activation and the release of biological response modifiers (BRMs). As a consequence, platelet concentrates (PCs) accumulate BRMs during processing and storage, and these BRMs are ultimately transfused alongside platelets. It has been shown that BRMs present in PCs can induce immune responses and posttransfusion reactions in the transfusion recipient. Several recent reports within the transfusion literature have investigated the concept of platelets as immune cells. Nevertheless, current and future investigations will face the challenge of encompassing the immunological role of platelets in the scope of transfusion.


Cells ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 564
Author(s):  
Haruki Watanabe ◽  
Myoungsun Son

The disruption of the immune tolerance induces autoimmunity such as systemic lupus erythematosus and vasculitis. A chromatin-binding non-histone protein, high mobility group box 1 (HMGB1), is released from the nucleus to the extracellular milieu in particular environments such as autoimmunity, sepsis and hypoxia. Extracellular HMGB1 engages pattern recognition receptors, including Toll-like receptors (TLRs) and the receptor for advanced glycation endproducts (RAGE). While the HMGB1-RAGE axis drives inflammation in various diseases, recent studies also focus on the anti-inflammatory effects of HMGB1 and RAGE. This review discusses current perspectives on HMGB1 and RAGE’s roles in controlling inflammation and immune tolerance. We also suggest how RAGE heterodimers responding microenvironments functions in immune responses.


2021 ◽  
Vol 22 (6) ◽  
pp. 3090
Author(s):  
Toshimasa Shimizu ◽  
Hideki Nakamura ◽  
Atsushi Kawakami

Sjögren’s syndrome (SS) is a systemic autoimmune disease characterized by chronic inflammation of the salivary and lacrimal glands and extra-glandular lesions. Adaptive immune response including T- and B-cell activation contributes to the development of SS. However, its pathogenesis has not yet been elucidated. In addition, several patients with SS present with the type I interferon (IFN) signature, which is the upregulation of the IFN-stimulated genes induced by type I IFN. Thus, innate immune responses including type I IFN activity are associated with SS pathogenesis. Recent studies have revealed the presence of activation pattern recognition receptors (PRRs) including Toll-like receptors, RNA sensor retinoic acid-inducible gene I and melanoma differentiation-associated gene 5, and inflammasomes in infiltrating and epithelial cells of the salivary glands among patients with SS. In addition, the activation of PRRs via the downstream pathway such as the type I IFN signature and nuclear factor kappa B can directly cause organ inflammation, and it is correlated with the activation of adaptive immune responses. Therefore, this study assessed the role of the innate immune signal pathway in the development of inflammation and immune abnormalities in SS.


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