Immunoglobulin E: Pathogenic Relevance in Urticaria and Eczema
Ana M. Giménez-Arnau, Howard I. Maibach in Contact Urticaria Syndrome, 2014
The innate immune system is characterized as generating a quick response after its encounter with the pathogen (antigen or allergen), whereas the adaptive immune system has a specialized response, amplifying it after repeated exposures to the same pathogen. During development, T-cell lymphocyte maturation is mediated by cytokines and cell–cell interaction. There are two important types of T-cell lymphocytes regarding cell-surface markers: 1) CD4+, also called helper T cells (Th) (60%–70%) and 2) CD8+, also called suppressor T cells (30%–40%). Depending on the type of cytokine produced, Th cells differentiate into type 1 (Th1), type 2 (Th2), and the newly identified subsets, Th17 and Th22.[1,2] Whereas interleukins (IL) 4 and 13 are cytokines that induce a Th2 balance, IL-2 and interferon-γ (IFN-γ) induce Th1 environment. Th2 cells stimulate immunoglobulin (Ig) E production by B cells. The balance of these stimulatory and inhibitory activities of the Th1 and Th2 is believed to determine an individual’s propensity to develop allergic disorders or atopy. The predominance of Th1 or Th2 response in each individual has been demonstrated to be influenced by environmental factors as well as by genetic predisposition by particular population.[3] In fact, children from allergic parents are more susceptible to develop allergic disorders.[4,5] On the other hand, Th17 and Th22 cells have been described in the context of asthma, where the neutrophil is predominant in the infiltrate, and in non-IgE-related atopic eczema as well as in chronic phases of atopic eczema.[2,6]
Experimental Protocols for Generation and Evaluation of Articular Cartilage
Kyriacos A. Athanasiou, Eric M. Darling, Grayson D. DuRaine, Jerry C. Hu, A. Hari Reddi in Articular Cartilage, 2017
Flow cytometry (Figure 7.16) assays can identify the presence or absence of cell surface markers using the same concepts as other antibody detection methods, such as ELISA. To accomplish this, cells are blocked with a normal serum and then probed with primary and secondary antibodies analogous to ELISA. However, instead of an enzyme-conjugated secondary antibody, a fluorescent dye-tagged secondary antibody is used. Also, to prevent nonspecific interactions, an isotype control primary antibody is used to ensure that the primary antibody binds specifically to the protein of interest. This isotype control antibody will be determined based on the type of primary antibody used. To detect the bound secondary antibody with fluorescent marker, the labeled cells will then be run through the flow cytometer. The detected amount of the fluorescent marker, relative to the isotype antibody control, is used to determine the number of cells expressing the surface marker of interest. As the gain settings on the flow cytometer can vary between groups, unstained control cells are used to determine the group-specific gain.
ENTRIES A–Z
Philip Winn in Dictionary of Biological Psychology, 2003
During their development in the thymus or bone marrow, lymphocytes are effectively tested for reactivity to body components: clearly one does not want immune cells capable of destroying the host body. (When this does happen it is known as an AUTOIMMUNE DISEASE). Cells with the capacity for autoimmune damage are dealt with by APOPTOSIS, preserving the 'self tolerance' of the body. All the cells in the body are marked by cell surface markers—self-antigens. These are GLYCOPROTEINS (in humans they are called HUMAN LEUKOCYTE ANTIGENS—HLA) and they are coded by a GENE complex known as the MAJOR HISTOCOMPATIBILITY COMPLEX (MHC). There are two classes of these: class I MHC are present on all cells that have nuclei (that is, virtually all cells in the body); class II MHC are found on specialized cells such as macrophages, B cells, activated T cells and cells in the thymus gland. The function of these MHCs is to present antigens to T cells: an infected cell will use the class I MHC to deliver antigen to a cytotoxic T cell (TC); class II MHC molecules are involved in presenting antigens collected by macrophages to helper T cells (TH). The function of the cytotoxic T cell is to destroy invading cells. The helper T cells on the other hand have a signalling role: they release various types of CYTOKINE (such as INTERLEUKIN) which stimualte cytotoxic T cells and B cells. A third type of T cell—suppressor T cells (TS)—appear to be involved in terminating immune response, but their mechanism of action is as yet unclear.
microRNA-130b-3p delivery by mesenchymal stem cells-derived exosomes confers protection on acute lung injury
Published in Autoimmunity, 2022
Xiaoxia Wang, Jifeng Feng, Huijun Dai, Jianlan Mo, Bijun Luo, Cheng Luo, Weikang Zhang, Linghui Pan
CD105, CD29, CD44 and CD34 are commonly used to identify MSCs, among which CD105, CD29 and CD44 is a positive marker, whereas CD34 is a negative marker [36,37]. The specific function of the cells is related to its surface markers, and cell surface markers can reflect some basic characteristics of cells. MSCs are a mixed cell population, and their surface antigens are also non-specific, expressing the surface markers of mesenchymal cells, endothelial cells and epidermal cells [38]. CD29, also known as integrin β1, VLA-β chain or gpIIa, is a receptor for various extracellular matrix proteins, and CD29 acts as a fibronectin receptor involved in various cell–cell and cell–matrix interactions. CD105, also known as endoglin, is a 90-kDa type I transmembrane glycoprotein of the zona pellucida protein (ZP) family. CD44, also known as Hermes, Pgp1, H-CAM or Hutch, is an 80–95 kDa glycoprotein, which is expressed in leukocytes, endothelial cells, hepatocytes and MSCs. CD34 is a transmembrane salivary mucin that may be involved in adhesion and anti-adhesion. Therefore, we chose CD105, CD29, CD44 and CD34 to identify MSCs. Flow cytometry showed that CD105, CD29 and CD44 were positive, and CD34 was negative (Figure 1(A)). Adipogenic and osteogenic differentiation experiments uncovered that after oil red O staining, there were red lipid droplets in the cells; in the osteogenic medium, Alizarin Red stained cubes and formed mineralized nodules, indicating that the cells had multi-directional differentiation abilities (Figure 1(B)).
The shifting paradigm of colorectal cancer treatment: a look into emerging cancer stem cell-directed therapeutics to lead the charge toward complete remission
Published in Expert Opinion on Biological Therapy, 2021
Jessica Kopenhaver, Madison Crutcher, Scott A. Waldman, Adam E. Snook
While the stem cell model of cancer provides an exciting new outlook on cancer progression and treatment options, the application of CSC-directed therapies may be somewhat challenging due to a number of obstacles. Chief amongst these issues is the lack of consistently reliable stem cell markers due to CSC population heterogeneity. Without reliable markers, targeted therapies would be more or less ineffectual for patient care and with potentially similar systemic toxicity compared to conventional treatments caused by off-target effects. Therefore, the largest challenge currently facing the field of CSC-targeted therapies is properly identifying markers and molecular targets that are not only common amongst heterogeneous CSC populations, but also distinct from markers of healthy stem cell populations. The hope is that cell surface markers can be identified and consistent between patients, allowing targeted therapies to be used broadly, either in lieu of, or as an adjuvant to, traditional therapies. Even with the development of various targeted therapies (vaccines, monoclonal antibodies, CAR-T cells, etc.), the lack of reliable and consistent receptors limits their utility in clinical practice.
Mechanisms of cellular and humoral immunity through the lens of VLP-based vaccines
Published in Expert Review of Vaccines, 2022
Hunter McFall-Boegeman, Xuefei Huang
In the last decade, a new subset of memory T cells, the tissue resident memory (TRM), has been characterized[153]. The hallmarks of such cells are not cell surface markers but rather mainly the fact that they are found in barrier tissues, such as the lungs, skin, reproductive tracts, etc., and do not circulate[154,155]. In fact, TRM cells can express different cell surface markers depending on the type of tissue they are in[156]. These cells are thought to play an important role in reactivation of the immune response to subsequent infections. VLP-based vaccines are able to elicit TRM cells[157]. For example, intranasal immunization of mice with P22 loaded with M and M2 proteins from the Respiratory Syncytial Virus (RSV), fused to the P22 scaffold protein, was able to elicit TRM cell populations in the lungs[158]. These cells were detected by flow cytometry analysis of bronchioalveolar lavage fluid up to 2 months post inoculation. Importantly, while there was a small decrease in total cell counts for both M- and M2-specific TRM cells, it was still protective as measured by lung viral titers, after re-challenge.