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Concept of the Traditional Medicinal System and Holistic Health
Published in Mehwish Iqbal, Complementary and Alternative Medicinal Approaches for Enhancing Immunity, 2023
B cells and T cells can particularise to turn into memory cells, which continue permanently or for extensive durations and can identify the antigen if experienced again, subsequently provoking a swift immune response that is pathogen-specific. An exploding immune reaction is catastrophic with regards to energy spent and results in deterioration of the tissues in the host; hence rapid and absolute rectification of an immune reaction is also important. Cytokines are involved in the resolution of immune reactions, while interleukin-10, which is synthesised by a variety of immune cells counting regulatory T cells, has anti-inflammatory activity and is included in subduing the synthesis of inflammatory cytokines (Saraiva & O'Garra, 2010).
Immunization
Published in Julius P. Kreier, Infection, Resistance, and Immunity, 2022
Michael F. Para, Susan L. Koletar, Carter L. Diggs
The clonal expansion and activation of lymphocytes of the various subsets result in the production of multiple types of effector systems. There may be multiplication of B lymphocytes with production of immunoglobulin directed against the antigenic determinants in the vaccine. The mechanisms of action of antibodies include direct neutralization of toxins (as in control of diphtheria), opsonization of pathogens (as in control of pneumococcal infections), complement-dependent microbial lysis (as in meningococcal infections), neutralization of viral infectivity (as in control of hepatitis B infection), and antibody-dependent cellular toxicity (as in the control of Salmonella typhi infections). Any or all of these effector mechanisms can in theory operate individually or collectively depending on the nature of the pathogen, the stage of the immune response, and other factors. Initial immunization also induces memory cells which promote a rapid secondary immune response at the time of exposure to the pathogen.
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
Some antigen-specific lymphocytes manage to survive the ‘shrinkage’ phase of the immune response known as long-lived memory cells. In the event of a second attack, pathogen-specific memory lymphocytes mount an accelerated and more vigorous immune response, resulting in faster elimination of the invading target. The two populations of memory T cells are: effector memory T cells and central memory T cells (Kaech et al. 2002). The effector memory T cells do not express CCR7 and L-selectin, homes to peripheral tissues and conveys immediate protection against pathogens by rapidly producing cytokines. Central memory T cells home to lymph nodes due to the expression of CCR7 and L-selectin. Upon antigen stimulation they differentiate into effector cells and migrate to the peripheral tissue.
Maintaining a ‘fit’ immune system: the role of vaccines
Published in Expert Review of Vaccines, 2023
Béatrice Laupèze, T. Mark Doherty
The kind of innate immune response that develops in the earliest stages of immune recognition can help shape the nature of the adaptive immune response that subsequently develops; for example, by altering the proportion of B cells that differentiate into plasma cells releasing into the bloodstream antigen-specific antibodies (immunoglobulin G [IgG]), and the proportion of those that migrate to mucosal surfaces such as the respiratory system or the gut and release IgA [16]. This differential response leads to the development of the different populations of memory cells that are capable of responding rapidly and appropriately to subsequent exposures to that specific pathogen. Likewise, the type of T cells that develop after activation by APCs influences the inflammatory mediators released by the activated cluster of differentiation 4 positive (CD4+) T helper (Th) cell sub-populations (Th1, Th2, Th17, Tfh), which in turn influence how effectively the pathogen can be removed or contained [17]. CD8+ cytotoxic T cells activated by the innate response can also activate a range of different behaviors, such as killing cells directly or via the release of cytotoxins.
Advances in SARS-CoV-2 receptor-binding domain-based COVID-19 vaccines
Published in Expert Review of Vaccines, 2023
Xiaoqing Guan, Yang Yang, Lanying Du
RBD-based vaccines confer protection against SARS-CoV-2 infection by inducing adaptive immune responses, including stimulating B cells to produce neutralizing antibodies. T cell-mediated cellular immune responses either enhance B cell responses or kill virus-infected target cells directly. RBD-based vaccines function by enabling antigen presenting cells (APCs) such as dendritic cells and macrophages to recognize the RBD protein. APCs, which are activated through pattern recognition receptors and migrate to the lymph nodes, present the peptides derived from the RBD fragment and activate CD4+ and CD8+ T cells via major histocompatibility complex-I (MHC-I) and MHC-II molecules. Activated CD4+ T cells drive B cell development in the lymph nodes, leading to maturation and secretion of antibodies specific for the RBD protein. The activated CD8+ effector T cells then kill and eliminate virus-infected cells. Immune memory cells, including memory B cells and CD8+ memory T cells, are also induced, which can trigger protection by activating and proliferating rapidly once they re-encounter pathogens. SARS-CoV-2 infection and RBD vaccine-induced immune responses are described in Figure 3 [8,45–49].
The tumor microenvironment and triple-negative breast cancer aggressiveness: shedding light on mechanisms and targeting
Published in Expert Opinion on Therapeutic Targets, 2022
Natsuki Furukawa, Vered Stearns, Cesar A. Santa-Maria, Aleksander S. Popel
Memory T cells have been classified into central memory T cells (TCM), effector memory T cells (TEM), stem cell memory T cells (TSCM), and tissue-resident memory cells (TRM). TCM cells home to lymphoid tissues, while TEM cells migrate to peripheral tissues. TSCM cells have high proliferative and survival capacity and can differentiate into other memory T cell subsets. TRM cells are exclusively found in peripheral tissues and do not enter the circulation. The current model of memory T cell differentiation is that naive T cells first differentiate into TSCM cells, then into TCM cells, and finally into TEM cells. Once TEM cells reach the peripheral tissues, they terminally differentiate into TRM cells [64].