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COVID-19
Published in Stephen T. Sinatra, Mark C. Houston, Nutritional and Integrative Strategies in Cardiovascular Medicine, 2022
Immunity involves a partnership of memory B- and T-cells. B-cells are responsible for humoral immunity which produces specific antibodies to the virus. However, T-cells are an important component to the immune system. T-cells respond directly to the virus in a form of cell-mediated immunity.31 CD4+ and CD8+ T-cells show a response to COVID-19 in 100% and 70% of convalescent COVID patients, respectively. T-cell responses target the spike, M, N, and other ORFs.31 T-cell reactivity to SARS-CoV-2 epitopes is also detected in approximately 50% of non-exposed individuals.31 Tests to measure T-cell reactivity are not routinely available. However, both the B-cell and T-cell arms of the immune system contain memory cells which activate within minutes of exposure to the virus, even after detectable levels are not evident. Mild COVID-19 may elicit strong T-cell responses in the absence of detectable virus-specific antibodies. Scientists see signs of lasting immunity to COVID-19, even after mild infections. Approximately 50% of patients who have had colds (coronavirus) have T-cells active against COVID-19.31 100% of patients who recover have T-cells active against COVID-19.31 The T-cell arm of the immune system contributes to herd immunity (Figure 15.3).
The Inducible System: History of Development of Immunology as a Component of Host-Parasite Interactions
Published in Julius P. Kreier, Infection, Resistance, and Immunity, 2022
The dramatic success of immunization against a large number of bacterial and viral infections has led scientists to try to understand the cellular and molecular bases for the inducible immune response. Inducible immunity was originally thought to be either a cellular phenomenon, as observed in the intense phagocytic activity of macrophages, or a humoral phenomenon, as observed by the presence of antibodies in the serum of immunized animals. Today we understand that both cell-mediated and humoral immunity operate in the inducible immune response.
Autoimmune Disorders across the Lifespan
Published in Michelle Tollefson, Nancy Eriksen, Neha Pathak, Improving Women's Health Across the Lifespan, 2021
The immune system consists of both the innate and adaptive system. A stronger innate and adaptive immune response in women contributes to an increased susceptibility to AIDs. The innate immune system is the body’s first line of defense and is activated immediately upon exposure of the body to a pathogen. The second line of defense, the adaptive immune system, is acquired, antigen specific, and categorized as humoral or cell mediated. Humoral immunity consists mostly of B cells. Cell-mediated immunity consists of T cells. A subset of T cells known as T helper cells are categorized as Th1 or Th2 and are the major producers of cytokines. Pro-inflammatory cytokines are produced by Th1 cells and anti-inflammatory cytokines are produced by Th2 cells.
Characterization of anti-SARS-CoV-2 monoclonal antibodies focusing on antigen binding, neutralization, and FcγR activation via formation of immune complex
Published in mAbs, 2023
Minoru Tada, Michihiko Aoyama, Akiko Ishii-Watabe
Antibodies play a pivotal role in humoral immunity for fighting viral infections, and monoclonal antibodies (mAbs) are promising therapeutics for the prevention and treatment of infectious diseases.1 The coronavirus disease 2019 (COVID−19) pandemic has accelerated efforts to develop neutralizing mAbs that target severe acute respiratory syndrome coronavirus 2 (SARS-CoV−2). Recent advances in antibody discovery technologies such as single-cell analysis and next-generation sequencing (NGS) have enabled researchers to isolate the mAbs quite rapidly and have allowed the cloning of more mAbs targeting SARS-CoV−2 than ever before.2 As of December 2022, 12004 antibodies had been registered in the Coronavirus Antibody Database (CoV-AbDab; opig.stats.ox.ac.uk/webapps/covabdab), and some of these anti-SARS-CoV−2 therapeutic mAb products received Emergency Use Authorization from the US Food and Drug Administration.3,4
The biological effects of electromagnetic exposure on immune cells and potential mechanisms
Published in Electromagnetic Biology and Medicine, 2022
Chuanfu Yao, Li Zhao, Ruiyun Peng
The immune system plays important role in maintaining homeostasis, including protecting body from external attacks, eliminating mutated, aged and apoptotic cells. Immune system involves several different cell types, which are differentiated from multifunctional hematopoietic stem cells (HSCs). Natural killer (NK) cells, T lymphocytes, B lymphocytes, and lymphoid dendritic cells (DC) are differentiated from lymphoid progenitor cells. Myeloid DC, neutrophils, monocytes, and macrophages are differentiated from myeloid progenitor cells (Han 2016). These immune cells participate in both cellular and humoral immunity via directly killing target cells or producing specific antibodies. Recently, the biological effects of electromagnetic exposure on immune cells have been investigated via both epidemiological study and experimental researches.
Bioactive Peptides as Therapeutic Adjuvants for Cancer
Published in Nutrition and Cancer, 2021
Nidia Quintal-Bojórquez, Maira Rubí Segura-Campos
Adaptive immunity is highly specific against potentially harmful antigens. This type of immunity is classified into two categories: cell-mediated and antibody-mediated (also called humoral) immunity. In cell-mediated immunity, T lymphocytes are effector cells that mediate the cellular immune response by secreting cytokines and interacting with antigen presenting cells (APCs). T lymphocytes are divided in helper T (Th) cells, cytotoxic (Tc) cells and regulatory (Treg) cells. Tc cells, also called CD8+, recognize endogenous antigens associated to the mayor histocompatibility complex (MHC) class I in order to kill cancer cells and cells infected with viruses. Th cells, also called CD4+, recognize exogenous antigens associated to the MHC class II. CD4+ cells secrete cytokines (IFN-y), interleukins (IL-2, IL-4, IL-5, IL-6, IL-10, IL-13 and IL-25) and participate in the activation of B cells, T cells and other immune cells such as macrophages. Treg cells are responsible for the suppression of the immune response and the prevention of autoimmune disorders (32).