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The Inducible Defense System: Antibody Molecules and Antigen-Antibody Reactions
Published in Julius P. Kreier, Infection, Resistance, and Immunity, 2022
IgG is the most abundant of the immunoglobulins. As noted earlier, IgG (M.W. 150,000) is composed of two heavy (M.W. 50,000) and two light (M.W. 25,000) chains linked by disulfide bonds. Approximately 65 percent of IgG molecules in humans have kappa light chains, while 35 percent have lambda. IgG is found in high concentrations in serum, with levels of 6–18 mg/ml. About 40 percent of IgG is intravascular and 60% is in the interstitial fluid. Because of its ability to diffuse between intravascular and extravascular spaces, IgG is effective in neutralizing bacterial toxins in both blood and tissues and is active against infectious agents that are disseminated in the blood, principally the Gram-posi tive bacteria. It neutralizes viruses and enhances the phagocytosis of microorganisms. It is therefore an opsonizing antibody. It is synthesized during the latter part of the primary response and is the major antibody synthesized during the secondary immune response. The half-life of IgG varies inversely with its serum concentration and is about twenty-one days, the longest of all the immunoglobulins.
Food Allergy
Published in Praveen S. Goday, Cassandra L. S. Walia, Pediatric Nutrition for Dietitians, 2022
Alison Cassin, Ashley Devonshire, Stephanie Ward, Meghan McNeill
Immunoglobulin E (IgE)-mediated food allergy is an adverse food reaction in which an affected individual is exposed to the implicated food protein and, often within minutes, develops an urticarial rash, angioedema, difficulty breathing, emesis, and/or hypotension. Affected patients often require immediate emergency medical evaluation and treatment with epinephrine and/or antihistamines, depending on the severity of the reaction. The prevalence of childhood food allergy is 7.6%. Milk is the most common allergen in infants <12 months of age; however, milk, peanut, and egg are the most common food allergens in toddlers 1–2 years of age. The prevalence of food allergy among adults is 10.8% and shellfish is the most commonly implicated allergen.
The immune and lymphatic systems, infection and sepsis
Published in Peate Ian, Dutton Helen, Acute Nursing Care, 2020
Michelle Treacy, Caroline Smales, Helen Dutton
Antibodies or immunoglobulins have a number of functions and effects: On activation, they bind to the pathogen, causing clumping or agglutination.Once bound, they act as opsonins, identifying or signalling that particular antigen for phagocytosis.Binding triggers the production of identical plasma cells or clones, which all produce the same antibody; this is called clonal expansion.Phagocytosis and the complement cascade system are also activated.
Risk factors of mortality and contribution of treatment in patients infected with COVID-19: a retrospective propensity score matched study
Published in Current Medical Research and Opinion, 2021
Yu Wang, Xin Yan, Chenglong Huang, Yan Sun, Chunlin Yao, Yun Lin, Weimin Xiao
The pathophysiology of COVID-19 caused by SARS-CoV-2 infection is aggressive inflammatory responses strongly implicated in the resulting damage to the airways Therefore, poor prognosis is not only related to the viral infection but also the host response. Thymosins was a family of polypeptides originally derived and characterized from the bovine thymus, and have been studied for a long time to characterize their immune restorative and immune-modulating properties. Interestingly, some molecules (thymosin α1 and thymosin β4), have been identified that their immunomodulatory efficacy including both immune enhancement and regulation20,21. Immunoglobulins have also been used to prevent and treat illness, neutralize drugs and poisons, and accentuate or depress the immune system22. Our study suggested that the use of thymosins or immunoglobulins is associated with fatal outcomes of COVID-19. On the other hand, there were also other studies that suggested that glucocorticoids are more common in fatal cases and indeed associated with COVID-19 death outcomes15,23. These may be related to the risks of prolonged viremia, corticosteroid-induced diabetes, avascular necrosis and psychosis24. Ammonium glycyrrhizate can produce glucocorticoid like effects for immunomodulatory therapy.
Pharmacology mechanism of Flos magnoliae and Centipeda minima for treating allergic rhinitis based on pharmacology network
Published in Drug Development and Industrial Pharmacy, 2019
Yulin Liang, Xiaofei Zhang, Junbo Zou, Yajun Shi, Yu Wang, Jia Tai, Yanjun Yang, Xiao Zhou, Dongyan Guo, Jing Wang, Jiangxue Cheng, Ming Yang
AR [1,2] is a chronic respiratory condition that is globally increasing in prevalence and it is a disease that is hard to cure [3]. It is an allergic disease characterized by nasal inflammatory symptoms caused by immunoglobulin E (IgE) after nasal mucosal contact allergen, which is related to the increased sensitivity of some specific allergens. Seemingly harmless symptoms of AR include sneezing, stuffy nose and runny nose [4]. The main pathological changes of rhinitis are nasal mucosa congestion, swelling, exudation, hyperplasia, atrophy, or necrosis [5]. Although the disease is not fatal, but the nasal symptoms and general discomfort are obvious, seriously affect the learning efficiency and quality of life of patients, and even cause or induce obstructive sleep apnea, and even affect the normal development of the maxillofacial region of patients [6].
Modulating effect of a new ester, 28-O-phosphatidylbetulin (DAPB), obtained from hen egg yolk lecithin and betulin on lymphocyte subsets and humoral immune response in mice
Published in Immunopharmacology and Immunotoxicology, 2019
Magdalena Lis, Barbara Barycza, Angelika Sysak, Aleksandra Pawlak, Agnieszka Suszko-Pawłowska, Marianna Szczypka, Czesław Wawrzeńczyk, Bożena Obmińska-Mrukowicz
Both compounds also affected the humoral immune response in the mice immunized with SRBC. Betulin, but not DAPB, administered four times before the SRBC injection enhanced the number of cells producing anti-SRBC antibodies (PFC). The level of total (IgM + IgG) hemagglutinin rose also in the animals treated with both doses of betulin before the immunization. While four exposures to 10 mg/kg of betulin after priming increased the production of total and 2-mercaptoethanol resistant (IgG) hemagglutinin. IgG is the most abundant class of antibodies in serum, and IgM is the first immunoglobulin class produced in a primary response to an antigen. The adaptive immune response is based on antigen recognition and presentation, specific T- and B-cells activation and proliferation, and antibody synthesis by B-cells. Unlike betulin, DAPB exerted only a little impact on the production of anti-SRBC antibodies. The compound at a dose of 1 mg/kg increased the level of total (IgM + IgG) hemagglutinin when administered before immunization and IgG titers when administered after priming. The change in betulin structure following esterification with phosphatidic acid could improve betulin capacity to accelerate immunoglobulin IgM isotype switching to IgG in B cells. Key role in this process is assigned to IL-5 secreted by Th2 cells [38].