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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.
Autoantibodies: Their Nature and Significance
Published in E. Nigel Harris, Thomas Exner, Graham R. V. Hughes, Ronald A. Asherson, Phospholipid-Binding Antibodies, 2020
Most autoantibodies arise from the expansion of multiple B cell clones. These antibodies have the properties of a secondary immune response. This response is highly focused on a relatively limited number of antigens which are often related in structure or function. These findings indicate that the autoantigen is itself playing an important role in induction or maintenance of autoantibody production. Exactly where the breakdown in self tolerance occurs—at the level of the antigen, the macrophage or the lymphocyte—is still not clear, nor is it known whether exogenous agents are necessary for the breakdown to occur. Despite these uncertainties, recent insights into the genetic susceptibility to autoimmune diseases as well as intensive research in tolerance induction in the thymus and the periphery should provide important groundwork for understanding autoimmunity.
B Cells and Humoral Immunity
Published in Constantin A. Bona, Francisco A. Bonilla, Textbook of Immunology, 2019
Constantin A. Bona, Francisco A. Bonilla
The immune response in an animal which has never before encountered a given antigen is called a primary immune response. The response in an animal which has been primed by at least one prior exposure to the antigen is called a secondary immune response. Primary and secondary responses differ with respect to the lag period (the time between exposure to an antigen and an observable immune response), the magnitude and duration of the response, and the isotypes and affinity of antibodies produced (Figure 5–14).
Immunoinformatics-guided designing and in silico analysis of epitope-based polyvalent vaccines against multiple strains of human coronavirus (HCoV)
Published in Expert Review of Vaccines, 2022
Bishajit Sarkar, Md. Asad Ullah, Yusha Araf, Nafisa Nawal Islam, Umme Salma Zohora
The immune simulation study of the best-selected vaccine V3 showed that the immune response of the vaccine within the host might be consistent with the typical immune response. After each of the vaccine injections, the primary immune response was found to be triggered, which later activated the secondary immune response. An increase in the concentrations of the memory Bcells, plasma B-cell, cytotoxic T-cells, and helper T-cells as well as different antibodies indicated that a good humoral and cell-mediated immune response might have been built in the body after each of the vaccinations and the memory B-cell was predicted to last for several months after the vaccinations. Again, the stimulated helper T-cells will also aid in increasing the growth and proliferation of B-cells, thus elevating the adaptive immunity. Moreover, the increase in the concentrations of macrophages and dendritic cells ensured very good antigen presentation and the increase in the cytokine profile after each of the vaccinations might also contribute to the immunity provided by the vaccine. On the other hand, the negligible Simpson index (D) suggests a diverse immune response [101]. Since the vaccine construct contained multiple numbers of B and T-cell epitopes, so it would be able to generate a diverse immune response. As a result, it can be declared that the vaccine V3 might be able to generate good immune response in the body.
Chicken egg yolk antibodies (IgY)-based antivenom for neutralization of snake venoms: a review
Published in Toxin Reviews, 2022
Ankit Choraria, Rajeswari Somasundaram, S. Janani, Selvakumar Rajendran, Naoual Oukkache, A. Michael
Prabhu et al. developed anti Naja naja IgY antivenom antibodies. IgY antivenoms purified after 40 days of immunization were able to neutralize venoms with lethality up to 2LD50 and up to 5 and 6LD50 after 60- and 90-days post-immunization (Prabhu et al. 2010). IgY anti- Bothrops antivenoms were produced by immunizing hens with Bothrops venom mixture. After immunizing three doses, there was an increase in the immune response at second week after immunization followed by immunizing hens with venom and saline alone. The secondary immune response was seen stable up to 25 weeks with subsequent booster immunizations. Higher levels of antibodies were seen even after 10 weeks post-immunization. They concluded their findings with three important statements namely there was not any macroscopic tissue damage observed during the experimental period; lower doses of venom induced higher levels of antivenom antibodies and similar method of purifying IgY antivenoms compared to equine IgG antivenoms (Araújo et al. 2010).
Exploring Klebsiella pneumoniae capsule polysaccharide proteins to design multiepitope subunit vaccine to fight against pneumonia
Published in Expert Review of Vaccines, 2022
Jyotirmayee Dey, Soumya Ranjan Mahapatra, S Lata, Shubhransu Patro, Namrata Misra, Mrutyunjay Suar
C-ImmSim server was used to mimic the actual immune responses in the body upon exposure to the designed vaccine construct. Usually, the primary immune response arises as a result of the first contact with an antigen and the first antibody produced is mainly IgM, although a small amount of IgG is also produced. As shown in Figure 12 the amount of the IgM significantly increased during the first injection of the vaccine construct (antigen) as a primary immune response. Secondary immune response occurs as a result of the second and subsequent exposure to the same antigen and is characterized by an increased level of IgM and IgG. Further, there was a noticeable increase in the level of IgM + IgG and decreased level of the antigen. Moreover, there was a striking increase in the level of IgM, IgG1 + IgG2, and IgG1 (Figure 12). These findings confirmed that the antibodies had a greater affinity to the vaccine construct (antigen) and would develop strong immune memory. Consequently, this resulted in increased clearance of the antigen upon subsequent exposures. Regarding the cytotoxic and helper T lymphocytes, high response in the cells populations with corresponding memory development was witnessed. Most importantly, the population of the Helper T lymphocytes remained higher during all exposure time. In the IFN- γ-induced epitopes prediction, the results showed a high IFN-γ concentration score compared to the other cytokines. The Simpson index D demonstrated the level of danger when the cytokines level increased which may result in complications during the immune response [63].