Abstract
Immunity is the ability of an individual to protect against invading pathogens. The machineries utilized by the immune system are intended to recognize pathogens, their destruction, and a memory to remember previous exposure.
The immunity is either an inborn reflex to eliminate pathogens (innate immunity) or developed slowly after the exposure of pathogens (acquired immunity). The components of innate immunity are anatomic and physiological barriers, immune effector cells, and soluble factors like antimicrobial peptides, complement system, cytokines, and interferons. The acquired immunity is either cell mediated associated with T lymphocytes or humoral, brought about by the antibodies produced from B lymphocytes. The pattern recognition receptors (PRRs) present in the immune effector cells recognize pathogens through pathogen-associated molecular pattern (PAMP) and damage-associated molecular pattern (DAMP). The toxins released by the pathogens are processed and presented by antigen-presenting cells (APC) with the help of major histocompatibility complex (MHC) as a mark of discrimination between self and nonself. After pathogen recognition, the effector responses such as phagocytosis, complement activation, and antibody-dependent cell-mediated cytotoxicity are initiated to eliminate the pathogens. The incoordination in the different immune components leads to immune pathology such as hypersensitivity, anaphylactic shock, and autoimmune disorders.J. Mukherjee (X) ∙ P. K. Das ∙ D. Banerjee
Department of Veterinary Physiology, West Bengal University of Animal & Fishery Sciences, Kolkata, West Bengal, India
A. Mukherjee
Department of Animal Biotechnology, West Bengal University of Animal & Fishery Sciences, Kolkata, West Bengal, India
© The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd.
2023P. K. Das et al. (eds.), Textbook of Veterinary Physiology, https://doi.org/10.1007/978-981-19-9410-4_5
Graphical Abstract
Description of the graphic: Immunity is the ability of the body to protect against pathogens. It has two important components such as innate and adaptive immunity. The innate immune system is equipped with several components like anatomical and physiological barriers (1), immune effector cells and cell surface receptors (2), and complement system (3). The adaptive immunity is of two types, humoral and cell-mediated immunity. The humoral immune response is mediated through B lymphocytes (4) capable of producing antibodies (5), which bind with antigens and make them vulnerable for destruction. The cell-mediated immune response is mediated through T lymphocytes that produce signals to activate phagocytic cells to destroy them (6)
Keywords
Antigens ∙ Innate immunity ∙ Adaptive immunity ∙
Antibodies ∙ Autoimmune disorders
Learning Objectives
• The components of immunity
• Antigens and their types
• Components of innate and adaptive immune system
• Hypersensitivity and immunological disorders system are the recognition and response. Immune recognition is a highly specific process to discriminate between foreign pathogens from the body’s own cells and proteins and to identify different types of foreign pathogens through their specific chemical compositions. The responses are in two ways. Firstly, the immune system neutralizes or eliminates the pathogens through a series of cellular and biochemical reactions once the recognition is completed. This is called an effector response. The immune system has the ability to remember previous exposure of foreign organisms and rapidly eliminates the pathogen after its second exposure through a rapid and strong protection called memory response.
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