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Antigen Processing and Presentation Types of Antigen Processing and Presenting Pathway Endogenous Antigens: Cytosolic Pathway 1. Peptides for Presentation Are Generated by Protease Complexes Called Proteasomes 2. Peptides Are Transported from the Cytosol to the Rough Endoplasmic Reticulum 3. Peptides Assemble with Class I MHC Aided by Chaperone Molecules Exogenous Antigens: Endocytic Pathway 1. Peptides … Read more
What are Superantigens (SAgs)? Superantigens (SAgs) are a type of antigens that stimulate the immune system excessively. It specifically results in non-specific T-cell activation, polyclonal T-cell activation, and large cytokine release. Features of Superantigens (SAgs) Classification of Superantigens (SAgs) The superantigens can be grouped generally into the subsequent families: Structure of Superantigens (SAgs) Examples of … Read more
Thymus-Independent Antigens (T Independent Antigen) Properties of Thymus-Independent Antigens (T Independent Antigen) Thymus-Dependent Antigens (T Dependent Antigen) Properties of Thymus-Dependent Antigens (T Dependent Antigen) Main steps during B-cell activation by a thymus-dependent antigen This CD40/CD40L interaction is crucial for B-cell survival, development of germinal centres, production of memory-cell populations, and somatic hypermutation (for affinity maturation). … Read more
What is Precipitation Reaction? Precipitation Reaction Definition Precipitation reaction refers to a chemical reaction in which two soluble substances react to form an insoluble solid compound, known as a precipitate. This reaction occurs when two aqueous solutions containing ions combine, resulting in the formation of an insoluble product that settles out of the solution as … Read more
What is Immunity? Definition of Immunity Immunity is the body’s ability to resist or protect itself against harmful pathogens or diseases. What is Immune System? Lymphoid Organs Primary lymphoid organs Secondary lymphoid organs Tertiary lymphoid organs How does Immunity Work? Mechanism of Immunity Types of Immunity The primary purpose of the immune system is to … Read more
Overview of Immune System Innate Immune System Adaptive (Acquired) Immune System a. Active Immunity b. Passive Immunity Organs of the Immune System Organs that function as barriers The skin and mucous membranes are the first line of protection against pathogens entering the body from the outside. They serve as a physical barrier with the assistance … Read more
The immune system is a complex network of organs, tissues, and cells that work together to keep the body healthy and protect it against outside intruders. Among the numerous components of the immune system, immune system cells play an important role in identifying and removing dangerous chemicals. Primary lymphoid organs and secondary lymphoid organs are … Read more
Features Adaptive (Acquired) Immunity Types of acquired immunity An acquired immunity against a microorganism may be produced through the host’s response to the bacterium or by the transfer of particular antibodies or lymphocytes. There are two types of immunity: active and passive. 1. Active immunity Types of Active immunity There are two varieties of active … Read more
What is Active Immunity? Definition of Active Immunity Active immunity refers to the immunity that is acquired when the body’s own immune system produces antibodies in response to exposure to a foreign antigen, such as a pathogen or vaccine. It provides long-lasting protection against specific antigens. Characteristics of Active Immunity Active immunity possesses several key … Read more
What is Passive Immunity? Definition of Passive Immunity Passive immunity is the temporary protection against infectious diseases provided by the introduction of pre-formed antibodies from an external source, rather than the body’s own immune response. Characteristics of Passive Immunity Passive immunity possesses several distinct characteristics that differentiate it from active immunity: Types of Passive Immunity … Read more
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