Question

Define immunogenicity and provide an example of an organism which either promotes an immune response or a poor immunogenic response. Please don't forget to reference your sources!

Answer 1

Answer : Immunogenicity - It is defined as the ability of a particular substance, such as an antigen or epitope, to provoke an immune response in the body of a human or animal.The response induced can be both humoral as well as cell mediated in nature.The degree of immunogenicity of an Antigen is determined by the following features:

• Phylogenetic distance
• Molecular size
• Epitope density
• Degradability (ability to be processed & presented to T cells)
• Chemical composition and heterogeneity

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Answer : Most of the Exogenous antigens such as Bacteria ( Sterptococcus sp. ) or Virus ( Flu or Influenza Virus ) enter into the host from the outside, through inhalation, ingestion, or injection.It is not the whole organism which elicits an immune response but parts or fragments such as coat, capsule, cell wall, flagella, fimbria, or toxin of bacteria, viruses, etc.Initially these exogenous antigens are taken up by endocytosis or phagocytosis into the antigen presenting cells (APCs), and degraded into fragments.This step is the beginning of the complex process of immune response which finally eliminates the pathogen from the host body.

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