Antigens

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Revision as of 06:11, 18 August 2008 (edit) Jasjit (Talk | contribs) (New page: '''Antigen''' (antibody generating) is a substance that prompts the generation of antibodies that can cause an immune response. Antigens can be * proteins * polysaccharides * conjugates ...) ← Previous diff		Current revision (09:55, 18 August 2008) (edit) (undo) Jasjit (Talk | contribs)
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	==EPITOPES==		==EPITOPES==
		+	* Discrete sites on immunogens recognized by antibodies or T cell receptors
		+	* Macromolecules contain many epitopes with different immunogenicities
		+	* Immunogenicity can vary between individuals and populations.
		+	* Some epitopes are immunodominant
-	• Discrete sites on immunogens recognized by antibodies or T cell receptors	+	==See also==
-	• Macromolecules contain many epitopes with different immunogenicities	+	* [[Antibody]]
-	• Immunogenicity can vary between individuals and populations.	+	* [[B Cells and T Cells]]
-	• Some epitopes are immunodominant	+

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Current revision

Antigen (antibody generating) is a substance that prompts the generation of antibodies that can cause an immune response. Antigens can be

• proteins
• polysaccharides
• conjugates of lipids with

  * proteins (lipoproteins) and
  * polysaccharides (glycolipids)

Antigens that enter the body from the environment would include

• inhaled macromolecules (e.g., proteins on cat hairs that can trigger an attack of asthma in susceptible people) • ingested macromolecules (e.g., shellfish proteins that trigger an allergic response in susceptible people) • molecules that are introduced beneath the skin (e.g., on a splinter or in an injected vaccine)

Antigens that are generated within the cells of the body would include

• proteins encoded by the genes of viruses that have infected a cell • aberrant proteins that are encoded by mutant genes; such as mutated genes in cancer cells

Contents 1 Immunogen 2 Immunogenicity of Antigens 2.1 Factors determining immunogenicity 2.2 Factors influencing immunogenicity 3 EPITOPES 4 See also

[edit] Immunogen

Any substance that can elicit an immune response

• All immunogens are antigens
• Not all antigens are immunogens, i.e. haptens

[edit] Immunogenicity of Antigens

[edit] Factors determining immunogenicity

• Foreignness
• Molecular Size
• Chemical Composition
• Degradability

[edit] Factors influencing immunogenicity

• Host genotype
• Dose and route of administration
• Presence of adjuvants

[edit] EPITOPES

• Discrete sites on immunogens recognized by antibodies or T cell receptors
• Macromolecules contain many epitopes with different immunogenicities
• Immunogenicity can vary between individuals and populations.
• Some epitopes are immunodominant

[edit] See also

• Antibody
• B Cells and T Cells