Antigens

Readings Resources Outline Objectives Videos Molecules Lexicon updated 03/10/00

The further one pursues knowledge the less one knows
Lao-Tse

Who Am I? I discovered haptens and showed the specificity of antibodies for antigens. I am most famous for the discovery of blood groups

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Antigens
Epitopes

Antigens : Graphic presentation that shows the factors that affect antigenicity, and compares epitopes recognized by B cells and T cells

Epitopes shows the molecular dissection of protein antigens

ASSIGNED READING

CHAPTER: pp 87-106

OUTLINE/SUMMARY

  1. Immunogenicity vs antigenicity
  2. Factors that influences immunogenicity
  3. Epitopes
  4. Haptens
  5. Mitogens

PERFORMANCE OBJECTIVES

DEFINE THE FOLLOWING KEY TERMS

Accessibility antigen antigenic determinants
antigenic site mobility antigenicity agreotopes
continous (linear) determinants) epitopes haptens
discontinous(conformational) determinants immunogen immunodominance
immunogenicity    

 

ON COMPLETION OF THIS SECTION THE STUDENT SHOULD BE ABLE TO:

  1. Differentiate between and antigen's inductive and reactive abilities.
  2. Explain the factors that bestow immunogenicity on molecules
  3. Describe the discrete and distinctive sites on and antigen that are recognized by a B cell
  4. Immunoglobulin
  5. Describe the discrete and distinctive sites on and antigen that are recognized by a T cell receptor
  6. Describe the discrete and distinctive sites on and antigen that are recognized by the Major
  7. Histocompatability Complex
  8. Discuss some important characteristics of protein antigenic determinants

SHORT ANSWER QUESTIONS

  1. Differentiate between immunogenicity and antigenicity.
  2. All immunogens are antigens but all antigens are not immunogens. Explain with the use of specific examples.
  3. An entire microbe or molecule does not induce and immune response. Explain.
  4. Irrespective of the number of epitopes that a molecule has, the immune response is biased and sees what it wants to see. Explain.
  5. Haptens are usually coupled to a carrier molecule before they are immunogenic. How can you demonstrate that the selected immunoglobulins are specific for the hapten and not for the carrier? As a corollory, would you expect ALL of the antibodies to be specific for the hapten? explain.
  6. Why is the definition of an antigen considered to be an operational definition.
  7. Differentiate between epitopes and agreotopes.
  8. Differentiate between epitopes recognized by B cell receptor and epitopes recognized by T cell receptors.