Major Histocompatability Complex

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Readings Presentation Outline Objectives Questions Multiple Choice Key Terms Updated 09/11/00

Who am I?: I and Rolf Zinkernagel demonstrated the phenomenon of MHC restriction.

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Major Histocompatibility Complex
MHC 1st Ed    
Gallery of Immune Molecule Structures
This site contains a wide range of images immune molecule structures.

URL --> http://www.umass.edu/microbio/rasmol/galmz.htm#abag

ASSIGNED READING

CHAPTER 9:pp 223-248

OUTLINE/SUMMARY

  1. General Organization of MHC
  2. MHC Molecules & Genes
  3. Genomic maps of MHC
  4. Cellular Distribution of MHC
  5. Regulation of MHC Expression
  6. MHC and Immune Responsiveness
DEFINE THE FOLLOWING KEY TERMS
alleles alloantigens bone marrow chimeras
Class I molecules Class I regions Class II molecules
Class II regions Class III molecules Class III regions
Determinant selection model H-2 complex K region
D region I region L region
S region hole in the repertoire locus
immune response genes congenic mice Human Leukocyte Antigens
Major histocompatibility complex MHC restriction, negative thymic selection
positive thymic selection public specificities private specificities
region Specificities superantigens.

 

PERFORMANCE OBJECTIVES

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

  1. Explain the connection between a trait and a gene using the specific example that MHC genes encode for molecules that allow specific immune responses.
  2. Describe the use of inbred mice for the elucidation of the genetics of the imune response
  3. Describe how congenic strains of mice are developed.
  4. Describe and draw MHC-I molecules
  5. Describe the function of MHC-I molecules
  6. Describe and Draw MHC-II molecules
  7. Compare the detailed differences in the structure of the aggreotope binding sites of MHC-I and MHC-II
  8. Describe the function of class III genes and in which cells they are expressed.
  9. Describe MHC restriction
  10. Discuss the differences between MHC restriction of CD4+ T cells and MHC restriction of CD8+ T cells.
  11. Draw maps of either the MHC gene complex in mice or HLA gene complex in humans
  12. Describe how the collection of MHC genes of an individual dictates either the ability or inability of the animal to respond to a particular antigen
  13. Describe an experiment that shows MHC restriction: between T and B cells, between T cells and macrophages between cytotoxic T cells and virally infected cells.
  14. Discuss the biological relevance of MHC molecules
  15. MHC molecules exhibit a range of structural diversity at the species level that is roughly equivalent to the range of antibody diversity at the level of the individual animal. DISCUSS

SHORT ANSWER QUESTIONS

  1. Null cells are not MHC restricted. Explain.
  2. Even though the immune system rejects transplanted kidneys and hearts its
  3. function is not to protect us against grafts.
  4. Why do we need histocompatability antigens?
  5. If we do not need protection against attack from foreign organs and tissues, why are MHC-I molecules so polymorphic?
  6. What is the connection between immunity and MHC genes.?
  7. Why are inbread/congenic mice important to immunlogical studies?
  8. Draw and label a diagram of a class I MHC molecule as it is found in the membrane.
  9. Draw and label a diagram of a class II MHC molecule as it is found in the membrane.
  10. How is the polymorphism or diversity of MHC, different from the generation of diversity in antibodies?
  11. How do MHC-II molecules allow immune cells to communicate with each other? Why is this communication important?
  12. What is the relationship between MHC-II molecules and Ir genes?
  13. Class III MHC molecules are not cell membrane proteins.
  14. What are they and what do they do?
  15. Describe an experiment to show MHC restricted cytotoxicity
  16. T-cells do not recognize free antigen, as antibody receptors do. Speculate why?
  17. Briefly discuss MHC restriction.
  18. Describe and experiment that describes MHC restriction.
  19. Why do T cells have such an elaborate way of reacting with antigen?
  20. Explain the following statement:
  21. "There is a direct relationship between an animal's MHC haplotype and its ability or inability to respond to a specific antigen."
  22. What is the difference between and F1 hybrid animal and a bone marrow chimera animal?
  23. What is the importance of a bone marrow chimera animal in immunological studies?
  24. Explain how the control of MHC restriction is the genetic basis for the functional specificity of T cells.
  25. Describe T cell differentiation in the thymus using CD4 and CD8 markers.
  26. T cell receptor diversity results from gene rearrangements, but T cells are also MHC restricted. MHC restriction is not preporgrammed into T cells. Describe two possible selective processes that program T cells to be MHC restricted. Where do these processes occur?
  27. T cells can react only with protein fragments. What is this process called? How does it occur? Which pathway leads to antigen interaction with MHC-I molecules? Which pathway leads to interaction with MHC-II molecules?