generation of diversity Flashcards
(32 cards)
What is the estimated number of antibody specificities?
At least 2.5 x 10^7
This estimation highlights the diversity of the immune response.
What is the central dogma of molecular biology?
One gene = one protein
How many genes are estimated to be in the human genome?
Approximately 3 x 10^4
How many immunoglobulin loci are there?
3
What does GOD stand for in the context of immunology?
Generation of diversity
What is the percentage of kappa chains in mice?
95%
What is the percentage of kappa chains in humans?
60%
What variations exist in immunoglobulin diversity?
Isotype, allotype, idiotype
What limits diversity in immunoglobulin production?
Allelic exclusion
What is produced first during the antibody response?
Heavy chain
What happens to specificities during the antibody response?
They switch isotype
What increases during the antibody response?
Affinity and specificity
What are complementarity determining regions?
Regions that determine antibody specificity
What are the two theories of immunoglobulin diversity?
- Germ line theory
- Somatic Variation theory
What does the germ line theory suggest?
A huge number of immunoglobulin genes are present in the genome
What does the somatic variation theory suggest?
A small number of genes mutate or recombine to provide diversity
What are the components of immunoglobulin loci?
- V
- (D)
- J
- C
What structural differences exist between germline and B cells?
In B cells, DNA is rearranged and some segments are lost
What is the human Ig loci composition?
- 30 V
- 4 functional J
- 4 functional C
What is the mouse Ig loci composition?
- 40 V
- 5 J
- 1 C
What is the consequence of immunoglobulin diversity?
Variation is largely combinatorial
What is a consequence of diversity in lymphocytes?
Many lymphocytes die
What can changes in lymphocytes lead to?
Pathogenic effects
What does successful immunoglobulin response lead to?
- Prevents further change
- Leads to gene expression
