Immunology 9: Induction of Autoimmunity

Question 1

Epitope

Answer 1

→ area of antigen complementary to an antibody
→ some antigens have similar or identical epitopes
→ ex, mouse serum albumin is very similar to a rats serum albumin, (both rodents and phylogenetically related). If we made antibodies in a rabbit against MSA, then added RSA to the same immune serum, also get a precipitin rxn because they have epitopes in common, as well as different ones

Question 2

Mouse serum albumin and rat serum albumin have epitopes in common, and are said to ____.

Answer 2

Cross React

Question 3

Immunization with antigens that cross react with a self antigen sometimes cause?
ex?

Answer 3

Autoimmunity (i.e. immunity to self antigens) directed against the self antigen
→ Hashimoto’s disease

Question 4

Hashimoto’s Disease

-treatment via cross reacting

Answer 4

immune system attacks thyroid gland (produces thyroxine): antibodies in serum react with thyroglobulin
→ untreated: don’t develop normally physically or mentally
→ treated via induction of autoimmunity

Question 5

Autoantibodies

Answer 5

antibodies that attack self antigens

Question 6

Induction of antigens with rabbits

Answer 6

→ immunization of rabbits with turkey thyroglobulin
→ turkey thyro. cross reacts with rabbit thryo., and produces antibodies for rabbit thryo.
→ immunization with rabbit thyroglobulin doesn’t result in anti-thyro. antibody production
→ shows that insufficient T helper cells specific for rabbit thyro. to activate B cells specific for rabbit thyro.

Question 7

Real life example: cross reactive antigen causes autoimmunity following infection with ____.

Answer 7

group A streptococci
→ bacteria cross react with heart tissue and development of rheumatic heart disease believed to be due to autoimmune response to heart tissue following this infection