Immunology - 19

Question 1

What are the four types of biomolecules that can elicit an immune response?

Answer 1

• Proteins
• polysaccharides (LPS is the most important one)
• nucleic acids
• lipids

Question 2

Which is the best type of molecule that elicits a response?

Answer 2

Proteins

Question 3

What size must a protein be to elicit a response?

Answer 3

Over 10,000 Da. The greater the complexity, the more vigorous response

Question 4

Why can’t polysaccharides be presented to a to a T cell?

Answer 4

Only peptides are presented to a T cell and peptides cannot come from polysaccharide

Question 5

What must a polysaccharide be attached to in order to elicit a response?

Answer 5

Proteins like glycoproteins

Question 6

Which is an example of a nucleic acid that elicits an immune response?

Answer 6

Systemic lupus erythematosus (SLE):

• autoimmune disease
• patients produce antibodies against native dsDNA
• once cells undergo apoptosis, DNA is visible to antibodies
• thought that dsDNA bound to antibodies get trapped in the kidney, attracts granulocytes, kidney failure

nucleic acids are poor activators of immune response

Question 7

Do lipids elicit an immune response?

Answer 7

Rarely, unless associated with a protein like glycolipids or lipoproteins (LPS is one of the most potent stimulators of the immune system)

Question 8

What is the difference between an antigen and an immunogen?

Answer 8

• An antigen is any foreign material or molecule that can be bound by an antibody and/or a T cell
• an immunogen is an antigen that can elicit an immune response

Anything can be an antigen but not all antigens are immunogens

Question 9

What can be used to help in antigen elicit an immune response?

Answer 9

An adjuvant (example is vaccines)

Question 10

Karl Landsteiner discovered haptens. His experiments showed that haptpens can be bound by antibodies. But, when injected into rabbits by themselves, they do not produce antibodies. Haptens are:
A - antigenic
B - immunogenic
C - both
D - neither

Answer 10

Antigenic

Question 11

Are haptens immunogenic?

Answer 11

No, they can be bound by antibodies but cannot induce an immune response by themselves. They can induce an immune response when conjugated to an immunogenic substance called a carrier protein