Antigens And Antigen Receptors

Question 1

Functions of immune system

Answer 1

1. Recognition
2. Removal/restraint
3. Regulation
4. Memory

Question 2

Antigen

Answer 2

Pathogen recognized by immune system

Question 3

Self-antigen

Answer 3

Something domestic that stimulates immune response

Question 4

Epitope

Answer 4

Smallest unit of antigen that can be recognized

1. Conformational- native structure
   * recognized by B cells, antibodies, and innate receptors
2. Linear (continuous)- denatured
   * only type presented on MHC to T cells
   * also recognized by B cells, antibodies, and innate receptors

Question 5

Multivalent antigen

Answer 5

Multiple copies of one epitope

Question 6

Polyvalent Antigen

Answer 6

Multiple different epitopes

Question 7

Conformational Epitopes

Answer 7

In native structure

*Recognized by antibodies, B cell receptors, and innate receptors

Question 8

Linear (continuous) epitopes

Answer 8

Denatured

• only type presented by MHC and recognized by T cells
• also recognized by B cells, antibodies, and innate cells

Question 9

Antigen types

Answer 9

1. Immunogens
2. Haptens
3. Tolerogens
4. Mitogens

Question 10

Immunogens

Answer 10

Bind and generate immune response

• usually proteins
• important for vaccines

Question 11

Haptens

Answer 11

Bind but CANNOT induce response alone

*needs carrier (usually immunogen) to induce response

Question 12

Tolerogens

Answer 12

Bind and induce response

• subsequent exposures decrease response
• used for tx of severe allergies, can be dangerous

Question 13

Mitogens

Answer 13

“Super immune inducer”
Induce non-specific division and differentiation
*T cells- non specific killing
*B cells- non specific antibodies
*Superantigens (sAg)- holds TCR:MHC together > cytokine storm (can lead to septic shock)

Question 14

Adjuvants

Answer 14

Used to boost immune response for pathogens that don’t cause response themselves
*used in vaccines

Question 15

Factors that influence immunogenicity

Answer 15

1. Size - larger = more epitopes
2. Route - subcutaneous most because it prevents pathogens from moving deeper
3. Similarity to self

Question 16

Pattern Recognition Receptors (PRRs)

Answer 16

Innate antigen receptors

1. Toll-like receptors (TLRs)
   * in and outside membrane
   * different ones, different specialties
2. NOD-like (NLRs)
3. RIG-I-like (RLHs)
4. STING- dependent pathways
   * cytosolic
   * many cell types

Recognize Pathogen-associated molecular patterns (PAMPs)

• MAMPs - microbe
• DAMPs- danger

Question 17

B Cell Receptors (BCRs)

Answer 17

Adaptive

Recognize conformational and linear antigens

Question 18

T cell receptors TCRs)

Answer 18

Only “see” antigens presented by MHC

• processed only
• linear
• regulates T cells