Chapter 11

Question 1

How do plasma cells respond in the secondary immunity?

Answer 1

• long-lived plasma cells
  
  • maintained by bone-marrow stromal cells and IL-6
  • produce highly specific antibodies

Question 2

How do responses of B cells differ in early primary, late primary and secondary responses?

Answer 2

• early
  
  • B cells activated by binding to antigen
  • becomes plasma cell
• late
  
  • naive B cell binds IgG coated pathogen
  • receives negative signal from inhibitory Fc receptor
  • apoptosis
• secondary
  
  • memory B cell binds pathogen
  • activated to become plasma cell
  • produces high affinity antibodies

Question 3

How is hemolytic anemia prevent in newborns?

Answer 3

• mother infused with anti-RhD IgG antibodies, RhoGAM -> coats fetal RBC
• no detection by naive B cells
  
  • instead binding to inhibitory Fc receptor on B cells
• infused second time after birth

Question 4

How do memory T cells emerge?

Answer 4

• from naive T cells
  
  • when binds to DCs -> mitosis
  • produces 2 cells (proximal = closer to DC and distal=further)
    
    • proximal gets more CD8 and metabolism is started to become effector cell
    • distal has slower metabolism, develops later in the primary immune response

Question 5

What are the two subpopulations of memory T cells?

Answer 5

• central memory T cells
  
  • L-selectin and CCR7 produced -> enter secondary lymphoid tissues
  • easily activated, produce IL-2
  • differentiate into effector T cells
• effector memory T cells
  
  • no L-selectin and CCR7
  • CCR6, CCR4, CXCR3, CCR5 -> enter non-lymphoid tissues, instead inflamed tissues
  • respond immediately

Question 6

What are resident memory T cells?

Answer 6

• tissue repair after infection -> memory T cells incorporated
  
  • fast response
• most numerous type of memory T cell

Question 7

What are the types of viral vaccines?

Answer 7

• killed (inactivated) virus vaccines
  
  • cannot replicate
• live-attenuated virus vaccines
  
  • mutant, not pathogenic, grows poorly in humans
  • better for vaccines -> capacity to infect (although small)

Question 8

What is a subunit vaccine?

Answer 8

• only surface protein purified from plasma membrane of people infected with the virus (ex. HBV)
• now gene encoding surface antigen of virus inserted into genome of yeast -> surface protein collected

Question 9

What are types of bacterial vaccines?

Answer 9

• toxic proteins (secreted by bacteria)
  
  • antibodies bind and neutralise them
  • for vaccine treated with formalin to destroy toxicity, inactivated proteins = toxoids
• live-attenuated bacteria
• capsular polysaccharides
  
  • some bacteria are in capsules -> specific for their species
  • prevents complement activation, can only be opsonised when ab are bound

Question 10

What are the adjuvants and their role?

Answer 10

• activate innate immunity -> inflammation
  
  • necessary for adaptive immunity
• source of antigens to stimulate adaptive immune response

Question 10

What are conjugate vaccines?

Answer 10

• contain epitopes recognised by B cells and T cells
  
  • synthetically linked