Immunology Review

Question 1

What is the importance of CD16?

Answer 1

It’s on NK cells.

-How NK cells recognize Fc (it;s an IgG Fc receptor found on NK cells)

Question 2

18 yr old man presents with pneumonia. Since 8 months he has had recurrent pneumonia and sinusitis due to streptococcus pneumoniae and haemophilus influenzae. What’s wrong with his immune system?

Answer 2

B cell problem.

• As maternal antibodies faded, capsulated, invasive microorganisms came in!
• Normal levels of B cells seen in patient, but very little IgG and IgM
• CVID = Common Variable Immunodeficiency - characterized by hypogammaglobulinemia
• Can have multiple causes

Question 3

What interleukin is produced by macrophages and stimulates fever producing in patient’s hypothalamic cells?

Answer 3

IL-1 (causes fever and acute inflammation). Activates endothelium to express adhesion molecules.

Question 4

What is important about IL-5?

Answer 4

• Made by activated helper T cells (Th2)
• Promotes B cell diff/class switch to IgA
• Activates Eosinophils

Question 5

What does IL-4 do?

Answer 5

• Stimulates Th2 production
• Released by Th2
• Stimulates B cells to undergo class switch recombination (to IgE and IgG)

Question 6

What is important about IgA and IgG?

Answer 6

IgG - placental transfer to child
IgA - From mothers milk & colostrum - only helps defend mucosal surfaces/respiratory tract and digestive system - will not become systemic

Question 7

3 yr old boy with repeated infections with staphylococci and streptococci bacteria. Has normal phagocytic function and delayed hypersensitivity responses. A lymph node biopsy would most likely reveal. . .

Answer 7

. . .absence of germinal centers (B cell centers)
-Patient likely has X-linked Agammaglobulinemia (Brutons) - disease onset usually after 6 months when mother’s antibody production starts to wain - you see lack of B cells!

Question 8

What type of T helper cell makes granulomas?

Answer 8

CD4 Th2 - makes granulomas, cleans up pathogens/infections