Immunology basics Flashcards
What is the order of T cell markings during development?
Double negative…neither CD4+ nor CD8+; then…
Double positive…both CD4+ and CD8+ (positive selection in cortex); then…
Single positive…either CD4+ or CD8+ (negative selection in medulla)
Why is there increased susceptibility to encapsulated organisms after a splenectomy?
↓ IgM → ↓ complement activation → ↓ C3 opsonization → ↑ susceptibility to encapsulated bacteria
What disease is associated with HLA-A3?
Hemochromatosis
What is the mnemonic for HLA-B27 associated diseases?
PAIR
What does the ‘P’ in “PAIR”…the HLA-B27 associated diseases mnemonic represent?
Psoriatic arthritis
What does the ‘A’ in “PAIR”…the HLA-B27 associated diseases mnemonic represent?
Ankylosing spondylitis
What does the ‘I’ in “PAIR”…the HLA-B27 associated diseases mnemonic represent?
Inflammatory Bowel Disease
What does the ‘R’ in “PAIR”…the HLA-B27 associated diseases mnemonic represent?
Reactive arthritis
What HLA subtype is associated with Celiac disease?
HLA-DQ2/DQ8
What diseases are associated with HLA-DR2?
Multiple sclerosis
Hay fever
SLE
Goodpasture syndrome
What HLA subtypes are associated with diabetes type I? What other diseases are associated with this subtype?
HLA-DR3 is associated with DMI, SLE, and Graves disease
HLA-DR4 is associated with DMI and rheumatoid arthritis
What HLA subtype is associated with pernicious anemia?
HLA-DR5
Antigens are presented on MHC II to Th cells. Th cells then secrete cytokines. What cytokines are secreted and what do they activate?
IL-12 → Th1 cells
IL-4 → Th2 cells
TGF-β + IL-6 → Th17 cells
TGF-β → T(reg) cells
What cytokines are secreted by Th1 cells?
IL-2 (all T cells)
IL-3 (all T cells)
IFN-γ
What does IL-2 do?
Stimulates T cells
What does IL-3 do?
Stimulates differentiation of bone marrow stem cells
What does IFN-γ do?
Activates NK cells to kill virus-infected cells
Activates macrophages
Inhibits Th2 cell differentiation
What cytokines are secreted from Th2 cells?
IL-2 (all T cells) IL-3 (all T cells) IL-4 IL-5 IL-6 IL-10 (also secreted by T(reg))
What does IL-4 do?
Induces differentiation into Th2 cells Promotes B cell growth Enhances class switching to IgE and IgG
What does IL-5 do?
Promotes differentiation of B cells
Enhances class switching to IgA
Stimulates the growth and differentiation of eosinophils
What does IL-6 do?
Causes fever
Stimulates production of acute-phase proteins
What does IL-10 do?
Modulates inflammatory response
Inhibits Th1 activation
What CD markers do T(reg) cells have? What type of cytokines are secreted by T(reg) cells?
CD3, CD4, CD25, and tsx factor FOXP3
T(reg) secrete anti-inflammatory cytokines (IL-10 and TGF-β)
What are some characteristics of the Fc portion of an antibody?
4 C's and a D Constant Carboxy terminal Complement binding Carbohydrate side chains Determines isotype (IgM, IgD, etc)
