Flashcards in Immunology basics Deck (34):
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?
What is the mnemonic for HLA-B27 associated diseases?
What does the 'P' in "PAIR"...the HLA-B27 associated diseases mnemonic represent?
What does the 'A' in "PAIR"...the HLA-B27 associated diseases mnemonic represent?
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?
What HLA subtype is associated with Celiac disease?
What diseases are associated with HLA-DR2?
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?
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)
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
Inhibits Th2 cell differentiation
What cytokines are secreted from Th2 cells?
IL-2 (all T cells)
IL-3 (all T cells)
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?
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
Carbohydrate side chains
Determines isotype (IgM, IgD, etc)
What are some characteristics of the Fab portion of an antibody?
Determines idiotype (antigen binding site)
What allows antibody diversity?
Recombination of VJ on light-chain (little guys on outside of 'Y')
Recombination of V(D)J on heavy-chain (tails of the 'Y')
Where are IgM and IgD expressed? What secretes IgA, IgE, or IgG?
IgM and IgD are on the surface of B cells
Isotype switching (in the germinal centers of lymph nodes) forms plasma cells that can secrete IgA, IgE, or IgG
Which Ig can cross the placenta?
Which Ig is released into breast milk?
What is seen with C1 esterase inhibitor deficiency (a complement disorder)?
ACE inhibitors are contraindicated
What increases the risk of severe, recurrent pyogenic sinus/respiratory tract infections and increases susceptibility to type III hypersensitivity reactions?
C3 deficiency (a complement disorder)
What causes increased susceptibility to recurrent Neisseria bacteremia?
C5-C9 deficiencies (complement disorders)
What causes paroxysmal nocturnal hemoglobinuria?
DAF deficiency...aka GPI anchored enzyme deficiency (a complement disorder)