Immuno p.203-207 Flashcards
Name all antigen presenting cells:
B cells, microphages, dendritic cells
How many signals are required for T cell activation, B cell activation, and class switching?
2
What is a “Costimulatory signal”?
interaction of B7 and CD28 (signal 2).
MHC II presents Ag to which CD cells?
CD4+ cell which are recognized by TCR
MHC I presents Ag to which CD cells?
Tc (CD8+) cell
5 steps in Naive T-cell activation:
- Dendritic cell samples and processes antigen.
- Dendritic cell migrates to the draining lymph node.
- Antigen is presented on MHC II, MHC I
- “Costimulatory signal”
- Th cell activates and produces cytokines. Tc cell activates and is able to recognize and kill virus infected
cell.
What is the first signal in B-cell activation and class switching?
Foreign antigen is presented on MHC II and recognized by TCR on Th cell
2nd signal of B-cell activation and class switching involves —– receptor on B cell binds —– on Th cell
CD40, CD40 ligand (CD40L)
4 steps of B-cell activation and class switching:
- Th-cell activation.
- B-cell receptor–mediated endocytosis; foreign antigen is presented on MHC II and recognized by TCR on Th cell (signal 1).
- CD40 receptor on B cell binds CD40 ligand (CD40L) on Th cell (signal 2).
- Th cell secretes cytokines –> B cell activates and undergoes class switching, affinity maturation, and antibody production.
— region of IgM and IgG fixes complement.
Fc region
— region consisting of light (L) and heavy (H) chains recognizes antigens.
Fab (variable)
In Digoxin toxicity what part of the antidote given targets Digoxin?
Fab (Digoxin immune Fab)
Which part of an Ab has carbohydrate side chains?
Fc
T or F? Fab has only 1 antigenic specificity expressed per B cell and has a carboxy terminal.
F. Fc has a carboxy terminal.
Which region determines isotypes like IgM or IgD?
Fc
Antibody diversity is generated by random recombination of – or — genes
VJ (light-chain)
V(D)J (heavy-chain)
What is the function of TdT during Ab diversification?
Terminal deoxynucleotidyl transferase Adds nucleotides to DNA during recombination.
Which lymphoid neoplasm has a TdT+ marker?
Acute lymphoblastic leukemia/lymphoma
(marker of pre-T and pre-B cells),
Mature B cells expresson which 2 immunoglobulins on their surfaces?
IgM and IgD
Isotype switching of Ig is mediated by what 2 components?
cytokines and CD40L
Which Ig has the lowest concentration in serum?
IgE
Most abundant Ig isotype in serum?
IgG
Ab that is a monomer in circulation or dimer (when secreted?
IgA
IgA is produced in GI tract by — and protects against gut infections.
Peyer patches
Main antibody in 2° (delayed) response to an antigen?
IgG
Ab that cross-links when exposed to allergen, mediating immediate (type I) hypersensitivity?
IgE
What shape is IgM on B-cells?
Monomer on B cells
Ab produced in the 1° (immediate) response to an antigen/
IgM
Why do vaccines often require boosters and adjuvants?
Because Ag lacking a peptide component (e.g., lipopolysaccharides from gram-negative bacteria)
cannot be presented by MHC to T cells.
Name an example of Thymus-dependent
antigen?
diphtheria vaccine
Name an example of Thymus-independent
antigen?
pneumococcal polysaccharide vaccine
Name the 5 Acute-phase reactants that are up-regulated?
C-reactive protein Ferritin Fibrinogen Hepcidin Serum amyloid A
APR are induced by:
induced by IL-6.
which of the APR correlates with ESR?
Fibrinogen
In anemia of chronic disease which APR is elevated?
Hepcidin
Which APR is internalized by macrophages to sequester iron?
Transferrin
Which APR is elevated in amyloidosis?
Serum amyloid A
Albumin is down or up regulated in inflammation?
down reg.
Membrane attack complex (MAC) defends against gram- —- bacteria.
negative
Lectin pathway is activated via:
mannose or other sugars on microbe surface.
Complements during anaphylaxis?
C3a, C4a, C5a
Two 1° opsonins in bacterial defense which enhance
phagocytosis?
C3b, IgG
paroxysmal nocturnal hemoglobinuria is deficient in which components of complement?
Inhibitors defect: decay-accelerating factor (DAF, aka CD55)
Another name for DAF?
GPI-anchored enzyme
ACE inhibitors are contraindicated in which Complement disorders?
C1 esterase inhibitor deficiency
Complement disorders causing susceptibility to type III hypersensitivity reactions?
C3 deficiency
Another name for osteoclast-activating factor?
IL-1
T or F? Interferon-γ causes cachexia in malignancy.
F. TNF-α does
Major chemotactic factor for neutrophils?
IL-8
T or F? TGF-β and IL-10 both aid the immune
response.
attenuate
Enhances class switching to IgE and IgG?
IL-4
Increases MHC expression and antigen presentation by all cells?
Interferon-γ
Functions like Sargramostim?
IL-3
it is a GM-CSF (granulocyte-macrophage colony stimulating factor)
Decreases expression of MHC class II and Th1 cytokines.
IL-10
Induces differentiation of T cells into Th1 cells?
IL-12
