Immunology Flashcards
site of fluid absorption and entrance for circulating lymphocytes to the node
high endothelial venules
endothelial cells have signals for antigen carrying cells:
• T cells remain in the deep cortex
• B cells migrate to the nodular cortex
embryologic derivation of the thymus
3rd and 4th pharyngeal pouches
distinguishing feature of the thymic medulla
Hassall corpuscle
contains mature T cells
keratinized center
part of the spleen that filters blood and contains macrophages for removal of RBCs
red pulp
Within the spaces of the bone, medullary cavity of young long bones and spaces of spongy bone
red bone marrow
Bone marrow not active in blood cell formation contains adipose cells giving it the appearance of adipose tissue
yellow bone marrow
present in the medullary cavity in adults
mediated by molecules in the blood and mucosal secretions (antibodies) produced by B lymphocytes. Principal defense mechanism against extracellular microbes & their toxins
humoral immunity
Innate or adaptive?
lysozyme, complement, CRP, mucus, defensins
innate immunity
LPS, flagellin, ssRNA
PAMPs = pathogen-associated molecular patterns
recognized by TLRs
encoded for by the HLA genes
MHC
these present antigen to T cells and bind TCRs (CD3)
loci for MHC I
expressed on all nucleated cells
present endogenously synthesized antigens (from inside the cell -> so recognizes self)
HLA: A, B & C
loci for MHC II
Expressed ONLY on APCs
presents exogenously synthesized proteins (ex from bacteria & viral capsids)
HLA: DR, DP, DQ
HLA subtype associated with PAIR diseases:(seronegative arthropathies) Psoriatic arthritis Ankylosing spondylitis Inflammatory Bowel Disease arthritis Reactive arthritis (Reiter syndrome)
B27
the B27 has a “pair” of engines on each wing
HLA subtype associated with hemochromatosis
A3
HLA subtypes associated with celiac disease
DQ2/DQ8
HLA subtype associated with: Multiple sclerosis hay fever SLE Goodpasture
DR2
HLA subtype associated with:
type I DM
SLE
Graves disease
DR3
HLA subtype associated with:
DM type 1
Rheumatoid arthritis
DR4
a “rheum” has 4 walls”
HLA subtype associated with:
pernicious anemia
Hashimoto thyroiditis
DR5
cell that responds to absence of MHC I
NK
use perforin & granzymes to induce apoptosis of virally infected cells and tumor cells
T cell that directly kills virally-infected cells
Delayed type hypersensitivity (Type IV)
Acute & chronic organ rejection
CD8
TCRs express high affinity for self antigens & undergo apoptosis
Negative selection -> occurs in the medulla of the thymus
Positive selection occurs in the cortex and is the survival of T cells that have TCRs that can bind self MHC
signal 2 of T cell activation
dendritic B7 and naive T cell CD28
helps deliver granule contents of CTL to target cell
perforin
produces IL-10 and TGF-beta (anti-inflammatory cytokines)
T regs
immunoglobulins that fix complement
IgG and IgM
binds mast cells and basophils
cross-links when exposed to allergen & mediates type I hypersensitivity through release of histamine & other inflammatory mediators
IgE
Acute phase reactants produced by the liver in both acute and chronic inflammatory states. Induced by IL-6, IL-1, TNF-alpha, IFN-gamma
serum amyloid A CRP -> opsonin ferritin fibrinogen -> correlates with ESR hepcidin -> prevents iron release from ferritin -> anemia of chronic disease
complement pathway activated by microbe surface molecules
alternative pathway
complement pathway mediated by IgG and IgM
classic pathway
“GM makes classic cars”
complement proteins of anaphylaxis
C3a, C4a, C5a
complement component for neutrophil chemotaxis
C5a
complement opsonin
C3b
“C3b binds bacteria”
MAC
C5b-9
prevent complement activation on self cells
DAF (CD55) and C1 esterase inhibitor
deficiency causes complement-mediated lysis of RBCs & paroxysmal nocturnal hemoglobinuria
DAF
deficiency causes hereditary angioedema
C1 esterase inhibitor
increases susceptibility to recurrent Neisseria infections
C5-C9 deficiency
increases susceptibility to recurrent pyogenic sinus and resp tract infections, as well as type III hypersensitivity
C3 deficiency
activates NK cells to kill virus-infected cells
IFN-gamma
enhances class switching to IgA growth & differentiation of eosinophils
IL-5
cytokine chemotactic for neutrophils
IL-8
Which cells do not have MHC I?
Red blood cells. All others do
MHC I molecule composition
Heavy chain & beta2 microglobulin
MHC I presents foreign antigen to cd8 T cells
Enzyme specific to mast cell and is elevated in drug hypersensitivity
Tryptase
Recurrent otitis media, sinusitis, bronchitis and GI infections
Transfusion with blood products can cause fatal anaphylaxis
Selective IgA deficiency
Form IgG antibodies to IgA
