Quiz 1 review Flashcards
low immunogenicity
Haptans
(require carrier)
ex. Penicillin
immunoglobin structure
N-terminal = Ag binding Fab = hypervariable
FC = complement fixation c-terminal = constant, defines Ab
Papain
cleaves hinge region
2 Fab, 1 FC
Pepsin
cleaves N-terminal
1 Fab, fragmented FC
no immune response
Hinge
rich in Proline
flexible
**IgG
**most common gamma 2IgG needed for complement *complement fixation **PLACENTAL TRANSFER mediates ADCC NK cell good opsonin
**IgM
chronic inflammation B cell surface complement fixation **FIRST PRODUCED (primary infection) no hinge
IgD
B cell surface
IgA
in secretions, blood, and lymph
- crosses epithelium
- TRANSFERRED IN BREAST FEEDING
- mucosal immunity
IgE
bound to FcR
allergic reaction
increased in parasitic infection
no hinge
light chain
kappa or lambda
**BCR
CD79
IgM & IgD
**somatic hypermutation
isotype switching
TCR
CD3 & zeta
alpha/beta -> VJ
gamma/delta -> VDJ
requires CD4 & CD8
RAG
cuts
23bp or 12bp
starts rearrangement @ small pre b cell
**TdT
*@ PRO B CELL
adds P & N
VD & DJ
*heavy chain only
AID
only active B cells
**deficiency in AID
no class switch -> Hyper IgM
**B cell markers
CD19, CD20*
B cell steps
Early Pro (CD19)
- h chain : DJ
Late Pro (CD19)
- h chain : VDJ + mu
(checkpoint: mu chain)
Large Pre (CD20)
- l chain - RAG only
Small Pre (CD20)
- l chain : kappa & lambda - IgM (expressed on immature b cells)
**T cell steps
committed double negative (CD2, IL-7/CD127)
double negative (IL-7, Notch1)
- beta, gamma, delta
double positive
- alpha
- *double positive (alpha/beta only)
- POSITIVE SELECTION (MHC restriction)
- MHC + TCR
- *double positive (alpha/beta only)
- NEGATIVE SELECTION (self-reactivity by AIRE)
single positive
- TCR + CD4 or CD8
somatic recombination
beta, gamma, delta
beta checked with pTalpha*
**MHC1 deficiency
no CD8
increased CD4
increased intracellular pathogens
**MHC2 deficiency
no CD4
increased CD8
increased extracellular pathogens
**AIRE deficiency
increased autoimmune diseases of specific tissues
hematopoiesis
early embryo -> yolk sac
fetus -> liver & spleen
after birth -> bone marrow
stem cell
multipotent CD34
IL-7
lymphoid (B, T, NK)
*IL-3
myeloid (innate immunity)
IL-11
platelets (thromboprotein)
IL-5
eosinophils
**spleen
blood borne
CYTOSOLIC PATHOGENS
B&T cells enter via
HEV
MALT entry of pathogen
M cell
classical pathway
third activated requires C1 (2 IgG or 1 IgM) activator: AG-AB complex C3b + CR1 -> opsonization adaptive immunity
Lectin-Mannose Pathway
second activated
innate immunity
activator: MBL (MASP1 & MASP2)
Alternative Pathway
first activated
innate immunity
activator: C3 hydrolysis
*C4b + C2a
C3 convertase
on pathogens, not human cells
MAC
requires exposed phospholipid bilayer
CD59, CD55 (DAF)
DAF & CD59
stabilize complement on pathway
**deficiency of DAF/CD59
Paroxysmal Nocturnal Hemoglobinuria
lysis of RBC
DARK URINE
Factor H & Factor I
inactivates C3b
**deficiency of Factor H & Factor I
depletion of C ->
increased complement activation *** ->
uncontrolled infections
anaphylatoxins
C3, C4, C5
inflammation
edema
C2b
MAC complex
C5b-9
cell lysis
deficiency of MAC
Neisseria (systemic infection)
*Hereditary Angioneurotic Edema (HAE)
deficiency in C1-INH
increased C2b
edema between skin and mucus membrane
**diagnosis: decreased C4
**TLR4
LPS
bacteria (gram neg)
TLR7
ssRNA
virus
TLR8
ssRNA
virus
TLR9
CpG DNA
bacteria
*TLR3
dsDNA
Extravasation (rolling, adhesion, diapedesis/migration)
rolling = selectins adhesion = integrins (LFA1/CD18) diapedesis/migration = PECAM/CD31
absence of CD18
(deficiency of LFA1)
Leukocyte Adhesion Deficiency
poor umbilical separation
chronic inflammation cells
macrophages
Granuloma
*NBT Test no IFN-gamma no CD40L no NADPH oxidase increased IL-1, IL-6, TNF-alpha
systemic shock
mutation in TLR4 (LPS)
excessive macrophages
DIC
increased TNF-alpha
