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Immunology Midterm
IM
98
Medical
Graduate
08/11/2009

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Cards

Term
Uses VDJ to code
Definition
Tcr beta chain and heavy chain
Term
Uses VJ code
Definition
TCR alpha and light chain
Term
primary adaptive immune response is initiated in...
Definition
secondar lymphoid tissue
Term
MHC Class I
Definition
presents to CD8 cells
from intracellular pathogens
Term
MHC Class II
Definition
presents to CD4 cells
from extracellular pathogens
macrophages,dendritic cell and B cells
Term
antibody function
Definition
adaptor proteins
facilitate phagocytosis
facilitate complement activation
Term
Original antigenic sin
Definition
when memory cell are available, the naive lymphocyte process is completely shut down
Term
antigen
Definition
any substance that can be bound by antibody
Term
immunogen
Definition
any Ag that can induce an immune response
Term
strongest immunogen
Definition
protein (>polysaccharides>lipid>nucleic acids)
Term
adjuvant
Definition
enhances immune response to Ag
Term
epitope
Definition
portion of Ag that antibody binds
(linear, discontinuos, neoantigenic--> newly formed due to refolding)
Term
hapten
Definition
to small to envoke immune response unless attached to larger antigen
Term
hypervariable region
Definition
most intimate contact with AG, subject to great variability, AKA CDR, changes cause change in affinity
Term
papain digestion
Definition
2 Fab and 1 Fc
Term
Fc
Definition
tail of Ab molecule, site of complement activation (IgM and IgG), helps IgG cross the placenta
Term
pepsin digestion
Definition
yields single frag with 2 Ag binding sites (F(ab)2), Fc portion is degraded
Term
IgM
Definition
pentamer (monomer on B cell surface), activates complement, largest Ig, first activated
Term
IgD
Definition
marker for naive B cell
Term
IgG
Definition
most prevalent in serum, inactivates viruses, activates complement, crosses placenta, promotes phagocytosis
Term
IgA
Definition
dimer in secretion, protects agst enzymatic breakdown of gut
Term
IgE
Definition
mediates allergic reactions, bound to mast cell and basophils
Term
C1 activation
Definition
C1q binds to Fc portion of IgM or IgG2
Term
c3 convertase
Definition
C4b2a, cleaves c3
Term
c5 convertase
Definition
C4b2a3b, cleaves C5
Term
c1 inihbitor
Definition
limits duration of C1 activity, binds to C1r and c1s and disass them from C1q
Term
c4 binding protein
Definition
disass C4b from C2a
Term
factor H
Definition
cofactor for factor I
Term
factor I
Definition
cleavse C3b into inactive iC3b
Term
DAF (decay accelerating factor)
Definition
diass Bb from C3b
same function as CR1
Term
CR1
Definition
diass Bb from C3b
binds to C3b
enhances phagocytosis
protects human cells from complement activation
Term
MCP (membrane cofactor protein)
Definition
disass Bb from c3b, cofactor for factor I, also binds C4b making it susceptible to factor I

aids in destruction of both c3 convertases
Term
S protein, clusterin, factor J
Definition
prevent c5b67 from attaching to cell surface
Term
Homologous restriction factor (HRF) and CD59 (protectin)
Definition
bind to C5-8, prevent C9 recruitment
Term
CR2
Definition
component or BCR
binds to IC3b
provides strong activation stimulus
Term
CR3/CR4`
Definition
binds iC3b, augments phagocytosis
Term
biologic functions complement
Definition
cytolysis, oponization, inflammation, immune complex removal
Term
kappa rearranges...
Definition
first
Term
RAG (recombination activation genes)
Definition
directs recombination
binds to RSS of 12 or 23 nucleotides
Term
alternative RNA processing
Definition
switches from membrane bound to secreted
Term
heavy chain class switching
Definition
association of VDJ segments with different C genes, changes isotype not specificity
Term
somatic hypermutation
Definition
single nucleotide substitutions in V regions in CDRs, may increase affinity for antigen
Term
stem B cell
Definition
H and L germline arrangement
no surface Ig
bone marrow
Term
pro B cell
Definition
H rearrangement, DJ then VDJ
L germline arrangement
no surface Ig (Ag unresponsive)
bone marrow
Term
pre B cell
Definition
has BCR (mu heavy chain and surrogate light chains)
BCR associates with Iga and Igb
BCR induces light chain rearrangement
Term
pre B cell
Definition
has BCR (mu heavy chain and surrogate light chains)
BCR associates with Iga and Igb
BCR induces light chain rearrangement
Term
immature B cell
Definition
expresses IgM and Iga/b complex
light chain either kappa or lambda
undergo negative selection
Term
mature B cell
Definition
express IgM and IgD
Ag responsive
Term
TCR race
Definition
whether gamma:delta occurs before beta
if beta happens first...
forms pre TCR (pTalpha), rearrangment stops
alpha rearragement begins (again a race with gamma:delta)
if a cell wins, cell is committed to alpha:beta
Term
CD3 comples
Definition
required for TCR expression
has four invariant membrane proteins
directs intracellular signaling via ITAMS
Term
MHC restiction
Definition
TCR must recognize both antigen fragment and MHC molecule
Term
double negative thymocyte
Definition
no CD4 or CD8 markers
germline configuration
Term
TCR rearragement B chain
Definition
marked by CD25 expression (IL2R) and decreased CD44 expression
Term
double positive thymocyte
Definition
expresses both CD4 and CD8
(expressed after B chain is complete)
Term
postive selection
Definition
recognizes peptides presented on self MHC molecules, in cortex of thymus
Term
negative selection
Definition
eliminates cells that bind with a high affinity to self peptides
Term
structure of MHC class I
Definition
alpha chain with 3 extracellular domains and one intracellular, B2 microglobulin -->invariant
binds small peptides due to structure
Term
structure of Class II mHC
Definition
alpha and beta chain
Term
IFN gamma
Definition
upregulates macrophages
Term
endogenous pathway for APC
Definition
1. ubiquitin
2. TAP- binds Ag fragments and transports them into ER
3. Tapasin- positions Class I for receiving peptide
Term
tapasin
Definition
positions Class I for receiving peptide
Term
LMP
Definition
made in response to IFN, skews proteosome to produce
Term
calnexin/calrecticulin
Definition
stabalize newly formed MHC I molecule until B2 invariant binds
Term
class II invariant chain
Definition
associates with newly formed MHC II in ER to prevent peptides from binding
Term
CLIP
Definition
invariant chain fragment left follwing cleavage
Term
HLA-DM
Definition
catalyses the release of CLIP and allows processed antigens to bind
Term
cross presentation
Definition
ER membranes form under phagocytotic cup, brings MHC Class I processing in close proximity
Term
cross priming
Definition
dendritic cell uptake of apoptic blebs, eventually displayed as class I
Term
CD1
Definition
displays lipids
Term
L-selectin
Definition
binds CD34, GLyCAM, MADCAM (on endothelium), allows T cells to roll across endothelial cells
Term
LFA-1 (intergin)
Definition
activated by local chemokines
binds to ICAM-1
allows for diapedesis
also loosely holds Tcell and APC together
affinity increases if TCR recognizes MHC+peptide
Term
CD2
Definition
binds LFA-3 on APC
Term
signal 1 for activation of T cell
Definition
TCR:MHC peptide and CD4/8
Term
signal 2 for activation of T cell
Definition
CD28:B7
costimulation
leads to clonal expansion
bacteria induces expression on macrophages and B cells
Term
signals produced by dendritic cells
Definition
CCL18- attracts naive T cells
DEC 205: phagocytosis
ICAM-3: T cells
Term
Needed for T cell activation
Definition
adhesion molecules (homing)
b7/CD28 (2nd signal for activation)
CD3 complex (intracellular signaling)
CD4/8 (essential for effective T cell stim)
Term
ZAP70
Definition
binds to phosphorylated ITAMS
Term
Lck
Definition
activates ZAP70 (which activated PLC gamma)
Term
PLC gamma
Definition
leads to DAG and Ip3 formation
Leads to NFAT and NFkB activation
Term
GEF
Definition
activated by ZAP70
FOs and Jun induction
AP1 activation
Term
Dendritic cell and CD8 activation
Definition
express high levels of B7 sufficient for CD8 activation
Term
transition from naive to effector cells
Definition
L selectin is turned off
VLA-4 is turned on
CD45RA --> CD45RO
Term
VLA-4
Definition
binds to VCAM-1, directs T cells to infected tissues
Term
CD45RO
Definition
associates with TCR and CD4
increases sensitivity to stimulation, requiring lower concentrations of peptide:MHC complexes
Term
fas ligand on CD8 cells
Definition
binds to Fas and causes caspase activation
Term
perforin
Definition
polymerizes to form pores in target cell membrane
Term
TH1 cells
Definition
type of CD4 cell
macrophage activation, Bcell activation, oponization, IgG1 production
elimination of extracellular and intravesicular pathogens
Term
TH1 differentation driven by
Definition
IL-12 (signals using STAT4)
and (IL27)(activates Tbet)
Term
Th1 cells produce and express
Definition
IFN gamma and CD40L
activate macrophages
increase expression of B7 and Class II
increases microbicidial substances
Term
Th2 cell
Definition
type of CD4 cell
involved in activation of B cells
Term
Th2 cell differentation driven by
Definition
IL-4 (leads to expression of GATA3 and STAT6)
Term
Th2 produce and express
Definition
IL4 and CD40L: drives B cell proliferation
IL5 and IL6: drive B cell differentation to AB secreting plasma cell
Term
Th17
Definition
IL23 from dendritic cells drive T cells to produce IL17
rapidly recruit neutrophils to the site of infection
Term
T reg cells
Definition
type of C4 cells
express CD4, CD25 and Foxp3
expresses CTLA-4 (binds to B7)
IL2 dependent
secrete IL10
contact dependent regulation
Term
Inhibit activation of Th1 cells
Definition
TGF-b and IL-10
Term
inhibits proliferation of Th2 cells
Definition
IFN-gamma
Term
IL-27
Definition
induces Tbet and STAT6
inhibits GATA3 activation
Term
macrophages produce these cytokines
Definition
Il-1, TNF, IL-6
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