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Immunology 2
DSE mini test
151
Veterinary Medicine
Undergraduate 3
03/16/2012

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Term
Bcells undergo differentiation and immune activation in...
Definition
...secondary follicles of lymphoid tissue
Term
zones of secondary follicel in lymphoid tissue =
Definition
1. mantle zone (outer)-smaller b cells
2. germinal centre - larger, dividing, activated b cells
Term
Where are T cells found in lymphoid tissue?
Definition
paracortex
Term
PALS of spleen =
Definition
periarteriolar lymphoid sheath

Tcells can be found here
Term
white pulp in spleen = full of what type of cells?
Definition
lymphocytes
Term
red pulp of spleen =
Definition
blood filtering areas of spleen
Term
trebeculae of spleen =
Definition
skeletion of spleen/c.t.
Term
MALT
GALT
BALT
NALT
CALT
Definition
Mucosa associated lymphoid tissue (mucosa ALT)

Gastrointestinal ALT
Bronchial ALT
Nasal ALT
Conjunctival ALT
Term
location of peyers patches
Definition
S.I
Term
peyers patches =
Definition
collection of lymphocytes in S.I (no capsule)
Term
Mcell is located between...
Definition
...peyers patch and lumen of S.I
Term
M cell =
Definition
dome shaped epi cell
Term
What does an M cell do?
Definition
sample food and potential pathogens and transports the appropriate material to the peyers patches
Term
lymphoblast =
Definition
stimulated T or B cell (in response to Ag)
BIGGER than lymphocytes
Term
Plasma cell =
Definition
late stage B cell that produces and secretes Abs.
Term
T cell surface molecules =
Definition
TCR
CD3
Term
B cell surface molecules =
Definition
smIg/BCR/Ig
FcR (binds with Fc found on Ig's)
C3bR
Term
Telling T cells from B cells via immunofluroecence:
Definition
1. antiserum to smIg of B cells conjugated with fluorochrome
2. + antiserum to unknown lymphocytes
3. expose to UV lights - fluorochrome (conjugated with anti-smIG which will now be bound to any B cells in unknown sample of lymphocytes) will flouresce.

can see fluorescing b cells, but cant see t cells
Term
why do lymphocytes recirculate?
Definition
to maximise the chance of contact between an Ag and the appropriate responding populations of lymphocytes
Term
immunological surveillance is achieved by...
Definition
...lymphocytes recirculating/continually moving around the body
Term
clonal selection theory
Definition
clonal proliferation of activated lympho
Term
HEV
Definition
specialised cuboidal cells, higher than normal bv endothelium. Needed so lymphocytes know when to leave the blood
Term
HEV are found...
Definition
...in LN, spleen and diseased tissues bv's (diseased tissues induce endotheilail cells of bv's to transform)
Term
HEV have what on their lumenal surface?
Definition
vascular addressin (shows adress of HEV - unique to that one HEV)
Term
HEV have what on their lumenal surface?
Definition
vascular addressin (shows adress of HEV - unique to that one HEV)
Term
HEV have what on their lumenal surface?
Definition
vascular addressin (shows adress of HEV - unique to that one HEV)
Term
vascular addressin on HEV interacts with what R on lympho?
Definition
homing R

this interatcion = slowing of WBC's and diapedesis)
Term
wide array homing R's are found on...
Definition
...virgin t cells (can get into any part of the body = gd immunosurveillance)
Term
blast restrictive specificity =
Definition
cloned lymphocytes =lost lots of their homing R's.

ONly got homing R's for specific part of the body where infection occured
Term
memory limited specificity =
Definition
lympho previously exposed to Ag = can now make stronger, quicker immune response, BUT has less ability to get round body
(have homing R's for parts of the body previously exposed to infection)
Term
specialised recirculation =
Definition
the common mucosal system - if have infection in gut, the exposed lympho can get off/enter all other mucosal systems
Term
specialised recirculation is important as it means...
Definition
...can get Abs in colostrum for neonate
Term
MHC
Definition
Major histocompatibility complex

Molecules on tissues to recognise self cells - specific to that individual
Term
MH Ags =
Definition
tissue Ags which cause allograft rejection.
Term
autograft
Definition
same person (skin from you put somewhere else)
Term
isograft
Definition
genetically identical (eg identical twin)
Term
xenograft
Definition
from diff. sp
Term
allograft
Definition
same sp. but diff genetic constitution
Term
most common graft type =
Definition
allograft
Term
graft rejection
Definition
recipients immune system recognises passenger leukocytes from graft that get into the blood and lymphatic system Recipients Igs damages vascular supply to graft = graft rejection
Term
If have graft and recipients immune system is suppressed...
Definition
....passenger leukocytes from the graft can attack the recipient = severe dz, and can be fatal!!
Term
HIstocompatability Ags
Definition
so body can recognise self cells
Term
MHC I alpha and beta domains =
Definition
alpha 1, 2 and 3 (one long alpha chain) - alpha 3 always closest to cell mb

betaa 2m (small/microglobulin beta chain)
Term
MHC II alpha and beta domains =
Definition
alpha 1 and 2
beta 1 and 2
Term
MHC I is found on the surface of...
Definition
...all nucleated cells
Term
MHC II is found on the surface of...
Definition
...immune cells
Term
MHC is on what chromosomes in dogs and cats?
Definition
chrom. 12 and 13
Term
MHC gene is highly...
Definition
...polymorphic
Term
why does everyone have unique MHC profile?
Definition
due to MHC polymorphism
Term
In middle of MHC gene complex =
Definition
genes coding for other immune molecules eg complement, cytokines and enzymes = class III MHC genes
Term
class I MHC genes code for...
Definition
...Ag presentation to CD8 T cells
Term
class I MHC genes code for...
Definition
...Ag presentation to CD8 t cells
Term
are MHC genes recessive, dominant or codominant?
Definition
co-dominant
Term
class I molecules of MHC =
Definition
A, B and C
Term
How many class I MHC molecules does a cell express?
Definition
6 (maternal ABC and paternal ABC)
Term
most inheritance of MHC is...
Definition
...'en bloc' (whole chunk of MHC from mum and whole chunk from dad)

however recombination can occur
Term
MHC inheritance is fundamentally...
Definition
...Mendelian
Term
MEndelian inheritance =
Definition
theres a 25% chance two siblings will be haplo-identical (have same alleles of MHC and therefore can be donors to one another)
Term
MHC complex can determine ...
Definition
... predisposition to certain dz's, espec immune mediated dz

and production traits of livestock
Term
canine MHC dz associations:
Definition
RA
IMHA
Diabetes mellitus
Addisons dz
lymphocytic thyroiditis
anal furunculosis
susuceptibility to leishmaniosis
Term
If cat kidney transplant do you have to match MHC and blood group?
Definition
only have to match blood group, not MHC
Term
MHC typing
Definition
pemranently ID animal via its MHC
Term
Can use MHC to determine...
Definition
...parents of puppies
Term
foreign Ag firstly has to be converted to......
Definition
...user friendly form by APC (eg small peptide fragment with a minimum of 7aa's)
Term
name 4 APC's
Definition
PROFESSIONAL APC's
1. macro
2. dendritic cells
3. Bcells
UNPROFESSIONAL APC's
4. induced APC
Term
macro in liver =
Definition
kupffer cells
Term
dendritic cells in epidermis of skin =
Definition
langerhans cells
Term
myeloid dendritic cells = ? derived
Definition
?=monocyte
Term
plasmocytoid dendritic cell = ? origin
Definition
?=lymphoid
Term
when dendritic cell is activated by Ag and goes into afferent lymphatic vessel it transofrms into......
Definition
...a veiled dendritic cell (stumpier dendrites)
Term
dendritic cell scanning molecules =
Definition
PRR's (pattern recognition R's on cell mb)
TLR's (toll-like R's on cell mb)
NOD-like R's (in cytoplasm)
Term
Ag molecules recognised by dendritic cells =
Definition
PAMP's (pathogen associated molecular patterns)-on pathogen DAMP's (damage associated molecular patterns) - on damaged self cells eg cancer cells
Term
specific immune response activated by dnedritric cell depends on...
Definition
...type of PAMP and PRR involved
Term
after large crude Ag has been converted to a user friendly form by the APC what happens?
Definition
the APC expresses the Ag on its surface to activate an immune response
Term
exogenous Ag expressed by...
Definition
...MHC II
Term
endogenous Ag expressed by...
Definition
...MHC I
Term
MHC II has an...
Definition
...invariant chain
Term
endogenous Ag processing involves...
Definition
...a proteosome (hollow cylinder organelle that breaks Ag into peptide fragments)
Term
exogenous Ag processing =
Definition
occurs in an endosome and the Ag is broken down into peptide fragments by enzymes
Term
cross presentation =
Definition
exogenous Ag enters the endogenous pathways = exogenous Ag is expressed by MHC I and MHC II

This makes a BIG immune response
Term
MHC I/II + Ag peptide fragment is recognised by...
Definition
...TCR of T cell
Term
MHC II presents Ag to...
Definition
....CD4 Tcells (Thelper cells)
Term
MHC I presents Ag to...
Definition
...CD8 T cells (cytotoxic T cells)
Term
what presents lipid Ags?
Definition
CD 1 (like MHC I) a transmb glycoprotien associated with beta microglobulin like MHC I and therefore has a similar pathway of Ag processing to MHC I/the endogenous pathway
Term
why do Bcells present Ags?
Definition
so they can become activated by t helper cells
Term
non-professional APC's =
Definition
cells that are induced to become APC's by IF-gamma. When induced they express MHC II
Term
give an example of a non-professional APC.
Definition
stratified squamous epidermal cell
Term
are cytokines soluble or insoluble?
Definition
soluble
Term
cytokines =
Definition
released by one cell and then bind to a specific R on another cell or the same cell and alter cell function
Term
lymphokine
Definition
cytokine from lymphocyte
Term
monokine
Definition
cytokine from monocyte
Term
give 2 examples of cytokines.
Definition
IL and IF
Term
cytokines are potent at ? concentrations
Definition
?=-picomolar (v. small)
Term
chemokine
Definition
cytokine that is a chemoattractent(carries out chemotactic recruitment of cells from blood into the tissues)
Term
give an example of a chemokine
Definition
complement
Term
cytokines can down or up regulate...
Definition
...eachother
Term
mature T cells express...
Definition
...TCR/CD3 complex
Term
what MHC does CD4 tcell have?
Definition
MHC II
Term
what MHC does CD8 tcell have?
Definition
MHC I
Term
TCR has a CD3 complex, what does this do?
Definition
tightens reaction between APC and TCR
Term
each TCR is specific to...
Definition
...a single Ag fragment
Term
polypeptide chains of TCR =
Definition
alpha and beta
Term
domians of alpha chain of TCR =
Definition
variable (V)
Joining (J)
Constant (c)
Term
domians of beta chain of TCR =
Definition
variable (V)
Diversity region (D)
Joining (J)
Constant (c)
Term
TCR alpha chain gene is found on chrom......
Definition
...14
Term
TCR beta chain gene is found on chrom...
Definition
...7
Term
on TCR beta chain gene how many sets/sequences are there of the V. D. J and C regions?
Definition
V = 1 D = 2 J = 2 C = 1
Term
assembly of TCR beta chain =
Definition
1. delete introns between V, D and J regions 2. transcription 3. attach C region by RNA splicing
Term
theoretically how many TCR's can be made
Definition
10^15
Term
realistically how many TCRs can be made?
Definition
20million (as some genes get lost)
Term
TCR degeneracy =
Definition
TCRs are able to recognise multiple Ags TCRs look for contact residues (a specific aa sequence found in several differenct Ags)
Term
tcells in the thymus travel from ? to *
Definition
? the cortex
*the medulla
Term
In the thymus get what type of selection of tcells?
Definition
-ive and +ive
Term
what % of tcells die in the thymus?
Definition
99%
Term
+ive selection =
Definition
select tcells that are functioning properly
Term
what cells examine tcells in the thymus for +ive selection?
Definition
thymic epi cells (they express MHC II/I and an unknown peptide)
Term
what cells examine Tcells in the thymus during -ive selection?
Definition
thymic dendritic cells (expressing MHC I/II and self Ag)
Term
where does -ive selection of tcells in the thymus occur?
Definition
in the medulla or at the junction between the medulla and the cortex
Term
tcells start off expressing....
Definition
...CD4 and CD8
Term
what happens to tcells in the medulla of the thymus after tcell examination?
Definition
tcell looses CD4 or CD8 depending on whether they encountered Ag on MHC I or MHC II)

Encounter MHC I = keep CD 8, loose CD4
Encounter MHC II = keep CD 4, loose CD 8
Term
activated t cell transorms to...
Definition
...t lymphoblast
Term
activated t cell expresses what cytokines?
Definition
IL-2R and IL-2 (or IL4) = IL-2 binds to IL-2R = activate own growth = autocrine growth factor!
Term
3signal events (that occur in parallel) to activate tcell =
Definition
1. MHC and CD/TCR bind
2. clustering of molecules between APC and Tcell = immunological synapse
3. release of cytokine from APC which binds to Tcell
Term
gamma delta t cell
Definition
special rare t cell with gamma and delta chains instead of alpha and beta

Thought to be more primitive tcell
Term
regulatory CD 4 tcells =
Definition
Th3
Tr1
Treg
Term
precursor tcell of Th1, Th17 and Th2 =
Definition
Th0
Term
Thelper cells function =
Definition
help to promote and activate immune response
Term
Th1-Th2 dichotomy/model
Definition
Th1 and Th2 = antagonists of one another

If one is activated the other is not, as cytokines of Th1 inhibit Th2 and vice versa
Term
Th2 releases...
Definition
IL's (except Il-2)
Term
Th1 releases...
Definition
...IF-gamma (which is a way of ID Th1 from Th2) and IL-2
Term
2ways CD8 can be activated =
Definition
1. directly (3signals)
2. with help from CD4 tcell (via release of Il-2)
Term
cytotoxcicity =
Definition
destruction of target cell
Term
what tcell has features of Th1 and Th2?
Definition
Th0
releases IL-2 and IF-gamma (like Th1)
and IL-4 (like Th2)
Term
what t helper cell decides most appropriate immune response
Definition
Th0
Term
4things that determine balance of Th1 and Th2 =
Definition
1. type of APC
2. type and dose of Ag
3. Th0
4. PAMP and PRR interaction
Term
What stops NK cells killing normal cells?
Definition
NK cells have KIR (kill inhibiting R) which binds to MHC I of normal cells = stops/inhibits NKcells from killing normal self cells

NKcells only kill cells with no MHC I eg cancer cells and pathogens
Term
how do cytotoxic CD8 tcells cause lethal cell injury?
Definition
1. perforin from granules punches holes in cell mb
2. TNF and IF-gamma released from CD8 Tcells and activate signalling pathways in target cell = apoptosis
3. fas ligands on cytotoxic cell bind to fas on target cell = cause apoptosis
Term
NOw think memory t cells undergo continual low level division due to periodic restimulation by Ag. Where does Ag come from for restim???
Definition
1. reservoir on Ag in lymphoid tissue 2. cross-reactive environmental Ags (other Ags in enviro have similar epitopes so restim memory tcells) 3. periodic re-introduction of Ag by boosters or natural reinfection
Term
gamma delta t cells:
a) involved in...
b) found at...
c)In what sp. do you find many gamma delta tcells in the blood?
d)where are theses cells prominant in the dog?
e)gamman delta tcells are v responsive to what type of infections?
Definition
a)...innate immunity
b)...mucocutaneous surfaces
c)cattle, sheep and pigs
d) the spleen
e) bacterial Ags
Term
what lymphocytes can recognise unprocessed Ags?
Definition
Bcells
Term
Bcell Ag R =
Definition
smIg
Term
2ways to activate a Bcell
Definition
1. thymus independent (Ag directly activates Bcell)
2. Thymus (tcell) dependent (need thelper cell) - MOST COMMON WAY OF ACTIVATION
Term
What Ig is only found on the surface of niave Bcells?
Definition
IgD
Term
Ig on immature Bcells=
Definition
IgM
Term
Ig on niave/virgin Bcells=
Definition
IgM and IgD
Term
activation of B cell by Ag =
Definition

Bcell converted to B lymphoblast

 

more MHC II expressed

 

 Ig class switch to one type of Ig (IGG, IGA or IgE - can be IGM but this is rare)

Term
Bcells can differentiate into ...
Definition
...plasma cells or memory B cells
Term
BCR diversity occurs by...
Definition
...gene conversion and somatic mutation in ileal peyers patches or bursa of fabricus (in birds)
Term
Ab production:
Day 0/day of infection:
Day 2-7:
Day 5-12:
Definition
Day 0: natural Abs - broad specificity (innate immunity)
Day 2-7: T-independant Ab production (Ab specific: IgM)
DAy 5-12: T-dependent Ab production
Term
Ag's can cause what two types of Ab responses?
Definition
mononlconal (1 immunodominant epitope)
or
polyclonal (if >1 immunodominant epitope on Ag) response
Term
How monoclonal Abs are made artificially.
Definition
1. inject niave/sterile mouse with Ag=immunise mouse = polyclonal response 2. kill mouse, remove spleen which will contain some Ag specific B cells and some non-specific 3. myleoma (cancer of plasma cells) in vitro - mix with spleen cells 4. +PEG (glue that fuses plasma and B cells together = hybridomas) 5. +HAT =unfused Bcells die as not immortal (die in few days) and unfused plasma cells die as they are HAT sensitive) - keep hybridomas and get rid of other cells 6. dilute so single cell in well 7. clone 8. harvest Ab of single specificity = monoclonal Abs
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