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? |
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Definition
|
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Term
|
Definition
periarteriolar lymphoid sheath
Tcells can be found here |
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|
Term
| white pulp in spleen = full of what type of cells? |
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Definition
|
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Term
|
Definition
| blood filtering areas of spleen |
|
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Term
|
Definition
|
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Term
|
Definition
Mucosa associated lymphoid tissue (mucosa ALT)
Gastrointestinal ALT
Bronchial ALT
Nasal ALT
Conjunctival ALT |
|
|
Term
| location of peyers patches |
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Definition
|
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Term
|
Definition
| collection of lymphocytes in S.I (no capsule) |
|
|
Term
| Mcell is located between... |
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Definition
| ...peyers patch and lumen of S.I |
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Term
|
Definition
|
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Term
|
Definition
| sample food and potential pathogens and transports the appropriate material to the peyers patches |
|
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Term
|
Definition
stimulated T or B cell (in response to Ag)
BIGGER than lymphocytes |
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Term
|
Definition
| late stage B cell that produces and secretes Abs. |
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Term
| T cell surface molecules = |
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Definition
|
|
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 |
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Term
| why do lymphocytes recirculate? |
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Definition
| to maximise the chance of contact between an Ag and the appropriate responding populations of lymphocytes |
|
|
Term
| immunological surveillance is achieved by... |
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Definition
| ...lymphocytes recirculating/continually moving around the body |
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Term
|
Definition
| clonal proliferation of activated lympho |
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Term
|
Definition
| specialised cuboidal cells, higher than normal bv endothelium. Needed so lymphocytes know when to leave the blood |
|
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Term
|
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 |
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|
Term
| specialised recirculation is important as it means... |
|
Definition
| ...can get Abs in colostrum for neonate |
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|
Term
|
Definition
Major histocompatibility complex
Molecules on tissues to recognise self cells - specific to that individual |
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Term
|
Definition
| tissue Ags which cause allograft rejection. |
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|
Term
|
Definition
| same person (skin from you put somewhere else) |
|
|
Term
|
Definition
| genetically identical (eg identical twin) |
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Term
|
Definition
|
|
Term
|
Definition
| same sp. but diff genetic constitution |
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Term
|
Definition
|
|
Term
|
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... |
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Definition
| ....passenger leukocytes from the graft can attack the recipient = severe dz, and can be fatal!! |
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Term
|
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... |
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Definition
|
|
Term
| MHC II is found on the surface of... |
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Definition
|
|
Term
| MHC is on what chromosomes in dogs and cats? |
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Definition
|
|
Term
|
Definition
|
|
Term
| why does everyone have unique MHC profile? |
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Definition
|
|
Term
| In middle of MHC gene complex = |
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Definition
| genes coding for other immune molecules eg complement, cytokines and enzymes = class III MHC genes |
|
|
Term
| class I MHC genes code for... |
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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
|
|
Term
| class I molecules of MHC = |
|
Definition
|
|
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 |
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|
Term
| MHC inheritance is fundamentally... |
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Definition
|
|
Term
|
Definition
| theres a 25% chance two siblings will be haplo-identical (have same alleles of MHC and therefore can be donors to one another) |
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|
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 |
|
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Term
|
Definition
| pemranently ID animal via its MHC |
|
|
Term
| Can use MHC to determine... |
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Definition
|
|
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
|
Definition
PROFESSIONAL APC's
1. macro
2. dendritic cells
3. Bcells
UNPROFESSIONAL APC's
4. induced APC |
|
|
Term
|
Definition
|
|
Term
| dendritic cells in epidermis of skin = |
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Definition
|
|
Term
| myeloid dendritic cells = ? derived |
|
Definition
|
|
Term
| plasmocytoid dendritic cell = ? origin |
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Definition
|
|
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 = |
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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? |
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Definition
| the APC expresses the Ag on its surface to activate an immune response |
|
|
Term
| exogenous Ag expressed by... |
|
Definition
|
|
Term
| endogenous Ag expressed by... |
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Definition
|
|
Term
|
Definition
|
|
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
|
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
|
|
Term
|
Definition
| ....CD4 Tcells (Thelper cells) |
|
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Term
|
Definition
| ...CD8 T cells (cytotoxic T cells) |
|
|
Term
|
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
|
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
|
|
Term
|
Definition
| released by one cell and then bind to a specific R on another cell or the same cell and alter cell function |
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|
Term
|
Definition
|
|
Term
|
Definition
|
|
Term
| give 2 examples of cytokines. |
|
Definition
|
|
Term
| cytokines are potent at ? concentrations |
|
Definition
|
|
Term
|
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
|
|
Term
| cytokines can down or up regulate... |
|
Definition
|
|
Term
| mature T cells express... |
|
Definition
|
|
Term
| what MHC does CD4 tcell have? |
|
Definition
|
|
Term
| what MHC does CD8 tcell have? |
|
Definition
|
|
Term
| TCR has a CD3 complex, what does this do? |
|
Definition
| tightens reaction between APC and TCR |
|
|
Term
| each TCR is specific to... |
|
Definition
|
|
Term
| polypeptide chains of TCR = |
|
Definition
|
|
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
|
|
Term
| TCR beta chain gene is found on chrom... |
|
Definition
|
|
Term
| on TCR beta chain gene how many sets/sequences are there of the V. D. J and C regions? |
|
Definition
|
|
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
|
|
Term
| realistically how many TCRs can be made? |
|
Definition
| 20million (as some genes get lost) |
|
|
Term
|
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
|
|
Term
| In the thymus get what type of selection of tcells? |
|
Definition
|
|
Term
| what % of tcells die in the thymus? |
|
Definition
|
|
Term
|
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
|
|
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
|
|
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
|
Definition
special rare t cell with gamma and delta chains instead of alpha and beta
Thought to be more primitive tcell |
|
|
Term
|
Definition
|
|
Term
| precursor tcell of Th1, Th17 and Th2 = |
|
Definition
|
|
Term
|
Definition
| help to promote and activate immune response |
|
|
Term
|
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
|
Definition
|
|
Term
|
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
|
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
|
|
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
|
|
Term
|
Definition
|
|
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
|
|
Term
|
Definition
|
|
Term
| Ig on niave/virgin Bcells= |
|
Definition
|
|
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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|
