Immuno

Front 1

Lymph Node

Back 1

Encapsulated w/ trabeculae

Functions:
- non specific filtration by macrophages
- storage/activation of B & T cells
- antibody production

Front 2

Follicle

Back 2

B cell localization and prolif
1* = dormant
2* = active w germinal centers

Front 3

Medulla

Back 3

cords and sinuses

Sinuses = communicate with efferent lymphatics and contain reticular cells and macrophages

Front 4

Paracortex

Back 4

T cells

Greatly enlarged in extreme cellular immune response (ex. viral)

Not well dev in DiGeorge pts

Front 5

Spleen

Back 5

Perarterial lymphatic sheath (PALS) = T cells

Red pulp = T cells

White pulp = B cells (follicles)

Macrophages of spleen: remove encapsulated bacteria thus if splenic dysfxn --> dec IgM, complement activ, C3b opsonization and inc. suscept to encapsulated organisms (S. pneumo, H. influ, Salmonella - like in sickle cell dz)

Front 6

Corticomedullary junction

Back 6

Site in thymus of positive and negative selection

Cortex of thymus = immature T cells
Medulla = mature T cells

Front 7

Helper T cell differentiation

Back 7

(bone marrow --> thymus cortex --> thymus medulla --> lymph node)

IL-12 --> Th1 cell
- makes IL-2, IFN-y (inhib Th2), activ macrophages

IL-4 --> Th2 cell
- makes IL-4, IL-5, IL-10 (inhib Th1)
- help B cells make Ab (IgE>IgG)

Front 8

MHC I

Back 8

HLA-A, HLA-B, HLA-C

ALL NUCLEATED CELLS

Ag loaded in ER of intracellular peptides
Mediate viral immunity
Pair w/ B2 microglobulin

Front 9

MHC II

Back 9

HLA-DR, HLA-DP, HLA-DQ

only on APCs
Ag loaded following rel of invariant chain in ACIDIFIED endosome
- failure to acidify lysosome? defic exp of MHC Class II bound to foreign Ag and subseq lack of interaction b/w APCs & T-cell

Front 10

NK cells

Back 10

ONLY LYMPHOCYTE MEMBER OF INNATE IMMUNE SYSTEM

enhanced by IL-12, IFN-beta, IFN-alpha

Kills when:
- non specific activation signal on target cell
- absence of Class I MHC on target cell surface

Front 11

CD3 complex

Back 11

cluster of polypepties assoc w/ TCR
Important in SIGNAL TRANSDUCTION

Front 12

Antigen presenting cells

Back 12

Macrophages

B cells

Dendritic cells

Front 13

Macrophage-lymphocyte interaction

Back 13

Activated lymphocytes release IFN-gamma

Macrophage - release IL-1 and TNF-alpha

stimulate each other

Front 14

Superantigens

Back 14

S. aureus + Strep pyogenes

cross link B-region of TCR to MHC Class II on APCs

result in uncoord release of
- IFN-y from Th1 cells
-IL 1, IL-6, TNF-alpha from macrophages

Front 15

Endotoxins/lipopolysacch's

Back 15

Gram neg bacteria

Directly stimulate macrophages by binding to endotoxin receptor CD 14

Th cells not involved

Front 16

Th activation

Back 16

1. Foreign body phagocytosed by APC

2. Foreign Ag presented to MHC II
- recognized by TCR on Th cell

3. Costimulatory signal via B7 and CD28

4. Th cell activated --> produce cytokines

Front 17

Tc activation

Back 17

1. Endogenously synthesize (viral or self) proteins presented on MHC I
- recognized by TCR on Tc cell

2. IL-2 from Th cell activates Tc cell to kill virus-infected cell

Front 18

B-cell class switching

Back 18

1. IL-4, 5, 6, from Th2

2. CD40 receptor activation via CD40 ligand on Th cell

Front 19

Fab fragment

Back 19

Ag-binding fragment

Determines idiotype

light chain hypervariable region + heavy chain

Front 20

Fc fragment

Back 20

CONSTANT

carboxy terminal
complement binding (IgG IgM only)
Carbohydrate side chains

Determines isotype
heavy chain only

Front 21

Mature B lymphocytes

Back 21

IgM + IgD surface expression only

Differentiate via isotype switching
- alternative mRNA splicing mediated by cytokines and CD40

Front 22

IgG

Back 22

- main 2* response antibody
- most abundant
- fix complemet
- CROSS PLACENTA
- opsonize bacteria
- neutralize bacterial toxin and viruses

Front 23

IgA

Back 23

- PREVENT ATTACHMENT of bacteria/viruses to mucous membranes
- does NOT fix complement
- monomer/dimer
- found in SECRETIONS
- picks up secretory component before secretion (prevents degrad)

Front 24

IgM

Back 24

- 1* response to Ag
- fix complement
- does NOT cross placenta
- Monomer or PENTAMER
- Ag receptor on B-cells

Front 25

IgD

Back 25

unclear fxn

Front 26

IgE

Back 26

Type I HSR --> rel of mast cells + basophils
- mediate worm immunity by activ eosinophils
- lowest concen in serum

Front 27

Isotype

Back 27

Ig epitope common to single class of Ig
- determined by heavy chain

Front 28

Idiotype

Back 28

specific for given antigen
determined by Ag-binding sites

Front 29

Allotype

Back 29

Ig epitope that differs among members of same species
- heavy chain or light chain

Front 30

Thymus independent antigen

Back 30

antigen LACKS peptide component
- can't be presented by MHC to T cells
- stimulate IgM only
- no immunologic memory

Front 31

Thymus dependent antigen

Back 31

Ag contains protein component
Class siwtching/immunol memory occurs

Front 32

Classic pathway

Back 32

Activated by IgG/IgM

Front 33

Alternative pathway

Back 33

Acitvated by surface of microbes (esp endotoxin)

Front 34

1* opsonins in bacterial defense

Back 34

C3b + IgG

Front 35

Prevent complement activation on self-cells

Back 35

DAF = decay accelerating factor
- if deficient --> PNH

C1 esterase inhibitor
- if defic --> hereditary angioedema

Front 36

C1-4

Back 36

viral neutralization

Front 37

C3b

Back 37

opsonizaation
bind bacteria

Front 38

C3a, C5a

Back 38

Anaphylaxis

C5a = neutrophil chemotaxis

Front 39

C5b-9

Back 39

MAC

Front 40

C3 defic

Back 40

Severe recurrent pyogenic sinus and resp tract infec's

Inc susceptibility to Type III HSR

Front 41

C5-C8 defic

Back 41

Neisseria bacteremia

Front 42

Ag variation

Back 42

Bacteria:
Salmonella
Borrelia
N. gonorrhea

Virus:
Influenza

Parasites:
Trypanosomes

Front 43

Anergy

Back 43

self reactive T cells are nonreactive without costim molecules

Front 44

HLA subtypes

Back 44

A3 - hemochromatosis

B27 - psoriasis, ankylosing spondyitis, inflammatory bowel dz, reiter's

B8 - Graves' disease

Front 45

HLA subtypes

Back 45

DR2 - MS, hay fever, SLE, Goodpasture's

DR3 - DM type I

DR4 - RA, DM type 1

DR 5 - Pernicious anemia, Hashimoto's

DR 7 - steroid responsive nephrotic syndrome

Front 46

Hyperacute rejection

Back 46

ANTIBODY MEDIATED
- preformed ANTIDONOR ANTIBODIES in transplant recipient

- occurs within MINUTES

Front 47

Acute rejection

Back 47

CELL MEDIATED
- cytotoxic T lymphocytes reacting against foreign MHCs
- WEEKS after transplantation
- reversible w/ cyclosporine or OKT3

Front 48

Chronic rejection

Back 48

T cell and Abmediated vascular damage
- obliterative vascular fibrosis

- MONTHS TO YEARS after transplant
IRREVERSIBLE

Front 49

GVHD

Back 49

Grafted immunocompetent T cells proliferate in the irradiated immunocompromised host

SEVERE ORGAN DAMAGE
sx's:
maculopapular rash
jaundice
hepatosplenomegaly
diarrhea