Term
| List the four major classes of cells of the immune system |
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Definition
Lymphocytes
Antigen Presenting cells
Dendritic cells
Effector cells |
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Term
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Definition
Express clonally distributed receptors for antigens
Only cells with specific receptors for antigens therefore are key mediators of adaptive immunity
CD – cluster of differentiation
Small
Large |
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Definition
Bursa of fabricus
Bone marrow derived
The only Ab-producing cells
mediate humoral immunity
Ag specific
Increase in number as a second response
Proliferates quickly |
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Term
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Definition
Regulate ONLY to protein antigens bound to MHC
Mature in Thymus
Increase in number
Cell mediated immunity
Ag receptors on surface
Secrete cytokines
Either activate phagocytes to destroy microbes or kill the host cell with the infection
Helper T cells – help B cells produce antibodies and phagocytes to destroy cells
Cytotolic or cytotoxic kill cells harboring intracellular microbes |
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Term
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Definition
natural killers
nonT, nonB markers
part of innate
eliminate tumor cells/virus infected cells
antibody dependent cell cytoxicity (ADCC) |
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Term
| Antigen Presenting Cells/Accessory Cells |
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Definition
Mononuclear cells
phagocytes in IS
bone marrow derived
release cytokines
monocytes
10-15 micrometers
Bean shaped nucleus
Circulating
macrophages
fixed in tissues (Kupffer cells in liver) |
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Definition
Accessory cells
Trap protein antigens 0-- lymph nodes
Interdigitating DC -- skin, every tissue and organ
Follicular DC -- germinal centers of lymphoid tissue |
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Term
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Definition
effect clearance of antigen
Granulocytes – cytoplasmic granules
NOT accessory cells
neutrophils, eosinophils, basophils, granulocytes |
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Definition
phagocytic
multiple loved nucleus (3)
predominant cell type in acute inflammation |
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Definition
receptor for IgE
allergic reactions (killing helminthes) |
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Definition
IgE receptors
immediate hypersensitivities i.e. anaphylactic shock |
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Definition
cytoplasmic granules
NOT accessory cells |
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Definition
Seconday Lympoid Tissue
Find T, B , Follicular, and marcophages
Bean-shaped
Lie along lymphatics
Neck, axillae, groin, aorta
Sample lymph for protein antigens
Lymphatic vessels drain fluid from tissues
phagocytic filter/phagocytize particulate matter
APC
B/T activate lymphocytes |
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Term
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Definition
Cortex/germinal centers/follicles – Bcells
Germinal center means the B-cell has recently responded to an antigen
Produce antibodies
Follicles contain FDCs involved in activation B cells
Paracortex – T cells
Medulla – macrophages |
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Term
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Definition
Secondary Lymphoid Tissue
Pharyngeal tonsils and Peyer’s patches
Samples blood for blood borne antigens
B/T cell activation
Filter blood – senescent/abnormal rbc’s destroyed
Store iron
Phagocytosis of bacteriam – opsonized bacteria – coated with antibody
White pulp – follicles/germinal centers- B
Periarteriolar – t cells
lymphocytes
Red pulp – RBC’s macrophages, DC |
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Term
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Definition
Primary Lymphoid Tissue
hematopoiesis
B cell Maturation (not T Cell) |
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Definition
Primary Lymphoid Tissue
cortex/medulla
T cell maturation/"education" |
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Definition
Secondary
Tonsils, adenoids, peyer’s patches, appendix |
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Definition
Secondary
Urogenital, lung, some in gut |
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Term
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Definition
Block entry of microbes
Elimnate microbes that enter host tissues |
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Definition
Block infections
Eliminate extracellular microbes
Activate macrophages to kill phagocytosed microbes
Kill infected cells
Eliminate reservoirs of infection |
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Definition
Mechanical/flushing
Chemical/Biochemical
Cells |
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Term
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Definition
skin – outer layer, dead cells
keratinized layer
Mucus – epithelial cells
mucin
prevent bacteria from adhering
traps bacteria – cilia flush it, sneeze cough
Fluids – saliva – contains enzymes/ Abs
Tears – lysozyme
Perspiration
Urine
Vomiting
Diarrhea |
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Term
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Definition
a. pH- stomach (2), urine, vagina – helicobacter pylori
b. organic acids – sebaceous glands
c. lactoferrin – binds Fe
d. HCl- denatures proteins
e. Bile salts – membranefunction of bacteria
f. Spermine – polyamines found in sperm/seminal fluid (inhibit Gm+) |
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Term
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Definition
Epithelial Barriers
Gamma Delta T-Cell
B-1 Lymphocyte |
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Term
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Definition
Epithelial barriers
Peptide antibiotic
Phagocytes – ingest/kill microbes
neutrophils PMN’s
most abundant WBC
4,000-10,000/mL blood 20,000 in an infection
50-70% of differential
Leukocytosis = too many = infection
1st responders especially bacteria and fungi
Production stimulated by column stimulating factors (CSF) m-CSF, g-CSF, bone marrow
6 hour life
Granules
Enzymes, defensins
monocytes/macrophages
500-1000 cells/ cm2
Persist longer – months
Found in connective tissue and every organ in the body
T cell
Primitive T Cell
Serve as sentinels
Limited repertoire of antigen receptore
<5% T cells
B-1 lymphocytes
Intraperiotneally
IgM
recognize CHO agns |
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Term
| steps involved in recruiting leukocytes to local tissues |
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Definition
Macrophages recognize microbe and produce cytokines (TNF and IL-1)
Cytokines stimulate endothelial cells to express E and P-selectin
Circulating neutrophils and monocytes express CHO that bind to selectins
Neutrophils become tethered to endothelium, blood disrupts binding, so leukocytes on the endothelial surface
As the cells are rolling, tissue macrophages that encountered the microbe respond to TNF and IL-1 and produce chemokines
Chemokines stimulate rapid increase in affinity of leukocyte integrins for their ligands on the endothelium
Binding of integrins to their ligands stops the rolling, the cytoskeleton of the leukocytes is reorganized and the cells spread out on endothelial surface
Chemokines also stimulate motility of leukocytes
Leukocytes begin to migrate to site of infection |
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Term
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Definition
(a, b, c generated in phagolysosome)
ROI – H2O2, -O2-, O2, OH•
phagocyte oxidase – chronic pyramulomatous disease
formed in response to a microbe we can’t kill
TB – WBC’s form a wall around TV
Tissue necrosis
myeloperoxidase +H2O2 hyperchlorite
iNOS – inducible nitric oxide synthase
arginine NO
NF iNOS eNOS regulates Blood pressure |
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Term
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Definition
Lysosomal proteins
Cationic proteins-cathepsim
Lactoferrin – Fe binding protein
Protection against O2 reactions
SOD – superoxidase dismutase
Catalase |
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Term
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Definition
TNF, IL-1/6, Il-12. IFN8
responsible for communications between leukocytes and between leukocytes and other cells
hormones of IS
leukocytes, lymphocyes, endothelia cells, fibroblasts
Pleiotropic – multiple biologic activities
principle source is macrophages
Act on very specific receptor
non-promiscuous
overproduction = septic shock =bacteremia – bacteria in blood (too much = sepsis)
produced in small amounts
shock – low bp
septic shockTNF/IL-1, IL-6
cardiovascular
metabolic – glucose/lipid metabolism
DIC – coagulation pathway
poor organ perfusion multiple organ failure You’re Gonna Die
blood flow, O2 cells |
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Term
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Definition
Chemotactic cytokines
8-12 kd
2 internal disulfide bonds
2 classes = C-C & C-X-C
IL-8/GRO-1 (polys)
MCP – 1, 2, 3 (monocyte)
MIP-11B (monocyte)
Eotaxin – eosinophils
Help tether leukocytes to endothelium
Increase affinity of integrins (tethered to endothelium)
TNF/IL-1= increase expression of ligans for integrins
PECAM-1 (Platelet-endothelial cell adhesion molecule)
Gradient of chemokines
Immunodefiency diseases
leukocyte adhesion deficiency
don’t make enough adhesion molecules (E, P, intregrins, ligands)
always get infections
leukocytes can’t reach local site |
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Term
| Plasma mannose-binding lectin (MBL) |
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Definition
Recognizes microbial carbohydrates
Coat microbes for phagocytosis or activate the complement cascade by the lectin pathway
Acute phase response |
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Term
| Agns Recognized by B Cells |
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Definition
membrane bound agn receptors
proteins, PS lipids, NA membrane bound OR soluble agns |
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Term
| Agns Recognized by T Cells |
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Definition
ONLY PEPTIDE ANGTIGENS ASSOCIATED WITH MHC’S
T Cell receptor recognizes some residues of peptide antigen
MHC restriction – recognition of MY antigens |
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Term
| Events that lead to antigen capture |
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Definition
APC – process and present peptides to T-Cells
skin, respiratory, cut, blood
Langerhan cells = dendritic cells (epithelial)
phagocytose or pinocytose agns
respond to chemo- and cytokines
change confirmation and migrate to lymph
go to lymph for high concentration of T-cells
microbes enter the body
immature dendritic cells express membrane receptors that bind microbes
dendritic cells use recepotors to capture and endocytose microbial antigens
combination of cytokines and direct TLR signaling activates the dendritic cell, resulting in several changes in phenotype and function
activated dendritic cells lose adhesiveness and express surface receptors for chemokines
chemokines direct dendritic cells to migrate via lymphatic vessels to lumph nodes |
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Term
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Definition
Humans
Class 1 – HLA-A, HLA-B, HLA-C
All codominant
Class II – DP, DQ, DR
Class III – not surface MHC, code for cytokines (steroid synthesis, TNF, complement proteins)
Mice
Class I – K
Class II – DM, I-A, I-E
Class III – Same as humans |
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Term
| Diagram an MHC molecule and show the domains |
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Definition
Class I
2 polypeptides
chain – in MHC locus
microglobulin – (not coded in MHC locus)
3 domains in external portion of chain
peptide binding cleft, bind in floor, highly polymorphic
2 – disulfide bonds
immunoglobulin domain, invariant, binds to CD8
Transmembrane region – 25-30 aa
Class II
polypeptides
1 Peptide binding cleft
10-30 size will fit because it doesn’t have to fit inside cleft
Extremely polymorphic
binds to CD4 on THC
Invariant
Immunoglobulin doman
2 – invariant, hydrophobic
Can’t bind to CD4
3 domains in external portion of chain |
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Term
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Definition
present peptides to T-cells
only 1 peptide at a time per MHC
low affinity
peptides bind to MHC molecules during assembly
MHC – self/non-self |
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