3A, 3B Flashcards
Only part of an organism (binds)
ANTIGEN
Self- or Non-self
o Presence and absence in the host
ANTIGEN
Pathogenic or Non-pathogenic
o Exposure to pathogen = INFECTION
o ALLERGIC RX ≠ INFECTION
ANTIGEN
Primary function: To bind Ags
ANTIGEN
AB-generator [both binds (antigenic) to and forms (immunogenic) AB]
ANTIGEN
AG binds to AB
Antigenicity
causes AB formation
Immunogenicity
Antigenic determinants
o Foreign proteins
o Viruses, bacteria, parasites, fungi
Epitope
Responsible for doing the two basic properties of an AG .
Very small (4 to 5 polysaccharide units)
Epitope
An AB is created against this epitope but not to the entire microorganism
Paratope
Antibody determinants
Paratope
cause AB formation - substance
Immunogen
Carrier/ Schlepper Molecules
↓MW (IS doesn’t actually react)
Partial AG
Hapten
↑MW – AB production
Complete AG
Carrier/ Schlepper Molecules
o Can cause damage to the body due to ↑MW
Carrier/ Schlepper Molecules
Carbohydrate and lipids (nonprotein)
Hapten
Protein (most complex biomolecule – heavy)
Carrier/ Schlepper Molecules
With own epitopes
Carrier/ Schlepper Molecules
Ex.: Albumin, polypeptide, globulin
Carrier/ Schlepper Molecules
Ex.: Penicilin; Dinitrophenol
o Can bind to an available AB
Hapten
Glycoproteins
ANTIBODY or IMMUNOGLOBULI N (Ig)
Bind AGs; interacts with AG
ANTIBODY
– plasma cells
AB + WBC (surface)
o B cells
– coating during phagocytosis
o Opsonins
Phagocytosis site
o Liver and spleen
Entry of water =
EXPLOSION/LYSIS
Extravascular destruction of cells
Phagocytosis
Intravascular destruction of cells
EXPLOSION/LYSIS
Surface
Complement
Protein in nature ↑MW Immunogenic and antigenic
Carrier
Nonprotein in nature ↓MW Antigenic
Hapten
(complete AG on its own)
Carrier
(incomplete AG)
Hapten
Carrier + Hapten
Complete Antigen
Immunogenecity + Antigenecity
Can bind to AB
Can cause AB formation
Complete Antigen
ANTIGEN
Ex. Complete Antigen
(heavy; both immunigenic and antigenic)
Carrier/ Schlepper Molecules
Addition of a carrier mol (dinitrophenol + penicilin) → (artificial addition of) EPITOPES
Complete Antigen
Hapten only
Incomplete Antigen
Ex. Incomplete Antigen
(light; antigenic only)
Hapten
Addition of a carrier mol (dinitrophenol + albumin) → COMPLETE AG OR COMPLEX HAPTEN (becomes visible)
Incomplete Antigen
Incomplete Antigen types
- Simple or precipitating
- Complex or nonprecipitating
(not visible; soluble AG)
- Simple or precipitating
(visible; insoluble AG)
- Complex or nonprecipitating
Ex. Body fluids (Saliva) – becomes visible via serologic staining
Incomplete Antigen
Precipitins
Soluble ag
IgM
Agglutinins
Insoluble ag
IgG
Soluble AG (small)
Precipitins (clumps)
IgG
Precipitation
Insoluble AG (large)
Agglutinins (aggregates)
IgM – most efficient
Agglutination
Seen in plasma, serum, body fluids, and cell surfaces
ANTIBODY
Seen in plasma, serum
IgA1
Seen in body fluids
IgA2
S IgA
WBC with a surface AB
B CELL
Can undergo transformation to become PLAMA CELLS
B CELL
Produces AB
No surface Ig
Has a very large cytoplasm with ABs ready for production
PLAMA CELLS
Are the only WBC with AB on their surfaces
B CELL
Binds plasma cells to plasma cells to inhibit their movement into the cells
Neutralize toxic substances
Serve as OPSONINS
ABs alone cannot kill the microorg. – only function is to bind to AGs
Facilitate phagocytosis and kill microbes
o Substances that coats the microorg. during phagocytosis (self-eating)
o Includes ABs, that binds to microorg. to enhance phagocytosis
OPSONINS
2 ways of microbial killing:
- Extravascular destruction
- Intravascular destruction
microorg. coated by an AB will be used by macrophages to enhance engulfment of microorg.
Extravascular destruction
AB is used as a lubricant or OPSOSNINS to coat microorg
Extravascular destruction
Exposure of microorg.
Extravascular destruction
Happens outside the BV
Extravascular destruction
AB coats the microorg. → microorg travels toward the LIVER and the SPLEEN → macrophages kills microorg coated by ABs (PHAGOCYTOSIS)
Extravascular destruction
microorg. coated by an AB will be used by protein complements system to puncture the surface of microorg
o Blood = 90% water
o Puncture → entry of water → large volume entering → LYSIS or EXPLOSION
Intravascular destruction
Happens inside the BV
Intravascular destruction
AB activates the complement pathway to break surfaces of the microorg = LYSIS
Intravascular destruction
long: 450 amino acids
Heavy chains
short: 220 amino acids
Heavy chains
Light chains ratio
65% : 35%
2:1
α – alpha
γ – delta
δ – gamma
ε – epsilon
µ – myu
Heavy chains
κ – kappa
λ – lambda
Light chains
FIRST (?) AA ARE VARIABLE
110
Intrachain
Interchain
Disulfide bonds
Disulfide bonds
– flexibility
– defective
– in urine
PROLINE
MULTIPLE MYELOMA
BENCE JONES PROTEIN
a – amino group, variable
Fab fragment
c – carboxylic group, constant
Fc fragment
special sections of AB molecules
DOMAINS
Domains
- L : 2 – VL, CL
- H : 4 – VH, CH, CH2, CH3
- H : 5 – VH, CH, CH2, CH3, CH4, CH5
- C
- V
- L : 2 – VL, CL
- H : 4 – VH, CH, CH2, CH3
- H : 5 – VH, CH, CH2, CH3, CH4, CH5
- C
- V