POST LAB EXP 4 and 5 Flashcards
adherence
PHYSICAL CONTACT
– squeezing of blood vessel walls; non-directional
Diapedesis
– directional
Chemotaxis
– associated with groups of pathogens; Innate immune system
Pathogen Associated Molecular Patterns (PAMPS)
- recognize and adhere to pathogens
Pattern Recognition Receptors (PRRS)
blood and lymph
Secreted PRRs
circulating that binds to PAMPs
Secreted PRRs
triggers the complement cascade leading to opsonization
Secreted PRRs
Binds to pathogen leading to release of effector molecules (cytokines)
Phagocytosis Receptors
recognize PAMPs with mannose
Phagocytosis Receptors
set of transmembrane receptors
Toll-like Receptors
Toll-like Receptors found in:
MACs, DCs, epithelial cells
fruitfly Drosophilia: antifungal
Toll-like Receptors
Toll-like Receptors inc conc:
monocytes, MACs, neutrophils
ingestion
FORMATION OF PHAGOSOME
phagosome + lysosome = PHAGOLYSOSOME
FUSION OF PHAGOLYSOS OME
respiratory burst
DIGESTION
failed phagocytosis (innate/1st line of defense)
PHAGOCYTIC
CAPABILITY
20 –
lymph nodes (bacteremia), thymus
10 –
bone marrow; spleen
Automated system for identifying cells based on light scattering
CELL FLOW CYTOMETRY
Segmented lymphocytes; labelled Abs
FLOW CYTOMETRY
Chronic granulomatous disease and Leukocyte adhesion deficiency
FLOW CYTOMETRY
NITROBLUE TETRAZOLIUM TEST
: reagent
NBT
Deep blue
NITROBLUE TETRAZOLIUM TEST
Colorless WBC - CGD
NITROBLUE TETRAZOLIUM TEST
CHEMICAL NATURE
excellent antigens
Proteins
High MW and structural complexity
Proteins
Less immunogenic than protein
Polysaccharides/Carbohydrates
Relatively smaller
Polysaccharides/Carbohydrates
considered too small to function as antigens
Polysaccharides/Carbohydrates
B cells do not recognize
Polysaccharides/Carbohydrates
Antigenic if linked w/ proteins
Lipids
Inferior Ag
Lipids
Relative simplicity
Lipids
Lack of structural stability
Lipids
Poor antigens
Nucleic acids
Relative simplicity, molecular flexibility, and rapid degradation
Nucleic acids
Easily degradable
Nucleic acids
– degree to which antigenic determinants are recognized as non-self by an individual’s immune system
Foreignness
↑ foreign
↑ immunogenic
↓ degradable
↑ immunogenic
For an antigen to be recognized as foreign by an individual’s immune system, sufficient antigens to stimulate an immune response must be present
DEGRADABILITY
↑ MW
↑ immunogenic
the better the molecule will function as an antigen.
The higher the MW,
The number of antigenic determinants on a molecule is directly related to its size.
MOLECULAR WEIGHT
↑ stable
↑ immunogenic
If a molecule is an effective antigen (?) is mandatory
structural stability
(e.g., gelatin),the molecule will be a poor antigen
structural stability
the greater is its effectiveness
COMPLEXITY
substance that stimulates antibody formation
Antigens
Antigens ex
protein, lipids, polysaccharides, nucleic acids
macromolecules capable of triggering an adaptive immune response by inducing the formation of antibodies or sensitized T cells in an immunocompetent host\
Immunogens
Immunogens ex
protein, large polysaccharides
Antigenic but not immunogenic
Hapten
a low-molecular-weight, nonantigenic substance that, when combined with an antigen, changes the antigenic specificity of that antigen
Hapten
a. According to relation to host
b. According to how the antigens are found in the body
c. According to their ability to stimulate immune response
d. According to serologic behavior
– same individual
Autologous
– identical – of the host
Syngeneic
–same species
Allogeneic/homologous/isoantigen
– animals
Xenogeneic
– unrelated plants and animals
Heterophile
cross-reacts with Abs
Heterophile
– different species giving the same response
Heteroantigen/Heterogeneic
- hidden antigens; not capable of inducing self-tolerance
Sequestered
– characteristic of one tissue/cell; associated with autoimmunity
Tissue-specific
– MHC/HLA
Tissue type
– ABO, Rh
Blood group
- protein; indirect stimulation
T-dependent
- polysaccharide; direct stimulation
T-independent
– able to elicit T-cell responses by circumventing normal Ag processing and presentation functions
Super antigens
ability to bind to invariant region of Class II
Super antigens
B- chain of the B cell Ag receptor
Super antigens
with 3 constant domains
IgG. IgA, IgE
pentamer
IgM
complement fixation
IgG. IgM
secretons
IgA
a. According to relation to the host
b. According to production in immune response
c. According to serologic behaviour
d. According to temperature reaction
– react with many RBCs
Polyagglutinin
– react against all reagent cells in an Ab panel rather specific cells
Panagglutinin
– formed after exposure to environmental agents
Naturally-occurring
– sensitization (transfusion, pregnancy)
Immune
– streptolysin O and S
Hemolysin
Warm reacting –
IgG
Cold reacting –
IgM
e. According to biologic fixation
f. According to clonal production
– against viral surface Ags
Neutralizing antibody
– mast cells/basophils and eosinophils
Allergic/reaginic antibody
heavy chain
a. Isotypes
constant chain
b. Idiotypes
variable regions
c. Allotypes
main Ab directed
a. Classical
with Ab
b. Alternate
c. Mannose-binding lectin
early defense
b. Alternate
Excess Ab; Serum dilution
Prozone
Excess Ag; Repeat test
Postzone
has the ability to bind to an antibody or a T lymphocytes antigen receptor
Antigens
may not be able to evoke an immune response initially (e.g., haptens)
Antigens
