Specific Acquired Immunity Flashcards
(49 cards)
1
Q
Antigen
A
Any substance or foreign particles that stimulate ur immune system to produce antibodies against it
2
Q
immunogen
A
Triggers specific immune response
3
Q
Epitope or antigenic determinant
A
Part of antigen recognized by antibody
4
Q
Tolerogen
A
Antigen that induces immunologic tolerance
5
Q
Allergen
A
Antigen that induces anaphylaxis
6
Q
Tumor antigens
A
- antigens presented by MHC I molecules on surface of tumor cells
7
Q
TSAs
A
- tumor specific antigens
- presented only by tumor cells & not normal ones
- result from tumor specific mutation
8
Q
Autoantigens
A
- normal protein or complex of proteins recognized by immune system of patients suffering from autoimmune disease
- under normal conditions, should not trigger immune response, but do due to loss of tolerance
9
Q
Not all antigens are _____ while all immunogens are ____
A
- immunogens; antigens
10
Q
Complete antigens
A
- proteins
- large
- capable of stimulating immune response
11
Q
Hapten antigen
A
- incomplete
- reacts w/ specific antibody, not immunogenic by itself
- made immunogenic by conjugation to carrier
- penicillin
12
Q
Endogenous antigen examples
A
- autoantigens
- tumor antigens
13
Q
2 good immunogens
A
- protein antigens
- polysaccharide antigens
14
Q
Weak to bad immunogens
A
- lipid antigens
- nucleic acid antigens
15
Q
T or F: Some glycolipids and phospholipids can stimulate T cells and produce CMI
A
True
16
Q
T or F: Nucleic acid antigens can become immunogenic when single stranded or complexed w/ proteins
A
True
17
Q
T-dependent antigens
A
- don’t directly stimulate antibody prod. w/o T cells
- example: microbial proteins
18
Q
T-independent antigens
A
- directly stimulate B cells to prod antibodies w/o T cells
- prod. almost only IgM
- no secondary response
- example: pneumococcal polysaccharide
19
Q
Superantigens
A
- cause excessive activation of immune system
- non specific activation of t cells causing polyclonal T cell activation and massive cytokine release
- produced by pathogens as a defense mechanism agains immune system
- example: staph and strep
20
Q
Conventional antigen
A
- stimulate production of monoclonal/oligoclonal t cell response
21
Q
Properties of immunogens that influence immunogenicity
A
- foreigness: discrimiation between self and non self
- molecular size: bigger=stronger, smaller=weaker or non-immunogenic
- chemical composition: more complex= more immunogenic
- physical form: particulate antigens more immunogenic than soluble; denatured antigens more potent than native
- susceptibility to antigen processing and presentation: easily phagocytosed=more immunogenic
22
Q
Biological system on host (influence on immunogenicity)
A
- genetic factors: patient lack/have altered genes code for receptors for antigens on B and T cells; may not have appropriate genes for APC to present antigen to helper t cells
- age
23
Q
Method of administration (factors that affect immunogenicity)
A
- dose: above or below= not optimal
- route: SQ and IM= more potent compared to IV and IG
- adjuvants
24
Q
Humoral immunity
A
Prod. of antibodies when antigens present and mediated by B lymphocytes
25
CMI
Prod. of cytotoxic T cells, activated macrophages, activated NK cells, and ctyokines in response to antigen
Mediated by t-lymphocytes
26
Adjuvant
- example: Aluminum-potassium sulfate
27
Jules freund (1930)
- freund’s incomplete adjuvant
- freund’s complete adjuvant
28
Freund’s complete adjuvant
- emulsion of h2O and mineral oil containing heat-killed mycobacteria
- stimulates production of TH1 cells
- administered @ early stage of immunization program
- rapid and immediate response
- can lead to development of disease in immunocompromised patients
29
Freud’s incomplete adjuvant
- emulsion of H2O and mineral oil w/o added mycobacteria
- stimulates production of Th2 cells
- administered @ later stage of immunization (usually for boosters after initial injection w/ complete adjuvant)
- slow response
- hard to formulate with antigen during vaccine prep.
30
Heat labule enterotoxin B (LTB)
- intramolecular adjuvant
- E. Coli version is strong mucosal adjuvant and immunogen; can be used as subunit vaccine candidate against ETEC-induced diarrhea
31
CD4
- glycoprotein co receptor for T cells
- found on APCs and helper t cells
32
CD8
- transmembrane glycoprotein
- co-receptor for TCR
- role in cell signaling, aiding w/ cytotoxic T cell-antigen interactions
33
CD3
- protein complex
- activated CD8+ and CD4+
34
Alpha/beta T cells-> CD4+ T cells ->…….
Th1, Th2, Th17, Treg
35
Th1
- produces: IFN-g, IL-2, TNF-b
- act on CD8+, T cell, NKs, Monocytes, B cells (Ig3)
- enhances cell-mediated cytotoxicity
36
Th2
- Produces IL-4, IL-5, IL-13
- act on eosinophils, B cells (IgE, Ig4)
- respond to worms and allergens
37
Th17
- act on neutrophils and eosinophils
- proinflammatory; response to extracellular bacteria and fungi
38
Treg
- produces TGF-b, IL-10
- acts on other lymphocytes
- inhibits function of T & B cells, dendritic cells, etc
39
Exogenous antigens assc w/ CD___ and class ___
CD4+; Class II
40
Endogenous antigens assc w/ CD___ and Class __
CD8; Class I
41
High IgM can mean
Potential current primary infection
42
Antibody functions during infection
- neutralization/ microbial binding
- cytotoxicity against virus infected cells
- opsonization
- complement fixation
- mast cell degranulation
43
IgG
- Major Ig in serum and formed in secondary responses
- escapes into extravascular spaces easily
- opsonize, agglutinate, and precipitate antigen
- increased amt in sera after initial lag after first immunization
- different in secondary responses
44
IgM
- 1st antibody formed in newborn vertebrates
- 1st/major Ig in primary immune response
- abt 900,000 daltons
- pentamer w/ j protein
- second highest in serum conc.
- intravascular, efficient in complement activation, etc.
45
IgA
- dimer w/ j protein
- minor serum component
- major Ig in external secretions in non-ruminants (IgG1 in ruminants)
- protects mucosal surfaces, mammary glands, eyes
- doesn’t activate complement system & isn’t opsonin
46
sIgA (secretory IgA)
- IgA secreted by plasma cell in mucosa & binds to receptor on epithelial cells
- protects IgA from proteolytic enzymes and facilitates sIgA into secretions
- in intravascular and secretions
47
IgD
- on membrane of B lymphocytes
- sensitive to proteolytic enzymes
- precise function unknown
- low concentration in serum
- role in antigen-triggered clonal prolif.
48
IgE
- Type I hypersensitivity
- binds mast cells and basophils & with antigen release vasoactive amines (histamine, serotonin)
- anti-parasitic immunity
- nasal secretions and saliva
- increased conc. In atopic skin diseases
49
IgY
Avian egg yolk
