Intro immunology Flashcards
1
Q
cause of type 1 diabetes
A
destruction of insulin producing B-cells
2
Q
what is autoimmune disease
A
adaptive immune response that becomes directed at self
3
Q
what is normal function of immune system
A
distiguish self from non self and destroy non-self
4
Q
what are 2 lines of innate defence
A
- anatomic
2. chemical/cellular
5
Q
what are 2 anatomic defecnes
A
- physical barriers (skin)
2. mech. barriers (sneeze etc.)
6
Q
what are 5 C’s of second line of defence
A
- cellular
- cytokines - chems that make cells do things
- complement - help other systems
- chemokines - chemicals that cause cells to migrate
- coagulation -
7
Q
what are cells involved in cellular defence
A
granulocytes, monocytes, NK cells
8
Q
3 keys points to innate immunity
A
- early recognition
- non-specific
- Activatyion leads to killing, cytokine release, connects to adaptive
9
Q
how does macrophage recognize a pathogen
A
TLR-4 Toll like receptor on surface can recognize pathogen
10
Q
what does phagocytosis lead to
A
- degradation in lysosome
- display of antigen on cell surface
- induction of pro-inflammatory cytokines
11
Q
3 important non WBC innate cells
A
- mast cells - early sentinels
- polymorphonuclear cells - main job to phagocytose
- NK cells - early viral defense
12
Q
what are 3 functions of complement cascade
A
- tag pathogen for phagocytosis (opsinization)
- promote inflammation
- poke enzyme holes in pathogen to kill
13
Q
main function of adaptive immunity
A
refine and strengthen system
14
Q
when does adaptive system come into play
A
when innate does not terminate
15
Q
2 main cells of adaptive system
A
B and T cells
16
Q
2 main types of T cells
A
humoral and cell mediated
17
Q
2 types of adaptive immunity
A
- humoral - B-cells
2. cell mediated - T-cells
18
Q
where do B cells develop
A
in bone marrow
19
Q
what happens when B cells contact antigen
A
proliferate into plasma cells that secrete antibodies
20
Q
where do T cells come from
A
produced in bone marrow and mature in thymus
21
Q
what happens when T cell comes into contact with antigen
A
proliferate into effector T cells
22
Q
how many antigens can lymphocytes respond to
A
one - all clones
23
Q
what is B cell receptor
A
immunoglobulin that will be expressed as the ultimate antibody
24
Q
what keeps BCR bound
A
trans membrane protein
25
what are 2 functional divs of BCR
1. variable region (what binds)
| 2. constant region
26
what is make-up of BCR
2 heavy and 2 light chains
27
what is antibody
BCR without tail attaching
28
what must a TCR have to work
co-receptor (CD4 or CD8)
29
how does TCR see antigen
peptide in form of MCH on antigen presenting cell
30
where are 2 classes of MHC molecules found
1. most nucleated cells
| 2. antigen presenting cells
31
what are co-receptors for to MHC classes
1. CD8
| 2. CD4
32
what is the function of the MHC protein
define the cell as self
33
what is a haplotype
our unique set of MHC genes
34
where does our haplotypes come from
one allele from each parent
35
what is T cell MHC restriction
only recognize peptide antigen in the scaffold of self MHC
36
what is T cell positive selection
in thymus, T cells can only continue to develop if they recognize self MHC on nearby stromal cells
37
what are specifc and non-specific parts of antibody
specific - variable region that bind pathogen
| non-specific - constant region that bind to receptor on immune cells
38
what does antibody opsiniization do
make the antigen more delicious and easy to phagocytose
39
what are (4) CD4 helper t-cells and functions
Th1 - intracellular pathogens - produce cytokines to activate macros
Th2 - extracellular pathogens - produce cytokines for humoral immunity
Th17 - extracellular bacteria - implicated in autoimmunity
Treg - regulatory
40
CD8 functions
direct killing
41
how does immune system have memory
keeps some surviving memory cells that can be quickly reactivated
42
what is diversity
ability to respond to many different organisms
43
most important way to generate diversity
production of B and T cell receptors
44
how is TCR made unique
somatic recombination of the variable region
45
what does this recombination create
each lymphocyte as a unique receptor
46
what is problem with random recombination
can potentially make a receptor for self antigen
47
at what level does tolerance occur
level of adaptive immunity
48
where does tolerance occur for T and B cells
B -bone marrow
| T - thymus
49
what is method of B cell tolerance
negative selection - if recognizes self - terminated
50
what are steps for T-cell tolerance
1. postive selction - keeps cells that recognize self MHC
2. negative selection - elim cells that recognize self-peptides (too tight)
3. peripheral mechanisms to deal with ones that escape
51
what is main function of inflammation
enables immune cells to come to infected tissue rapidly
52
problems with inflammation
causes tissue damage and if not fixed can cause irreparable damage
53
what CAN cause chronic inflammation
autoimmunity - presence of non-infectious antigens that are stimulating an immune response
54
what does autoimmunity develop from
failure to develop tolerance mechanisms
55
2 types of mechanisms that contribute to self-tolerance
1. central
| 2. peripheral
56
3 features of central mechanisms for self-tolerance
1. negative selection
2. expression of tissue specific proteins in the thymus
3. generation of Treg cells
57
3 features of peripheral mechanisms for self-tolerance
1. suppression of autoimmune responses by Treg cells
2. induction of anergy in autoreactive cells
3. immune privledge
58
how are tissue specific proteins expressed in the thymus
dendritic cells carry "systemic" antigens to thymus via soluble serum proteins
59
what is gene that enables thymic cells to to produce self-proteins
AIRE gene - internal image of self
60
what do Treg cells do
inhibit T cells and effector T cells that recognize self antigen
61
what other regulatory cells exist
B cells and for most other immune cell subsets
62
what 2 things are requires for naive T cell activation
1. antigen specific stimulation
| 2. costimulation signal
63
how does T-cell become anergic
lack of costimulations
64
what happens in anergy
functional unesponsiveness
65
what is immune privledge
tissues that have evolved to be protected from the immune system
66
what tissues have immune privledge
brain, eye, testes, placenta, fetus
67
what are 2 mechanisms of immune privledge
1. mechanical factors - barriers
| 2. active factors - immunosupressive molecules
68
when is immune privledge a problem
when exposed, they do not have self antigen and are seen as foreign
69
5 general concepts in autoimmunity
1. results from failure of T and B cells to develop tolerance
2. main contributing factors are genetics and env. triggers
3. various effector mechanisms are responsible for tissue damage
4. may be systemic or organ specific
5. tend to be chronic and progressive
70
5 main types of T cells
1. helper
2. cytotoxic
3. memory
4. regulatory
5. natural killer
71
what are the effector mech in autoimmunity (2)
same as regular attack
1. chronic inflammation
2. interference with tissue function
72
4 types of autoimmune reactions
1. autoantibodies against self
2. antigen immune complexes deposited in organs
3. autoreactive T cells against self
4. combo of the above
