5.1. Introduction To The Immune System Flashcards

1
Q

Bone marrow

A

Site of production of myeloid cells, natural killer cells & B and T lymphocytes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Thymus

A

Immature precursors of T lymphocytes migrate from bone marrow to thymus and complete development there

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Anatomical physical barriers

A

Epithelium of skin
Alimentary tract
Respiratory tract
Urigenital tract

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q
Mechanical factors 
(I.e. fly swatters)
A

Associated mucous secretions and ciliated cells
Secretions of tears
Flushing action of urine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Biochemical factors

I.e. Doom

A

Secretion of lysozyme one tears
HCl of stomach
Antimicrobial substances

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Microbial factors

A

Commensal bacteria

Other microorganisms

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Commensal bacteria

A

Own body flora (skin, stomach lining etc.)

-> pathogenic bacteria cannot get through

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Innate immune cells

A
Macrophages 
Neutrophils, 
eosinophils 
Basophils
Mast cells 
Natural killer cells
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Opsonin

A

Any molecule that enhances phagocytosis by tagging a pathogen/ microbe, or dead cells for recycling

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Mannose R

A

Receptor to mannose

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

LPS R

A

Lipopolysaccharide receptor

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

TLR

A

Toll like receptor

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

FcR

A

Receptor to Fc (constant region) portion of antibody

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

NLR

A
  1. Nod-like receptor
  2. Recognizes molecules released by damaged cells
    E.g. ATP
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

PAMPS

A

Pathogen molecular patterns on microbes

E.g. LPS (receptors are Toll like receptors: TLRs)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

DAMPs

A

Damage associated molecular patterns

E.g. uric acid, ATP (receptors are NOD like receptors: NLRs)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

CR

A

Complement receptor

- CR recognizes 3b on surface

18
Q

Phagocytes

A

Cells that protect the body by ingesting (phagocytosing) harmful foreign particles, bacteria, and dead or dying cells

19
Q

Phagolysosome

A

Phagosome fuses with lysosome

20
Q

Oxygen dependent

A

(Respiratory burst)

  1. NADPH oxidase in phagolysosome membrane converts O2 into superoxide O2
  2. This is converted into hydrogen peroxide by superoxide dismutase (SOD)
  3. Myeloperoxidase and chloride produce hypochlorite (HOCl)
21
Q

Oxygen independent

A

(Enzymes & toxic molecules)

1. Lysozyme, nucleases & proteases degrade pathogens/ antigens

22
Q

Process of phagocytosis

A
  1. Phagocyte adheres to pathogens or debris
  2. Phagocyte forms pseudopods that eventually engulf the particles, forming a phagosome
  3. Lysosome fuses with the phagocytic vesicle, forming a phagolysosome
  4. Lysosomal enzymes digest the particles, leaving a residual body
  5. Exocytosis of the vesicle removes indigestible & residual material
23
Q

Humoral component

A

Complement acute phase proteins

24
Q

Complement

A
  1. A group of proteins that are produced by the liver & circulate i. The blood
    - numbered in the sequence that they were discovered e.g. C1, C2
  2. Infection activates complement pathways that cut complement proteins into fragments
    - act as chemo-attractants e.g. C3a, C5a
    - opsonins e.g. C3b
    - forms the membrane attack complex (MAC) (C5b678 and multiple 9) which forms a pore in the pathogen/ microbe wall and lyses the cell
25
Q

Acute phase proteins

A

Proteins made by liver in response to activated macrophages and neutrophils

  • CRP
  • MBL
26
Q

CRP

A

C reactive protein

27
Q

MBL

A

Mannose binding lectin

28
Q

Adaptive immune response

A
  1. This is the response of lymphocytes each with its own unique receptor that are specific for either a peptide associated with a MHC protein (T cell) or epitope on the pathogen/ microbe (B cell)
  2. Consists of:
    - B lymphocytes
    - T lymphocytes
  3. Selection of antigen-specific lymphocytes occurs - only fe lymphocytes will have receptors that specifically recognize the peptides from pathogens/ microbes presented on MHC or epitope on exterior surface of pathogen/ microbe
  4. Now these lymphocytes need to proliferate to produce a clone
  5. Hence the adaptive response is delayed
  6. Memory cells are produced that give an immediate and stronger response to a second exposure to pathogen/ microbe
29
Q

B lymphocytes

A

Have B cell receptors (BCR)

30
Q

T lymphocytes

A

Have T cell receptor (TCT)

31
Q

Lymph nodes

A

Excess extra cellular fluid with pathogen/ microbe from ECM drains to it and dendritic cells carry engulfed pathogen/ microbe to it and there meet circulating naive lymphocytes

  • monotreneal tissues
32
Q

Spleen

A

Pathogens/ microbes present in blood are trapped here by resident macrophages and dendritic cells and they activate naive lymphocytes entering via blood vessels

33
Q

MALT

A
  • mucosa associated lymphoid tissue
    1. Pathogens/ microbe entering through mucosa are engulfed by resident dendritic cells which then activate naive lymphocytes in the mucosa
  • tonsils
  • Peyers patches
  • appendix
34
Q

Naive B cells

A

Activated by binding of microbe/ pathogen to BCR

35
Q

Effector CD4 T cells

A

Further activate naive B cells

36
Q

Antibodies

A
  1. Secreted BCR
  2. Bind to specific epitope on its antigen:
    Pathogen/ microbe
  3. Different classes have different constant regions which determine their function
  4. Act as opsonin or activate classical complement pathway
37
Q

TCR-CD8 T cells

A

Cytotoxic

38
Q

TCR-CD4 T cells

A

Helper

39
Q

Adaptive immune response: T cells

A
  1. Each T lymphocyte has its own unique TCR made from rearranges gene segments
  2. They have a co-receptor CD4 or CD8
  3. The CD8 T cells are the cytotoxic T cells
  4. The CD4 T cells are divided up into helper and regulatory T cells
40
Q

Naive T cells

A

Activated by dendritic cells in secondary lymph organs to become effector T cells

41
Q

Effector T cells

A

Perform the cellular functions of the adaptive immune response:

  1. CD8 T cells kill infected body cells
  2. CD4 T cells
    - activate dendritic cells to activate CD8 T cells more efficiently
    - activate macrophages to be better killers
    - activate B cells to become plasma cells and secrete antibodies
42
Q

Immunological synapse

A
  1. Cell to cell interaction between body cells or antigen presenting cells, and T cells
  2. This is how naive CD8 and CD4 T cells are activated by dendritic cells
  3. This is how effector CD8 T cells recognize the cell to kill
  4. This is how CD4 T cells activate macrophages, dendritic cells, and B cells to become plasma cells