Adaptive immunity Flashcards

1
Q

immune memory consists of

A

T and B lymphocytes

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

T cells and antibodies can

A

recognise infinite number of targets

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

when does the adaptive system kick in

A

2-4 days after

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

adaptive immune system is specfic

A

to the given organism

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

why is the adaptive immune system useful

A

it is rapidly protective on re-exposure from the same infectious agent

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

property of the adaptive immune system

A

forms basis for the protective effects of vaccination

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

antigen

A

any molecules or part of a molecule recognised by the variable antigen receptors of lymphocytes are known as antigens

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

what does a vaccine do

A
  • Priming the body for a pathogen
  • Ability of body to remember an infectious agent to which it has been exposed – basis for natural and artificial immunity
  • initiates production of memory cells
  • they will recognise agent an produce massive number of lymphocytes and immunoglobulins that overwhelm invaders
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

founding father of immunology

A

Edward Jenner

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

E Jenner

A
  • Observed that naturally occurring pustualar eruptions on the teats of cows could be transferred to the hands or arms of milkers but they had natural immunity against smallpox
    o Demonstrated that injecting fluid from cowpox pustules into skin of children led to acquisition of a high degree of immunity to smallpox
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

the lymphatic system provides

A

a critical interact bw activated dendritic cells and lymphocytes

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

Lymphocytes enter the…

A

lymphoid tissue to be activated by dendritic cells

-return to the bloodstream though the lymph if not activated

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

what controls migrations through lymphoid tissue and cellular interactions

A

guided and controlled by adhesive cell surface molecules whose expression is regulated by cytokines and chemokine

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

name 4 innate granulocytes

A
neutrophils
eosinophil
basophil
monocyte
dendritic cell
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

name 2 cells of the adaptive immune system

A

B lymphocyte (matures in bone marrow)

T lymphocyte (matures in thymus)

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

name some lymph tissue

A
  • adenoid
  • tonsil
  • lymph node
  • thymus
  • heart
  • thoracic duct
  • spleen
  • Peyers patch in small intestine
  • appendix
  • large intestine
  • bone marrow
  • lymphatics- e,g. in legs
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

how do T lymphocytes recognise antigens?

A

via T cell receptors generated during their differentiation- they interacts wit AMPCs via complementary ligand

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

each T lymphocyte expresses an antigen receptor of only

A

one specificity- whole population of lymphocytes is collectively capable of recognising any antigen

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

describe the structure of the T cell receptor

A
  • transmembrane
  • invariant constant (c) region- closest to the membrane and the same in all T cells
  • V variable regions made up of an alpha and beta chain and different in all T cells
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

what are Clusters of Differentiation

A
  • major classes of T cells often referred to as CD4 and CD7
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

CD4

A

a marker of helper T cells- MHCII

22
Q

CD8

A

a marker of cytotoxic T cells- MHC I

23
Q

MHC are

A

co-receptors that plan an important role in signal transduction on antigen bind by T cells

24
Q

dendritic cells

A

play a crucial role in activating the adaptive immune system

25
Q

dendritic cells begin life

A

as a phagocyte but activated by conserved components of micro-organism of by inflammatory cytokines released by macrophages

26
Q

once activated dendritic cells become dedicated to

A

displaying components of ingested micro-organism for recognition by naive T cells and subsequent differentiation of naive T lymphocytes into effector T cells

27
Q

T lymphocytes role

CD8T+/cytotoxic T cells

A

kill viruses, infected and cancerous cells

28
Q

T lymphocyte role

CD4+

A

activate other cells of the immune system

29
Q

B lymphocytes

A

secrete immunoglobulins

30
Q

lymphoid lineage

A

cellular differentiation

31
Q

mature lymphocytes which have no yet encountered antigen are known as

A

naive lymphocytes

32
Q

how Naive cells differentiate

A

differentiation into effector cells is stimulated by encounter with antigen and preceded with a vigorous proliferation that selectively expands the numbers of those lymphocytes with receptors specific for the inducing antigen.
clonal expansion of antigen-specific lymphocytes

33
Q

where do T helper cells and cytotoxic T cells fully mature

A

peripheral tissue- äter stimulation in lymphoid tissue by dendritic cells

34
Q

Natural Killer cells

A

Lymphoid lienage contains third major cell type which lacks antigen-specific receptors and is capable of killing virus-infected cells immediately without prior activation or clonal expansion.

Regarded as part of INNATE immune system- don’t need prior activation.

35
Q

activation of NK cells

A

occurs via binding of activated receptors to surface molecules produced by cell damage e.g. cancer or those encoding infectious viruses

36
Q

what stimulate the lymphoid pathway

A

cytokines

37
Q

describe the lymphoid pathway

A
  • Move into either blood stream or thymus (thymocytes- a nursery for T cells)- then move into the blood cell as mature but naïve helper T cells, then migrate to secondary lymphoid tissues and wait to receive info from dendritic tissues)
  • Dendritic cells go straight from bone marrow into the blood and then to the secondary lymphoid tissue where is interacts with T cell
38
Q

where are dendritic cells numerous

A

epithelial and mucosal surfaces

39
Q

langerhans

A

o first recognised in the skin in the 19th century. They are as a subset of dendritic cells that reside in the keratinised epidermis for several months

40
Q

Second population of skin-resident dendritic cells is found in the dermal layer - known as

A

dermal dendritic cells

41
Q

in mucosal epithelium of the gut

A

dendritic cells are concentrated are specialised sites of antigen collection which overlie lymphoid tissues

42
Q

some cells of the mucosal epithelium of the gut

A

have specialised surface properties that enable them to extend their long dendritic processes between the cells of the epithelium and into the lime to sample antigens
–> these cells are directly exposed to ingested antigens and to commensal bacteria

43
Q

processes of the dendritic cell (in the mucusal epithelium)

A

have a specialized role in preventing inflammatory responses to harmless gut residents

44
Q

summary of activation of the adaptive immune system

A

1) dendritic cell displays a component of microorganism for recognition by T cell bearing a receptor for that component
2) stimulates it to proliferate and differentiate into effector cell
3) when effector cell recognised the same antigen displayed on the surface of B cell, the T cell activates the B cell
4) B cell proliferates and secretes antibodies that recognised the micro-organism

45
Q

T cell targeting

A

Unlike B cells whose surface immunoglobulin molecules are adapted to serve as antigen receptors, T cells are unable to interact directly with intact antigen so must interact with other cells of the immune system.

46
Q

who do T cells know which cells to interact with

A

T cells are focused on their target cell by MHC molecules
- which carry fragment of antigen (usually peptide fragments of proteins) fro internal compartments of the target cell surface and display them for recognition by T cells

47
Q

all naive T cells are

A

activated by antigen fragments displayed on MHC molecules on the surface of Dendritic cells
- after activation they are triggered to kill or activate cells displaying the same complex of MHC and antigen

48
Q

which cells have MHC molecules

A

dendritic cells

49
Q

who discovered that MHCs were related tot he rejection of skin grafts

A

Peter Medawar (1944)

50
Q

Peter Medawar

A

Became a clinical immunologist because of WWII - the large number of burns victims presented an opportunity to research skin graft rejection. Established that the timing and vigor of rejection is
related to the degree of differences between histocompatibility antigens of donor and recipient.
- Differences in the MAJOR HISTOCOMPATIBILITY
COMPLEX result in rejection within the first week
- Differences in the MINOR HISTOCOMPATIBILITY
COMPLEX result in a slower rejection process.

Medawar’s work led the way to the routine use of tranplantation. Matching of major histocompatibility antigens, at times with the use of immunosuppressants, means that kidney, lung and heart transplants are now commonplace.