Blood Cell production Flashcards

1
Q

What is haematopoiesis?

A

The production of blood cells

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

The cell lifespan - are these different between cells in the blood?

A

Yes

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

How long do neutrophils live?

A

1 - 2 days

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

How long do platelets live?

A

7 - 10 days

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

Where are blood cells produced?

A

Bone marrow

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

How long do lymphocytes live?

A

Weeks to years

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

What does disruption of haematopoiesis lead to?

A

Anaemia’s
Polycythemias
Immunodeficiencys
Myeloproliferative disorders
Leukaemias/ lymphomas

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

How long do RBCs live?

A

100 - 120 days

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What can you treat blood disorders with?

A

Cell therapy

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

What cell therapy treats accidents, surgery, anaemia, thalassemias?

A

Red blood cell transfusion

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

What cell therapy treats clotting disorders, BM transplants, chemotherapy?

A

Platelets transfusion

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

What cell therapy is a longterm (cure) of cancer, leukemia and immune disorders?

A

Blood stem cell transfusions

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

What are short term cell therapy fixes?

A

Red blood cell and platelets (because these do not survive as long and blood stem cells)

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

What do blood transfusions/platelets contain?

A

Mature cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What does bone marrow/umbilical cord blood transplantations contain?

A

Stem cells

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

What is a stem cell?

A

Undifferentiated cells capable of self renewal (undifferentiated progeny) and differentiation (generate mature cell types and regenerate tissue after injury)

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

Do you need homeostasis of the haematopoietic system?

A

Yes

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

What is probability of self maintenance?

A

When half of a stem cells progeny differentiates and the other half remain as stem cells. If this changes e.g. too many stem cells = expansion or by too many differentiated cells = depleted. This is bad.

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

Why is the haematopoietic system controlled?

A

Maintain the stem cell pool,
respond to environmental changes such as injury, inflammation and disease, oxygen levels etc.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What controls the haematopoietic system?

A

Precise regulation of expression and activity of many transcription factors, cytokines and cytokine receptors.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What are cytokines?

A

Interleukines which signal to cells inflammation/damage

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What are totipotent stem cells?

A

Give rise to all cell types including extraembryonic and intraembryonic cells.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What are pluripotent stem cells?

A

Gives rise to all cells in the body e.g. induced pluripotent stem cells.

24
Q

What are multipotent stem cells?

A

Stem cells which can only give rise to cells in their cell lineage e.g. haematopoietic stem cells (HSC)or tissue stem cells

25
Q

What do the HSC’s differentiate into?

A

Multipotent progenitor

26
Q

Where can we find HSC’s?

A

Umbilical cord, bone marrow, peripheral blood after mobilisation with drugs e.g. C-CSF.

27
Q

How do we identify and purify HSC’s from a donor?

A
  • Morphology - this is not uniques but low cytoplasm to nucleus ratio.
  • Low staining with viral dyes,
  • Density gradients
  • Expression of surface markers such as lack of lineage markers, Sca1, Kit (K), CD34 or SLAM receptors
28
Q

How do you find blood stem cells using lasers?

A

You would stain the cells with antibodies and flourescent markers. You will then be able to sort the cells based on the expression of these cells.
We can then isolate and transplant these.

29
Q

Why would you use lineage negative cells?

A

HSC’s do not need to be differentiated and therefore you use lineage negative cells without markers to identify them. These will be immature

30
Q

How do you get lineage negative cells?

A

Deplete for any mature HSC as these will have markers

31
Q

How do we test cells we think are progenitor cells?

A

Colony assays in vitro - these quantify the cells which can proliferate and differentiate.

32
Q

What results can you obtain from functional assays for stem cells?

A

Frequency of progenitors for various lineages and what lineages contributed.

33
Q

How do you use an in vitro colony assay?

A

Its a semi solid medium and has cytokines - these cytokines signal to cells that we need one specific lineage to grow over another.

34
Q

Why cant you see stem cells in an in vitro colony assay?

A

They are not commited to any lineage and therefore will not be able to proliferate into the different lineages.

35
Q

What assay do you use for true HSCs?

A

Transplantation assay

36
Q

What is the transplantation assay?

A

We deplete mice HSC’s and inject them with the cells we want to test. After a few weeks we take their blood and see if there is blood cells. If yes then the cells we injected must have been HSc.

37
Q

What results can you get from a transplantation assay?

A

Lineage contribution and short term or long term reconstitution.

38
Q

After identifying HSC’s through transfusion assay do you have to do this a second time to confirm?

A

Yes

39
Q

Can you use flow cytometry and transplantation assay together?

A

Yes, e.g. CD150 + and CD150- they identified cells through flow cytometry and then used a transplantation assay to see which ones where HSC’s or not (CD150 + was).

40
Q

When cells become progitors do they become negative e.g. CD150 -?

A

Yes

41
Q

Where do you get pluripotents stem cells?

A

Embryos

42
Q

What do you make when you manipulate ESCs and inject them into a blastocyst?

A

Chimaeric animals e.g. mouse

43
Q

What are induced pluripotent stem cells?

A

We take differentiated cells and transform them back into embryonic stem cells - this overcomes all ethical issues regarding use of embryonic stem cells

44
Q

What can you use iPSCs to do?

A

Drug testing
Disease modelling - we can mutate these cell types
Cell therapy

45
Q

Why are iPSC’s useful in haematopoietic development?

A

Can identify cells that are common progenitor of blood cells and endothelial cells.

Identify molecular pathways controlling blood development/ lineage

46
Q

Can you make mouse mutants with iPSCs to test the roles of specific genes on haematopoiesis?

A

Yes

47
Q

Could you use iPSC’s to produce mature cells for therapy?

A

Yes

48
Q

What are some issues with blood transfusion?

A

Donor dependant
Transfusion transmitted disease
Limited storage time
Blood group matching/ compatibility
No blood transfusion services in the developing world

49
Q

Could all the problem with blood transfusions be avoided by using iPSC?

A

Yes

50
Q

Can you make red blood cells from PSCs?

A

Is currently in research and very complication with low results

51
Q

What are the big challenges of making red blood cells from iPCS?

A

Can we produce mature RBC?
Can we scale up to therapeutic quantities?
Would is be affordable?

52
Q

How do we overcome the challenges we face when making RBC’s from PSC’s?

A

Study the development of blood cells naturally and copy this e.g. where do HSc’s come from in the embryo - there is various niches, different cell types, various molecular pathways.

53
Q

There is 3 waves of embryo development - where do HSC’s sit?

A

In the third wave

54
Q

Can iPSCs easily differentiate into cells found in embryonic wave 1 and 2 e.g. macrophages but not wave 3?

A

Yes

55
Q

Do we know how HSCs develop and why/ why not?

A

No we dont as its hard to access human fetal tissue and know the mechanisms behind this.