2-Peripheral Blood, Bone Marrow & Stem Cells

Front 1

What 3 cytoskeleton proteins give RBC's their shape and flexibility?

Back 1

1. Spectrin
2. Ankryn
3. Actin

Front 2

What are 2 primary and 2 secondary causes of polycythemia?

Back 2

Primary:
- Myeloproliferative disorder
- Mutation in EPO receptor gene (thinks EPO always there)

Secondary:
- Hypoxia (lung disease, env, defective hgb)
- Increased EPO production

Front 3

What has:
- nucleus with 2-5 lobes
- granules in the cytoplasm
- 12-15um diameter?
What are of it's functions?

Back 3

Granulocytes!
- phagocytosis and destruction of foreign material
- Cytotoxic (e.g. by having a respiratory burst)
- inflammation
(- generate radicals from iron bound to bacteria)

Front 4

Granulocytopenia is caused by:
1. Decreased production (5 causes?)
2. Increased destruction (3 causes)

Back 4

1. Decreased production:
- defective differentiation
- substrate deficiency (B12/folate)
- Marrow infiltration
- Toxicity to precursors (medication/infection)
- Congenital or benign increase in apoptosis
2. Increased destruction:
- hypersplenism
- autoimmune (e.g. lupus)
- alloimmune (HIV, medication, etc)

Front 5

What are 3 causes of granulocytosis (DRS)?

Back 5

1. Demargination - stress can cause them to go from endothelium to blood
2. Reactive - inc production d/y cancer, infection, inflamm. etc.
3. Primary - leukemia

Front 6

What are 3 causes of monocytosis?

Back 6

1. Chronic inflamations (IBS, rhematoid)
2. Chronic infections (TB, syphillis)
3. Malignancies (leukemia)

Front 7

What are 3 functions of monocytes?

Back 7

Phagocytosing debris and microbes
Antigen presentation
Acute inflammation

Front 8

List some causes for each of the following:
- psedothrombocytopenia (2)
- thrombocytopenia (dec production=4; inc destruction=3)
- thrombocytosis (3)

Back 8

Pseudo: Platelet clumping/satelitism (in vitro phenomena)
Thrombocytopenia:
- acquired or congenital defect in differentiation
-substrate deficiency (B12/folate)
-marrow infiltration; toxicity
Increased destruction: consumption (DIC, sepsis), Immune (viral, auto), Sequestration (hypersplenism)
Thrombocytosis:
- reactive (infection, bleeding, Fe deficiency)
- primary (myeloproliferative disorders)
- redistributive (post splenectomy)

Front 9

How does bone marrow change with age?
- 3-6 months
- birth
- adolescents

Back 9

Yolk sac--> paraortic region --> liver --> bone marrow
Liver major source from 3-6 months.
At birth bone marrow is in all bone cavities. Marrow replaced by adipocytes as you age.
By adolescents only in central bone cavities.

Front 10

What is one thing that BM does NOT have?

Back 10

lymphatic channels!

Front 11

The BM is a 'microenvironment', what is the function of the following 3 components?
1. Stromal cells
2. Accessory cells
3. Extracellular matrix

Back 11

1. Stromal cells
- produce cytokines and negative regulators
2. Accessory cells
- T cells: IL-3, TNF, IFN-y
- Mphages: eat dead RBC's & expelled nuclei; express VCAM for adhesion
3. Extracellular matrix (produced by stromal cells)
- homing and mobilization of stem cells (adhesion molecules bind specific precursor cells to certain sites in the BM)

Front 12

Where does the following occur (in the BM)?
1. Erythropoiesis
2. Granulopoiesis
3. Megakaryopoiesis

Back 12

1. Erythropoiesis: Erythroid islands surrounding a central Mphage
2. Granulopoiesis: Adjacent to bony trabeculae
3. Megakaryopoiesis: Adjacent to sinus endothelium

Front 13

Trace the order of Granulopoiesis from stem cell to Neutrophil:
myeloblast --> _____--->_____ ---> metamyelocyte --> ______ --> ______
From what point are the cells no longer dividing and instead maturing?

Back 13

* stem cell
* Myeloblast
* Promyelocyte
* Eosino/neutro/basophilic myelocyte
* Metamyelocyte
* Band cell (Stab cell)
* Granulocytes (Eosino/neutro/basophil)

Cells are maturing only from the myelocyte onwards!

Front 14

How long do neutrophils last in the blood?

Back 14

- a few hours then they regress into the tissues. When a chemokine binds their CXCR1,2 receptors they move out of the blood
- GM-CSF prolongs neutrophils in circulation

Front 15

How does an eoisinophil develop? What chemokines stimulate it?
What causes it to leave circulation?

Back 15

All the same as a neutrophil only ending in a eosinophil under the direction of IL3 & 5.
Eotaxin made in allergic infiltrates or asthmatic lungs, draws eoisinophils out.

Front 16

What 2 chemokines stimulate the development of a basophil?
What do their granules contain? (H H L P) What don't they contain?

Back 16

IL-3 and KIT ligand.
Granules have: Heparin, histamine, lipid, proteoglycan, but NO hydrolytic enzymes.

Front 17

What is the order of cells in the development of monocytes?
CFU-GM --> monoblast --> _____ -->_____
What chemokines stimulate them?
Monocytes circulate in the blood for ___ days then do what (2)?

Back 17

CFU-GM --> monoblast--> promonocytes --> monocytes
- Chemokines: M-CSF and IL-3
- circulate in blood for 3 days then become tissue macrophages or dendritic cells (APC)
** they also produce cytokines! (accessory cells of BM)**

Front 18

What do dendritic cells do (2)? What don't they do (1)?
What precursors can they arise from (3)?

Back 18

Dendritic cells:
- Antigen presentation
- stimulate primary T cell response
They DO NOT phagocytose!
Can arise from:
-lymphoid, meyloid or monocyte precursors

Front 19

What is the origin and function of an osteoclast?

Back 19

Differentiate from CFU-GM
They sit on the trabeculae and are responsible for the resorption of bone.

Front 20

What is the order of cells in erythropoiesis?
Proerythroblast --> ______ --> _____ --> normoblast --> _______ --> *erythrocyte*
EPO is acting from what cell onwards?

Back 20

Proerythroblast --> Basophillic erythroblas --> Polychromatic Eblast --> normoblast --> polychromatophilic Ecyte --> -->*erythrocyte*
From proerythroblast onwards, development is EPO dependent alone!

Front 21

For erythropoietin, what
- stimulates its release
- effect on tissue
- negative feedback

Back 21

- EPO release is stimulated in response to hypoxia in renal cells
- EPO binds surface cell receptors and is essential proliferation, differentiation and survival of cells
- Heme and TNF inhibit EPO
** EPO receptors are absent from mature RBC

Front 22

What do megakaryocytes develop from? Order of 2 precursor cells?
How Mkcytes develop?

Back 22

Develop from: BFU-MK and CFU-MK
Mblast --> ProMcyte --> M
** stimulated by TPO **
Grow by having ongoing DNA synthesis w/o mitosis = increasing DNA content such that nucleus folds and lobulates w/o separating.

Front 23

What 2 things happen as a megakaryocye matures (ie before platelets start budding off?)

Back 23

- acquires surface glycoproteins (VmF, GP1b/2a)
- develops granules (alpha, delta, gamma, peroxisomes).

Front 24

What is the life span of the following cells:
- RBC
- WBC
- Platelet

Back 24

- RBC = 120 days
- WBC = 3-4hrs
- Platelet = 10days

Front 25

Natural Killer Cells
- function (2)
- appearance
- origin

Back 25

Function:
- non-restricted cytotoxicity
- produce cytokines that influence hematopoiesis and immunity

Appearance: large cells with cytoplasmic granules

Origin: common lymphoid progenitor

Front 26

What is the definition of:
-totipotent
-pleuripotent
-multipotent

Back 26

-totipotent: can generate any type of cell including extra-embryonic membranes
-pleuripotent: same as above except can make extra-emb membranes
-multipotent: able to generate multiple cell types but only of a particular tissue type

Front 27

What are the 3 attributes of hematopoietic stem cells?

What are the 3 choices that every HSC has open to it?

Back 27

1. Capacity for self-renewal
2. Able to differentiate into any of the mature blood lineages
3. Able to regenerate the hematopoietic system post-radiation

1. Self-renew
2. Differentiate
3. Apoptosis

Front 28

In addition to Stem Cell Factor and Flt3, what are some other cytokines that guide stem cell decisions?
1. T
2. H
3. B
4. N
+ delta
+ jagged

Back 28

1. TPO - enhances megakaryocytic prolif and diff.
2. HedgeHog Protein: up-regulated BMP's and induces primitive hematop.
3. BMP - induce primitive hematop., and bone/cart formation
4. NOTCH - transmembrane receptor:
+ delta = increased generation of HSC and inc ability to diff
+ jagged = decreased proliferation

Front 29

What factors w/in HSC will affect what the stem cell does?
1. Genes - A, M, G, I and H (what does this one do if up and down regulated?)
2. How is transcription regulated?

Back 29

1. Genes: AML1, MYB, GATA2 and IKAROS,
Homeobox: up regulated = leukemia
down regulated = poor granulation

Transcription regulation is acheived by modifying histones to increase or decrease differentiation of HSC

Front 30

What triggers apoptosis in HSC?

Back 30

Overexpression of the gene BCL-2
-Lymphoma cells do not express BCL-2 at all and thus continue to grow and accumulate unchecked.

Front 31

What are 3 ways of identifying stem cells?

What are 3 sources of HSC?

Back 31

1. Cell surface antigens - do a phenotypic analysis (HSC won't have markers of specific mature lineages)

2. Efflux of dyes - HSC will pump out Rhodamine 123 and Hoechst - 33342

3. Cultures -- if placed on stromal cells of BM will differentiate into different lineages depending on what the environment favors

Sources of HSC: Peripheral blood (easiest to harvest), cord blood (only get a small amount) and bone marrow (most painful/invasive).