Lecture 9: Blood cell production Flashcards
How long does each type of blood cell live?
Neutrophils- 1-2 days, platelets- a week, RBCs- 120 days, lymphocytes- weeks or years
What is polycythemia?
High numbers of RBCs
What types of therapy can be used to treat a blood disorder?
Either a transfusion (short-term fix) or a transplant (long-term fix)
What key properties does a stem cell have?
Self-renewal and differentiation into any cell type
What type of stem cells are haematopoietic stem cells (HSC)?
Multipotent- able to give rise to more than one lineage of cells.
What happens when G-CSF is given to a blood donor?
It draws stem cells into the periphery so they can donate HSCs without having to give bone marrow.
What surface markers do HSCs have?
No specific lineage markers, Sca1, CD34, SLAM receptors
How are HSCs isolated?
Using flow cytometry, cells that stain for specific markers are excluded because they are mature cells
What does a colony forming unit- spleen (CFU-S) assay test?
The short term repopulating ability of a HSC population
How are in vitro colony assays done?
A cell population is planted in semi-solid medium containing a range of cytokines and if multipotent cells are present they will form a colony
What are osteoblasts?
Bone cells which maintain HSCs. When contact with osteoblast is lost, HSC differentiate into common lymphoid and myeloid progenitors.
What is involved in the HSC niche?
A complex mix of cells such as macrophages, adipocytes, fibroblasts as well as osteoblasts and a mix of cytokines and chemokines.
What can problems can defects in the SCF/KIT pathway cause?
Either defects in stem cell factor which is a growth factor, or defects in the stem cell factor receptor, c-KIT.
What more ethical alternative can be used instead of embryonic stem cells?
Induced pluripotent stem cells from skin tissue.
What is the benefit of using induced pluripotent stem cells?
You can provide patient derived cell types, can use them for disease modelling, drug testing or cell therapy.
