Stem Cells (Lec 8) Flashcards
Stem Cell
A cell that is not yet specialised, can self-renew and is able to differentiate
Types of Stem Cells
Embryonic Stem Cells: can differentiate into all cell types present in an organism
Adult Stem Cells (somatic cells): reserve supply of cells that can multiply when required
Potency of Stem Cells
- Totipotent
- Pluripotent
- Multipotent
- Unipotent
- Induced Pluripotent
Totipotent Stem Cells
Formed from: cells that makeup the fertilised egg and 1st few mitotic divisions
Potential for: somatic cells, progenitor cells, primitive germ-line stem cells
Pluripotent Stem Cells
Formed from: Descendants of Totipotent stem cells
Potential for: all cell types (multi-lineage differentiation)
- e.g. Endoderm, Mesoderm, Ectoderm
Multipotent Stem Cells
Formed from: Descendants of Pluripotent stem cells
Potential for: multiple, but limited cell types
- e.g. Hematopoietic stem cells
Unipotent Stem Cells
Formed from: Descendants of Multipotent stem cells
Potential for: 1 cell type
- e.g. RBC’s, WBC’s, platelets
Induced Pluripotent Stem Cells (iPSC’s)
Adult differentiated cells that have been genetically programmed to a pluripotent emryonic cell
Allogenic Stem Cell Transplantation
Donor and recipient of stem cells are different people
- possiblity for graft vs. host disease (rejection of ‘non-self’ tissue)
- Allogenic HSC donors and recipients must have matching HLA (Human Luekocyte Antigen) type
Human Luekocyte Antigen (HLA)
Control immune responses through recognition of ‘self’ and ‘non-self’ peptide presentation on immune cells
- HLA = MHC (Human Major Histocompatibility Complex)
Autologous Stem Cell Therapy
Donor and recipient of stem cells same person
- harvested stem cells are purified, assessed for quality and then reintroduced back into patient
- no rejection
