Adult Stem Cells

1. Adult Stem Cells • Adult Stem Cells are undifferentiated cells found throughout the body in adult tissue. • Also known as somatic stem cells, these cells are multipotent.

2. What’s the difference between Multipotent and Pluripotent stem cells?

3. Multipotent- These cells can only give rise to cells in their own lineage or closely related family of cells. • Pluripotent-These cells are descendants of totipotent stem cells and can give rise to cells of the three germ layers: endoderm, mesoderm, and ectoderm. They have no contribution to extraembryonic membranes or the placenta.

4. What are the three classes of Hematopoetic Stem Cells

5. Lymphocyte-biased HSC’s (Ly-bi) • High L/M ratio. Lymphocytes >10. • 2. Myeloid-biased HSC’s (My-bi) • Low L/M ratio. Lymphocytes >0, <3. • 3. Balanced HSC’s (Bala) • Lymphocytes > or = 3 and < or = 10

6. Lymphocytes(Lymphoids) • There are three types of Lymphocytes under the two classes, Large and small lymphocytes. • T-cells (thymus-derived cells)-Small Lymphocyte • Mostly involved in cell-mediated immunity • 2. B-cells (bursa-derived cells)- Small Lymphocyte • Mostly involved in humoral immunity • 3. Natural Killer cells (NK Cells)- Large Lymphocyte • Play a major role in defending the host from tumors and virally infected cells.

7. Monocytes(Myeloids) • These cells make up 3-8 percent of leukocytes or white blood cells. • Main purpose is to be used in the innate immune system against pathogens and other harmful cells. • Migrate into tissue where they are then differentiated into macrophages which do the same job as monocytes. • Activate Lymphocytes.

8. What are some Hematopoietic Stem Cell sources?

9. Bone Marrow • First stem cell source ever used, back in 1945. still in use today. • Patient is given anesthesia and the needle is inserted through the back, to the pelvic bone. • Marrow is thick, extracted through the needle then if filtered and then put into special solution bags and freezed. • Thawed when needed. Easy to maintain.

10. Peripheral Blood • Patients are given hormone growth factors to increase stem cell acount which causes stem cells to go from the bone marrow to the blood. • A very thin flexible tube is inserted into the donors vein, called a catheter and attached to other tubing which is attached to a special machine. • This machine separates the blood from the stem cells and sends the blood back into the donor while just taking the stem cells. • Like bone marrow, the stem cells are filtered further then put in a bag and frozen until a patient needs it.

11. Umbilical Cord Blood • Around 30% of hematopoeitic stem cell transplants are from cord blood. First transplant in 1988 • The umbilical cord attached to the baby and mother right after the mother gives birth, is always snipped off. • This cord has been found to have a lot of stem cells.

12. Which Source is Best? • Bone Marrow Pros- Relatively Simple Procedure, can be done to almost anyone. No growth hormones needed, sufficient supply of stem cells achieved. Scientists know a lot about it. • Bone Marrow Cons- slight chance of graft vs. host disease. More efficient ways to extract stem cells, could accidentally damage bone. • Peripheral Blood Pros- Able to extract only or close to only stem cells. The cells engraft in the bone marrow quicker than in bone marrow cells due. • Peripheral Blood Cons- Process of extraction takes several hours and may repeat for a few days to get enough stem cells. Risk of graft vs. host disease is slightly higher than bone marrow.

13. Umbilical Cord Blood Pros- Does not have to be as closely matched to the recipient as bone marrow and peripheral blood does.