Lecture notes Cells and Immunity Haematopoiesis (BI2BC45)

28.01.20


L10 - Haematopoiesis
Definitions:
Haemotopoiesis (deriving cells from the bone marrow)

Lecture:
 White blood cell circulation Granulocytes
o Neutrophils (50-70%)
o Lymphocytes (20-40% - B/T cell adaptive
immunity)
o Monocytes(1-5%) macrophage precursor
o Eosinophils (1-3%) parasites
o Basophils (>1%) overreaction = allergies
 Blood cells come from haematopoietic stem cell pop
o Multipotent/pluripotent stem cell
o Then it will produce myeloid (everything else
RBCs/platelets) and lymphoid (granulocytes)
 Have 2l of bone marrow
o Most haematopoiesis sites are in the: pelvis,
vertebrae, sternum, cranium and shoulder joints
o 1/10k cells in bone marrow = haematopoiesis cell
 In division decide whether lymphoid or
myeloid
 Leukemia
o Cure patient of cancer by wiping out
haematopoiesis cells and then give bone marrow
transplant
 Around the crest of the hip/pelvis
 Bone marrow produced 4x1011 cells per day
o Neutrophils 2-3 days
o T-cells 20-30 years
o Infection/blood loss = ↑ by 10/20-fold
 Control of haematopoiesis
o Stromal cells = support cells
 Fibroblasts, osteoclasts/blasts, endothelial
cells)
o Stromal cells send growth factors eg colony
stimulating facts (CSF) and Erythropoietin (EPO)
o Altered chemical signals and ratio of chemicals =
determines cell types
 Mechs of Haematopoiesis homeostasis
o Control levels/types of chemokines produced by
stromal cells
o Control of synth of cytokines
o Alter the expression of cell surface receptors
 If multiple signals are being received, the priority is synthesized