Ppt Part 2 Flashcards
STEM CELL THEORY
•YEAR- Till and McCulloch:
1961
Stem cell theory by
Till and McCulloh
= COLONIES of HSCs
Aplastic Mice + Intravenous injection of marrows
(CFU-S)
COLONY-FORMING UNITS-SPLEEN
• Capable of self-renewal and production of differentiated progeny
COLONY-FORMING UNITS-SPLEEN (CFU-S)
• NOW: committed myeloid progenitors or colony-forming unit-granulocyte, erythrocyte, monocyte, and megakaryocyte (CFU-GEMM)
COLONY-FORMING UNITS-SPLEEN (CFU-S)
Unrecognizable hematopoietic progenitor
• 2 Major Types:
Non committed or Undifferentiated HSCs
Committed Progenitor cells
: can differentiate into progenitor cells committed to either lymphoid or myeloid lineages
Undifferentiated HSC
Undifferentiated HSC: can differentiate into progenitor cells committed to either
lymphoid or myeloid lineages
2 Theories
Monophyletic theory (widely accepted theory)
Polyphyletic theory
•HSCs 3 Possible fates:
Self renewal
Differentiation
Apoptosis
• HSC: 2 divides to…
2 identical daughter cells
(symmetric division/asymmetric division/ apoptosis)
• A group of specific glycoproteins
CYTOKINES & GROWTH FACTORS
CYTOKINES & GROWTH FACTORS
• A group of specific_______
glycoproteins
• Regulate the proliferation, differentiation, and maturation of hematopoietic precursor cells
CYTOKINES & GROWTH FACTORS
• Responsible for stimulation or inhibition of production, differentiation and trafficking of mature blood cells and their precursors
CYTOKINES
• Diverse group of soluble proteins that have direct & indirect effects on HSC
CYTOKINES
CYTOKINES
• Responsible for stimulation or inhibition of…
production, differentiation and trafficking of mature blood cells and their precursors
Examples of CYTOKINES
Interleukins (IL)
lymphokine
monokines
interferons
chemokines
CSFs
: Kit ligand, FLT3 ligand, GM-CSFIL1,IL3,IL6,IL11
POSITIVE INFLUENCE
: Transforming factor B, TNF a, interferons
NEGATIVE INFLUENCE
POSITIVE INFLUENCE:
Kit ligand
FLT3 ligand
GM-CSF
IL1
IL3
IL6
IL11
NEGATIVE INFLUENCE
Transforming factor B
TNF a
interferons
CYTOKINES
• Prevent precursor cells from dying by…
inhibiting apoptosis