Cytokines and hematopoiesis (Heck) Flashcards
Describe the components of blood in a test tube with an anti-coagulant present
clear/liquid portion: plasma consisting of proteins (albumin, fibrinogen), hormones, antibodies, vitamins and salts
buffy coat: white blood cells and platelets
cellular: RBCs
Describe the components of blood in a test tube in absence of fibrinogen
liquid: Serum
blood clot at base
What percent of the blood is RBCs
45
what does thrombopoiesis stand for
formation of platelets
What are colony forming units
committed precursor cells for hematopoiesis
lymphoid cells
will differentiate into B cells and T cells (lymphocytes)
myeloid cells
differentiate into every but lymphocytes
When does hematopoiesis begin in development and where?
in the yolk sac around 3 weeks. formation on hemangioblasts
What is the big transformation of RBC formation in 7th month of development?
Switch to hematopoiesis being done in the bone marrow
general trends in hematopoiesis
cell size decrease, cytoplasm becomes less basophilic, changes in nuclear:cytoplasmic ratio,
changes in nuclear condensation rxns (euchromatin and heterochromatin)
2 characteristics of Hematopoietic Stem Cells HSCs
pleuripotent–> give rise to many cell types
self renewing–> divide to maintain own population
Stem cell factor/ c-kit ligand is produced where?
bone marrow in stromal cells and in fetal tissue during development
C-kit R is expressed by what and what type of R
HSCs
tyrosine kinase R–> (MAPK, JAK/STAT, IP-3)
what type of mutation in c kit R leads to cancer
gain of function
protooncogene–>oncogene
how is c kit ligand used clinically?
used in marrow transplant cases–> to determine which RBS are HSC based on whether they have C-kit ligand (acts as a marker)
Imatinib (drug) does what?
Inhibitor of tyrosine kinase activity
reducing differentiation of HSCs
used for chronic myeloid anemia
Linear Restricted Progenitor cells
arise from HSCs, multipotent
differentiate into lymphoid or myeloid cells.
These do NOT renew themselves
3 categories of blood elements
erthyrocytes RBCs
leukocytes WBCs
platelets
2 types of leukocytes
granulocytes and agranulocytes
Anatomy of RBCs
biconcave Anucleate lack of organelles PM unique cytoskeleton contains hemoglobin contain glycolytic enzymes
how long do RBCs stay in circulation
120 days.
ABO blood groups are what?
assemblies on cell surface.. glycoproteins
O antigen
lacking functional enzymes
(default)
no sugars
A antigen
N- acelylgalactosamine on O structure
B antigen
galactose transferase enzyme to add galactose O antigen
What cytokines affect erthyropoiesis?
IL-3 IL-4 and erythropoietin