Cells & Organs of Immune system Flashcards
Hematopoiesis
What is the definition of Hematopoiesis?
Formation & Development of red & white blood cells
Hematopoiesis
What is the migration path of HSCs ( Hematopoietic stem cells )?
Embryonic Yolk sac -> Fetal liver -> Spleen -> Bone marrow
Hematopoiesis
What are the two characteristic of HSC that allows it to consistently produce new and different blood cells?
Self renewal ( Though decrease in level at old age )
Multi - potent : Able to differentiate and generate various cells
Hematopoiesis
What happens with stem cell mitosis when
a) Normal
b) Injury
c) Infection
Normal : No increase in stem cells
Injury : Increase in stem cells
Infection : Increase in differentiating cells
Hematopoiesis
What are the 4 factors involve in hematopoietic homeostasis?
Control of levels & types of cytokines produced by Bone - marrow stromal cell
Production of cytokines w/ hematopoietic activity by other cell types
(e.g. Activated T cells & macrophage (during infection))
Regulation of expression of receptors
Removal of certain cells by apoptosis
Hematopoiesis
What is the anti - apoptotic protein that regulates activated B - cell numbers by apoptosis?
Bcl - 2
Cells of Immune System
What are the 3 types of lymphocytes?
B cells
T cells
NK cells
Cells of Immune System
What is 4 attributes that only lymphocytes possess?
Diversity
Specificity
Memory
Self / Non-self recognition
Cells of Immune System
What are the 2 fates of antigen - activated lymphocytes?
Effector cell
-> Apoptosis
Memory cell
Cells of Immune System
What are the 4 molecules expressed on the membrane of Mature B cells?
mIg ( membrane - bound immunoglobulin )
Class ll MHC
B7-1 & B7-2
CD40
Cells of Immune System
What are the 2 sites of maturation for B lymphocytes?
Bursa of Fabricius ( birbs )
Bone marrow
Cells of Immune System
What is the site of maturation for T lymphocytes?
Thymus
Cells of Immune System
What is the cell marker for B lymphocyte?
BCR ( B - cell receptor )
-> mIg ( membrane - bound immunoglobulin )
Cells of Immune System
What are the cell markers for T lymphocytes?
TCR
-> recognizes only antigen on self - cells
- -> MHC restriction
CD4 ( T helper : Th1 & Th2 )
CD8 ( T cytotoxic )
Cells of Immune System
What is the cytokines released in Th1 ( MHC ll restricted )?
What are their functions?
IL - 2 & IFN - y ( gamma )
Functions :
-> Activation of macrophages
-> Inflammation
Cells of Immune System
What is the cytokines released in Th2 ( MHC ll restricted )?
What are their functions?
IL - 4 & IL - 5
Functions :
-> Stimulation of B lymphocytes
Cells of Immune System
Is NK cells ( Natural killer cell ) part of the innate or adaptive immune system?
Innate
Cells of Immune System
Does NK cells have antigen receptors?
They don’t have antigen receptor