imm 2 Flashcards
Where are all our immune effector cells derived from?
From a common pluripotent progenitor cell (Hematopoietic stem cells/0 type in bone marrow
What are all our immune effector cells a part of?
Our Hematopoietic blood system
What are pluripotent progenitor cell?
Hematopoietic stem cells (hematopoietic relating to blood)
What are all our white blood cells called?
Leukocytes
Name some white blood cells
Ganulocytes| Megakaryocyte
Following stem cell division what can a daughter cell do?
- Divide| 2. Differentiate
Why is it a benefit that some of our daughter cells don’t differentiate but divided into more stem cells?
Means we have stem cells to replenish our blood system as we get older
What is the first step of differentiation a stem cell can take?
Cells can either become:1. A Common lymphoid progenitor 2. A common myeloid progenitor
What do Common lymphoid progenitor give rise to?
B cellsT cellsNK cells
What do Common myeloid progenitor give rise to?
Granulocytes and megakaryocytes (White blood cells)| Or dendrites
What happens to a cell as it further differentiates?
They lose the ability to self renew
Name our adaptive effector cells
B cells (which give plasma cells)T cells (which give activated T cells)
Name our innate effector cells
NK cells (which give us activated NK cells)Dendritic cells (both mature and immature)Neutrophils EosinophilsBasophils MonocytesMast cellsMacrophages
What lineage do dendritic cells come from?
Ether a myeloid or lymphoid lineage
Name the only type if lymphocytes that are considered innate
NK cells| natural killer cells
What are monocytes?
The precursor to macrophages
Which is the mature effector: the macrophage or the monocyte?
The macrophage
Where are immature monocytes found?
They circulate the blood
Where are mature macrophages found?
Found in most tissues in sub mucosal layers.
What is the function of monocytes and macrophages
- They are the first responders2. Phagocytic3. Engulf and kill pathogens and infected cells4. Clear dead cells and debris5. Bactericidal6. Present antigen to T cells7. Activate other immune cells8. Induce inflammation
Do macrophages and monocytes have a long or short lifespan?
Relatively Long
What does it mean a cell is phagocytic?
They can engulf and kill pathogens and infected cells| They can also clear dead cells and debris
What is another name for granulocytes?
Polymorphonuclear leukocytes
Name the 3 types of granulocytes
- Neutrophils2. Eosinophils3. Basophils
Which of the 3 types of granulocytes has a role in the immune response?
Neutrophils
What is the main role of Eosinophils and Basophils?
Main role is anti parasitic
Where are neutrophils found?
In the blood they migrate to infection sites
What are the functions of granulocytes?
- Phagocytic| 2. Bactericidal
Describe the life span of neutrophils
They have a relatively short life span
What is pus made up of?
Dead neutrophils
Describe the morphology of neutrophils
They have lobes nuclei| Their cytoplasms is speckled with cytotoxins
Where are immature dendritic cells found?
Under surface epithelia and in solid organs| They migrate to lymph nodes and mature there
What are the functions of dendritic cells?
- Phagocytic /Macropinocytosis2. Take up antigen to present to adaptive arm3. Activate cells of the adaptive arm
Where are natural killer cells found?
In the blood| They migrate to infected tissues and tumours
What are the functions of natural killer cells?
- Extracellular release of cytotoxic granules2. Anti viral3. Anti tumour
What type of cells are natural killer cells?
They are lymphocytes but are considered within the innate arm of the immune system
How do dendrites mature?
They are immature in the tissues but when they engulf bacteria and migrate they mature
What do dendritic cells do?
Take antigens from the site infection to the lymph nodes and they initiate the adaptive immune response
Describe the morphology of natural killer cells
They have a large single lobed nucleus Bigger nucleus to cytoplasm They have cytotoxins
Which cells do our NK cells kill?
Non- self cells
Name some phagocytic cells we have
- Macrophages 2. Neutrophils 3. Dendritic cells
How to phagocytic cells decide what they want to engulf?
By using different receptors on their cell surface and within the cell
What do Fc receptors look for?
Antibody coated pathogens
What do compliment receptors look for?
Activated compliment molecules like: CRb
What do receptors on phagocytic cells look for?
- Self cells| 2. Non-self cells
What does PAMP stand for?
Pathogen associated molecular patterns
What do pattern recognition receptors look for?
Common structures we see in microbes (PAMPs)
What do we call common structures we see in microbes but not in higher organisms?
Pathogen associated molecular patterns (PAMPs)
Name the different types of PAMPS
- Lectin like. Dectin 1
- Scavenger receptors.
- Toll like receptors
Give examples of toll like receptors
TLR4| TLR6
What are toll like receptors always expressed as?
Diamers| Some are homodiamers and some are hetero diamers
Describe how phagocytosis is activated
- Compliment activation leads to deposition of c3b on the bacterial surface2. Compliment receptor 1 (CR!) on macrophage binds to C3b on bacteria3. Endocytosis of the bacterium by the macrophage 4. Macrophage membrane fuses creating a membrane- bounded vesicle (Phagosome)5. Lysosomes fuse with the phagosomes forming phagolysosomes
What is a phagosome?
When macrophage membrane fuse creating a membrane-bounded vesicle
What are phagolysosomes?
When lysosomes fuse with phagosomes