Flashcards in White blood cells Deck (31)
Large granular lymphocyte (NK cells).
B cells and T cells are antigen specific because of their receptors.
B cells release antibodies.
T cells and NK cells release cytokines.
NK cells are not antigen specific
Part of the innate immune system.
Mononuclear phagocytes release cytokines and activates complement pathways.
Axillary cells ONLY found in the tissue- where they differentiate and mature.
They release granules containing histamine and other active agents- affects vascular permeability.
Expresses FceRI- which binds to IgE, form of opsonisation.
They release inflammatory mediators and are part of the innate immune system.
Number of neutrophils per mm3
7.3 x 10^3
This accounts for 50-70% of the total number of leukocytes.
A type of axillary cell that circulates in the blood and contains:
Heavily granulated cytoplasm
Does not undergo phagocytosis.
Releases pharmacologically active agents from their granules:
Expresses Fc(e)RI which binds to IgE---> binds to allergens.
A phagocyte that is mainly located in the tissues and contains:
- Bilobed nuclei.
- Granulated cytoplasm- granules release toxin proteins and free radicals.
- Can migrate from blood to tissue.
- Expresses Fc(e)RI when activated.
- Involved in allergic reactions and release toxins to attack parasites in GI, respiratory and genitourinary tracts.
Toxin in the large granules of eosinophils
Cationic protein- apoptosis.
Peroxidase- reactive oxygen species
Hypobromous acid (HOBr)- dissociates into hypobromite ion, a strong oxidising agent.
Products synthesised by eosinophils which amplify inflammatory responses
Phagocytes found in the blood contains:
- Myeloperoxidase and reactive oxygen species (ROS)
- First leukocytes recruited to the sites of infection/ injury.
Has a short lifespan
A mononuclear phagocytes that is the premature form of a macrophage.
- Kidney shaped nucleus.
- Circulate the blood stream and enlarge.
- Reservoir located in the spleen.
A mononuclear phagocytes that is tissue specific- differentiated monocyte.
5-10 times larger than monocytes and contains more organelles than them.
Alveolar macrophage- lung
Histiocytes- connective tissue
Kupffer cells- liver
Microglial cells- brain
An enzyme commonly found in neutrophils which produced hypochlorous acid:
This acid is a strong oxidising agent that kills pathogens, especially bacteria.
It is stored in the granules of neutrophils and since it has a haem pigment it appears green in pus and some mucus.
What wbc main increase in bacterial infection
Monocytes when infection is chronic.
Main wbc involved in viral infections
Monocytes also involved
Main wbc in parasitic infections
Mast cells also activated
Main wbc involved in fungal infections
Main Wbcs involved in allergic reactins
Eosinophils- when chronic.
Low molecular weight regulatory proteins that act as chemical messengers.
Generally act via paracrine signalling.
Cytokines which are directly involved in chemokines- attracts monocytes and neutrophils to site of infection.
Monocyte chemotactic protein-1
Chemokine that attracts monocytes.
Initial contact of leukocytes to the endothelium
P-selectin and E-selectin on endothelium recognise sulfated sialyl-Lewis ^x on leukocytes.
This forms a temporary attraction between the cells.
Tight contact of leukocytes to the endothelium
Intracellular adhesion molecules (ICAMs) on the endothelium recognise integrins on leukocytes.
Lymphocyte function-associated antigen-1
An integrin that binds to ICAM-1 (CD54): tight adhesion
Very late antigen-1
An integrin that binds to VCAM-1 (CD106) in a tight adhesion during chemotaxis.
An adhesion molecule on endothelium cells and found in atheromas-
They bind to monocytes and lymphocytes.
Cytokines released from activated macrophages.
Macrophage mannose receptor
A pattern recognition receptor on macrophages that recognise conserved carbohydrate structures on pathogens.
These ligands activate the macrophage to undergo phagocytosis.
A PRR that recognises:
- Anionic polymers
- Acetylated and oxidised LDL
Recognition of these ligands lead to phagocytosis.