White Blood Cells Flashcards
Does innate immunity have a memory response?
No
Innate immunity has ____ specificity
Limited
Speed of innate vs. adaptive immune responses.
Innate = fast
Adaptive = slower
Adaptive and innate immunity can be further subdivided into 2 categories. What are those?
Humoral
Cell-mediated
The complement system is part of the ____ immune system.
Innate, humoral
Cytokines and chemokines are part of the ______ immune system.
Innate humoral
Granulocyte material is part of the ____ immunity.
Innate humoral
Neutrophils, monocytes and macrophages are part of the ______ immune system.
Innate cell-mediated
Natural killer cells are part of the ____ immune system
Innate cell mediated
B-cells are part of the _____ immune system
Adaptive humoral
T-cells are part of the ______ immune system
Adaptive cell-mediated
What cells are present in the “buffy coat”?
Granulocytes (neutrophils, eosinophils, basophils)
Monocytes
NK-cells
T-cells
B-cells
Neutrophils
- Describe the granules.
- How do they appear under staining?
- Neutral, light purple
- Polymorphonuclear (multi-lobed)
How do eosinophils appear during stain? What is their function?
They have red granules. They dampen inflamatory responses
How do basophils stain? What is their function?
They appear dark blue / dark purple due to granules. They incite inflammation.
Most neutrophils have ______ nuclear lobes separated by_______
2-5
thin chromatin strands
Neutrophils contain _____ levels of granules.
3 - primary, secondary and tertiary
What are some important neutrophil primary granules to know?
Myeloperoxidase
Lysosomal enzymes
Elastase
Antibacterial proteins
What are important neutrophil secondary granules to know?
Lysozyme
What is an important neutrophil tertiary granule to know?
Alkaline phosphatse
Describe neutrophil degranulation.
The neutrophil migrates towrad inflammatory molecules (chemokines) and binds to particles that have been coated with antibodies and phagocytizes these molecules. The neutrophil then degranulates by fusing with vacuole containing the ingesting microbe / particle which results in death of the neutrophil. The granules could also be released into environment instead.
Describe where neutrophils will be recruited from when the body needs them.
Approximately 2% of neutrophil reserves are cirulating. If more are needed, they are first drawn from the marginated pool of neutrophils that are transiently adhering to vessel walls (~3%). If that is not enough, then more will be recruited from the storage pool (~75%) in the bone marrow. Additionally, more wil be produced from precursor cells for a high demand of neutrophils (20%)
Neutrophils make up ___% of the blood.
5
What signals cause release of neutrophils from storage pools?
Is neutrophil release and action slow or fast?
Inflammation, infection, cortisol, catecholamines
Fast
- What is a neutrophil band?
- What is a left shift?
- What is toxic granulation?
- What do all these signs suggest?
- A subset of circulating slightly immature neutrophils
- A generic term for an increase in neutrophil bands in the blood
- Toxic to invader –> neutrophils seen in cytoplasm of activated cells
- An increase in the number of neutrophils being recruited from the storage pool
Are basophils common in the blood?
No
Basophils mediate what 2 clinical conditions?
Asthma and allergies
Describe basophil kinetics
Basophils spend 5-7 days in the marrow where they are responding to IL-3 to mature to basophils. Then they are released into the circulation. Then they enter the target tissue and exert immune or infectious response. Their lifespan after leaving bone marrow is 2-3 days.
What granule is specific to basophils that is important in inflammatory response?
Histamine
Eosinophils are granulocytes with ____ nuclei and numerous _____ granules
Bilobed
Red
Describe eosinophil kinetics
Allergen or parasite –> activation of T-helper 2 cells –> stimulate IL-5 production –> activate differentiation into eosinophils in bone marrow (7 days) –> release to circulation –> randomly exit ~ 18 hours –> remain in tissue exerting effects for >6 days
Describe how eosinophils interact with B-cells to dampen inflammatory responses?
B cell is activated / sensitized due to presence of allergen and secretes IgE in response. IgE then binds to eosinophil, allowing adhesion and locomation into tissues. Eosinophils contain granules that degrade histamines and other molecules that incite inflammation so they dampen inflammatory response via degranulation.
What are 5 important graules in eosinophils?
Histaminase (degrades histamine)
Arylsulfatase (degrades leukotrienes)
Major basic protein
Eosinophil cationic protein
Peroxidase
Describe monocyte appearance under staining.
Large, irregular shape, folded nuclei, a lot of cytoplasm
Describe monocyte kinetics.
It takes 4-5 days to produce monocytes from the bone marrow. After entering circulation, they randomly exit the circulation after ~ 8 hours and settle down in tissue. Once settled in tissues they are macrophages, which target local infection and inflammation. Macrophages can last weeks or months in the tissues.
Which cell type is the key to mobilizing the adaptive immune system?
Monocytes –> tissue macrophages
Describe the innate and adaptive immune functions of macrophages.
(I) phagocytosis of foreign material
(I) consume dead tissue and / or cancer
(I) synthesize biologically active molecules
(A) present antigens from digested material on surface via MHCII which is used to activate lymphocytes
Macrophages are important for recycling and storing what ion?
Iron
Describe what resting lymphocytes look like.
Small, dark round nuclei and very little cytoplasm.
Describe what activated lymphocytes look like.
They are larger than resting, with more abundant cytoplasm
Where do b-cells mature?
Bone marrow
Where do t-cells mature?
What do they become?
Thymus
Cytotoxic t-cells that destroy damged / infected cells and helper t-cells that assist in activation of b-cells
Natural killer cells function within the ____ immune system.
NK cells (do/do not) require MHC to recognize target.
Innate
Do not
How are white blood cells differentiated from one another?
A class of surface molecules called “Cluster of Differentiation” proteins (CD) are used to identify cells with the same activity from one another. These CD molecules have been assigned numbers and distinguish specific cell types and are identified via flow cytometry.
What are the CD markers on a B-cell?
What are the CD markers on a B cell in a person with Chronic Lymphoid Leukemia (CLL)?
What are the CD markers on a T cell?
What are the CD markers on a helper T-cell?
What are the CD markers on a cytotoxic T cell?
What are the CD markers on a NK cell?
What is flow cytometry used for?
To count cells or diagnose a disease
What is a resting lymphocyte doing?
Wandering the bloodstream looking for stimulation (most t-cells)
What is a reactive lymphocyte doing?
These are scouring the blood when the body signals to the lymphoid tissues that there is an infection/allergen/toxin/drug or in autoimmune diseases
What do NK cells look like under staining?
If you perform a blood smear, will you identify cells of the innate immunity, the adaptive immunity, or both?
Innate immunity
Adaptive requires flow cytometery to ID
Describe the process of neutrophil kinetics.
It takes 14 days for neutrophils to mature in the bone marrow. From there, they enter circulation and randomly exit after a day or less, depending on whether they are called to a site of inflammation. They then either degranulate in the tissues or die and that process can take 1-3 days.
Describe how a basophil incites an inflammatory response.
Presence of an allergen causes a B-cell to secrete IgE antibodies, which then bind to IgE receptors on basophils. The bound IgE antibodies then crosslink with the antigen, which activates the basophil and results in degranulation. One of the contents of basophil granules is histamine, which is an incitor of inflammation.
What type of reactions do basophils and mast cells promote?
Hypersensitivity reactions
What are the 2 types of B-cells?
- Plasma cells that produce antibodies when activated by ligand to do so
- Memory b cells, which express receptors on their surface for antigens. When antigen binds to receptor, triggers B cell to become plasma cell and secrete antibodies.
