Leukon #1: Morphology and Function Flashcards
1
Q
Neutrophil - Size
A
~11 microns
2
Q
Neutrophil - Nucleus
A
- Segmented 2-4 lobes
- Dark, purplish to almost black
- Condensed, “mature” chromatin
3
Q
Neutrophil - Cytoplasm
A
- Clear to faint pink
- Feline - slight blue
4
Q
Neutrophil - Inclusions
A
- Granules do not stain (neutral) or light pink
- Two main types of granules (lysosomes)
- -Primary (or azurophilic)
- -Secondary (or specific)
- -(Also Tertiary - less important)
- Granule contents:
- -Sequestered in granules to protect the cell
- -Secreted into phagocytic vacuoles for killing
5
Q
Neutrophil - Barr Body
A
- Sex chromatin lobe
- Low percentage of neutrophils of female mammals
- Inactivated X chromosomes
6
Q
Primary Granules
A
- Small reddish-purple granules
- Similar to lysosomes
- Contain acid hydrolases
- Contain myeloperoxidase (MPO)
- -Neutrophils can be marked based on presence of MPO
- Give neutrophils their function
- BM: formed at late myeloblast/ early promyelocyte stage
- Don’t normally stain very well in blood smears
7
Q
Secondary Granules
A
- Stain neutral
- Specific granules
- Most numerous
- Contents involved in the inflammatory response
- ID the cell
- BM: develop at myelocyte stage
- -Other granulocytes uptake stain based on pH
8
Q
Tertiary Granules
A
- Contain secretory enzymes
- Can insert adhesion molecules on the surface of the cell
9
Q
Granule Considerations
A
- Fine/faint pink granulation common
- Mostly artifact: pH, sample age
- Healthy neonatal foals: healthy
- Toxic granulation
10
Q
Granulopoiesis - Maturation
A
- Myeloblasts have nucleoli
- As they mature
- -Size - smaller
- -Cytoplasm - less basophilic
- -Nucleus - more lobulated
- -Chromatin - more coarse and condensed
11
Q
Neutrophil - Function
A
- Primary function: Phagocytosis and Bacterial Killing
- -Respond to strong irritants
- –Bacterial products, chemical toxins, tissue injury
- Metabolically active processes
- -Adhere and transmigrate through vessel wall
- -Chemotaxis (migration along chemical gradient)
- -Phagocytosis (ingestion) - forms phagosome
- -Degranulation - into phagosome or externally
- -Killing
1. Granule contents (microbiocidal, enzymes)
2. Respiratory burst - toxic reactive oxygen species - Also assist with lower grade irritants:
- -Fungal organisms, yeasts, algae, parasites, viruses, foreign bodies
- Receptors
- -Cytokines
- -Toll-like receptors
- -Pathogen products (LPS, f-MLP)
- -Adhesion molecules (selectins, integrins)
- Activation of NADPH oxidase and microbial systems during phagocytosis
1. Complement and antibody receptors promote
2. Uptake of microorganisms
3. Degranulation
4. Production of ROS
12
Q
Eosinophil - Size
A
~12-14 microns
- Greater than size of neutrophil
- Less than or equal to size of basophil
13
Q
Eosinophil - Nucleus
A
- 2-3 round to irregular lobes
- Chromatin dark, condensed
14
Q
Eosinophil - Cytoplasm
A
-Clear, faint pink/blue
15
Q
Eosinophil - Inclusions
A
- Secondary granules differ by species
- -Dog: round, variable sizes
- -Sighthounds: gray granules
- -Cats: rod-shaped granules
- -Horse: large and round
- -Ruminants and pigs: small and round
- Secondary granule contents:
- -Major basic protein - cytotoxic to parasites, protozoa, and bacteria
- -Eosinophil peroxidase - generates ROS toxic to helminths, bacteria, mycoplasmas, fungi, protozoa, viruses, and tumor cells
- -Eosinophil cationic protein - toxic to helminths, protozoa, and bacteria
- -Eosinophil-derived neurotoxin - toxic to myelinated nerve fibers
- Tertiary granules:
- -Contain secretory enzymes
- -Can insert adhesion molecules on the surface of the cell
16
Q
Eosinophil - Function
A
- Association: worms, wheezes, and weird diseases
- -IgE mediated conditions (released by plasma cells)
- -Recruited to the tissues by IL-5 (released from Th2 cells)
- Helminths
- -Eosinophils bind to and degranulate
- -Release major basic protein
- -Release eosinophil-specific peroxidase
- -Production of ROS
- -Aided by complement and T-cell perforins
- Hypersensitivity
- -Attracted by mast cell/basophil chemicals
- –Ex: histamine (respond with release of anti-histamine)
- -Can promote inflammation, tissue damage
- –Allergies, asthma - bind IgE-Ag and exocytose
- –Inflammation, fibrosis, etc.
- -Phagocytosis (possible, but not as efficient at it as neutrophils are)
- Tumor associated eosinophilia
- -Often paraneoplastic by IL-5 production by tumor cells
- -Ex: mast cell tumor, T-cell lymphoma, carcinoma, fibrosarcoma
- Rapid blood transit time
- Long life in the tissues: lungs, GI tract, and skin
17
Q
Basophil - Size
A
~14-15 microns
- Greater than or equal to size of eosinophils
- Less than or equal to size of monocyte
18
Q
Basophil - Nucleus
A
- 2-3 lobes, may look ribbon like
- Medium to dark chromatin
- Varies from seg to monocyte-like chromatin density
19
Q
Basophil - Cytoplasm
A
-Clear, blue/gray, magenta blue
20
Q
Basophil - Inclusions
A
- Secondary granules vary by species
- -Dog: indistinct lavender to purple granules
- -Cat: pale to distinct lavender, rod-shaped
- -Horse and ruminant: purple
21
Q
Basophile - Functions
A
- Associated with similar conditions as eosinophils (worms, wheezes, and weird diseases)
- Associated with similar functions as mast cell (similar granule contents)
- -Histamine: both
- -Heparin (involved in hemostasis): mast cells
- -Share a progenitor in marrow, but…
- –Different nuclear morphology
- –Basophils leave marrow mature
- –Mast cells leave marrow agranular
- –Mast cells mature in tissues (rarely seen in blood)
22
Q
Mononuclear cell - General info
A
- NOT devoid of granules
- -Granules still present, just fewer - less obvious
- -Large Granular Lymphocytes (LGLs)
- –Focal pink/purple granules
- –May be cytotoxic T cells or NK cells
23
Q
Monocytes –> Macrophages
A
Monocytes become macrophages and dendritic cells in the tissues
- Collectively called Mononuclear Phagocyte System (MPS)
- -Includes:
- –Blood monocyte-derived macrophages
- –Dendritic cells and fixed
- –Tissue-specific cells
24
Q
Monocyte - Size
A
Greater than or equal to 15 microns
25
Q
Monocyte - Nucleus
A
- Oval, reniform, bilobed, trilobed
- Light, lacy chromatin, some clumped
26
Q
Monocyte - Cytoplasm
A
-Light to dark blue-gray
27
Q
Monocyte - Inclusions
A
- Vacuoles common
- -Round, variable sizes, ‘punched out’ v. foamy
- -Some may be sample age/storage induced
- Fine pink granules possible (lysosomes)
28
Q
Monocyte - Tissue Differentiation
A
- Blood monocyte-derived macrophage activation leads to specialization:
- -Phagocytic cells (classic macrophage)
- –Increased vacuolated cytoplasm
- –Enhanced phagocytosis, clean up
- –Organisms, debris, foreign material
- -Epithelioid cells (signaling)
- –Orchestrate inflammation through secretory functions
- Blood monocyte-derived dendritic cells
- -APCs in various tissue sites
- –Skin (Langerhans cells)
- –Mucosal sites: respiratory, digestive, etc.
- –Lymphoid tissues
- –Link innate and adaptive immune systems
- Fixed tissue macrophages
- -Ex: Kupffer cells (liver), microglia (CNS), alveolar cells (lungs), osteoclasts (bone), etc.
- -Long lived (weeks/months)
- -Thought all were blood monocyte derived
- -Recent reports suggest these may be seeded in sites early in life and replicate there
29
Q
Monocyte/Macrophage - Functions
A
-Respond to low-grade irritants (v. neutrophil)
- Phagocytize: foreign materials, dead/effete cells
- -Clean up foreign and domestic debris
- -Not as efficient as neutrophils on bacteria
- –Higher order bacteria: mycobacteria, nocardia, actinomyces
- –Protozoa: leishmania, toxoplasma
- –Fungi: balstomycosis
- -Kill cell function (immune)
- –Ab-mediated cytotoxic function (viral-mediated, tumor cells)
- Secrete: orchestrate inflammation and tissue repair
- -Inflammation
- –Chemotaxis factors, complement, collagenase, elastase, etc.
- –G-CSF, GM-CSF:
- —PMNs: increase marrow divisions, inhibit apoptosis, “prime” functions
- -Hematopoiesis
- –Major source of CSFs, cytokines
- —G-CSF, M-CSF, IL-1, IL-3, TNF
- –Iron metabolism –> erythropoiesis
30
Q
Lymphocyte - Size
A
~8-10 microns (normal and small)
- High NC ratio
- Bigger than RBC, smaller than neutrophil
- Ruminants: small and large (less than or equal to 15 microns)
- Sizing lymphocytes:
- -Small: nucleus fits inside neutrophil
- -Intermediate: nucleus is same size as neutrophil
- -Large: neutrophil fits inside nucleus
31
Q
Lymphocyte - Cytoplasm
A
- Clear to faint blue
- Darker blue edges if reactive
32
Q
Lymphocyte - Nucleus
A
- Round to slightly angular
- Ruminant: large lymphocytes more irregular
- Stimulated neoplastic lymphocytes –> +/- pleomorphic
- Moderately condensed chromatin
33
Q
Lymphocyte - General Information
A
- Morphology alone only IDs plasma cells and LGLs
- Cell markers (CD markers) are needed to subtype lymphocytes
- Have a heterogeneous population
- Lymphocytes recirculate
34
Q
Lymphocyte - Inclusions
A
- Granular lymphocytes (should only be ~10% granular)
- -Small pink or purple granules
- -Often in perinuclear clear area
- -Mostly cytotoxic T or NK cells
- -Can be normal, reactive, or neoplastic
35
Q
Lymphocyte - Artifacts
A
Sitting in EDTA 30-60 minutes
- Possible vacuoles, lobulation, or smudging of nuclei
- Make smears ASAP after drawing blood
- True in other cells to varying degrees
36
Q
Lymphocyte - Functions
A
- B cells
- -Humoral (antibody) immunity
- -Divide and transform into effector cells that produce IG
- -Plasma cells are the most differentiated cell
- T cells
- -Cell-mediated immunity
- -Divide and transform into effector cells that produce lymphokines and mediate cellular immunity
