First Aid, Chapter 2 Cells Involved in Immune Responses, Neutrophils Flashcards
Describe neutrophil nuclei, how big are they?
Have a multilobulated nucleus and are 12–15 μm in size (Figure 2-10).
What are the surface receptors on neutrophils?
Surface receptors for IgG, IgA
What stimulates survival, differentiation, and proliferation of neutrophils?
Derived from myeloid precursor (Figure 2-3). Survival, differentiation, and proliferation stimulated by IL-3, GM-CSF and G-CSF.
How many neutrophils are made daily? How long do they circulate for?
- Approximately 1 × 1011 is made per day in a healthy individual.
- Circulate for only 4–10 hours (mostly in the bone marrow).
What causes migration of neutrophils into tissues?
Migrate into tissues via IL-8 (CXCL-8), IFN, f-met-leu-phe (fMLP), MIP-1, LTB4, and C5a as well as interactions between Sialyl-Lewis X, E-/Pselectins, and LFA-1/ICAM-1.
Why are neutrophils, eosinophils, and basophils called polymorphonuclear cells? What are they named based on?
Neutrophils, eosinophils, and basophils are each considered polymorphonuclear cells because of the multilobulated appearance of their respective nuclei. They are named for their characteristic appearance after H&E stain. Basophils stain a basic blue. Eosinophils stain an acidic, bright red. Neutrophils stain a neutral pink.
What cells secrete cytokines that activate neutrophils?
Th17 cells
What is the neutrophil abnormalitiy in Chediak-Higashi syndrome? In Specific granule deficiency?
Primary granules are enlarged in ChediakHigashi syndrome, but secondary granules are absent in specific granule deficiency. The exact mediators in each are less important.
What are the mediators found in azurophilic granules of neutrophils?
Azurophilic (primary) granules: Myeloperoxidase, defensins, elastase, lysozyme, and cathepsin
What are the mediators found in specific granules of neutrophils?
Specific (secondary) granules: Lactoferrin, cathelicidin, fMLP, and CD11b
What are the mediators in gelatinase granules of neutrophils?
fMLP, CD11b, lysozyme, and gelatinase
What are the mediators in secretory granules of neutrophils?
fMLP, CD11b, and alkaline phosphatase
What are the primary functions of neutrophils?
- Function primarily as phagocytes.
- Phagosomes fuse to lysosomal granules (see Table 2-10) and kill invaders via respiratory burst.
- Also secrete detectable amounts of cytokines.
- Undergo apoptosis in tissue and can “feed” surrounding cells.
What is mild, moderate, and severe neutropenia?
o Mild: ANCA
What conditions can neutropenia cause?
A predisposition to severe bacterial infections, ulcerations, abscess formation, and gingivitis.
