Flashcards in Lecture 2, Cells Deck (37):
What body area provides structural and molecular support for stem cell renewal and differentiation?
What general type of cells provide support & growth factors for HSC maintenance & differentiation?
What are the 2 main types of immune progenitor cells HSCs can differentiate into?
Common myeloid progenitors and common lymphoid progenitors
*Name 8 "cells" that the common myeloid progenitors (innate) can differentiate into.
- Megakaryocyte (gives off platelets)
- Mast cell (directly)
- Macrophages (from monocytes)
- Dendritic cells (from monocytes)
*Name the 3 main cells that the common lymphoid progenitors (adaptive) can differentiate into.
- T lymphocytes (helpers + killers)
- B lymphocytes (can become plasma cell)
- Natural killer cells
Naive lymphocytes reach lymph nodes from the __________, while antigens reach the lymph node from the ___________. They both return to the blood via the ___________.
- thoracic duct (enters left subclavian)
*Besides phagolysosomal formation, what 2 other mech can neutrophils use to destroy their enemy?
- NETs (neutrophil extracellular traps)
*What 4 substances do eosinophils release from their granules?
- Major basic protein
- Eosinophil collagenase
- Eosinophil-derived neurotoxin
What does major basic protein do?
Toxic to parasites + surrounding tissue; triggers mast cell histamine release
What do leukotrienes do when released by eosinophils?
- Causes smooth muscle contraction to increased vascular permeability
- Increased mucus secretion
What's a dangerous side-effect of chronic activation of eosinophils during allergies?
Tissue remodeling (e.g. in chronic allergic asthma)
What are the major effects of mast cell degranulation?
- Local increase in blood flow
- Increased vascular permeability via smooth muscle constriction
- Increased fluid and AB accumulation in tissue
- Extravasation of immune cells
- Increased flow of antigen in lymph to regional lymph nodes
What major issue could be caused by systemic mast cell degranulation? Skin only?
- Systemic: anaphylaxis
- Local: urticaria (can be widespread)
T cells are formed in the ____________, B cells (and NK cells) are formed in the ___________.
- bone marrow
*Are NK cells part of the innate or adaptive response? How can you tell this from their receptors?
- Receptors are invariant
What types of cells prevent a viral infection from "going viral?"
NK cells (kill virally infected cells and contain them until T cells proliferate)
Some of the principal molecules involved in HSC differentiation include _______ and _______ for common myeloid progenitors; ______ for common lymphoid progenitors.
- IL‐3 and GM‐CSF
Some of the principal molecules involved in HSC differentiation include ______ for basophils.
Some of the principal molecules involved in HSC differentiation include ______ for neutrophils.
Some of the principal molecules involved in HSC differentiation include ______ for eosinophils.
Some of the principal molecules involved in HSC differentiation include _____ and/or ______ for macrophages and monocytes.
GM-CSF and/or M-CSF
Some of the principal molecules involved in HSC differentiation include ______ for DCs.
A principal molecules involved in HSC differentiation includes ______ for T cells.
HSC niches consist of what 2 cell types?
Osteoblasts or sinusoidal endothelial cells
HSCs return to the circulation is controlled in a ____________ manner.
Explain the process of phagolysosome formation for a neutrophil.
1. Bound pathogen (often bacterial) is engulfed & internalized: phagosome
2. Phagosome is acidified
3. Lysosomes fuse with phagosome
4. Phagolysosome formation
5. Enzymes & other antimicrobial substances are released & pathogen is destroyed
What 2 types of granules can PMNs release, and how do they perform their functions?
- Primary (azurophilic) granules- direct toxic/enzymatic activity
- Secondary (specific) granules- free radical formation
What are the 2 methods by which DC's sample the environment?
What is the main function of eosinophils?
Killing of parasites.
How would you ID an eosinophil?
Bilobed nucleus, bright pink granules.
How would you ID a neutrophil?
2-5 (3-4) lobed nucleus, Light-pink H&E staining granules that are electron-dense
How would you ID a monocyte/macrophage?
Large cells with eccentrically-placed, vesicular nuclei
- Contain abundant amounts of lysosomes
Besides being an APC, what else can monocytes/macrophages do?
How would you ID a mast cell?
- Very dark basophilic granules rich in histamine & heparin
How would you ID a basophil? (rare)
2-3 poorly defined/obscured nuclear lobes
- Dark basophilic granules rich in histamine & heparin
How would you ID an NK cell?
Large cells; mononuclear
- Distinctive granular cytoplasm