Lecture 2, Cells Flashcards
What body area provides structural and molecular support for stem cell renewal and differentiation?
Bone marrow
What general type of cells provide support & growth factors for HSC maintenance & differentiation?
Stromal cells
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)
- Erythrocyte
- Mast cell (directly)
- Basophil
- Neutrophil
- Eosinophil
- Monocytes
- 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 ___________.
- blood
- lymphatics
- thoracic duct (enters left subclavian)
*Besides phagolysosomal formation, what 2 other mech can neutrophils use to destroy their enemy?
- Degranulation
- NETs (neutrophil extracellular traps)
*What 4 substances do eosinophils release from their granules?
- Major basic protein
- Eosinophil collagenase
- Leukotrienes
- 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 ___________.
- thymus
- bone marrow
*Are NK cells part of the innate or adaptive response? How can you tell this from their receptors?
Innate
- 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
- IL‐7
Some of the principal molecules involved in HSC differentiation include ______ for basophils.
IL-4
Some of the principal molecules involved in HSC differentiation include ______ for neutrophils.
G-CSF
Some of the principal molecules involved in HSC differentiation include ______ for eosinophils.
IL-5
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.
Flt3L
A principal molecules involved in HSC differentiation includes ______ for T cells.
IL-2
HSC niches consist of what 2 cell types?
Osteoblasts or sinusoidal endothelial cells
