L1 Flashcards
Adaptive or innate: specificity inherited in the genome.
Innate
Adaptive is randomized
What are the 2 cell lineages that arise from hematopoietic stem cell division? Name cells that arise from each.
Lymphoid - (adaptive cells) B, T, NK cells
Myeloid - (innate cells) RBCs, platelets, granulocytes
How do stroma cells in bone marrow contribute to blood cell division?
Make GFs that push cells into various differentiation paths
Hematopoietic stem cells divide and produce 2 different cells. What are they?
1 cell that differentiates
1 stem cell - self-renewing mechanism in division
What are the main granulocytes? What is their goal?
Pro-inflammatory granules
- Eosinophils
- Basophils
- Mast cells
Describe a neutrophil on histo.
PNM = multilobar nuclei (3-5 lobes)
Where do monocytes mature?
Monocyte enters tissue b/c chemokine gradient
@ tissue - differentiate into macrophages
What are the main functions of an activated macrophage?
Phagocytose pathogen
APC the phagosome
Secrete pro-inflam cytokines
What receptor is present on all T cells?
CD3
Helper = CD4 & CD3
Cytotoxic = CD8 & CD3
What happens when a lymphocyte becomes activated?
Lymphocyte = T/B cell precursor
Activated –> effector T or B cell
Are cytokines general or specific?
Specific!
Need receptors to bind cytokine
What are defensins?
Innate immune particles on skin to kill microbes before they get in
Describe why innate immunity has conserved receptors?
DNA encoded receptors for well established pathogens encountered throughout evolution
Looking for PATTERNS
Which granulocyte is the “first responder”?
Neutrophils
Which granulocyte is important for parasitic infections?
Eosinophils
Do granulocytes or phagocytes release cytokines when activated?
BOTH can!
Why are adaptive immune receptors randomly generated?
Create large # possibilities
Cover your bases for pathogens you’ve never seen
How does the adaptive immune system portray clonality?
1 cell w/ specific receptor gets activated
Divides
All have that specific receptor because it is the one that bound the antigen - clonal to that first precursor
What are PAMPs?
Pathogen associated molecular patterns
The PATTERNS innate immune cells are looking for
What are PRRs? Where are they located?
Pattern recognition receptors
ON and IN innate immune cells - @ membrane & vesicles
Bind PAMPs
What cytokine do innate immune cells produce when PRRs bind PAMPs? What does this cytokine do?
IL1
Activate inflammation
Why chemokines generally attract innate immune cells to a tissue?
IL1 & TNF
Allow APCs to migrate into tissue
When innate immune cells enter a tissue, they increase expression of a certain receptor. Which one and why?
CCR7
Causes trafficking to nearest lymph node
Where do APCs bind antigens? Where do they go once bound?
Bind @ peripheral tissue
Go to nearest lymph node
When APCs bind antigen, the antigen is presented on MHC2. What other surface molecule is increased?
Co-stimulatory molecules increased
Needed for secondary activation of other immune cells (“confirmation signal”)
Describe T and B cell distribution in lymph nodes?
T cells = central
B cells = outside as follicles
Movement between regions
What is a lymphocyte vs leukocyte? Which cytokines are specific to each group?
Leuko = WBCs
- ILs allow communication between leukos
Lympho = adaptive immune cells
- Lymphokines for communication between lymphocytes
How does innate immunity recruit adaptive? Give the general picture for both T and B cells.
Complement - B cells
APCs - T cells
What receptors are on all B cells?
CD19
CD24
MHC 2
Fc receptors (surface Ab)
What receptors are on all NK cells?
CD16 - Fc receptor for IgG
What is the goal of Th1 cells? What cells do they act on?
T helper cell w/ goal = ACTIVATION
Make cytokines
Activate macrophages & CD8
What is the goal of Th2 cells?
T helper w/ goal = create Abs - neutralize the pathogen
Recruit IgE & eosinophils
What is the goal of Th17 cells?
T helper w/ goal = acute inflammation
What is the goal of Treg cells?
T helper w/ goal = dampen immune response
What happense without appropriate leukocyte mgration?
WBCs can’t follow or lacking a chemokine gradient
Can’t get to source of infection - won’t fight it
What did David the Bubble Boy have?
SCID = severe combined immune deficiency
Inherited lack of innate AND adaptive immune systems
