Lecture 2 - Innate vs Adaptive Immunity Flashcards
Before the induction of the immune response occurs, what must be reached?
Threshold level of antigen must be activated by the infecting microorganism
What is the difference between the following situations:
- No innate immunity
- No adaptive immunity
- Normal immunity
- No innate = infection will never initiate an adaptive response
- microorganism replicates until completely infects the host - No adaptive
- increase in level of microorganism but eventually plateaus
& microorganism will be cleared - Normal immunity includes:
- Establishment of infection
- Induction of adaptive response
- Adaptive Immune response
- Immunological memory once the pathogen is cleared
What is a crucial aspect of adaptive immunity?
INNATE immunity!
The following describes innate or adaptive immunity?
- Germline encoded defense
- Highly conserved global strategies (no gene rearrangement/somatic hypermutation)
- Function within WBC’s of myeloid lineage
INNATE
What are some cells of innate immunity in the blood that are of MYELOID origin(5)? Of lymphoid origin (2)
In the Tissues?(3)
- of which origin?
Myeloid:
- Monocyte
- Neutrophil
- IMMATURE Dendritic Cells
- Eosonophils
- Basophils
Lymphoid:
- T cell
- NK cell
Tissues - Myeloid:
- Mature dendritic cell
- Immature Dendritic cell
- MACROPHAGE
What are the KEY cells in the innate immune response, that are not found in the ADAPTIVE immune response?
What are the two types?
- PHAGOCYTES
- leukocytes that recognize, ingest, and kill invading microbes
Two types:
a)Macrophages
B) Neutrophils
What are the main differences for Macrophages and Neutrophils:
- Life span
- Location of origin
Macrophages:
- LONG life span
- widely distributed in tissues
Neutrophils:
- short lived
- NOT in normal tissues, but instead in the blood
The following describes macrophages or neutrophils?
- Long lived
- Widely distributed in normal tissues
- Terminally differentiated cells (don’t actively divide/differentiate)
- FIRST RESPONDERS
- Derived from monocytes
- High number at site of injury/inflammation
MACROPHAGES
The following describes macrophages or neutrophils?
- Most common circulating WBC
- RAPID responders
- Short lived
- RARELY in normal tissue
Neutrophils
What are the 4 main functions of macrophages & neutrophils?
- Phagocytosis
- Mediator Production
- PAMP recognition
- Inflammatory response
What is opsonization?
What is an example within adaptive & innate immunity?
The coating of particles by molecules that enhance recognition by phagocytes
ex: adaptive immunity can opsonize pathogens with antibodies
Innate: opsonize with proteins of the complement system
What is mediator production?
What are some mediators that macrophages and neutrophils produce? (5)
What are their functions?
Produce a large variety of substances to combat the invading microorganism
- Cytokines
- program cells for combat - Chemokines
- recruit leukocytes to infection site - Hydrolases
- assist in clearing pathogens - Lipid Mediators
- act like cytokines to affect how cells behave - Reactive Nitrogen species & Oxygen
- bleaching the area
Which cells highly express are PRR’s (PAMP recognition receptors)?
What type of signals do they recognize?
What signals do they initiate?
- Highly expressied in MACROPHAGES & dendritic cells
- PRR’s are highly conserved and recognize bacterial, viral, and fungal components
- Initiate signals that recruit B and T cells
What are some important PRR receptors?
- TLR (toll like receptor)
- NLR - nod like receptors
- RLR (RIG- I helices like receptors)
- CLR (C-type lectin receptors)
What is inflammation?
Initiation of inflammation is innate or adaptive immune response?
What is acute inflammation?
Accumulation of fluid, plasma proteins, and WBC’s when tissue is injured, infected, or immune response is activated
INNATE immune response = inflammation
Acute inflammation is the inflammation that results from the innate response to a threat
What are the main functions of Inflammation?
- Fundamentally Protective
(contain/destroy bacteria) - Trigger by INNATE CELLS that release pro-inflammatory mediators
- Destroy/Contain pathogens
- Interwoven with tissue repair
- Can be destructive if not controlled (prolonged)
What are the 4 pillars of the immune response?
What are the 3 key events?***
- Redness
- Pain
- Heat
- Swelling
- Increased Blood flow
- Increased Vascular Permeability
- Infiltration of WBC’s to the area
Describe the purpose of the following responses to inflammation:
- Increased Blood flow
- Increased Vascular Permeability
- where does this occur primarily
- what can occur if this is prolonged - Infiltration of WBC’s to the area
(which cells invade 1st,2nd, 3rd)
- Increased Blood flow
- vasodilation to have more movement of serum mediators and White cells to the area of insult - Increased Vascular Permeability
- endothelial cells contract
- widened intracellular junctions
* primarily in VENULES*
- can cause necrosis/detachment
MAIN: Serum components leak into the tissue space
- Infiltration of WBC’s to the area
- neutrophils invade 1st
- Macrophages 2nd
- lymphocytes 3rd
What turns on the innate System/Response?
PAMPS/DAMPS!!!
(DAMPS recognize if DNA is outside the cell)
- PRR’s on Dendritic Cells or Macrophages activate an immune response
- specific PAMP is activates to eliminate the type of infecting organism that bears the PAMP
What happens after the PRR binds to PAMP/DAMP and initiates the Immune Response?
leads to expression of pro inflammatory cytokines & antimicrobial proteins
What kind of PAMPS do TLR’s recognize specifically?
Viral Nucleic Acids
– LPS (gram negative bacteria)
What are 4 classes of PRR’s and what do they specifically do?
Which are extracellular?
- Toll-like Receptors:
sense extracellular pathogens like bacteria/viral - C-Type: recognize sugars exposed on the surface of certain fungi (fungal infections) =
EXTRACELLULAR - Nod Like Receptors:
conserved molecules on the surface of bacteria, danger associated molecular patterns (DAMP)
recognize both viral and bacterial
(INTRACELLULAR) - RLR: Rig – I receptors :
recognize RNA molecules (often viral RNA molecules)
recognize the structural differences in the RNA
(INTRACELLULAR)
What do TLR’s recognize specifically?
Phagocytosed bacteria
or Extracellular Bacteria
What happens when a TLR is activated?
LPS binds TLR 4
- -> transmits a signal–> MyD88
- -> transmits to IRAK –> NF kB
