Ch. 14 - Innate Immune Response

Name all the types of first line defenses

1. Physical Barriers

2. Antimicrobial substances

3. Normal microbiota

Skin and mucous membranes belong to what (A) line & (B) category of defense?

A. First-line

B. Physical Barriers

Skin

Serves as initial block against breach attempt due to multiple layer thickness

What does the mucociliary escalator do?

Moves mucus up and out of respiratory tract to clear out microbes

Name all the types of antimicrobial substances

1. Lysozyme

2. Lactoferrin

3. Anti-microbial peptides (AMPs)

Lysozyme

1. Antimicrobial substance

2. Destroys/breaks down peptidoglycan

Lactoferrin

1. Antimicrobial substance

2. inhibits bacteria from getting iron

Defensin is a type of what?

Anti-microbial peptide

What does defensin do?

1. Antimicrobial substance

2. Forms pores (“pokes holes”) that damage microbial cells

Acid in the stomach, urinary tract flushing, and tears are all examples of what line of defense?

First-line defense

Competitive exclusion, bactericins, and tolerance are all a type of (A) line & (B) category of defense

A. First-line defense

B. Normal microbiota

Competitive Exclusion

1. Normal Microbiota

2. Compete with foreign microbes (potential pathogens) for nutrients & a physical spot to colonize

Bactericins

1. Normal microbiota

2. Toxic compound to to foreign microbes produced

Immune Tolerance

1. Normal Microbiota

2. Tolerance of harmless materials seen as “regulars”

Surface receptors

Proteins spanning the cytoplasmic membrane that binds to a specific type of ligand

What happens when a ligand binds to a cell’s surface receptor?

Binding triggers cell response and subsequent effect

A cytokine is a type of _______

Soluble ligand; “voice” of a cell

A chemokine is a sub-category of: _______

Cytokines

What is the result of chemokine binding?

Chemotaxis for immune cells to site of injury/infection

Interferons are a sub-category of _______ and are ________ and regulate __________.

1. Cytokines

2. Antiviral (respond to viral infection)

3. Immune responses

What are Pattern Recognition Receptors (PRRs)?

Sensors that allow the body’s cells to “see” signs of microbial invasion

What cells are PRRs found on or in?

A. Sentinel Cells

1. Macrophages

2. Dendritic cells

B. Virally infected cells

Name all sentinel cells

1. Macrophages

2. Dendritic cells

What locations are PRRs found in?

1. Cell surface

2. Cytoplasm

3. Phagosomes (endosomes)/Lysozomes

What do cell surface PRRs detect?

Detect microbial components present in the cell’s surroundings

What do cytoplasm PRRs detect?

Detect cell damage as well as microbial components

What to phagosome/lysozome PRRs detect?

Detect components of microbes ingested by the cell

What do PRRs detect?

MAMPs or Microbial Associated Molecular Patterns

What is another term for MAMPs?

PAMPS or Pathogen Associated Molecular Patterns

Peptidoglycan

1. MAMPs

2. NAG-NAM

LPS

1. MAMPs

2. Gram negative outer membrane

Flagella

1. MAMPs

2. Subunits

Microbial nucleic acids

1. MAMPs

Mannose

1. MAMPs

2. Unique sugar on bacterial surface

Viruses

1. MAMPs

2. Capsids (capsomeres)

What (A) line & (B) type of defense are PRRs?

1. Second-line

2. Cell communication

What line of defense is phagocytosis?

Second-line

What is the first step of phagocytosis?

Chemotaxis

Chemotaxis

1. Cell lets out distress signal (chemokines) at site of infection

What is an example of chemotaxis?

C5a

What does C5a do?

Recruits phagocytes to the site of infection via chemotaxis

How do immune cells move to site of infection

Follow chemicals (chemotaxis)

What is step two of phagocytosis?

Recognition and Attachment

How do normal microbiota serve as a first line of defense?

1. Produce bacterins

2. Competitive exclusion

3. Aid in immune system development (tolerance)

Are antibodies a part of innate immunity?

No, they are are part of the adaptive immune system.

Place the steps of phagocytosis in the correct order:

1) exocytosis

2) engulfment

3) chemotaxis

4) fusion of phagosome and lysosome

5) destruction and degradation of microbe

6) recognition and attachment

3, 6, 2, 4, 5, 1

The first leukocytes to the site of infection during the inflammatory response that are involved in phagocytosis of microbes are the _________.

Neutrophils

The squeezing of phagocytic cells in between endothelial tissue cells to get to the site of an infection during the inflammatory response is known as _______________.

Diapedesis

What complement proteins are involved directly in cytolysis using a membrane attack complex?

C5b, C6, C7, C8 and C9