The Innate Immune Response

Question 1

Compliment system

Answer 1

A sensor that circulated in the blood and tissue fluids. It’s a set of proteins that are inactive when circulating but become active when they detect stimuli and results in removal and destruction of invading microbes
Can act with adaptive immune responses
Recruit phagocytes
Bind to foreign material

Alternative pathway (C3b binding), lectin pathway, and classical pathway (antibody binding) leads to formation of C3 convertase…leads to opsinization (C3b binds to microbial cells and prepares it for eating, phagocytes) and inflammatory response (C3a and C5a) and lysis of foreign cells (C5b makes membrane attack complexes that lyse cells…gram positive bacteria are resistant because their thick peptidoglycan layer)

Question 2

Innate responses

Answer 2

Inflammation: results when various sensor systems detect infection or tissue damage and leak proteins and phagocytes into tissues.
Fever: high temperatures interferes with growth of some pathogens and can enhance effectiveness of other responses

Question 3

First line defenses

Answer 3

Skin: sweat (salt production), has keratin which repels water..dead skin cells fall of and take virus with it.
Digestive tract: peristalsis moves microbes to feces
Respiratory tract: ciliated cells mov microbes to throat for it to be swallowed
Epithelial cells
Anti microbial substances: lysosome: degrades peptidoglycan…lactoferrin binds iron to protein (microorganisms need iron to grow)
Normal microbiota; competitively exclude other organisms. Engulf nutrients, cover binding sites, and produce toxins that destroy infectious viruses.

Question 4

Hematopoiesis

Answer 4

Formation of blood cells
Form from bone marrow
All blood cells originate from the hematopoietic stem cells

Question 5

Dendritic cells

Answer 5

Sentinel cells (scouts). Engulf materials from tissues and bring to adaptive immune system. 
Develop from monocytes.

Question 6

How do cells communicate with each other to recruit white blood cells.

Answer 6

Surface receptors; proteins that span the cytoplasmic membrane and look out for invaders and then it binds to a cells receptor to let it know that there is an invader near, triggering chemotaxis.

Cytokines: voices of the cell…binding of the cytokine to the cell induces a change in the cell such as growth, differentiation, movement, or cell death.

Interferons: important in a number of regulatory mechanisms. Stimulates response of some cells and inhibiting response in others.

Question 7

Innate immune defenses

Answer 7

Anything that crosses first line defense is considered an invader.
Certain host cells serve as sentinels (lookouts or guards) that detect if invaders have breached the defense. They use pattern recognition receptors (PRRs). Some are located on surface of cells (detect surrounding invaders), others are within cells’ endosomes and phagosomes (determines what they engulfed)

Question 8

Inflammatory response

Answer 8

When normally sterile body sites or when tissues are damaged the area is inflamed to contain the site of damage, localize the response, eliminate the invader, and restore tissue function.

Detection of Microbes and tissue damage signals cells to produce proinflammatory cytokines and chemicals (ex histamine)
Causes dilation of blood vessels and more blood flow. Fluid leaks (fluid contains neutrophils, compliment system proteins, and antibodies) phagocytes tumble and halt and then squeeze between the endothelial cells and enter tissues. Neutrophils attack first. Phagocytosis occurs and blood clot forms. This prevents bleeding and stops spread of invading microbes

Inflammation in delicate systems (brain and spinal cord) can be deadly. Phagocytes release enzymes and toxic products.

Question 9

Pyroptosis

Answer 9

Opposite of apoptosis (antiinflamatory response)
Has an inflammatory response
Triggered by PRR’s in the macrophages cytoplasm.