Innate immunity

Question 1

What are the three levels of defense?

Answer 1

Level 1: Skin, mucous membranes, stomach acid, cilia, lysozyme in tears,

Level 2: Macrophages, neutrophil.s, eosinophils, basophils, monocytes
Complement system

Level 3: Adaptive immunity
Cellular (cytotoxic)
Humoral( Antibodies)

Question 2

Which immunity has a fast nonspecific response, and has no memory?

Answer 2

innate immunity

Question 3

List the cardinal signs of inflammation

Answer 3

Swelling (tumor)
Pain (dolor)
Redness (rubor)
Heat (Calor)

Question 4

What are the causes of inflammation

Answer 4

Injury
Pathogen
Chemical or radiation

Question 5

What are the important role players of inflammation?

Answer 5

Microvasculature
Circulating blood cells
Immune cells n tissue
Cytokines (e.g. histamine and prostaglandins)

Question 6

State function and location of mast cell

Answer 6

Mast cell: Secretes cytokines (e.g. Histamine, Heparin). Dilates BVs, starts the inflammatory response. Found in CTs and mucous membranes.

Question 7

State function and location of macrophages

Answer 7

2.Macrophages: Phagocytic and stimulates response of other immune cells. Migrates from BVs into tissues.

Question 8

State function and location of Natural killer cells

Answer 8

3.NK cells: Kills tumor cells and virus-infected cells. Circulates in blood and migrates into tissues.

Question 9

State function and location of dendritic cells?

Answer 9

4.Dendritic cells: Antigen-presenting cell, thus it triggers adaptive immunity. Found in epithelial tissue, but migrates to the lymph nodes when activated.

Question 10

State function and location of monocytes

Answer 10

5.Monocyte: Differentiates into macrophages and dendritic cells in response to inflammation. Stored in spleen, moves through blood vessel to infected tissue.

Question 11

Function and location of neutrophil

Answer 11

6. Neutrophil: First responder at the site of infection or trauma. Releases toxins that kill or inhibit microorganisms. Recruits other immune cells to the site of infection. Migrates from blood vessels into tissues.

Question 12

Function and location of Basophil

Answer 12

7. Basophil: Responsible for defense against parasites. Releases histamines that cause inflammation and may be responsible for allergic reactions. Circulates in blood and migrates to tissues.

Question 13

Function and location eosinophils

Answer 13

8.Releases toxins that kill bacteria and parasites by also causes tissue damage. Circulates in blood and migrates to tissue

Question 14

Name the surveillance cells located in circulation

Answer 14

Neutrophils

Monocytes: Differentiate into macrophages at tissue

Question 15

Name surveillance cells located in tissues

Answer 15

Resident macrophages

Mast cells

Question 16

How does the immune system know when the body is under attack?

Answer 16

The immune cells have PRRs (Pattern Recognition Receptors) which detect PAMPs (Pathogen Associated Molecular Patterns) which are found in invading pathogens

Question 17

What are toll-like receptors and how do they work?

Answer 17

BINDS LIGAND
Toll like receptors are proteins found on the cell membrane and vesicles of immune cells. They are stimulated by different things found in the pathogen, e.g. flagellum.
When these receptors are activated, they send signals to the nucleus to activate a gene for the production of cytokines such as interferons, Interleukin 1, Tumor necrotic factor, etc. This enhances inflammation by:

Increasing phagocytosis
Increasing costimulatory molecules
Increasing immune cell migration
increasing antigen presentation

Question 18

What are NOD-like receptors?

Answer 18

They are receptors found on the inside of the cell (in the cytoplasm) and they pick up signals from inside the cell.
-They have similar outcomes as TLRs
TLRs and NLRs —-> Inflammasomes—–> Caspase 1——> Release of mature cytokines (IL-1 and IL-8)

Question 19

Name the inflammatory mediators
(TAKE ACTIVE PART ON RESPONSE TO INFLAMMATION)

Answer 19

Neutrophils and macrophages: cytokine release—–> recruitment and activation of other WBCs

Liver: Releases C reactive proteins for the complementary system

Question 20

List and state function of cytokines

Answer 20

Colony-stimulating factors: development and differentiation of immune cells from bone marrow precursors.

Interferons (IFN): IFN-α and IFN-β inhibit viral replication, IFN-γ regulates immune responses

Interleukins (IL): Communication between leukocytes.

Tumor necrosis factor (TNF) family: Mixed collection of cytokines, promote inflammation (TNF-α and TNF-β), stimulate osteoclasts and bone resorption (osteoprotegerin).

Chemokines: cell movement in response to chemical stimuli

Question 21

How do interferons work?

Answer 21

• They signal uninfected cells to destroy RNA and reduce protein synthesis.
• They signal neighbouring infected cells to undergo apoptosis.
• They activate immune cells

Question 22

What are the main functions of interferons?

Answer 22

• Inhibits viral replication
• Tumor surveillance
• Alter expression of all cells to be resistant to infection

Question 23

What stimulates diapedesis?

Answer 23

Histamines and leukotrines produced by mast cells.

Question 24

Describe the process of phagocytosis

Answer 24

Neutrophils —-> form pseudopodia —-> encloses particle in chamber—–> forms phagosome
Macrophages —–> more powerful phagocytes —–> digest particles and extrude residual particles
Lysosomes digest engulfed particles

Question 25

What is in a phagosome?

Answer 25

Proteolytic enzymes Lipases (macrophages) Bactericidal agents Oxidizing agents – superoxide, hydrogen peroxide, hydroxyl ions

Question 26

Where are resident macrophages found?

Answer 26

``` Skin and subcutaneous tissue Lungs (alveolar macrophages) Liver sinusoids Spleen and bone marrow Lymph nodes ```

Question 27

Describe the process of inflammation

Answer 27

Vasodilation of local blood vessels Increased permeability of the capillaries, allowing leakage of large quantities of fluid into the interstitial spaces Clotting of the fluid in the interstitial spaces because of increased amounts of fibrinogen and other proteins leaking from the capillaries Migration of large numbers of granulocytes and monocytes into the tissue Swelling of the tissue cells Walling off –immediate effect via fibrinogen clots 1st line defense – resident macrophages (1st hour) 2nd line defense_ Neutrophil invasion – first few hours 3rd line defense- Secondary macrophage invasion – several days, monocytes need 8 hours to mature in tissue 4th line defense- Bone marrow takes 3-4 days to synthesize new granulocytes

Question 28

Define chemotaxis

Answer 28

Movement of an organism in response to a chemical stimulus

Question 29

Describe how neutrophils migrate from the blood vessels to the tissue

Answer 29

``` Cytokines: TNF an IL-1 Adhesion molecules: Selectins and ICAM-1 Integrin on neutrophils – bind (margination) Capillaries become “leaky” – diapedesis Chemotaxis ```

Question 30

Describe pus formation

Answer 30

``` Necrotic tissue Dead macrophages and neutrophils Tissue fluid Tissue eventually autolyzes End products abdorbed into lymph and surrounding tissue ```

Question 31

List the cells involved in allergy formation

Answer 31

``` Basophils (in circulation) Mast cells (tissue resident) Histamine and Heparin Propensity for IgE Release eosinophil chemotactic factor ``` Eosinophils – parasitic infections Collect in peribronchial tissues during asthma

Question 32

Functional cells in innate

Answer 32

Granulocytes, macrophages, mast, dendritic, natural killer (EXCEPT T and B cells)

Question 33

Difference between toll-like and nod-like receptors

Answer 33

Toll-like: inside,cell membrane Nod-like: inside,cytoplasm

Question 34

Interleukins released by TLR and NLR

Answer 34

IL1 and IL8

Question 35

Results after the release of cytokines (IL1 and 8)/ what does cytokines enhance

Answer 35

increased phagocytosis cell migration antigen presentation stimulatory molecules

Question 36

Inflammation during chemotaxis

Answer 36

In response to a cut; 1. Mast cells release histamine (COULD ALSO E OTHER MEDIATORS, CYTOKINES) which cause 2. Dilation of blood vessels 3.Neutrophils and monocytes leave a cell 4. Monocytes mature to macrophages 5.Macrophages phagocytisise 6. Neutrophils invade 7.COMPLEMENT SYSTEM (opsonization) 8. Dendtritic cells

Question 37

Defense of inflammation

Answer 37

1. Resident macrophages 2. Neutrophil invade 3. Secondary macrophage 4. Granulocytes and monocytes

Question 38

Resident macrophages

Answer 38

Skin Alveoli Liver sinusoid Spleen Bone marrow

Question 39

Neutrophil invasion cytokines

Answer 39

TNF and IL-1

Question 40

Adhesion molecules of neutrophil invasion

Answer 40

CAM1 and selectin

Question 41

Main cells for innate immunity (inflammation) SURVELIANCE

Answer 41

Mast cells Macrophages Neutrophils Monocytes