The Inate Immune System

Question 1

What chemical mediators do macrophages produce?

Answer 1

Interleukin-1, IL6 and tumour necrosis factor

Question 2

What are the effects of chemical mediators produced by the macrophages?

Answer 2

Cause the hypothalamus to increase body temperature, cause the synthesis of prostaglandin, and cause CRP, antitrypsin and fibrinogen to be produced by the liver

Question 3

What can CRP be used for?

Answer 3

To monitor disease activity and the response to diseases.

Question 4

What is the function of CRP?

Answer 4

Binds to phospholipids on the surface of bacteria, then acts as an oposin, stimulating phagocytosis, and also activates the complement system through the lectin pathway.

Question 5

Name a feature of the acute phase response other than CRP>

Answer 5

The production of Granulocyte colony stimulating factor, leads to a rapid increase in the production of neutrophils by the bone marrow.

Question 6

What are some of the roles of the immune system?

Answer 6

Pathogen recognition, controlling and eliminating the infection, regulating itself to cause minimum damage, and remembering pathogens

Question 7

What are some of the physical barriers to infection?

Answer 7

Skin, the mucosa membranes of the gut and the repsiratory tract.

Question 8

How does the respiratory tract act as a barrier to infection?

Answer 8

It is protected by the mucociliary escalator, and the mucous forms a layer that traps the mircorganisms, and the cilia waft towards the mouth, where trapped organisms can be removed by coughing and sneezing.

Question 9

What are some of the chemical barriers to infection?

Answer 9

Low ph of skin, stomach and the vagina (maintained by lactobacillus) and antimircobial molecules such as IgA, Lyzoenzyme, mucous, beta defferins and gastric acid and pepsin

Question 10

What are the benefits of a normal biological flora?

Answer 10

Compete with pathogens for attachement and resources, produce antimircobial chemicals and allow for the synthesis of vitamins

Question 11

When do the clinical problems start with the normal bacterial flora?

Answer 11

When it is displaced from its normal location to a stile location, or when it overgrows when the host becomes immunocomprimised or when normal flora is depleted by antibiotics

Question 12

What are some of the chemical barriers to infection?

Answer 12

The low pH in areas such as the stomach and the vagina which is maintained by lactobacillus, and antimircobial molecules such as IgA which is found in the savlia, lysoenzyme and mucous, as well as gastric acid and pepsin

Question 13

Describe some of the differences between the inate and the adaptive immune system.

Answer 13

Innate is much faster, innate has a lack of specificy whereas the adaptive is extremely specific, the innate has a lack of memory whereas the adaptive has a immunological memory, and the innate has no changes in intensity and the adaptive has lots of changes in intensity

Question 14

What are the roles of the immune system?

Answer 14

Remebering pathogens, regulating itself, pathogen recognition, and containing as well as eliminating the infection

Question 15

What is phagocytosis?

Answer 15

The internalisaiton of particulate matter inside cells, triggered by the recognition systems

Question 16

What are some of the key features of macrophages?

Answer 16

They are myeloid cells, present in all organs and they ingest and destroy microbes, as well as produced cytokines and chemokines, and are produced by the maturation of monocytes

Question 17

What are some of the key features of neutrophils?

Answer 17

Present in the blood, are increased during infection and ingest and destroy pyogenic bacteria such as staph pyogens, and thet are recruited by the chemokines towards the site of infection

Question 18

What are some of the features of basophils?

Answer 18

Early actors of inflammation and basophils are also important within the immune response

Question 19

What are some of the features of dendritic cells?

Answer 19

These help to present the mircobial antigens to the t cells

Question 20

What are some of the features of esophils?

Answer 20

They are a defence agasint the multicellular parasites

Question 21

What are some of the features of natural killer cells?

Answer 21

Kill all the abnormal cells

Question 22

What are some of the molecules involved in pathogen recognition?

Answer 22

PAMPs (pathogen associated molecular proteins), such as carbohydrates, lipid proteins and nucelic acids.
Pathogen recognition receptors
Toll like receptors- a family of at least ten different receptors, recognise different cell surface molecules such as lipopolysaccharide

Question 23

What are some of the molecules involved in the oponistion of microbes?

Answer 23

Antibodies such as IgG and IgM and complement proteins such as C3b and C4b and acute phase proteins such as C reactive proteins and mannose binding lectin

Question 24

What are the stages involved in the process of phagocytosis?

Answer 24

Chemotaxis and adherence of the molecules, ingestion of the microbe by the phagocyte, and the formation of a pahgosome, and fusion of phagosome and a lysosome to form a phagolysosom, digestion, formation of a residual body of the indigestible parts of the mircobe, and exocytosis of any of the rest of the contents

Question 25

What are the oxygen dependant introacellular killing mechanisms?

Answer 25

Toxic 02 products are formed to attache the pathogen, such as hydrogen peroxide and hrodroxyl radicals, and nitric oxide dingle oxygen radicals

Question 26

What are the key features of the complement system?

Answer 26

20 serum proteins involved in the immune resposne

Question 27

What are the two pathways for activating the complement system?

Answer 27

The alternative pathway, which is initated by cell surface mirobial contact, with endotoxins in the case of the.
There is also the MBL (mannose binding lectin) pathway, where MBL binds to the mannose containing residue on the proteins of many mircobes

Question 28

What are the functions of some of the key complement proteins?

Answer 28

C3a and C5a recruitment of phagocytes,
C3b and C4b is the opsonisation of pathogens
C5- C9 killing of pathogens and the membrane attack complex

Question 29

What are the key antimircobial actions of TNF-a, L1 and IL6

Answer 29

Liver create the oponsisn CRP and MBL, in the bone marrow causes the neutrophil mobilisation and has inflammatory actions that include vasodilation, vascular permeability and adhesion molecules

Question 30

What are some of the issues surrounding the reduction of phagocytosis?

Answer 30

Decrased splenic function, in aspelnic or hyposlepic patietns, decreased neutrophil number in cacncer treatment and with certain drugs, decrased neutophil function in chronic granulmoatous disease where there is no oxidative burst, and cheion hipgashi syndrome where there is no phagosome formation