Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

1- Meera's ODDR Immunology > Immunology 1 > Flashcards

Immunology 1 Flashcards

1
Q

Define “Pathogen”

A

Micro-organism that causes disease

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Define “Chemokine”

A

Chemical attractant protein stimulating migration and action of cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Define “Cytokine”

A

Small protein affecting the behaviour of other cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Define “Zymogen”

A

Inactive form of an enzyme; must be modified before they become active

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Name 4 types of pathogens:

A

1- Viruses e.g. HIV

2- Bacteria e.g. Perio, syphilis

3- Fungi e.g. Candida

4- Parasites e.g. Perio, Protozoa

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What is the complement System

A

Many distinct plasma proteins that react with one another to opsonize pathogens and induce inflammatory response to help fight infection

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Name 3 activation pathways:

A

1- Classical

2- MB-Lectin (Manose binding)

3- Alternative

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What are the stages of the classical activation pathway

A
  • C3a + C5a - enhance inflammation = mast cells release histamine
  • C3b - opsonisation + cell lysis = complement proteins; C1q, C1r, C1s, C4, C2
  • C1 complex = C1q, C1s + 2x C1r - activated on binding of antibody-antigen complex
  • C1 cleaves C2= C2a + C2b and C4= C4a + C4b
  • C2b and C4b combine- protease = C3convertase (C4bC2a)
  • C3 convertase cleaves C3= C3a + C3b (C3a released)
  • C3b bind to bacteria surface adjacent to C4bC2a complex and associate with it
  • Forming C4bC2aC3b protease acts as C3a and C5a convertase
  • C4b binds to surface of bacterium through amide/ester linkages
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Stages of cell lysis:

A
  • The C4bC2aC3b protease binds C5, C5b and C5a is formed
  • C5b acts in a component in the membrane attack complex (MAC)
  • C5b assembles with C6 and C7, the C7 molecule allows the complex to be inserted into the bacterial cell membrane
  • C8 binds with the C5bC6C7 complex, and also inserts into the membrane
  • The C5bC6C7C8 complex catalyses the assembly of many molecules of C9, this creates a cylindrical pore spanning the cell membrane
  • The cylindrical pore leads to cell lysis when it disrupts ion/osmotic gradients
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Stages of MB (Manose binding)-Lectin Pathway:

A

Complement proteins involved: (Ficolin), MASP-1, MASP-2, MBL, C4, C2 (Ficolin binds to the oligosaccharides on the bacteria surface membrane)

  • Similar to the classical pathway in a sense that it also creates C3 convertase
  • Ficolin binds to the oligosaccharides on the bacteria surface membrane
  • MASP-1 and MASP-2 is also bound to Ficolin
  • MBL (Manose binding Lectin) binds to Manose parts of the pathogen
  • MASP-1 and MASP-2 (Manose associated serin protease) is also bound to MBL
  • C3 convertase is made from these complexes
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Stages of alternative pathway:

A
  • Is a result of C3 convertase creating C3b
  • C3b binds to the surface of the pathogen
  • C3b + Factor B + Factor D = C3 convertase (C3bBb) (A different type of C3 convertase)
  • C3b + Properdin = C3 convertase (C3bBb) (A different type of C3 convertase)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Stages of Opsonisation

A
  • C3b pepper the surface of the pathogen
  • The macrophage binds to the c3b protein via the CR1 receptor
  • This allows the macrophage to engulf the pathogen via phagocytosis
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Name 3 physical/chemical barriers:

A
  • Epithelial layers (skin + gut lining)- involve mechanical mechanisms (cilia remove mucus + cell debris)
  • Acidity + enzymes (found within gut lining)
  • Healthy microflora outcompetes the pathogens
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Features of the Innate immune system:

A
  • Eliminates some virus causing micro organisms
  • Controls the proliferation of microbes
  • The pathogens must penetrate the physical/chemical barriers before the innate immune system is activated
  • The innate immune system activates the adaptive immune system
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Features of the Adaptive immune system:

A
  • Much more potent than the innate immune system (has a larger effect)
  • Can clear + destroy more virus causing diseases
  • Increases the activity of the innate immune system (as they act in unison)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

3 soluble immune effector molecules in saliva:

A
  • Lysozymes (glycosidase enzyme) break down the bonds between N-acetyglucosamine and N acetylmuramic acid (Polymer of these repeating units is the peptidoglycan layer)
  • Lysozymes are most against G+ bacteria (S.Mutans)
  • The breakdown of the peptidoglycan layer allows for other microbial agents (of the innate immune system) to enter and destroy the pathogen G- Bacteria have an extra lipid membrane this acts as an extra protection layer from these antimicrobial agents
17
Q

Antimicrobial peptides:

A
  • Found in the blood, Saliva and other bodily fluids
  • Produced by macrophages but are also secreted by the gingival epithelium
  • The inactive proform of these peptides are known as zymogens
  • Zymogen – An inactive form of an enzyme that becomes active by being proteolytically cleaved
    • The fact that zymogens are activated when necessary means they can be present in the blood stream without causing any harm
18
Q

The antimicrobial peptides in saliva:

A

Defensins – amphipathic (has hydrophobic and hydrophilic parts) + insert into membrane to generate pores - this causes the membrane to become leaky

  • a Defensins – excreted by neutrophils
  • b Defensins – excreted by epithelial cells

Cathelicidins – also amphipathic - acts in disrupting membranes

  • LL-37 is the only type that is expressed in humans

Histatins - Produced by: Parotid, Sublingual, Submandibular glands.

  • Histidine rich
  • Active against fungal pathogens
19
Q

Compare the Innate vs Adaptive immune response:

1) Response speed
2) Recognition of what is self (host) and non-self (pathogen)
3) Lasting memory/ Protection

A

Innate:

1)

  • Acts first (mins-hours)
  • Proforms are always present ready to detect pathogens
  • Decrease the proliferation of pathogen, ready for adaptive arm to act

2)

  • Limited range of receptors
  • Receptors are unchanged during immune response
  • Receptors encoded by genome (DNA is inherited from parents)

3) No lasting memory

Adaptive:

1)

  • 4 days to weeks
  • Activated by the innate arm of the immune system

2)

  • Vast range of receptors
  • Receptor recognition improves during adaptive immune response
  • DNA changes from inherited form during immune response

3) Lasting immunity observed

20
Q

Innate arm provides:

A
  1. Initial defences against pathogens (decrease proliferation)
  2. Control against virulent pathogens
  3. Role in inducing adaptive immune response
21
Q

Adaptive arm provides:

A
  1. Increases in potent activity to control the virulent pathogens
  2. Takes time in raising population in number of cells to act against pathogen
  3. Clears away/eliminates pathogen to prevent infection
22
Q

Diversity of recognition:

A
  • Adaptive immunity increases the variety of receptors but the innate arm doesn’t
  • Pathogens reproduce quicker/ increase genetic turnover/ increase rate of mutation/ take part in conjugation
  • We have only 25,000 genes in our body, the adaptive immune system acts in reassembling our genome - over 25,000 receptors are observed in the body
23
Q

Response speed:

A
  • Antibodies + Igs are produced by adaptive arm
  • Amount of antibody produced = antibody titre
  • When a person is re-infected with pathogen A, the specific antibody is produced much quicker
  • Antibodies also bind stronger to the antigen, as they are recognised quicker

1- Meera's ODDR Immunology (2 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions