Brainscape's Knowledge GenomeTM

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


See full index

Immunology > Mucosal Immunity > Flashcards

Mucosal Immunity Flashcards

1
Q

Describe the structure of an antibody

A

A Y-shaped structure consisting of 4 polypeptides

  • 2 heavy chains, 2 short chains
  • With disulfide bonds between the chains
  • 2 Antigen binding sites
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What is agglutination and why can it occur?

A

Agglutination is the clumping of bacteria

-can happen as an antibody has 2 antigen-binding sites

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

What are immunoglobulins?

A

Antibodies

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

How many classes of immunoglobulins are there and what makes the classes different?

A 
There are 5 classes of immunoglobulins 
-each class has a different heavy chain constant region
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What is immunoglobulin class switching?

A

It is also known as isotopic switching

-It is the biological mechanism that changes a B cells production of immunoglobulin from one type to another

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

What are the 5 different types of immunoglobulins?

A

IgA-secreted at mucosal sites
IgD- B cell receptor
IgE-parasite responses and allergies
IgG-multi-purpose, high affinity and crosses the placenta
IgM- first to be made on first encounter with antigen

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

How are B cells activated?

A

Via 3 signals:

  • from the antigen binding to the BCR
  • Co-stimulation frm a helper T cell
  • Cytokines from a helper T cell (cause class switching)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

How do cytokines regulate expression of antibody classes?

A

As which ever cytokine the helper T cell secretes causes class switching and determines which antibody the B cell produces

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What are the subclasses of immunoglobulins?

A

IgG- IgG1, IgG2, IgG3, IgG4
IgA- IgA1, IgA2

-IgM, IgD and IgE dont have subclasses

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What is the effect of IL-4 on antibody class expression?

A

Inhibits: IgM, IgG3, IgG2a
Induces: IgG1, IgE

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What is the effect of IL-5 on antibody class expression?

A

Increases production of IgA

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What is the effect of IFN-gamma on antibody class expression?

A

Inhibits: IgM, IgG1, IgE
Induces: IgG3, IgG2a

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What is the effect of TGF-beta on antibody class expression?

A

Inhibits: IgM, IgG3
Induces: IgG2b, IgA

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What is the effect of IL-21 on antibody class expression?

A

Induces: IgG3, IgG1, IgA

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What are the 3 main functions of antibodies?

A

Neutralisation
Opsonisation
Complement activation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

How do antibodies neutralise pathogens?

A

Antibodies bind bacterial toxins and virus particles

- This stops them binding receptors on the cells and prevents damage to tissue

17
Q

What is opsonisation?

A

Antibodies coating dangerous antigens in opsonins, which promote phagocytosis

18
Q

How do antibodies cause NK cell sensitisation?

A
  • IgG Antibodies binds antigen on the surface of target cells
  • Fc receptors on NK cells recognise bound antibody
  • Cross linking of Fc receptors signals the NK cell to kill the target cell by apoptosis
19
Q

How do antibodies cause mast cell, eosinophil and basophil sensitisation?

A
  • IgE binds to Fc receptors on mast cells, causing the mast cell to degranulate releasing histamine
  • Eosinophils recognise IgE bound to parasites and release granules to kill the parasite
  • Soluble IgD binds to basophils activating antimicrobial and proinflammatory mechanisms
20
Q

What is the function of lymph nodes in immunity?

A

Entrap pathogens/ antigens entering the lymphatic system from tissues
-packed with lymphocytes, macrophages and dendritic cells

21
Q

Describe how the lymph nodes process foriegn antigens?

A
  • Antigen and APC from tissue travel to lymph node via lymphatic fluid
  • Processed by dendritic cells in paracortex
  • Specific helper T cells activated
  • B cells activated in primary follicle
  • Leads to production of a secondary follicle, germinal centre and antibody producing plasma cells
22
Q

What is clonal selection and expansion of activated B cells?

A

Clonal selection- how a single B cell that recognises an antigen that enters the body is selected from a pool of different antigen specificities
Clonal expansion- many copies of that specific B cell are produced with the shared affinity and specificity of the antigen

23
Q

What is the function of the spleen?

A

Functions as a fliter for blood

-not supplied by lymphatic vessels therefore spleen responds to systemic infections

24
Q

What are the 2 distinct regions of the spleen and how are they seperated?

A

Red pulp and white pulp

-seperated by a diffuse marginal zone

25
Q

What does the red pulp of the spleen contain?

A

Contains mainly macrophages, red blood cells with few lymphocytes

26
Q

What does the white pulp of the spleen contain and what does it surround?

A

Predominantly populated by T cells

- the white pulp mainly surrounds the arteries in the slpeen, forming a periarteriolar lymphoid sheath (PALS)

27
Q

Describe how the spleen processes foreign antigens?

A
  • Foriegn antigen carried into the spleen from the splenic artery into marginal zone where it is captured by dendritic cells
  • In the PALS dendritic cells activate helper T cells
  • Active helper T cells activates B cells
  • Leads to production of a secondary follicle with germinal centre
28
Q

What is a germinal centre?

A

Germinal centres are a specialised enviroment for B cell proliferation and somatic hypermutation

29
Q

What is the structure of a germinal centre?

A

Contains a mantle zone around the edges

Inside there is a light and a dark zone

30
Q

What is somatic hypermutation?

A

A way of introducing increased antibody diversity

-introduces point mutations in the variable region of DNA at a very high rate

31
Q

What is the process of somatic hypermutation in a germinal cell?

A
  • Somatic hypermutation happens in the dark zone of the germinal centre
  • Selection of survival in light zone
  • Cells with disadvantageous BCR mutations killed through apoptosis
  • Cells with advantageous BCR mutations (e.g increased affinity) move further into the light zone
  • Recieve signal from helper T cells to differentate into plasma or memory B cells (can induce class switching)
32
Q

What are MALTS?

A

Mucosa Associated Lymphoid Tissue

-they defend the body agaisnt pathogen entry via the mucous membranes

33
Q

What are the 2 main types of MALTS?

A

BALTS- Bronchus-Associated Lymphoid Tissue

GALTS- Gut-Associated Lymphoid Tissue

34
Q

What structures fall under GALTS?

A 
Peyer's Patches (small intestine only)
Isolated Lymphoid follicles (throughout the intestine)
Appendix
Palatine tonsils
Adenoid glands
Lingual tonsils
35
Q

What are tonsils and what is their function?

A

Tonsils are nodular structures with a meshwork of reticular cells, macrophages, granulocytes and mast cells

  • contains follicles and germinal centres
  • functions in the defence against antigens entering the nasal and oral epithelia
36
Q

What are peyers patches and what are their function?

A

Comprised of 30-40 nodules in outer wall of the small intestine
The nodules contain follicles which will develop germinal centres on antigen exposure

37
Q

What are M cells and what is their function?

A

Microfold cells are intestinal epithelium cells that sample and transport pathogen/antigens from the luminal surface to the sub-epithelium (transcytosis)

Immunology (10 decks)

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