Partridge Flashcards Preview

MBB311 Molecular Immunology > Partridge > Flashcards

Flashcards in Partridge Deck (43)
Loading flashcards...
1
Q

Immunology

A

Study of the immune system

2
Q

What does the immune system do?

A
  • Provides protection or immunity against infection disease
  • Distinguishes between self and non-self
  • May also recognise danger signals caused by damage to cells and tissue, e.g. cancer
3
Q

What are the external threats to the body?

A
  • Viruses
  • Bacteria
  • Fungi
  • Protozoa
  • Parasites
  • Prions ?
4
Q

What are the internal threats to the body?

A
  • Cancer: danger from “altered self”
  • Necrosis: danger from damaged tissue
  • Prions ?
5
Q

What are prions?

A

Prions are misfolded proteins that can transmit their misfolded shape onto normal variants of the same protein; they are involved in neurodegenerative disease

6
Q

How is the immune system a “double-edged sword”?

A

The immune system can cause disease if inappropriately activated by attacking normal self or innocuous environmental materials

7
Q

Active immunisation (vaccination)

A

Where the immune system is stimulated by weakened/inactive forms of a pathogen to generate a memory component, so when it comes across the pathogen again it is able to quickly respond

8
Q

Passive immunisation

A

When immune components from an immunised source are administered to an individual

9
Q

What is Herceptin?

A

A monoclonal antibody used to treat breast cancer that is HER2 receptor positive

10
Q

What are the features of the innate immune system?

A
  • Limited specificity
  • Resistance not improved by repeat infection
  • Rapid response
11
Q

What are the features of the adaptive immune system?

A
  • Highly specific
  • Resistance improved by repeat infection
  • Slow response
12
Q

Which leucocytes are involved in the innate immune system?

A
  • Phagocytes

- Natural killer (NK) cells

13
Q

Which leucocytes are involved in the adaptive immune system?

A
  • B lymphocytes

- T lymphocytes

14
Q

What are some of the soluble factors involved in the innate immune system?

A
  • Lysozyme
  • Complement
  • Interferons
15
Q

Which soluble factor is involved in the adaptive immune system?

A

Antibodies

16
Q

Neutrophils

A
  • Main phagocyte in the blood
  • Short-lived but lifespan increases when infection occurs
  • Fast-moving
  • Contain specialised lysosomes which release enzymes
17
Q

Mononuclear phagocytes

A
  • Monocytes in the blood, macrophages in the tissues
  • Monocytes generally cycle in the blood for a few days before entering the tissues as macrophages
  • Long-lived
  • Help initiate adaptive responses
  • Act as sentinel cells; they alert the body to infection
18
Q

Natural killer cells

A
  • Type of lymphocyte
  • Kill infected cells non-specifically
  • Have a possible anti-tumour role; receptors on NK cells recognise “altered self”
19
Q

What are the myeloid cells?

A
  • Monocytes
  • Macrophages
  • Neutrophils
  • Basophils
  • Eosinophils
  • Mast cells
  • Dendritic cells
  • Megakaryocytes
20
Q

What are the lymphoid cells?

A
  • Tc cells
  • Th cells
  • Plasma (B) cells
  • Memory (B) cells
  • Natural killer cells
21
Q

What type of receptors do myeloid cells have?

A

Pattern recognition receptors (PRRs) which recognise pathogen associated molecular patterns (PAMPs)

22
Q

What are PAMPs?

A

Patterns of molecules or receptors that are commonly found on pathogen cells but not on human cells

23
Q

Defensins

A

Insert into microbial cell membranes to disrupt them by forming pores

24
Q

Complement

A

Can destroy bacterial cells directly and initiate inflammation to help phagocytes to destroy bacteria

25
Q

Interferons

A

Proteins that interfere with viral protein replication

26
Q

Lysozyme

A
  • Found in tears and other bodily fluids

- Can break down the peptidoglycan cell walls in gram-positive bacteria

27
Q

What is an inflammatory response?

A

An integrated local response to infection

28
Q

B lymphocytes

A
  • Made and mature in bone marrow
  • Have antibodies as receptors
  • They secrete antibodies into bloodstream
  • Are an example of humoral immunity since antibodies are soluble
  • They are used in extracellular bacterial and secondary viral infections
29
Q

T lymphocytes

A
  • Made in bone marrow, mature in thymus
  • Have T cell receptors
  • They kill infected host cells and make cytokines
  • Are an example of cell-mediated immunity
  • They are used in viral and intracellular bacterial/parasitic infections
30
Q

Immunoglobin classes

A

IgG, IgM, IgA, IgD and IgE

31
Q

IgG

A
  • Main class of antibody in serum and tissues
  • Important in secondary responses
  • Involved in immune memory; made by B lymphocytes
32
Q

IgM

A

Important in primary responses, i.e. first time you come across a pathogen

33
Q

IgA

A
  • In serum and secretions

- Protects mucosal surfaces

34
Q

IgD

A

?

35
Q

IgE

A
  • Present at very low levels

- Involved in allergy and protection against large parasites

36
Q

What are the two major subpopulations of T lymphocytes?

A
  • T helper cells

- T cytotoxic cells

37
Q

T helper cells

A
  • CD4 +ve
  • Help B cells make antibodies
  • Activate macrophages and natural killer cells
  • Help development of T cytotoxic cells
38
Q

T cytotoxic cells

A
  • CD8 +ve

- Recognise and kill infected host cells

39
Q

Cytokines

A
  • Can be produced by any cell under the correct conditions

- Small secreted proteins involved in communication between cells of the immune system

40
Q

Immunomodulators

A
  • Usually produced and act locally

- Bind to specific cytokine receptors on target cells

41
Q

What are some of the main groups of cytokines?

A
  • Interleukins: usually made by T cells
  • Interferons (IFNs): used in viral infections and for cell activation
  • Chemokines: involved in cell movement or chemotaxis
42
Q

Primary lymphoid tissue

A

Where lymphocytes reach maturity

43
Q

Secondary lymphoid tissue

A

Where mature lymphocytes are stimulated by antigens