Inflammatory Response

Question 1

What is an inflammatory response?

Answer 1

Non-specific defence that is innate from birth and occurs when tissues are injured, causing blood vessels to leak fluid into the tissue (swelling).
A localised process

Question 2

What are the phagocytic cells associated with non-specific responses?

Answer 2

Neutrophils (neutrocyte)
Eosinophils
Monocytes (leukocyte)
Macrophages

Question 3

What are the non-phagocytic cells associated with non-specific immune response?

Answer 3

NK Cells (Natural Killer cell)
Mast Cells
Basophils

Question 4

Name the two types of inflammatory responses

Answer 4

Acute- mins/hours

Chronic- weeks/years

Question 5

Describe the characteristics of acute inflammatory response.

Answer 5

Redness
Heat
Swelling
Pain
Loss of function
Increase permeability 
Oedema 
Cell recruitment & migration

Question 6

Describe the characteristics of chronic inflammatory response

Answer 6

Macrophages
Lymphocytes
Granuloma formation (mass of granulation tissue/ new connective tissue)

Question 7

Name the mediators of a non-specific response.

Answer 7

Vasoactive amines (histamine, serotonin)
Arachidonic acid metabolites
Cytokines
Complements system

Question 8

What is the complement system?

Answer 8

Series of proteins in plasma activated by immune system or infection.

Question 9

What are the products of the complement system?

Answer 9

Opsonins
Anaphylatoxins
Chemotactic factors

Question 10

What are cytokines?

Answer 10

Hormone like molecule produced by many cell types.

E.g. Interleukins (IL-1), colony stimulation factors (CSF), tumour necrosis factors (TNF).

Question 11

What’s the function of cytokines?

Answer 11

Chemotaxis (movement of Cells due to inc or Dec of substance)
Cellular proliferation, differentiation, activation, apoptosis.

Question 12

How does cell recruitment and migration occur in non- specific response?

Answer 12

Selective process...
Margination (capture)
Adhesion- to endothelium (pavementing), involves expression of adhesion molecules on leucocytes and receptors on endothelial cells.
Migration
Chemotaxis
Proliferation

Question 13

Describe the acute phase response.

Answer 13

Whole body (systemic) response to infection.
Caused by monocytes/macrophages releasing cytokines =
Inc. number of neutrophils
Inc. production of acute phase proteins.

Question 14

What are the symptoms of acute phase response?

Answer 14

Fever
Drowsiness
Loss of appetite
Muscle break down

Question 15

How is the SPECIFIC immune response characterised?

Answer 15

Specific to pathogen
Diversity (many different pathogens)
Immunological memory
Self-non-self discrimination

Question 16

Name the types of lymphocytes.

Answer 16

B lymphocytes
T lymphocytes:
1) cytotoxic T lymphocytes (CD8+)
2) helper T lymphocytes (CD4+)

Question 17

Where do lymphocytes mature?

Answer 17

B- bone marrow

T- thymus

Question 18

Describe the cell surface receptors of lymphocytes

Answer 18

B- membrane bound antibodies on surface

T- T cell receptors on surface

Question 19

Define immunogen

Answer 19

Stimulates a specific immune response

Question 20

Define Antigen

Answer 20

Combines with the products of an immune response

Question 21

Define Epitope

Answer 21

The part of the immunogen recognised by a small lymphocyte (T or B) to which an antibody binds.

Question 22

Describe the process of clonal selection and expansion (selective inflammatory response)

Answer 22

All small lymphocytes have receptors for epitope
They bind = proliferation and differentiation (clonal expansion, requires cytokines)
Most Cells differentiate into effector Cells
Some remain as memory cells

Question 23

What are antibodies?

Answer 23

Immunoglobulins (glycoproteins in plasma fluids and secretions)
Specific to epitopes
Bind to epitope and stimulate removal of immunogen (phagocytes & activation complement)

Question 24

Name the classes of antibodies

Answer 24

1) IgG
2) IgM
3) IgA
4) IgE
5) IgD

Question 25

How does immunological memory work?

Answer 25

Response activated earlier
More cells released to fight
Much more sustained/ for longer

Question 26

What are the two types of specific immune response?

Answer 26

Humoral Immunity- antibody production by B cells (extracellular pathogens)
Cell mediated immunity- production of cytotoxic T cells (intracellular pathogens)

Question 27

How are helper T cells stimulated in specific immune response?

Answer 27

Interact with antigen presenting Cells (e.g. Macrophages)
Don’t directly kill infected cells
Then activate, proliferate, differentiate (activate cytokines secretor)

Question 28

What are the two types of T helper Cells?

Answer 28

Th1- secretes IL-2 cytokines, TNF & IFN. Supports cell mediated immunity against intracellular parasites.
Th2- secretes IL-4, 5, 6, 10 cytokines. Support humoral immunity against extracellular parasites.

Question 29

Describe the process of humoral immunity.

Answer 29

Immunogen presented on APC.
B cell has antibodies for epitope
Activated to plasma cell (fully differentiated B cell) that produces lots of antibodies specific to epitope
Cytokines produced by t helper used to activate.
Some B cells also activated to memory cells.

Question 30

Describe the process of cell mediated immunity (specific immune response)

Answer 30

Normally for a viral infection
Any cell can be infected
T cell responds to viral epitope on cell.
MHC1 molecule (all cells have this marker) so know its own cell.
Once activated needs IL-2 from Helper T
Turns into cytotoxic T cell
Can either kill directly or indirectly (NK cells)

Question 31

How are infected cells killed in cell mediated immunity?

Answer 31

Granules in cytotoxic cells contain perforin which degranulates and released onto target cell to form channels, degradation enzymes released and go through perforin channels and kill cell