Questions
What is immunology?
The study of how the body defends itself against infection by microorganisms, including
bacteria, viruses, fungi and parasites
What are antigens?
Anything that causes a response within the immune system. Antigens can be entire
pathogens, like bacteria, viruses, fungi, and parasites, or smaller proteins that pathogens
express
What’s innate immunity?
Natural immune response that is nonspecific
What’s adaptive immunity?
Antigen-specific immune response
What are cytokines?
They are signalling cells or cells used for cell to cell communication
What are chemokines?
They are a type of cytokines that are released by infected cells to warn neighbouring cells of
potential threats and to start an immune response
State some of the effector cells for innate immunity
Phagocytes (macrophages, neutrophils), mast cells, NK cells, eosinophils
State some of the effector cells for adaptive immunity
Lymphocytes (T cells and B cells)
Which of the 2 immune systems are slower?
Adaptive immune system
In terms of the innate immune system, name some of the defences we have
- Mechanical (cells are joined by tight junctions, mucus production and movement by
cilia)
- Chemical (fatty acids, low pH, lysozyme in saliva, pepsin in the stomach, sweat, vaginal
lactic acid)
- Microbiological (symbiotic bacteria compete for nutrients)
What are phagocytes?
Cells the engulf, digest and destroy bacteria
What are the two different types of phagocytes?
Macrophages and neutrophils
, What do macrophages circulate in the blood as?
Monocytes
What is the most abundant white blood cell?
Neutrophil
Where are macrophages found?
In the tissues
Briefly state how you would distinguish between the cells of the innate immune system
(macrophages, neutrophils, mast cells, NK cells and eosinophils)
- Macrophages: large mononuclear cells found in tissues and circulate in the blood as
monocytes
- Neutrophils: multi-lobed nucleus, many granules in the cytoplasm, circulate in the blood
- Mast cells: found in tissues,
- NK cells:
- Eosinophils: bi-lobed nucleus, granules released upon contact with parasites, found
mainly in tissue but number found in circulation increases following an infection
What do B cells mature into and why?
Plasma cells, so they can produce large quantities of specific antibodies
T cells are produced in the bone marrow but mature where?
Thymus gland
What does PAMPs stand for and define it?
Pathogen associated molecular patterns. They are sequences which are found on pathogens
but not on human cells
What is the meaning of the terms “self” and “non self”?
Self – body cells
Non self – foreign substances
What are toll like receptors (TLRs)?
These are receptors that recognise PAMPS
Where are TLRs found?
Some are on the cell surface however, others may be found intracellular
What is opsonisation?
When the surface of the pathogen is changed by the addition of complement component
C3b
Which complement receptor recognises complement component C3b?
Complement receptor 1 (CR1)
, Is the phagocytosis of an unopsonised or opsonised bacteria faster and why?
Opsonised because the phagocyte is able to recognise the pathogen quicker due to the
attachment of the C3b to the CR1
What’s the complement system?
The part of the immune system that enhances the ability of antibodies and phagocytic cells
to to clear microbes and damaged cells from an organism, promote inflammation, and attack
the pathogen's cell membrane
What type of reaction is needed in the alternative pathway for C3 to be converted into C3b
and what is needed?
Hydrolysis using a C3 convertase (C3,Bb in alternative pathway)
What are the products of hydrolysis of C3?
C3b and C3a
How is C3b stabilised?
By binding to microbial cell surfaces
How many pathways for complement activation are there and what are they called?
3. Classical pathway, lectin pathway and alternative pathway
Does C3b opsonise bacteria and host cells or just bacteria?
Only bacteria
What is the name of the factor that is found on bacteria cell surfaces which increases the
number of C3b molecules available by binding and stabilising C3b,Bb complex?
Factor P/ properdin
What factor turns C3b molecules into C3b,B?
Factor B
What factor turns C3B,B molecules into C3b,Bb?
Factor D
What’s an opsonin?
An antibody or any other substance which binds to foreign microorganisms or cells making
them more susceptible to phagocytosis
What do host cells express which inactivates the C3B,Bb complexes?
Complement regulatory proteins
What’s the inactive form of C3b?
iC3b