Flashcards in immunology Deck (55)
Describe the properties of the skin as a physical barrier to infection
It is constantly renewed
It has a low pH
It has a low oxygen tension
Sebaceous glands secrete hydrophobic oil which makes it hard for pathogens to bind
Mucous line all _____ that come into contact with the _______
Mucous contains many constitutes which can fight potential pathogens, what are these?
Lactoferrin- starve induing bacteria of iron
What are commensal bacteria?
Bacteria that reside in the body and on epithelial surfaces naturally
They have a symbiotic relationship with the body and can eradicate most normally infections
They ensure there is no undefended ecological niche
The components of the immune system can be split into which two categories?
2. Humoral immunity (soluble factors)
Which 3 main groups of cells are involved in the immune system?
When a cell is infected with a virus what will it secrete?
Interferons (alpha and beta)
The antiviral state initiated by interferons achieve what?
It down regulates protein synthesis which slows virus production
What is an antigen?
A substance able to stimulate an adaptive immune response- it can be protein, carbohydrate, nucleic acid, lipid, metal etc
Where are T and B cells formed?
Where do B cells mature?
Where do T cells mature?
In response to an infection B cells will produce what?
Antibodies and memory cells
What are the two types of T cells?
Helper T cell (CD4+)
Cytotoxic T cells (CD8+)
How does a virus evade the immune system?
It will usually hide within body cells
How can cytotoxic T cells discover viruses hiding in the body cells?
The host cell constantly samples its cytoplasm and displays proteins on its surface- this is mediated by MHC class 1 proteins
These displayed proteins can "show" cytotoxic T cells which cells are infected
How do viruses evade the process of cytoplasm sampling mediated by MHC class I proteins?
They down regulate the production of MHC class I proteins. This reduced cytoplasm sampling
How do natural killer (NK) cells retaliate to viruses that down regulated MHC class I production ?
NK cells can detect a lack of MHC class I proteins on a cell surface
They can then attack and destroys such cells
How are parasitic works (helminths) attacked by the immune system?
Antibodies and mast cells
What is the complement system and where is it produced?
Family of around 30 different proteins produced in the liver
How does the complement system function?
When activated, the proteins activate each other in a. cascade fashion
This involves great amplification and plays a role in inflammation
When do monocytes differentiated into macrophages?
When they exit the blood and migrate to peripheral tissues
What are Kupffer cells?
Macrophages of the liver
What are mesangial cells?
Macrophages of the kidney
What are macrophages of the nervous system called?
How can neutrophils be differentiated from macrophages ?
Their multi-lobed nucleus
What is the role dendrite cells?
They engulf pathogens, phagocytose and then present antigens on their surface to T cells
What are the main functions of neutrophils?
Killing and degradation
What are the main functions of macrophages?
Killing, degradation, wound healing, anti-inflammatory and antigen presentation