Introduction to Immunology Flashcards
What is the need for an immune system? - -
Protection against infectious organisms - bacteria, viruses, fungi, protozoans, worms Protection against cancer
Name the two major systems of immunity:
Innate Immunity Adaptive Immunity
What is innate immunity? - Facts about innate immunity: - - - - What is it comprised of? - - -
'’A first line of defence’’ - Present at birth - Responds rapidly - Has no specificity - Has no memory Comprised of: - Barriers - Cells - Soluble factors
Name the physical barriers of innate immunity - -
- Impermeable outer surface, e.g. skin, epithelial cell layer lining mucosal surfaces - Cilia in nasal passages and bronchi
Explain how cilia work 1. 2.
- Airborne bacteria are trapped on mucus secreting goblet cells 2. Cilia waft bacteria back towards mouth and nose
Name the chemical barriers of innate immunity - - -
- Acidity in stomach - Alkaline secretions - Lysozyme in tears: enzyme which can attack cell walls
What is the biological barrier of innate immunity?
Competition between commensal organisms with pathogenic micro-organisms that may try to invade
Cells involved in innate immunity and their function: - - -
- Phagocytes: eat up foreign material - Natural Killer (NK) cells: kill tumour cells and virally infected cells - Eosinophils: attack and kill parasites
Explain the action of phagocytes: - - - -
- Adhere to bacterium - Engulfs into membrane bound vesicle - Meets with lysozyme which empties its contents - Lysozyme will attack and breakdown bacterium
Soluble factors of innate immune system: - - - -
- Lysozyme - Complement - Cytokines, particularly interferons - Acute phase proteins
What is the key thing between different aspects of the innate immune system?
Cooperation between components of the innate immune system, they also cooperate with the adaptive immune system
Adaptive immune system key features: - - - - - -
- Slow to start - Adaptive - Highly specific - Has memory (would eliminate micro-organism quickly second time round) - Recognition of self and non self - Has humoral and cellular components which cooperate together
What does humoral immunity refer to? What are they?
Antibodies (immunoglobulins) are specific proteins produced against pathogens, produced by B lymphocytes
What is cellular immunity?
Mediated by lymphocytes which recognise specific pathogenic structures called antigens
Name the cells involved in cellular immunity: - -
- B lymphocytes - T lymphocytes
What are the two principle types of T lymphocytes and their function?
- Helper T cells: help B cells produce antibodies - Cytotoxic cells: destroy own cells which have been infected by the virus
Which response does this graph show?
How many days does it take for the antibody to respond?
What does this lead to?
- Primary (10) Response
- There is more infectious agent being produced than antibodies
- It takes around 10 days to respond, which could lead to disease
Draw the Secondary response graph:
Dark blue line = amount of infective agent
Light blue = antibody produced
What is a vaccination thought to be?
Who were the pioneers?
The most successful application of immunological principles.
The pioneers in developing this were Edward Jenner and Louis Pasteur
What are the two roles of the immune system?
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Recognition Function: identifies a substance or body (antigen) as foreign
Effector Function: removes foreign invader
What is an antigen?
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What are antigenic determinants recognised by?
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- Any substance which elicits an immune response
- Portion recognised is called the epitope or antigenic determinant
Antiigenic determinants are recognised by:
- Antibodies (humoral)
- T cells (cellular)
but the two see different epitopes
Types of Antigens
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What is the key point?
- Proteins
- Carbohydrates
- Nucleic acids
- Lipids
- Drugs e.g. penicillin
- Inorganic molecules of nickel
Key point is: Antigens are foreign (non-self)
