11.1 Antibody production and vaccination Flashcards
What can the immune system distinguish between?
Self and non-self
What is self?
All nucleated cells of the body that possess unique and distinctive surface molecules
What is non-self?
Any substance that is recognised as foreign and is capable of triggering an immune response
How will the immune system react to the presence of foreign materials?
A response that eliminates the intruding material from the body
What are self markers called?
Major histocompatibility complex molecules (MHC class I)
What must a self cell have for the immune system not to react to it?
The self markers
What recognises antigens?
Lymphocytes
What do lymphocytes do?
Bind to and detect the characteristic shape of an exposed portion
What do lymphocytes trigger?
Antibody production
How do lymphocytes bind to epitopes?
Complementary paratopes
What are three examples of antigenic determinants?
Surface markers on foreign bodies in blood/tissue
Self markers of cells from another organism
Proteins from foods
What is an antigen?
A molecule that the immune system recognises as foreign
What is an antigen?
A molecule that the immune system recognises as foreign
Where are self markers present?
On the surfaced of all nucleated body cells
What do self markers identify the cell as?
Part of the organism
What prevents transplantation of tissues?
Different organisms have distinct self markers
Why do red blood cells not possess the same distinctive and unique self markers as all other body cells?
They are not nucleated
What does the fact red blood cells not having a unique self marker allow?
The transfer between individuals without automatically causing immune rejection
What limits the capacity of blood transfusions?
They possess basic antigenic markers
How may red blood cells possess surface glycoproteins?
Independently or in combination or not at all
Why are blood transfusions not compatible between certain blood groups?
As humans produce antibodies against foreign antigens
What blood type can AB blood groups receive?
Any other type
Why can AB blood groups accept any other type?
As they already possess both antigenic variants on their cells
What blood type can A blood groups not receive?
B blood or AB blood
Why can A blood groups not receive B or AB blood?
As the B isoantigen is foreign and will stimulate antibody production
What blood type can B blood groups not receive?
A blood or AB blood
Why can B blood groups not receive A blood or AB blood?
As the A antigen is foreign and will stimulate antibody production
What blood groups can O blood groups receive transfusions from?
Only other O blood donors
What determines positive or negative blood groups?
An additional glycoprotein called rhesus factor
What determines positive or negative blood groups?
An additional glycoprotein called rhesus factor
What is the universal blood type recipient?
Type AB
What is the universal blood donor?
Type O
What is a pathogen?
An agent that causes disease
What are the three types of pathogen?
Microorganism
Virus
Prion
What is a disease?
Any condition that disturbs the normal functioning of the body
What is an illness?
A deterioration in the normal state of health of an organism
Why are pathogens capacity to cause disease limited to a particular species?
Pathogens are species-specific
What are four examples of human only diseases caused by pathogens?
Polio
Syphilis
Measles
Gonorrhoea
What do certain pathogens have the ability to cross?
The species barrier
What happens when a pathogen crosses the species barrier?
They can infect and cause disease in a range of hosts
What are zoonoses?
Diseases from animals that can be transmitted to humans
What are examples of zoonotic diseases?
Rabies
Strains of influenza
Bubonic plague
What are the four ways of disease transmission?
Direct contact
Contamination
Airborne
Vectors
What is direct contact disease transmission?
The transfer of pathogens via physical association or the exchange of body fluids
What is contamination disease transmission?
Ingestion of pathogens growing on or in edible food sources
What is airborne disease transmission?
Certain pathogens can be transferred in the air via coughing or sneezing
What is vectors diseased transmissions?
Intermediary organisms that transfer pathogens without developing disease symptoms themselves
How will the body responds when it is challenged by a foreign pathogen?
With a specific and non specific immune reaction
What are non-specific immune cells called?
Macrophages
What do macrophages do to pathogens?
Engulf them non selectively and break them down internally
What will a proportion of macrophages present the antigenic fragments to?
Specific lymphocytes
What will a proportion of macrophages present the antigenic fragments to?
Specific lymphocytes
What does the body contain millions of different?
T lymphocytes andd B lymphocytes
What are antigenic fragments presented to?
Specific helper T lymphocytes
What are antigenic fragments presented to?
Specific helper T lymphocytes
What do T lymphocytes release when activated?
Cytokines
What do cytokines stimulate?
A specific B-cell that produces antibodies to the antigen to divide and form clones
In clonal selection, what will most clones develop into?
Short lived plasma cells that produce large quantities of specific antibody
What will a small proportion of clones differentiate into?
Long-lived memory cells that function to provide long term immunity
What do pathogens typically contain multiple of on their surface?
Distinct antigenic fragments
Due to having multiple distinct antigenic fragments on their surface, what is a single pathogen likely to stimulate?
Several different T and B lymphocytes to produce a variety of specific antibodies
What happens when a specific B lymphocytes is activated following antigen presentation?
It divides into plasma cells and memory cells
What do plasma cells secrete?
High numbers of antibodies that are specific to a particular antigen
Are plasma cells long or short lived?
Short lived
What are the five ways antibodies aid in the destruction of pathogens? (Panic)
Precipitation
Agglutination
neutralisation
Inflammation
Complement activation
How do antibodies do precipitation?
Soluble pathogens become insoluble and precipitate
How do antibodies do agglutination?
Cellular pathogens become clumped for easier removal
How do antibodies do neutralisation?
Antibodies may occlude pathogenic regions
How do antibodies do inflammation?
Antibodies may trigger an inflammatory response within the body
How do antibodies do complement activation?
Complement proteins perforate membranes
How does the action of antibodies enhance the immune system collectively?
By aiding the detection and removal of pathogens by the phagocytic leukocytes of the innate immune system
What does the adaptive immune system rely on?
The clonal expansion of plasma cells to produce sufficiently large numbers of antibodies
There is a delay between the initial exposure to a pathogen and what?
The production of large quantities of antibodies
What happens if pathogens were to reproduce rapidly during the delay period?
They can impede normal body functioning and cause disease
What are memory cells produced to prevent?
The delay in subsequent exposures and thus disease symptoms developing
What happens when B lymphocytes are activa6ted and form plasma cells?
A small proportion differentiate into memory cells
Are memory cells short or long living?
Long living
What will memory cells produce low levels o?
Circulating antibodies
What will memory cells do if a second infection with the same pathogen occurs?
They will react more vigorously to produce antibodies faster
Why can pathogens not reproduce in sufficient amounts to cause disease symptoms?
As antibodies are produced faster
How is an individual described when pathogen exposure no longer causes the disease to occur?
The individual is immune
What is an allergen?
An environmental substance that triggers an immune response despite not being intrinsically harmful
Where is the immune response during an allergic reaction?
Localised to the region of exposure
What is a severe allergic reaction called?
Anaphylaxis
What does an allergic reaction require?
A pre-sensitised immune state
What happens when a specific B cell first encounters an allergen?
It differentiates into plasma cells and makes large quantities of antibody
What do IgE antibodies attach to?
Mast cells
What do IgDE antibodies do to mast cells?
Effectively primes them towards the antigen
What do IgDE antibodies do to mast cells?
Effectively primes them towards the antigen
What do the IgE primed mast cells do upon re-exposure to the allergen?
Release large amounts of histamine which causes inflammation
What does the release of histamine as an inflammatory response result in?
Allergic symptoms
What does inflammation improve?
Leukocytes mobility to infected regions by triggering vasodilation and increasing capillary permeability
What is vasodilation?
The widening of blood vessels to improve the circulation of blood to targeted regions
What two things do vasodilation cause?
Redness and heat
What does capillary permeability describe?
The capacity of leukocytes to leave the bloodstream and migrate into the body tissue
What two things does increased capillary permeability lead to?
Swelling and pain
What do vaccinations induce?
Long-term immunity to specific pathogenic infections by stimulating the production of memory cells
What is a vaccine?
A weakened or attenuated form of the pathogen that contains antigens but is incapable of triggering disease
What may the antigenic determinants in a vaccin be conjugated to?
An adjuvant
What does an adjuvant function to do?
Boost the immune system
How does the body respond to an injected vaccine?
Initiation in primary immune response which causes memory cells to be made
What do memory cells tigger when exposed to the actual pathogen?
A more potent secondary immune response
What is the consequence of the more potent immune response?
Disease symptoms do not develo
What is the length of time a person is immune to infection following a vaccination depended on?
How long the memory cells survive for
What is the length of time a person is immune to infection following a vaccination depended on?
How long the memory cells survive for
Why may individuals require a booster shot to maintain immunity?
Memory cels may not survive a lifetime
Why are vaccination programmes implemented?
To reduce the outbreak of particular infectious diseases within population
What is an epidemic?
A substantially increased occurrence of a particular infection within a given region
What is a pandemic?
An epidemic that has spread across a large geographical area
How does vaccination confer immunity to vaccinated individual and indirectly protect non-vaccinated individuals?
Herd immunity
What is herd immunity?
When individuals who are not immune to a pathogen are protected from exposure by the large amounts of immune individuals within the community
What was the first infectious disease of humans to have been eradicated via vaccination?
Smallpox
What is a disease considered when it stops circulating in the region?
Eliminated
What is a disease considered if it is eliminated worldwide?
Eradicated
What is a disease considered if it is eliminated worldwide?
Eradicated
Why was smallpox easily eradicated?
- smallpox is easily identifiable
- transmission is only through direct contact
- global cooperation
- short infection period
What is epidemiology?
Study o patterns causes and effects of health and disease conditions in a defined population
What three things must you remember when analysing vaccination data?
- populations have increased annually
- improvements on healthcare
- different regions experience different levels of exposure
What are monoclonal antibodies?
Antibodies artificially derived from a single B cell clone
How are monoclonal antibodies created? (3)
- animal infected with antigen and produces antigen-specific plasma cells
- plasma cells are removed and fused with tumour cells that can endlessly divide
- the resulting cell is a hybridons, capable of making large quantities of monoclonal antibody
What can monoclonal antibodies be used for?
Therapeutic treatment and clinical detection of disease
What are monoclonal antibodies commonly used to provide?
Protection for individuals who contract harmful diseases
What arde therapeutic monoclonal antibodies named according to?
The source organism from which the antibodies were derived
What are monoclonal antibodies used to test for?
Pregnancy
What do monoclonal antibodies test for in a pregnancy test?
HCG in urine
What is hCG?
A hormone produced during foetal development
What does the presence of hCG in urine indicate?
Pregnancy
In pregnancy tests, how is a substance identified? Simple
Via colour change
How does the dye change colour in pregnancy tests?
Free monoclonal antibodies specific to hCG are conjugate to an enzyme that changes the Color of a dye
What do the second set of monoclonal antibodies do in pregnancy tests?
They are immobilised to the dye substrate
What will hCG do if it is present in the urine?
Interact with both sets of monoclonal antibodies
What happens when both sets of antibody are bound to hCG?
The enzyme is bought into close proximity with the dye changing its colour
What functions as a control in pregnancy tests?
A third set of monoclonal antibodies
How does the third set of monoclonal antibodies act as a control?
They will bind to any unattached enzyme-linked antibodies
