Immunity Flashcards
what are the types of immunity?
active and passive
what is active immunity?
Protection by adaptive immune response Individual’s immune system is activated against an antigen Time to develop Immunological memory Immunity develops over weeks
what is passive immunity?
Transfer of antibodies
Immediate immunity
Does not last as no memory
Antibodies degrade overtime
what is natural passive immunity?
Mother to foetus through placenta or milk
Weeks of months of protection which own immune system develops
what is artificial passive immunity?
Receiving antibodies in antiserum from another organism
Antiserum contains specific antibodies
Serum is the fluid of blood
Useful if death will occur before the immune system kicks in
Can suppress active immunity when it is harmful
Snake bite
what is natural active immunity?
Immunological memory from an infection
what is artificial active immunity? types?
Administration of antigens to induce the active immune response
Vaccination
Vaccine is altered or weakened or killed or inactivated
Boosters needed to activate a stronger secondary response
- live attenuated vaccines
- inactivated vaccines
- subunit vaccines
what are live attenuated vaccines? advantages, disadvantages
Weakened living microbe through repeated culturing
Advantage: long lasting as a strong immune response was induced, producing many antibodies
Disadvantage: not safe for people with weak immune systems, cross placenta in pregnant woman and infect baby
what are inactivated vaccines? advantages, diadvantages
Aka killed vaccines
Inactivated by heat, chemicals, radiation
advantages: result in production of many different antibodies, safe for all
disadvantages: stimulate a weak response so require a booster
what are subunit vaccines? advantages, disadvantages
Contain parts of microbes
Advantages: safe, stable, easier to store
disadvantages: need boosters to be more powerful
what is herd immunity?
For immunisation to be effective, a sufficient number of people need to be vaccinated
Essential for those who cannot be vaccinated
what is the allergic reaction? how dangerous? what happens? what antibody is involved?
Allergic reaction
Rapid overreaction to antigens that are harmless (allergens)
Pollen
Mild to life-threatening
Pollen allergy or hay fever is a reaction to antigens on pollen
Release of histamine from mast cells
Antibody immunoglobulin E (IgE) is produced by plasma cells
IgE binds to mast cells and when allergen binds across two antibodies (bridging the gap) mast cell releases histamine
what does the release of histamine cause?
Blood vessel dilation
Increase of blood vessel permeability
Contraction of muscles in air ways
Fluid-secreting cells- teary eyes, runny nose which expel antigens
what are autoimmune diseases?
Adaptive immune system response directed against self-antigens
T cells attack tissues directly
B cells work indirectly, relating antibodies
what are the types of autoimmune disease?
Organ-specific are located in a localised area
Generalised autoimmune diseases are located throughout the body
autoimmune haemolytic anemia
Type II hypersensitivity because antibodies are directed against self-antigens on red-blood cells
rheumatoid arthritis
Type III because involved deposition of antigen-antibody immune complexes in tissue which results in inflammation and damage
Also thought to be type IV as T cells attack antigens in joints
type 1 diabetes
T cells attack and destroy beta cells in the pancreas
Beta cells make insulin which regulates glucose levels
Must inject insulin to maintain glucose balance
Mediated by T cells so Type IV
multiple sclerosis
Myelin sheath is affected
Condition of signals is impaired
Helper and cytotoxic T cells are involved as well as plasma cells producing antibodies and target proteins and lipids in myelin sheath
Oligodendrocytes (produce myelin sheath) are damaged and undergo apoptosis as a result
Macrophages also destroy oligodendrocytes
Type IV
Damage eventually occurs to axons
Suppressors of inflammation and immuneosupressants are used
what is immunodeficiency? what are types?
Immune system cannot adequately respond to antigens or fails to react at all
types: primary and secondary
Primary is when you are born with it
Secondary is squired, can be temporary or permanent eg. AIDS which becomes HIV
what Is HIV? what does it do? what results?
HIV is a retrovirus where virus DNA is inserted into cell DNA so that it produced viruses
Immune system responds but some copies of the virus survive
HIV has a high mutation rate which helps it stay ahead of the immune system
Impairs the immune system by infecting T helper cells
AIDS develops when the immune system is impaired
AIDS puts people are risk of other disease which cause death
how is HIV transmitted?
Present in body fluids of infected people
Transmitted through unprotected sex, sharing needles, to a foetus through placenta
HIV treatment
Antiretroviral therapy (combination of medications to stop AIDs developing):
Blocking binding of HIV to cells
Blocking the transcription of DNA by virus
Blocking the enzymes that integrate the DNA
what is cancer? how can it be caused?
Abnormal cell that multiples
Growth is caused by changed to genes that control growth and a resistance to apoptosis
Carcinogens damage cell DNA
Can be caused by viruses
what are tumours? what are the types? metastasis?
Clump of abnormal cells
Benign tumours are not cancerous as they don’t spread
Malignant tumours cause cancer as they invade
Metastasis occurs when cells break from tumours and travel in blood or lymph to other parts
what are the typical cancer treatments?
Chemotherapy: drugs that are cytotoxic to cells that divide rapidly. Not specific enough not to target other quickly dividing cells
Radiation therapy: kills cells by damaging DNA, directed at cancerous cells but gets others
Surgery: remove solid tumours but harms the body and some can be left
how does the immune system respond to cancer?
Weakened immune systems are more likely to have cancer
Express defective MHC-I markers so that T cell cannot detect cancer cells, producing immunosuppressive cytokines, or by releasing enzymes that suppress T cell responses
what are the features of cancer immunotherapy?
Non-specific: stimulates immune system eg. Injecting cytokines
Specific: act on cancer cells by stimulating the adaptive immune response against them eg. Cancer vaccines and monoclonal antibody therapy
what do cancer vaccines do? what are the types?
Stimulate the immune system to attack cancer cells
Proteins from cancer cells may be injected to stimulate a response
Sometimes cells are harvested, exposed to these antigens and injected to produce a immune response
- preventative cancer vaccines, therapeutic cancer vaccines, personalised cancer vaccines
what are preventative cancer vaccines?
Directed against cancers that cause cancer eg HPV
Introduce specific viral antigens creating a response that will lead to memory
what are therapeutic cancer vaccines?
Have cancer
Made up of antigens for that cancer and boost immunity by increasing its ability to destroy cancer cells
what are personalised cancer vaccines?
Have cancer
Tumour cells that have been altered to make them more obvious to the immune system
Present antigen from tumour to the patient’s dendritic cells
Activated dendritic cells are injected back
what is monoclinal antibody therapy?
Clone B cells to produce many antibodies in culture
Target specific antigens
Target cells of the immune system and direct the immune response in a way that helps destroy tumour cells
production of monoclonal antibodies?
Antigens are injected into mice
Antibodies are made by B cells, these B cells are then isolated to the spleen of mice
B cells are fused with myeloma cells which are an immortal cell line (forms hybridoma)
Hybridoma is more stable in a tissue culture and produced antibodies which are harvested
humanised monoclonal antibodies
Mice produced antibodies are detected as foreign and an immune response is mounted against them
A memory is made and the next time they are injected they are destroyed fast
Some parts have been replaced with human components using recombinant DNA techniques
conjugated mAbs
Been attached to a chemotherapy drug, toxin or radioactive particle
Deliver treatment to cancer cells
Limits toxic affects on surrounding cells
Bi-specific mAbs
Artificially produced using recombinant DNA technology
Activate immune system and target cancer cells
Two binding sites
Binds to T cell proteins and antigen identifying cancer cells and delivering them to the immune system
