The Adaptive Immune Response Flashcards
The bodies inflammatory response is part of which immune response?
The innate immune response.
Name three barriers within the innate immune system
Skin, phagocytes (neutrophils and macrophages) and mucous membranes
When does the active immune response become initiated?
If the innate immune response fails to clear infectious pathogens
Where are immune system cells made?
In the haematopiotic stem cells of the bone marrow
Name the 6 primary immune cells
Macrophages, Neutrophils, Basophils, Eosinophils, Monocytes and Lymphocytes
What process do macrophages undertake and what do they produce?
They undertake phagocytosis and produce cytokines
What do monocytes develop into once they enter the body tissues?
Macrophages
What is the role of neutrophils?
Neutrophils play a primary role in the innate immune response where they are driven to areas of infection to phagocytise toxins
What are the two primary functions of basophils and eosinophils?
To defend against larger pathogens which cannot be phagocytised such as ticks and worms. They are also involved in allergic responses.
What is the role of mast cells?
They produce histamine and play a critical role in the allergic response.
Where are mast cells most commonly found?
Beneath epithelial skin surfaces and within mucosa
Where are dendritic cells found?
In the lymph nodes and body tissues.
What is another name for a dendritic cell?
An antigen presenting cell.
What are the two types of lymphocytes?
T cells and B cells
Where do T cells and B cells originate?
In the bone marrow
Where do T cells mature?
In the thymus
Where do B cells mature?
In the bone marrow
What is the primary role of cytokines?
To act as signalling molecules within cell to cell communication and regulate the immune response
Name the three primary components of the lympathic system
Lymph nodes, lymph vessels and lympathic organs
What is lymph derived from?
Blood plasma
What is drained into the lympathic vessels?
Tissue fluid, cell debris and microorganisms
Name the 3 main types of antigen
Foreign antigen, tumour antigen and self antigen
What are antigens?
Most antigens are proteins which exist on the surface of microorganisms. They are targeted by antibodies within the adaptive immune response
The antigens coating our own body cells are known as
self antigens
Describe how B cells work
B cells recognise an antigen on the surface of a microorganism. They then become activated and divide to produces clones. Some clones develop into plasma cells which secrete antibodies, others return to the lymph nodes and develop into memory B cells.
What do B cells require to become activated?
Helper T cells
Antigens of the same class are reffered to as:
Immunoglobulins
Briefly describe the three ways antibodies work to destroy pathogens
- Neutralisation: antibodies coat the pathogen and prevent it from interacting with the host cell surface
- Oponisation: antibodies coat the pathogen enhance phagocytosis
- Complement function: antibodies coating the pathogen complement the complement system of blood proteins- stimulating a further immune response
What is monoclonal antibody therapy and what is it used for?
Monoclonal antibody therapy targets specific antigens. It is commonly used within cancer treatment to target specific tumour antigens.
What is the role of the cytotoxic T cell?
To destroy virus infected cells by releasing cytotoxic molecules.
What is the role of the helper T cells?
To activate B cells and cytotoxic T cells.
What is the role of antigen presenting cells?
To engulf microorganisms and present their antigens to T cells in the lymph nodes. Engulf microorganisms through phagocytosis.
Describe active immunity.
Occurs when someone is exposed to the actual disease causing microorganism or a vaccine. Involves stimulation of the active immune response and produces memory cells which provide immunity for life. Generally takes days-weeks to develop.
Describe passive immunity.
Occurs when someone is given antibodies against a pathogen or bacterial toxin. May be passed on from mother to baby or given as temporary immunoglobulins.
Define hypersensitivity
An excessive immune reaction which causes damage to body tissues
Which 3 types of antigen may trigger hypersensitivity?
- normally harmless environmental entigens stimulate an allergic reaction
- antigens from microbes may cause an exaggerated immune response
- self antigens causing autoimmune disorders
What are the 4 types of hypersensitivity reaction?
- Immediate (allergies)
- Antibody mediated (reactions to blood transfusions)
- Immune complex (autoimmune conditions)
- Delayed (reactions mediated by helper T cells)
Define immunodeficiency
Occurs when the immune system is unable to fight infections
What is the difference between primary and secondary immunodeficiency?
Primary: occurs as a result of rare genetic mutations
Secondary: occurs as a result of complications of another condition
Name 3 conditions which can lead to secondary immunodeficiency
Viral infections, age, immunosupressing medications, poor nutrition.
The first line of defence which changes very little during our lifetime is called:
Innate immune response
Which white blood cells are responsible for active immunity?
Lymphocytes
Which molecule stimulates the active immune response?
Antigens
What sort of immunity is gained by aquiring ready made antibodies?
Passive immunity
Deficiencies in the cell mediated immune response will lead particularly to infections by:
Viruses
Which property of the adaptive immune response is the basis of immunity to previously encountered infections>
Memory cells
The major antibody class involved in the adaptive immunity response is:
IgG
Autoimmunity arises following a breakdown in self……
Tolerence
What are the three key features of the adaptive immune response?
Antigen specificity
Diversity
Memory
What are antigen presenting cells also known as?
Dendritic cells
What is the top part of an antibody called and where does it connect to the antigen?
The variable region. The antigen binding site connects to the antigen (of course)
What is the whole bottom part of the antibody called? What is the very bottom part of the antibody called?
Constant region (because it remains the same) FC stem region
What happens during type one hypersensitivity?
An allergen is encountered which stimulates B cells to release IgE antibodies. The antibodies bind to mast cells which normally secrete histamine. Following further exposure the mast cells which initiate an abnormal immune response.
Which cells in particular are infected by the HIV virus. What does this lead to?
Dendritic cells in the lymph nodes. It then is passed onto helper T cells which quickly replicate and spread the virus before dying. Without helper T cells, many B cells are unable to become activated leading in severe immunodeficiency.
