B1 Adaptive immunity Flashcards
What are antibodies?
Proteins that are produced by the immune system in response to a foreign substances like a virus or bacteria
What are antibodies made up of?
4 polypeptide chains held together by disulphide bridges, antigen binding sites, the constant region, the variable region and light polypeptide chain
What is the adaptive immune response?
When the immune system is activated, and antibodies are produced.
What are examples of APC?
Infected body cell, a macrophages and cancer cells
Describe the cell mediated reponse
1) After phagocytosis, antigens are presented on the cell surface (APC)
3) T helper cells have receptors that attach to antigens on APC (clonal selection)
3) This activates T helper cells and causes them to divide by mitosis and make clones (clonal expansion)
4) Cloned T helper cells differentiate into different cells. Some remain as T helper cells, some stimulate macrophages and some become T memory cells or T killer.
What is the role of T helper cells?
Activating phagocytes and B cells
What is the role of T killer (cytotoxic)?
They destroy abnormal, foreign and infected cells
What is the role of T memory cells?
They provide long term immunity
What is the cell mediated response?
The response of T cells to a foreign antigen. They only respond to antigens on the surface of cells.
What is the Humoral response?
The activation and production of specific B cells to produce antibodies for specific non-self antigens. It can only take place after the cell mediated response.
What are lymphocytes and where are they made?
White blood cells involved in the specific immune response. They are made in the bone marrow.
Describe the Humoral response?
1) T helper cells for a specific antigen will bind to and activate a B cells
2/3) The activated B cell divide by mitosis to make more B cells
4) The B cells divide by mitosis to make more copies of B cells
5) Some B memory cells. These remain in the body as an active response to pathogens if there is future infection, providing long term immunity
6) Some become B plasma cells which produce antibodies
Describe the Humoral response?
1) T helper cells for a specific antigen will bind to and activate a B cells
2/3) The activated B cell divide by mitosis to make more B cells
4) The B cells divide by mitosis to make more copies of B cells
5) Some B memory cells. These remain in the body as an active response to pathogens if there is future infection, providing long term immunity
6) Some become B plasma cells which produce antibodies
What is the primary immune response?
The initial response caused by a first infection
What happens during the primary response?
Antibodies specific to the pathogen’s antigens are produced. This process takes longer and the body needs to begin to make these antibodies.
What is the secondary immune response?
A stronger and more rapid response caused by a second infection to the same pathogen. This process is quicker as clonal selection and clonal expansion are skipped due to B memory cells already being in the body.
What can antibodies act as?
Opsonins, agglutinins and anti-toxins
What happens when an antibody does agglutination?
Antibodies bind to antigens on pathogens forming an antigen antibody complex. This causes them to clump together and target them for destruction. Phagocytosis follows and phagocytes can recognise and destroy the pathogen in a large group .
What happens when antibodies act as anti-toxins?
They bind to the toxins produced by pathogens, neutralising their harmful effects.
What happens when antibodies act as opsonins?
Antibodies bind to dangerous antigen so that they can be easily recognised by antibodies or complementary receptors on phagocytic cells. This neutralises the pathogen and stimulates phagocytosis.
What is passive immunity?
Antibodies are made by another organism not by yourself.
