Immune Response Flashcards
(31 cards)
Role of cytokines
To attract other phagocytes to site of infection
And are produced by phagocytes at the site of infection
What is the role of opsonins in phagocytosis
Opsonins bind to complementary receptors on phagocytes and complementary antigens on pathogens, which allows the phagocyte to locate and destroy pathogens
This increases the rate of phagocytosis
They also prevent the pathogen repelling phagocytes
Four Ways a plant could respond to an infection
Abscission
Callus production
Necrosis
Release of toxic chemicals
Potato late blight
Protocista or fungi
Malaria
Caused by plasmodium
Vector: mosquito
Protoctista
What is a lymphocyte
A type of white blood cell that identifies non self cells
What is an antigen?
Protein in the cell surface membrane that triggers an immune response
How do lymphocytes recognise antigens
Lymphocytes have specific antigens receptors on their cell surface membrane, and will bind to complementary and specific antigens
This activates the lymphocyte to trigger a specific immune response
Describe the process of phagocytosis
1.opsonins will bind to antigens on the pathogen, and also bind to complementary and specific receptors on the phagocyte
- Receptors bind to the pathogen and recognise it as non self
- Phagocyte then engulfs the pathogen and encloses it into a vesicle cause a phagosome
- Lysosomes in the phagocyte fuse with the phagosome and release digestive enzymes, which breaks down the pathogen to form, a phagolysosome
Describe a phagocyte
They are complementary to a specific molecular pattern found on all pathogens so they are not specific to one antigen
What happens when a naive B cell encounters a pathogen
The B cells receptor binds to the complementary and specific antigen on the pathogen
B cell internalises the pathogen and breaks it down
How are B cells cloned?
After breaking down the pathogen the B cells receptor binds keeps the antigens, processes them and then presents them on the cell surface membrane becoming an antigen presenting cell.
This means a complementary helper T cells receptor binds will bind to the processed antigen
This causes the helper T cell to release interleukins that cause differentiation of B cell into a plasma cell or memory B cell
Describe plasma cells
Produced by B cells
And will secrete the specific antibodies produced by naive B cells in response to the presence of a specific antigen
What is agglutination
Clumping antigens together using antibodies
As monoclonal antibodies have two complementary antigen binding sites so they could bind to two pathogens antigens at once and form multiple antigen antibody complex
What are monoclonal antibodies
Antibodies with the same tertiary structure produced from cloned B cells
Name the antibodie responsible for agglutination
Agglutinin
Three functions of antibodies
Agglutination
Assisting phagocytes to recognise pathogens (opsonins)
Act as anti-toxins to neutralise toxins released by pathogens
Describe two differences between naive B cells and memory B cells
Naive B cells produce less plasma cells compared to memory B cells, so memory B cells produce a higher concentration of antibodies
Memory B cells act much faster, so person is less likely to display any symptoms
What is the humoral response
The primary and secondary immune response involving B cells
What to T cells bind to
They only bind to antigens on antigen presenting cells
Cells that act as antigen presenting cells
B- cells
Phagocytes
Body cells
These all process antigens and then present them on their cell surface membrane
Why do T cells only bind to antigen presenting cells
As when antigens are processed they are slightly changed
And T cells are only complementary to the antigens with these changes
Four uses of cloned helper T cells in three cell mediated response
Binding to B cells, which releases interleukins and stimulates B cells to clone
Can release chemicals that attract phagocytes to a pathogen, which stims phagocytes
Stimulates killer T cells to target infected body cells
Can develop into memory T cells which can rapidly clone and differentiate into killer T cells
How does a T killer cell kill an infected body cell
The killer T cells complementary antigen receptors, bind to the processed antigen on the antigen presenting body cell
This stimulates the release of perforin which causes holes to form on the cell surface membrane
Ions then flow in and out of the infected cell In an uncontrolled way which disrupts the balance in the cell causing it to die
