Communicable Diseases Flashcards
When are antibodies produced?
In response to a non-self antigen
What are antibodies produced by?
B lymphocytes
What type of molecule(carb, lipid, protein etc) is an antibody?
Y shaped glycoproteins called immunoglobulins
What is the role of the hinge region?
Allows the ‘arms’ to move, to give flexibility to the molecule
What does the receptor site bind to?
A white blood cell
What holds the light and heavy chain together?
Disulfide bridges
What is agglutination?
The process of antibodies causing pathogens to
clump together, which immobilise them
What is the benefit of agglutination?
The clump becomes too big to enter host cells
The clump cannot travel around due to its size (immobilised) so easier to consume via phagocytosis
What are the two ways antibodies neutralise antigens?
1) Acting as anti-toxins and binding to the antigens toxins produced by the pathogen
2) Antibodies block receptors on the pathogen to prevent them being able to bind and enter the host cell
How do antibodies act as opsonins?
Antibodies bind to antigens on pathogens and ‘tag’ them marking them for destruction by phagocytes
What is the role of the variable region?
To give the antibody specificity to different antigens
How many variable regions does an antibody have? Why?
2, allows for binding of more than one of the same anitgens
Which lymphocyte does cell mediated immunity use?
T lymphocytes
What two types of lymphocyte are there? Where do they mature?
T lymphocytes- thymus gland
B lymphocytes- bone marrow
When does cell mediated immunity occur?
In response to self cells changing in some way
Give 4 examples of when cell mediated immunity occurs
Virus infection
Antigen processing
Mutation
Cells from transplanted tissue
What are the 4 types of T lymphocytes involved in cell-mediated immunity?
T regulator cells
T memory cells
T killer cells
T helper cells
What are interleukins?
Type of cytokine
Produced by T helper cells which stimulate the T helper cells to divide via mitosis to produce a clone of T helper cells.
Involved in stimulating phagocytosis
What are the 3 roles of T helper cells?
Stimulate activity of B cells - increasing antibody production
Stimulates production of other types of T cells
Attracts and stimulates macrophages to ingest pathogens with APCs
What is the role of a T killer cell? How do they perform this?
Destroy pathogen carrying antigen
Produce a chemical called perforin which kills pathogen by making holes in cell membrane so it is easily permeable
What is the role of T memory cells?
Part of immunological memory
Come into contact with an antigen for second time, divide rapidly to form T killer cells
What is the role of T regulator cells?
Supress immunes system acting to control and regulate it.
Stop immune system once pathogen has been eliminated
Prevents an autoimmune response occuring
Describe the steps of cell-mediated immunity
1) Non-specific defence system,macrophages turn into APCs
2) Some T helper cells fit antigens
3) T helper cells become activated and produce interleukins which stimulates more T cells to divide rapidly by mitosis
4) Clones of T cell formed and could do 4 different things
Developed in to T memory cells
Produce interleukins that stimulate phagocytosis
Produce interleukins stimulate B cells to divide
Stimulate development of T killer cells
What does humoral response occur in response to?
Body responds to antigens found outside the cells and APCs. The humoral response produces antibodies that are soluble in blood and tissue fluid and are not attached to cells