The adaptive immune system Flashcards
What does the adaptive immune system rely on?
Recognition of antigens.
What is the name of receptors on lymphocytes that can recognise foreign antigens?
The lymphocyte repertoire.
What causes the diversity of recognition receptors and antibodies?
Gene recombination.
What is the TCR?
The T cell receptor on the surface of T cells that is responsible for recognizing fragments of antigen.
What are they key cells in the adaptive immune system?
B cells, T helper cells and T cytotoxic cells.
What is the difference between humoural immunity and cell mediated immunity?
Humoural - antibodies produced, cell mediated - T cells induce apoptosis of the infected cells.
Where are B cells derived from?
Bone marrow - and mature here.
Where are T cells derived from?
The thymus.
What are Treg cells?
T regulatory cells.
What are the characteristics of lymphocytes?
They are small, round cells that have a high nucleus to cytoplasm ratio. They are a type of mature B cells.
What are antigen presenting cells?
Specialised cells that capture microbes and another foreign antigens, and present them to lymphocytes in conjunction with other costimulatory signals.
What are the main antigen presenting cells?
Dendritic cells in epithelia and most organs.
What do dendritic cells do to antigens?
Take up antigen, process it and carry it to T cells in lymph nodes.
What other types of cells can act as antigen presenting cells?
Macrophages and B cells.
Where do lymphocytes originate?
In the bone marrow, derived from haemopoietic stem cells.
