Adaptive immunity Flashcards
What is humoral immunity?
Antibody immunity
Briefly describe the process of humoral immunity.
Antigen is recognised by receptor on B lymphocyte
B lymphocyte matures to plasma cell and starts producing loads of antibodies against the antigen
Which pathogens is humoral immunity better at fighting?
Extracellular bacteria
Secondary viral infections
What are the 2 purposes of antibodies?
- Antigen recognition: Fab regions bind specifically to antigens
- Antigen elimination: Once antibody has bound to pathogen, its Fc region binds to complement, phagocyte or NK cells which initiates antigen elimination
What’s the role of Fab regions of antibodies?
- Neutralise toxins
- Immobilise motile microbes
- Prevent pathogens binding to and infecting host cells
- Form complexes
What’s the role of Fc regions of antibodies?
- Activate complement
2. Bind to Fc receptors on phagocytes, mast cells, NK cells
What do mast cells do?
Release inflammatory mediators
Where do T cells mature?
Thymus
Name the types of T cells.
T helper
T cytotoxic
T regulatory (TREGs)
What do T helper cells do?
Help plasma cells make antibodies
Activate macrophages and NK cells
Help the development of cytotoxic cells
What do T cytotoxic cells do?
Recognise and kill infected host cells
What do TREGs do?
Suppress immune responses, preventing them getting out of hand
Preventing autoimmunity
What does the T cell receptor (TCR) do?
Recognises cell-associated antigens (ones that have been processed already by B cells or dendritic cells
MHC proteins help them do this!
What do MHC proteins do?
Take samples from within infected cells and present them on the surface of that cell so that T cells can see that the cell is infected
What are cytokines and what do they do?
They are small proteins
Involved in communication between cells of immune response
Produced and act locally
What cells make interleukins?
T cells
What type of infections are interferons involved in?
Viral
What do chemokines do?
Facilitate cell movement / chemotaxis
What does CSF stand for? What does it do?
Colony stimulating factor
Involved in leukocyte production
What does TNF-a stand for?
Tumour necrosis factor - alpha
What cells produce TNF-a?
T cells
Macrophages
NK cells
What does TNF-a do?
Activates neutrophils and endothelial cells
Induces cachexia (loss of muscle and body fat)
What are the sub-categories of T helper cells?
TH1
TH2
TH17
TREG
What do TH1 cells produce?
IL-2
gamma-interferon
TNF-b
