Soluble Mediators
Cytokines
A large group of molecules which signal between cells during immune responses.
All are proteins, some are glycoproteins
There are the following groups of cytokines:
- Interferons
- Limit spread of viral infections
- IFNα and IFNβ are produced by virally infected cells
- IFNγ is released by activated T cells
- Create antiviral resistance in uninfected cells
- Interleukins
- Direct other cells to divide and differentiate
- IL-1 to IL-22
- Produced by T cells, mononuclear phagocytes, tissue cells
- Colony-stimulating factors
- Direct division and differentiation of bone marrow stem cells
- Direct further differentiation of cells outside the bone marrow e.g. M-CSF promotes development of monocytes and macrophages
- Chemokines
- Are chemotactic
- Some activated specific functions of cells
- Other cytokines
- Tumour necrosis factor (TNFα and TNFβ), transforming growth factor-β (TGFβ)
- Have many functions including inflammation and cytotoxic reactions