Cytokines which exert their effects on macrophages

IFN-gamma

Interferon-gamma is produced by Th1 T-lymphocytes and by activated Natural Killer (NK) cells. IFN-gamma activates macrophages to kill pathogens and upregulates macrophage MHC class II expression.
IFN-gamma with lipopolysaccharide (LPS) upregulates respiratory burst and nitric oxide production.

IL-4

Interleukin 4 is produced by Th2 T-lymphocytes and its effects can oppose those of IFN-gamma.
IL-4 causes macrophage fusion to form multinucleate giant cells in culture.
IL-4 induces MHC class II.
IL-4 induces Mannose receptor expression and endocytosis in macrophages .
IL-4 induces an alternative form of macrophage activation.
IL-4 has many effects on B-cells including up regulation of MHC class II and Ig class switching.

IL-13

Interleukin 13 has very similar biological effects on macrophages to IL-4. Its receptor has a specific chain and a chain shared with IL-4.

TGF-beta

Also produced by macrophages.
Transforming Growth Factor-b primes some macrophage functions (eg chemotaxis, TIMP secretion) but inhibits other macrophage functions (eg macrophage NO synthesis).
TGF-b1 is found at highest concentration in platelets.
TGF-b stimulates osteoblasts and inhibits osteoclasts playing an important role in bone remodelling.
TGF-b inhibits activated macrophage production of reactive oxygen and reactive nitrogen metabolites.
TGF-b stimulates macrophage secretion of various growth factors eg PDGF-B .
TGF-b stimulates macrophage secretion of extracellular matrix components.

M-CSF

Macrophage Colony Stimulating Factor (M-CSF or CSF-1) is produced by many cells eg fibroblasts including macrophages themselves and is important for the survival, proliferation and differentiation of monocytes, macrophages, osteoclasts and their precursors.
M-CSF is an important cytokine for upregulation of Macrophage Scavenger Receptor activity.
M-CSF exerts its biological effects through binding to the M-CSF receptor, the product of the c-fms proto- oncogene.