CC Chemokines

The diagram shows the conservation of cysteine residues in the major members of the CC family of Cytokines. All the sequences can be aligned with a minimal number of deletions and insertions. A number of other CC Chemokines are not included in the diagram; these include hLD-78, hACT-2, C10, MIP_1g.

Abbreviations used are:-

MIP-1a           Murine Macrophage Inflammatory Protein-1 alpha
MIP-1b           Murine Macropahge Inflammatory Protein-1 beta
RANTES           RANTES
MCAF             Monocyte chemo-attractant and activating protein (MCP-1, JE)
I-309            Human I-309
HC-14            Human HC-14

MCAF/MCP-1 A monocyte chemoattractant activity. Activates monocyte superoxide ion production. Will activate cultured human monocytes to be cytostatic for several types of tumour cell lines, over a period of several days, although it does not directly inhibit tumour growth.

RANTES Has been reported to act as a selective chemoattractant for human monocytes raher than neutrophils. Is also a chemoattractant for subsets of memory T lymphocytes. It has also been reported to increase the adherence of monocytes to endothelial cells.

hLD78 This is the human homologue of the murine protein mMIP-1a.

hAct-2 This is the human homologue of the muine protein mMIP-1b.

mMIP-1b A mixture of mMIP-1b and mMIP-1a is reportedly chemokinetic for human neutrophils in vitro but not monocytes. The mixture also stimulates neutrophils to produce hydrogen peroxide and to release lysozomal enzymes.

mMIP-1a While the mixture of mMIP-1b and mMIP-1a enhances the growth of more mature progenitor cells, mMIP-1a inhibits the growth of early hematpoietic stem cells. Thus mMIP-1b and mMIP-1a may be distinct gene products.