Page 82 - Veterinary Immunology, 10th Edition

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FIG. 3.4 The classification of chemokines is based on the location
and spacing of their cysteine (C) residues and their separation by
other (X) amino acids.

In addition to structural criteria, chemokines may be classified

functionally. Thus inflammatory chemokines are upregulated in
inflammation and are mainly involved in leukocyte recruitment.
Others promote new blood vessel growth. Some are homeostatic

and are found in normal tissues where they regulate cellular
migration and homing, and many have overlapping functions.
One of the most important chemokines is CXCL8 (also called
interleukin-8). CXCL8 attracts and activates neutrophils, releasing
their granule contents and stimulating their respiratory burst

(Chapter 5). Another important CXC chemokine is CXCL2
(macrophage inflammatory protein-2, MIP-2), which is secreted by
macrophages and also attracts neutrophils.

CC chemokines act predominantly on macrophages and dendritic
cells. Thus CCL3 and CCL4 (MIP-1α and -1β) are produced by
macrophages and mast cells. CCL4 attracts CD4+ T cells, whereas
CCL3 attracts B cells, eosinophils, and cytotoxic T cells. CCL2
(monocyte chemotactic protein-1, MCP-1) is produced by

macrophages, T cells, fibroblasts, keratinocytes, and endothelial
cells. It attracts and activates monocytes, stimulating their
respiratory burst and lysosomal enzyme release. CCL5 (also called

RANTES) is produced by T cells and macrophages. It attracts
monocytes, eosinophils, and some T cells. It activates eosinophils
and stimulates histamine release from basophils.
Two chemokines fall outside the CC and CXC families.

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