[Chemokines and chemokine receptors. Review article].

Chemokines form a new superfamily of small glycoproteins. They are key molecules that activate and direct the migration of different types of leukocytes from the blood stream into sites of infection and inflammation. In addition to this role certain chemokines have been reported to act on different types of cells (e.g. hematopoietic progenitor cells, dendritic cells, fibroblasts, keratinocytes). Other of them also play a role in wound healing, in angiogenesis and in viral infections. These molecules have a high degree of amino acid sequence homology and they have four conserved cysteins forming two essential disulphide bonds. They are divided into four classes (families) depending on the position of the first two cystein residues. Chemokines mediate their proinflammatory effects by binding to a variety of specific receptors, belonging to the G protein-coupled superfamily of seven-transmembrane (serpentine) receptors. Some of this receptors serve as coreceptors for HIV-viruses, some of them could be expressed as markers preferentially in Th1 or Th2 subpopulations. This paper summarizes data on chemokines and their receptors, target cells and production in physiological and pathological conditions.