Intracellular signalling pathways induced by chemokines in natural killer cells

Chemokines are small peptides involved in the recruitment of various cell t ypes into inflammatory sites. They are divided into four-sub-families depen ding on the presence of amino acids separating the cysteine residues in the ir N-terminal region. These are the alpha (CXC), beta (CC), gamma (C) and d elta (CX3C) chemokines. In addition, five CXC chemokine (CXCR1-5), nine CC chemokine (CCR1-9), one C chemokine (XCR1) and one CX3C chemokine (CX(3)CR1 ) receptors have been identified. These receptors belong to the seven trans membrane spanning domain family, and are coupled to the heterotrimeric guan ine nucleotide binding (G) proteins. Chemokines activate various immune cel ls, and in particular the anti-viral/anti-tumour effecters, the natural kil ler (NK) cells by activating members of the heterotrimeric G proteins. The importance of the family of chemokines is highlighted by the ability of its members to inhibit the replication of HIV-1 strains in CD4+ cells, where c hemokine receptors act as HIV-1 co-receptors. This review discusses the int racellular signalling pathways induced by chemokines in NK and other cell t ypes, and the relationships to HIV-1 signalling in these cells. CELL SIGNAL 11;6:385-390, 1999. (C) 1999 Elsevier Science Inc.