The Chemokines as example of gene discovery in immunologyGCOE Program Seminar(Global Education Seminar)

The chemokines are a superfamily of small proteins that regulate a number of physiological processes, many of them in the immune system. They are master regulators of homing of different lymphocyte populations, and as such they determine the distribution of the lymphoid populations in the human body. The chemokines can be divided into inflammatory and homeostatic. The inflammatory chemokines regulate inflammatory responses while the homeostatic chemokines participate in various processes, including organogenesis. We have produced a comprehensive database of gene expression in the human body that includes more than 105 tissues. Using this database, we have screened for novel genes in the immune system. We did not detect new chemokines, but we have found many new secreted and transmembrane proteins. We believe that the last chemokine ligand to be discovered was CXCL17 and there are at least 3 chemokine receptors that remain to be discovered (CXCL14, CXCL17, and CCL18). The implications of these observations will be discussed.