Structure and mapping of the human beta-defensin HBD-2 gene and its expression at sites of inflammation

We cloned a second human beta-defensin gene, HBD-2, and determined its gene structure and expression in inflamed tissue sections. The entire gene span ned about 2 kb with two small exons and one intron. Radiation hybrid studie s confirmed the location on chromosome 8p, were consistent with the order H NP-1, HBD-1 and HBD-2, and located HBD-2 as the most centromeric of the gen es. By three-color fluorescence in situ hybridization on both free chromati n fiber mapping and interphase mapping, HBD-1, HBD-2 and HNP-1 were mapped to chromosome 8p23. HBD-1 was within 40-100 kb of HNP-1, while HBD-2 was ab out 500-600 kb from HBD-1, with the most likely order HNP-1, HBD-1, HBD-2. The expression of HBD-2 was locally regulated by inflammation. HBD-2 mRNA w as markedly increased in the epidermis surrounding inflamed regions, but no t detectable in adjacent non-inflamed areas, a distribution that was confir med at the peptide level by immunostaining with HBD-2 antibody. The HBD-2 g ene is the first member of the human defensin family that is locally induci ble by inflammation. (C) 1998 Elsevier Science B.V. All rights reserved.