Characterization of Rat Monoclonal Antibodies against Human β-Defensin-2

Defensins are a family of cationic antimicrobial peptides that participate in host defense. Human β-defensin (hBD)-2 has a potent bactericidal activity against a wide spectrum of microorganisms. Because human gingival epithelium is constantly exposed to a variety of microbial challenges, it is considered that hBD-2 has an important role in the protective mechanisms against oral bacterial infection. However, little is known about the production of hBD-2 in tissues of the oral cavity. Six rat monoclonal antibodies (MAbs) raised against chemically synthesized hBD-2 have been characterized. Rat MAbs were specific for the conformational epitopes on hBD-2, but not to hBD-1. To identify the epitope on hBD-2, a series of six overlapping peptides covering the hBD-2 whole sequence were synthesized and the immunoreactivities of six MAbs were examined. The FCPRRYK domain in hBD-2 was recognized by all six MAbs and suggested to be an epitope region. By immunocytochemistry, hBD-2 was localized focally in the epidermis ...