Defensin Beta 103B (DEFB103B)

Two classes of defensins, alpha and beta, differ in their disulfide bond pairing, genomic organization, and tissue distribution. Alpha-defensins are expressed in neutrophils and in Paneth cells and other epithelia, and beta-defensins are expressed in epithelia. Epithelial beta-defensins are broad-spectrum cationic antimicrobial peptides. They may also act as chemokines for immature dendritic cells and memory T cells via CCR6, bridging the innate and adaptive immune systems. DEFB103 belongs to the beta class of defensins. The predicted 67-amino acid DEFB3 protein is 43% identical to DEFB2 and has the 6-cysteine motif typical of beta-defensins. PCR analysis of cDNA panels revealed expression in adult heart, skeletal muscle, and placenta as well as in fetal thymus. RNA dot blot analysis detected expression most readily in esophagus.