GENE-EXPRESSION, IMMUNOLOCALIZATION, AND SECRETION OF HUMAN DEFENSIN-5 IN HUMAN FEMALE REPRODUCTIVE-TRACT

This study describes the novel localization of the antimicrobial pepti de human intestinal defensin-5 (HD-5) in female genital tract epitheli a, Using a 3' rapid amplification of cDNA ends (RACE) protocol, HD-5 w as cloned from a vaginal epithelial cell RNA preparation, and its iden tity was confirmed by sequencing, Tissue samples from multiple donors were subsequently screened for HD-5 expression by reverse transcriptio n polymerase chain reaction. HD-5 message was invariantly expressed by normal vagina and ectocervix and inflamed fallopian tube, but variabl y expressed by normal endocervix, endometrium, and fallopian tube (60, 64, and 29% of specimens, respectively). Expression in endometrium wa s the highest during the early secretory phase of the menstrual cycle. Using immunohistochemistry and confocal microscopy, HD-5 peptide was localized in the upper half of the stratified squamous epithelium of t he vagina and ectocervix, with the intensity of cellular staining incr easing toward the lumen. In positive endocervix, endometrium, and fall opian tube specimens, HD-5 was located in apically oriented granules a nd on the apical surface of a proportion of columnar epithelial cells, Using Western blot analysis, secreted HD-5 was detected in cervicovag inal lavages, with the highest concentrations found during the secreto ry phase of the menstrual cycle. We hypothesize that HD-5 is an intrin sic component of the female urogenital innate immune defense system an d that its expression may be modulated by hormonal and proinflammatory factors.