Characterization of low molecular weight antimicrobial peptide from human female reproductive tract

BACKGROUND & OBJECTIVES The mechanisms that protect female upper genital tract from ascending infection by microbes present in vagina are only partially understood. It is expected that epithelial cells in mucosal surfaces and their secretions directly interfere with microbial colonization and invasion. This study was aimed to demonstrate the expression of 2 kDa antimicrobial peptide which was identified and purified from female genital tract tissues using chromatographic techniques. METHODS Low molecular weight proteins were isolated from human female reproductive tract tissues obtained from premenopausal women. Antimicrobial activity of these LMW proteins was assessed against different reproductive tract pathogens viz., Neisseria gonorrhoeae, Group B streptococcus, Gardnerella vaginalis, Escherechia coli and Candida albicans. The expression of these peptides were also documented in reproductive tract tissues with the help of hyperimmune sera raised against the rabbits. The purified peptide was characterized by N-terminal sequencing. RESULTS Immunohistochemical and immunofluorescence studies demonstrated that 2 kDa peptide was expressed in the stratified squamous epithelial cells of the ectocervix while it was absent in columnar epithelial cells of upper genital tract. Upregulation of the expression of this peptide was observed in patients of chronic non-specific cervicitis and acute on chronic cervicitis. This purified antimicrobial peptide also showed broad spectrum antimicrobial activity against different reproductive tract pathogens. INTERPRETATION & CONCLUSIONS Considering the emerging bacterial resistance against conventional antibiotics, isolation and understanding of the expression of antimicrobial peptides from female reproductive tissue extracts may provide some leads towards the development of strategies for the treatment of reproductive tract infections.