Purification of antimicrobial factors from human cervical mucus.
BACKGROUND
The aim of this study was to separate bactericidal proteins from healthy female cervical mucus.


METHODS
Cervical mucus was collected and dissolved in 1% acetic acid. The antimicrobial activity of acid-soluble extracts was detected by gel overlay assay against Escherichia coli ATCC 43827. The extracts showed considerable amount of antibacterial activity with a clearly visible band. The bactericidal band was purified by reverse-phase high performance liquid chromatography and the antibacterial activity of the eluate was examined using radial diffusion assay.


RESULTS
Two antimicrobial proteins were purified and were further characterized by Tricine sodium dodecyl sulphate-polyacrylamide gel electrophoresis, N-terminal sequencing and matrix-assisted laser desorption ionization time-of-flight mass spectrometry. The proteins were identified as high-mobility group nucleosomal-binding domain 2 (HMG N2) and secretory leukocyte peptidase inhibitor (SLPI). SLPI is an antimicrobial peptide already known in the cervical mucus while HMG N2 in the cervical mucus had not been previously reported. The expression of HMG N2 mRNA was detected in Hela cells and cervical epithelial cells by RT-PCR. Slit hybridization showed abundant amounts of the HMG N2 protein in the cervical mucus.


CONCLUSIONS
These results suggest that the expression of HMG N2 and SLPI in the healthy female cervical mucus may be relevant to their immune surveillance and defense against potential pathogens in human reproductive system.
Ming
Li
L
Research Center of Medical Science, Guangdong Provincial People's Hospital, Guangzhou 510080, and Research Unit of Infection and Immunity, West China Medical Center, Sichuan University, Chengdu, People's Republic of China. lim940523@yahoo.com.cn
Xiaoling
Pan
P
Yan
Li
L
Lili
Wang
W
Qi
Wu
W
Xiyong
Yu
Y
Boyao
Wang
W
Ning
Huang
H
D019342:Acetic Acid / Q000737:chemistry; D000890:Anti-Infective Agents / Q000737:chemistry*; D002584:Cervix Uteri / Q000378:metabolism*; D004591:Electrophoresis, Polyacrylamide Gel; D004847:Epithelial Cells / Q000378:metabolism; D004926:Escherichia coli / Q000378:metabolism*; D005260:Female; D006367:HeLa Cells; D006801:Humans; D007109:Immunity; D009093:Mucus / Q000378:metabolism*; D012333:RNA, Messenger / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D053481:Secretory Leukocyte Peptidase Inhibitor / Q000302:isolation & purification / Q000494:pharmacology; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
D000890:Anti-Infective Agents; D012333:RNA, Messenger; D053481:Secretory Leukocyte Peptidase Inhibitor; D019342:Acetic Acid