Surfactant protein D is present in the human female reproductive tract and inhibits Chlamydia trachomatis infection.
Surfactant protein D (SP-D) is a lung collectin involved in innate host defence mechanisms in the lung. SP-D is also expressed at other mucosal sites throughout the human body. In the present study, we show that SP-D mRNA and protein are expressed in the human female reproductive tract. SP-D protein was localized in the apical portion of the reproductive epithelial cells. We also demonstrate that endometrial and endocervical cell lines and primary endocervical cells in culture produce SP-D mRNA and protein. Chlamydia trachomatis is an intracellular pathogen that infects the female reproductive tract, primarily the cervix, and is responsible for the most prevalent infectious disease in the USA. Untreated chlamydial infections of the female reproductive tract often result in sterility of the infected woman. Since SP-D protein is produced in cervical glands, we examined the effect of SP-D on chlamydial infection of cervical epithelial cells in vitro. We found that SP-D protein inhibits the infection of HeLa cells (an endocervical epithelial cell line) by C. trachomatis in a dose-dependent manner. We further demonstrate that the SP-D lectin-binding domain is involved in inhibiting infection of HeLa cells by Chlamydia. In conclusion, we detected SP-D in the female reproductive tract and determined that one of the functions of the SP-D protein may be to protect cervical epithelial cells from infection by C. trachomatis.
Department of Anatomy and Cell Biology, University of Iowa, Carver College of Medicine, Iowa City, IA 52242, USA.
Rebecca E
RE
Oberley
Kelli L
KL
Goss
Kevin A
KA
Ault
Erika C
EC
Crouch
Jeanne M
JM
Snyder
D000818:Animals; D000942:Antigens, Bacterial / Q000032:analysis / Q000378:metabolism; D001425:Bacterial Outer Membrane Proteins / Q000032:analysis / Q000378:metabolism; D001426:Bacterial Proteins / Q000378:metabolism; D002584:Cervix Uteri / Q000276:immunology* / Q000378:metabolism / Q000382:microbiology*; D002690:Chlamydia Infections / Q000276:immunology / Q000378:metabolism; D002692:Chlamydia trachomatis / Q000187:drug effects / Q000378:metabolism / Q000502:physiology*; D004717:Endometrium / Q000276:immunology* / Q000378:metabolism / Q000382:microbiology; D005260:Female; D006367:HeLa Cells; D006801:Humans; D017434:Protein Structure, Tertiary; D037663:Pulmonary Surfactant-Associated Protein D / Q000032:analysis* / Q000494:pharmacology / Q000502:physiology*; D012333:RNA, Messenger / Q000032:analysis / Q000378:metabolism; D051381:Rats
D000942:Antigens, Bacterial; D001425:Bacterial Outer Membrane Proteins; D001426:Bacterial Proteins; D037663:Pulmonary Surfactant-Associated Protein D; D012333:RNA, Messenger