A role for surfactant protein D in innate immunity of the human prostate.
OBJECTIVE
Surfactant protein D (SP-D) is a member of the collectin family of proteins, which are involved in host defense mechanisms in the lung. In the present study, we found that SP-D is produced in the human prostate where it may play a role in innate immunity.


RESULTS
Using reverse-transcriptase PCR and Western blot analysis, we demonstrate that SP-D mRNA and protein are present in human prostate tissue. In situ hybridization and immunohistochemistry revealed that SP-D mRNA and protein are localized in epithelial cells of prostate glands. Prostate glands that are surrounded by inflammatory cells produce increased amounts of SP-D protein. We also show that SP-D inhibits the infection of LNCaP and P69SV40T prostate epithelial cells by Chlamydia trachomatis in an in vitro infection assay. Furthermore, using truncated human SP-D mutants, we demonstrate that SP-D binds to Chlamydia trachomatis via its carboxy-terminal lectin domains.


CONCLUSIONS
Our in vitro studies suggest that SP-D protects the prostate from infection by pathogens. SP-D protein levels are increased at sites of inflammation in the prostate, suggesting SP-D may also contribute more generally to inflammatory regulation in the prostate.
Oberley
Rebecca E
RE
Department of Anatomy and Cell Biology, University of Iowa College of Medicine, Iowa City, Iowa 52242, USA.
Goss
Kelli L
KL
Dahmoush
Laila
L
Ault
Kevin A
KA
Crouch
Erika C
EC
Snyder
Jeanne M
JM
D000328:Adult; D000368:Aged; D015153:Blotting, Western; D045744:Cell Line, Tumor; D002690:Chlamydia Infections / Q000276:immunology / Q000382:microbiology; D002692:Chlamydia trachomatis; D004847:Epithelial Cells / Q000276:immunology / Q000378:metabolism; D006801:Humans; D007150:Immunohistochemistry; D017403:In Situ Hybridization; D008297:Male; D008875:Middle Aged; D011467:Prostate / Q000276:immunology* / Q000378:metabolism; D011472:Prostatitis / Q000276:immunology / Q000378:metabolism / Q000382:microbiology; D037663:Pulmonary Surfactant-Associated Protein D / Q000096:biosynthesis / Q000235:genetics / Q000276:immunology*; D012333:RNA, Messenger / Q000096:biosynthesis / Q000235:genetics; D011993:Recombinant Fusion Proteins / Q000276:immunology; D020133:Reverse Transcriptase Polymerase Chain Reaction
D037663:Pulmonary Surfactant-Associated Protein D; D012333:RNA, Messenger; D011993:Recombinant Fusion Proteins