Lipopolysaccharide-binding protein is produced in the epididymis and associated with spermatozoa and prostasomes

• Published in: Journal of reproductive immunology Vol. 66; no. 1; pp. 33 - 43
• Main Authors: Malm, Johan, Nordahl, Emma Andersson, Bjartell, Anders, Sørensen, Ole E., Frohm, Birgitta, Dentener, Mieke A., Egesten, Arne
• Format: Journal Article
• Language: English
• Published: Shannon Elsevier Ireland Ltd 01-06-2005; Elsevier Science
• Subjects: Acute-Phase Proteins - analysis; Acute-Phase Proteins - biosynthesis; Acute-Phase Proteins - genetics; Annan klinisk medicin; Basic Medicine; Biological and medical sciences; Carrier Proteins - analysis; Carrier Proteins - biosynthesis; Carrier Proteins - genetics; Clinical Medicine; Epididymis - cytology; Epididymis - metabolism; Epithelial Cells - immunology; Farmakologi och toxikologi; Fundamental and applied biological sciences. Psychology; Gene Expression; Humans; Klinisk medicin; Lipopolysaccharide-binding protein; Läkemedelskemi; Male; Mammalian male genital system; Medical and Health Sciences; Medicin och hälsovetenskap; Medicinal Chemistry; Medicinska och farmaceutiska grundvetenskaper; Membrane Glycoproteins - analysis; Membrane Glycoproteins - biosynthesis; Membrane Glycoproteins - genetics; Microbiology in the medical area; Mikrobiologi inom det medicinska området; Morphology. Physiology; Other Clinical Medicine; Pharmacology and Toxicology; Prostasomes; Prostate - secretion; Reproduction; RNA, Messenger - analysis; RNA, Messenger - metabolism; Secretory Vesicles - chemistry; Semen - immunology; Sperm Head - immunology; Sperm Tail - immunology; Spermatozoa; Spermatozoa - chemistry; Spermatozoa - immunology; Vertebrates: reproduction; Lipopolysaccharide-binding protein; Reproduction; Spermatozoa; Prostasomes; Human; Semen; Male genital duct; Germinal cell; Male genital system; Defense; Binding protein; Epididymis; Lipopolysaccharide; Seminal plasma; Gram negative bacteria
• ISSN: 0165-0378; 1872-7603; 1872-7603
• DOI: 10.1016/j.jri.2005.01.005

Lipopolysaccharide-binding protein (LBP) is an acute phase protein known to play a central role in the defense against Gram-negative bacteria. It binds lipopolysaccharides of Gram-negative bacteria and, after binding to CD14, the complex signals through Toll-like receptor (TLR)-4, eliciting host-defense responses, such as cytokine production, in inflammatory cells. The present study demonstrates constitutive expression of the gene encoding lipopolysaccharide-binding protein in the epithelium of the human epididymis by in situ hybridization. Using immunohistochemistry lipopolysaccharide-binding protein was shown to be present in the same cells and also attached to the heads and tails of spermatozoa. Cell-free seminal plasma, lysed spermatozoa and lysed prostasomes were subjected to Western blot; all showed immunoreactive bands corresponding to the size of lipopolysaccharide-binding protein. Gel filtration demonstrated that lipopolysaccharide-binding protein colocalizes with prostasomes. The concentration of lipopolysacharide-binding protein in seminal plasma was 127
±
42
ng/mL (mean
±
S.D.; range 73–215
ng/mL). Taken together, our results suggest roles for lipopolysaccharide-binding protein during human reproduction.