Seminal Plasma Levels of Fucosyltransferase, Galactosyltransferase and Sialyltransferase in Normospermic and Oligospermic Men

Ronquist, Gunnar

doi:10.1159/000281874

Cited by 3 publications

(2 citation statements)

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“…Another interesting finding is that the level of HSP-associated ␣-fucosyltransferase activity greatly exceeds the ␤-galactosyltransferase activity in vitro (24). This observation is consistent with the content of fucosylated oligosaccharides present in HSP.…”

Section: Discussionsupporting

confidence: 73%

The Expression of Free Oligosaccharides in Human Seminal Plasma

Chalabi

Easton

Patankar

et al. 2002

Journal of Biological Chemistry

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Human seminal plasma is a complex mixture of proteins, glycoproteins, peptides, glycopeptides, and prostaglandins secreted by organs of the male reproductive tract. The components of this fluid have been implicated in the suppression of immune response, agonistic effects on sperm-egg binding, and promotion of successful implantation of the human embryo. Fractionation followed by biophysical analyses revealed that free oligosaccharides constitute a major component of the total glycoconjugates within seminal plasma. Significant findings of our analyses include the following: (i) the concentration of free oligosaccharides is 0.3-0.4 mg/ml; (ii) monoand difucosylated forms of the disaccharide lactose are major components; (iii) many of the remaining oligosaccharides are also rich in fucose and carry Lewis x and/or Lewis y epitopes; (iv) a subset of the oligosaccharides express the reducing end sequence (GlcNAc␤1-3/4Glc) not reported in human milk oligosaccharides; (v) oligosaccharides in seminal plasma exclusively express type 2 (Gal␤1-4GlcNAc) but not the type 1 sequences (Gal␤1-3GlcNAc) that predominate in human milk glycans; and (vi) the structural diversity of seminal plasma oligosaccharides is far less than human milk oligosaccharides. The agonistic effect of both fucose and fucosylated glycoconjugates on human sperm-egg binding in vitro suggests that fucosylated oligosaccharides may also promote fertilization in the female reproductive tract.Human semen contains a variety of different cell types including sperm, neutrophils, monocytes, and lymphocytes (reviewed in Ref. 1). If incubated for a brief period of time, semen undergoes a process known as liquefaction that leads to clearing of this fluid and a partial loss of its viscosity (2). Centrifugation of partially liquefied semen leads to the separation of the cellular components from the viscous acellular fluid known as human seminal plasma (HSP). 1 HSP is more than simply a liquid medium for transporting sperm into the vagina. It is an extremely complex mixture of proteins, glycoproteins, peptides, glycopeptides, and prostaglandins secreted by the organs of the male reproductive tract (reviewed in Ref. 1). A plethora of different studies indicate that HSP supports sperm function, modulates maternal immune responses directed against sperm, and promotes successful implantation of the human embryo (reviewed in Refs. 1, 3, and 4). The components of HSP may therefore profoundly impact male fertility in the female reproductive tract.Previous studies confirm that HSP contains a specific glycoprotein with immunomodulatory activities (5) now known as glycodelin-S (6). Glycodelin-S also promotes human sperm binding to homologous zona pellucida in the hemizona assay system (6). This intriguing combination of biological activities led us to investigate further the glycosylation of other components associated with HSP. By using fast atom bombardment (FAB) and electrospray (ES) mass spectrometry to screen HSP for novel glycoconjugates (7), we have made the surprising disc...

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Section: Discussionsupporting

confidence: 73%

The Expression of Free Oligosaccharides in Human Seminal Plasma

Chalabi

Easton

Patankar

et al. 2002

Journal of Biological Chemistry

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“…The later results may be due to the use of STases from species other than human. For example, STases are present in human cervical epithelium (45,46) and human seminal plasma (47), and they vary in activity depending on the hormonal state (46) or sperm concentration (47) . In future studies it will be important to locate where the putative gonococcal STase activity resides (inner or outer membrane, intracytoplasmic), whether human STases can modify gonococcal LOS, and whether these STases have any role in vivo.…”

Section: Discussionmentioning

confidence: 99%

In vitro and in vivo modification of Neisseria gonorrhoeae lipooligosaccharide epitope structure by sialylation.

Mandrell

Lesse

Sugai

et al. 1990

The Journal of Experimental Medicine

171

136

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Previous studies have shown that human serum, guinea pig and human red cells, and human white cells contain low and high M, substances that induce gonococcal strains to become serum resistant (1-4) and change lipooligosaccharide (LOS)' pattern (5, 6) . In more recent studies, the same investigators have shown that the low Mr substance in-blood is cytidine monophospho-N-acetylneuraminic acid (CMP-NANA) or a related compound (7,8) . These studies suggest that in vivo, sufficient concentrations of CMP-NANA might induce serum resistance by sialylation of LOS. Because gonococci are not able to synthesize CMP-NANA and it is not present in the usual media, previous in vitro studies of gonococcal LOS may have dealt with different LOS structures than those that occur in vivo .Each gonococcal strain makes multiple types of LOS (9)(10)(11), and the physical (Mr) and antigenic heterogeneity of a strain's LOS reflects physicochemical differences in their glycan moieties (10, 12). mAbs 3F11 and 06B4 identify epitopes on meningococcal and gonococcal LOS that are immunochemically similar to Galo1-4G1cNAc-containing molecules present in human erythrocytes and on other human cells (13) . These epitopes are conserved on gonococcal LOS (11,14) and are variably expressed This work was supported by U. S .

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