Immunological identification of lactoferrin as a shared antigen on radioiodinated human sperm surface and in radioiodinated human seminal plasma

Goodman, S. A.; Young, Leona G.

doi:10.1016/0165-0378(81)90014-0

Cited by 24 publications

(9 citation statements)

References 16 publications

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“…Although numerous proteins have been identified as being on the surface of human spermatozoa, relatively little is understood about their functional interactions. Based on data presented here and previously published work [1,13,14,15], eppin, LTF, and CLU are synthesized in the testis and are present in Sertoli cells and on testicular spermatozoa, indicating that the EPC is most likely assembled from secreted components on the surface of spermatozoa during the last steps of spermiogenesis. Although the EPC of eppin, LTF, and CLU may be formed on testicular sperm, it is likely that the EPC present on ejaculate sperm is also of epididymal origin because eppin [1], CLU [13,16], and LTF [15] are all also secreted by epididymal epithelial cells.…”

Section: Discussionmentioning

confidence: 84%

Characterization of an Eppin Protein Complex from Human Semen and Spermatozoa1

Wang

Widgren

Richardson

et al. 2007

Biology of Reproduction

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Eppin (SPINLW1; serine peptidase inhibitor-like with Kunitz and WAP domains 1 (eppin); epididymal protease inhibitor) coats the surface of human ejaculate spermatozoa and originates from Sertoli and epididymal epithelial cells. In this study, we have isolated native eppin from ejaculate supernatants (seminal plasma) and washed ejaculate spermatozoa using column chromatography and two-dimensional SDS-PAGE, and identified by mass spectrometry and Western blots an eppin protein complex (EPC) containing lactotransferrin (LTF; also known as lactoferrin), clusterin (CLU), and semenogelin (SEMG1). To confirm the association of eppin with LTF, CLU, and SEMG1, antibodies to CLU and LTF were used to immunoprecipitate CLU and LTF from human sperm lysates. In both cases identical results were obtained, namely, the immunoprecipitate of the EPC. Additionally, we localized eppin, LTF, and CLU in human Sertoli cells and on human testicular and ejaculate spermatozoa, implying that the EPC is present on spermatozoa from the time they leave the seminiferous tubule. On ejaculate spermatozoa eppin, LTF, and CLU colocalize on the tail. The identification of the EPC components suggests that LTF, CLU, and/or eppin receptors may function as sperm plasma membrane receptors for the EPC, implicating the complex as a central player in a network of protein-protein interactions on the human sperm surface. The EPC may provide a surface network with microbicidal properties that protects spermatozoa as well as regulates the sperm's transition to a motile, capacitated sperm.

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Section: Discussionmentioning

confidence: 84%

Characterization of an Eppin Protein Complex from Human Semen and Spermatozoa1

Wang

Widgren

Richardson

et al. 2007

Biology of Reproduction

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“…The most abundant transport protein is lactoferrin, which is present in solution and has an antimicrobial role to play in seminal fl uid. Lactoferrin binds to the sperm surface membrane during ejaculation, and seems to be a major sperm-coating antigen (Goodman et al 1981). It has been suggested that the affi nity of lactoferrin for sperm and its potential role in protecting sperm from the immunocompetent environment of the female reproductive tract might be regulated by its clustering with some of the other proteins of seminal plasma (Thaler et al 1990).…”

Section: Discussionmentioning

confidence: 99%

Proteomic analysis of heparin-binding proteins from human seminal plasma: a step towards identification of molecular markers of male fertility

et al. 2009

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Glycosaminoglycans, especially heparin, are involved in various cell processes such as apoptosis, cell cycle control, platelet activation, capacitation, acrosome reaction and sperm decondensation. Heparin-binding proteins (HBPs) are essential constituents of human seminal fluid, which bind to sperm lipids containing the phosphorylcholine group and mediate the fertilization process. We utilized a proteomic set-up consisting of affinity chromatography, isoelectric focusing (IEF) coupled with matrix-assisted laser desorption/ionization time-of-flight tandem mass spectrometry (MALDI TOF/MS) for protein analysis of human HBPs. We resolved 70 different spots on two-dimensional (2-D) gel and subsequently identifi ed these proteins. Forty different types of proteins were identified. Functional analysis revealed that 38% of the proteins belonged to the enzyme category, 20% were involved in RNA processing and transcription, 18% in structure and transport function, and 16% in cell recognition and signal transduction. We also identified 8% of proteins with unknown functions, although their expression in seminal fluid has been documented. Proteins of seminal fluid that bind heparin may be directly involved in sperm capacitation and acrosome reaction (AR), which are the two critical steps for fertilization. This information on HBPs would be useful for identifying potential biomarkers of fertility in the near future.

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“…Few human tissues (haematopoietic cells aside) are convincingly positive, with reports of lactoferrin in secretory phase endometrium (Tourville et al, 1970) and in seminal plasma (Goodman & Young, 1981) as a major sperm-coating antigen (Heckman & Rumke, 1969). Immunocytochemical staining has been reported (Mason & Taylor, 1978) in gastric mucus neck cells, some duodenal absorptive epithelia, glandular bronchial glands and most strongly in glandular epithelia (and their secretions) of lactating breast; also in the odd sample of uterus and a basal cell skin carcinoma.…”

Section: Discussionmentioning

confidence: 98%

Isolation of a lactoferrin cDNA clone and its expression in human breast cancer

Campbell

Skilton²,

Coombes³

et al. 1992

Br J Cancer

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Summary A cDNA library constructed from mRNA from a human breast carcinoma metastasis was screened with a polyclonal antibody to deglycosylated human milk fat globule membrane, resulting in the isolation of eight clones from a total of 105 plaques. One of these (J16) was identified as lactoferrin. It was highly expressed (as a 2.5 Kb mRNA) in lactating breast and in both normal resting tissue taken from adjacent to carcinoma or from reduction mammoplasties. Immunoreactive lactoferrin was localised to ductal cells and their secretions in both normal and mildly hyperplastic ducts. In a normal tissue screen J16 was highly expressed in stomach, poorly in skin and lymphocytes and absent from other organs examined. It was variably expressed in 33/59 invasive primary breast tumours; lactoferrin protein in these was heterogeneously distributed in epithelial tumour foci. Presence of J16 was inversely related to expression of oestrogen receptor protein (P = 0.0001). There was no significant relationship to other clinical parameters. We also found immunoreactivity in 20/41 (49%) cases of ductal carcinoma in situ. Expression was not observed in any breast or gastric cell line examined. Thus lactoferrin appears to be down regulated in some forms of cancer. The presence of lactoferrin could be a contraindication for effective endocrine therapy.

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Immunological identification of lactoferrin as a shared antigen on radioiodinated human sperm surface and in radioiodinated human seminal plasma

Cited by 24 publications

References 16 publications

Characterization of an Eppin Protein Complex from Human Semen and Spermatozoa1

Characterization of an Eppin Protein Complex from Human Semen and Spermatozoa1

Proteomic analysis of heparin-binding proteins from human seminal plasma: a step towards identification of molecular markers of male fertility

Isolation of a lactoferrin cDNA clone and its expression in human breast cancer

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