Complement Regulatory Proteins on the Sperm Surface: Relevance to Sperm Motility

Jiang, Haixiang; Pillai, Subbi

doi:10.1111/j.1600-0897.1998.tb00360.x

Cited by 32 publications

(15 citation statements)

References 10 publications

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“…This is consistent with the evidence that expression of mCd59b in spermatozoa progressively increases during their development and maturation (17,18). Our in vivo data showing decreased motility of sperm in mCd59b Ϫ/Ϫ is consistent with the previous demonstration by two different groups that spermatozoa ejaculated from healthy human donors lost their motility after exposure to anti-human CD59 Abs (48,49).…”

Section: ) C Complement Activity In Mcd59bsupporting

confidence: 82%

Further Characterization of Reproductive Abnormalities in mCd59b Knockout Mice: A Potential New Function of mCd59 in Male Reproduction

Qin

Dobarro

Bedford

et al. 2005

The Journal of Immunology

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CD59 is a GPI-linked membrane protein that inhibits formation of the membrane attack complex of complement. We reported recently that mice have two CD59 genes (termed mCd59a and mCd59b), and that the targeted deletion of mCd59b (mCd59b−/−) results in spontaneous hemolytic anemia and progressive loss of male fertility. Further studies of the reproductive abnormalities in mCd59b−/− mice reported in this study revealed the presence of abnormal multinucleated cells and increased apoptotic cells within the walls of the seminiferous tubules, and a decrease in the number, motility, and viability of sperm associated with a significant increase in abnormal sperm morphologies. Both the capacitation-associated tyrosine phosphorylation and the ionophore-induced acrosome reaction as well as luteinizing hormone, follicle-stimulating hormone, and testosterone serum levels were similar in mCd59b−/− and mCd59b+/+. Surprisingly, the functional deficiency of the complement protein C3 did not rescue the abnormal reproductive phenotype of mCd59b−/−, although it was efficient in rescuing their hemolytic anemia. These results indicate that the male reproductive abnormalities in mCd59b−/− are complement-independent, and that mCd59 may have a novel function in spermatogenesis that is most likely unrelated to its function as an inhibitor of membrane attack complex formation.

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Section: ) C Complement Activity In Mcd59bsupporting

confidence: 82%

Further Characterization of Reproductive Abnormalities in mCd59b Knockout Mice: A Potential New Function of mCd59 in Male Reproduction

Qin

Dobarro

Bedford

et al. 2005

The Journal of Immunology

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“…Regulatory molecules such as ␣ 2 M are present in cervical secretions (85), and C1-INH is present on human spermatozoa (86) and in ovarian follicular fluid (87). Our study set out to examine the role of MBL in activating complement on the gonococcal surface and the effect of serum protein regulators, which more adequately represent conditions that these bacteria may encounter in vivo.…”

Section: Discussionmentioning

confidence: 99%

Regulation of the Mannan-Binding Lectin Pathway of Complement on Neisseria gonorrhoeae by C1-Inhibitor and α2-Macroglobulin

Gulati

Sastry

Jensenius

et al. 2002

The Journal of Immunology

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We examined complement activation by Neisseria gonorrhoeae via the mannan-binding lectin (MBL) pathway in normal human serum. Maximal binding of MBL complexed with MBL-associated serine proteases (MASPs) to N. gonorrhoeae was achieved at a concentration of 0.3 μg/ml. Preopsonization with MBL-MASP at concentrations as low as 0.03 μg/ml resulted in ∼60% killing of otherwise fully serum-resistant gonococci. However, MBL-depleted serum (MBLdS) reconstituted with MBL-MASP before incubation with organisms (postopsonization) failed to kill at a 100-fold higher concentration. Preopsonized organisms showed a 1.5-fold increase in C4, a 2.5-fold increase in C3b, and an ∼25-fold increase in factor Bb binding; enhanced C3b and factor Bb binding was classical pathway dependent. Preopsonization of bacteria with a mixture of pure C1-inhibitor and/or α2-macroglobulin added together with MBL-MASP, all at physiologic concentrations before adding MBLdS, totally reversed killing in 10% reconstituted serum. Reconstitution of MBLdS with supraphysiologic (24 μg/ml) concentrations of MBL-MASP partially overcame the effects of inhibitors (57% killing in 10% reconstituted serum). We also examined the effect of sialylation of gonococcal lipooligosaccharide (LOS) on MBL function. Partial sialylation of LOS did not decrease MBL or C4 binding but did decrease C3b binding by 50% and resulted in 80% survival in 10% serum (lacking bacteria-specific Abs) even when sialylated organisms were preopsonized with MBL. Full sialylation of LOS abolished MBL, C4, and C3b binding, resulting in 100% survival. Our studies indicate that MBL does not participate in complement activation on N. gonorrhoeae in the presence of “complete” serum that contains C1-inhibitor and α2-macroglobulin.

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“…This maturation process has been described for three other spermatozoa proteins (summarized in [20]) but its biologic significance is unexplained. Variations in CD46 expression on spermatozoa have been associated with infertility [61,62] and CD46 is a target for anti-sperm antibodies [63]. Rabbit and mouse antibodies against CD46 inhibit both binding and penetration of human sperm to zona-free hamster eggs and to human zona (reviewed in Ref.…”

Section: Reproductionmentioning

confidence: 99%

CD46: expanding beyond complement regulation

Riley-Vargas

Gill

Kemper

et al. 2004

Trends in Immunology

157

121

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Complement Regulatory Proteins on the Sperm Surface: Relevance to Sperm Motility

Cited by 32 publications

References 10 publications

Further Characterization of Reproductive Abnormalities in mCd59b Knockout Mice: A Potential New Function of mCd59 in Male Reproduction

Further Characterization of Reproductive Abnormalities in mCd59b Knockout Mice: A Potential New Function of mCd59 in Male Reproduction

Regulation of the Mannan-Binding Lectin Pathway of Complement on Neisseria gonorrhoeae by C1-Inhibitor and α2-Macroglobulin

CD46: expanding beyond complement regulation

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