Human spermatozoa antigens in unexplained infertility

OBJECTIVE

To determine and compare the immunolocalization of functionally important antigens in human spermatozoa in an unexplained infertility (UI) group.

MATERIALS AND METHODS

In this study, the sperm samples of 20 patients undergoing evaluation belonging to normozoospermic group, whose primary reason of infertility was under investigation for this purpose, were screened. CD46, CD55 and CD52, CD69, CD98, fMLP, HI307, and 80280 were stained on the spermatozoa through indirect immunofluorescence technique.

RESULTS

In addition to CD46, CD55, and CD52 antigens, which are known to be localized on human spermatozoa, significant immunolocalization of several novel antigens including: CD52, CD69, CD98, fMLP, HI307, and 80280 were determined on the spermatozoa of the unexplained infertility group, possibly reflecting important roles in the pathophysiology of such unresolved clinical situations.

CONCLUSION

Identification and characterization of antigens present on sperm cells is crucial for understanding of the diagnosis and treatment of unexplained infertility. Further studies were conducted to evaluate a possible correlation between the expression of these antigens and clinical outcomes in different well-defined infertility groups.

Evidence for the presence of N-formyl-methionyl-leucyl-phenylalanine (fMLP) receptor ligands in human amniotic fluid and fMLP receptor modulation by physiological labour

OBJECTIVES

The presence of amniotic binding sites for N-formyl-methionyl-leucyl-phenylalanine (fMLP), an inflammatory peptide, and its ability to induce prostaglandin E2 synthesis in the human amnion prompted us to investigate for: (1) the presence of fMLP receptor ligands (fMLPRL) in the amniotic fluid; (2) expression of the fMLP receptor in amniotic tissue; (3) the effect of amniotic fMLPRL on neutrophil cyclic AMP (cAMP) level and calcium concentration ([Ca2+]i) during physiological pregnancy and labour.

METHODS

Binding assays were performed on neutrophils to determine the presence of fMLRL in the amniotic fluid at the 17th week of pregnancy, as well as at term, before and after the onset of labour. The expression of fMLP receptor mRNA was evaluated by RT-PCR, the cAMP level by a radiochemical assay, and the calcium concentration by Fura-2 AM fluorescence measurement.

RESULTS

fMLPRLs were detectable in amniotic fluid throughout pregnancy, and their levels did not vary during gestation. Labour significantly increased both the amniotic fMLPRL level and the expression of fMLP receptor in amnion tissue. The increased amniotic fMLPRL concentration noted during labour significantly increased neutrophil cAMP level and [Ca2+]i.

CONCLUSIONS

These findings demonstrate for the first time the presence of fMLP receptor ligands in amniotic fluid, and indicate a modulation of the fMLP system by the events of physiological labour.

Modification of membrane markers on THP-1 cells after ozone exposure in the presence or absence of fMLP

The impacts of ozone and N-formyl-methionyl-leucyl-phenylalanine (fMLP) on the detection of membrane markers on non-differentiated THP-1 cells were evaluated for in vitro exposures. Several markers, specific for monocytes and macrophages, were identified on the THP-1 cells, allowing their use as a model for alveolar macrophages. Ozone exposure modified not only the detection of membrane markers, especially CD13 and CD14, monocyte and macrophage markers, but also the detection of the specific receptor for fMLP, formyl peptide receptor (FPR). Activation by fMLP also reduced the detection of the CD antigens, and a combined exposure to ozone and fMLP amplified this decrease, probably due to an additive effect of these chemicals. Overall, these results suggest important membrane rearrangements for short-term treatments to ozone and/or fMLP.