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Human In Vitro Suppression as Screening Tool for the Recognition of an Early State of Immune Imbalance
Published on: July 22, 2011
Immunochemical characterization of the suppressor factor from early human decidual cells
1Second Department of Surgery, Kyoto Prefectural University of Medicine, Japan.
Insights
Researchers isolated an immunosuppressive protein from human decidual cells. This protein inhibits key immune responses, including lymphokine production and lymphocyte activation, offering insights into immune regulation.
Area of Science:
- Immunology
- Cell Biology
- Reproductive Biology
Background:
- Early human decidual cells produce factors that modulate the maternal immune response during pregnancy.
- Understanding these factors is crucial for managing immune tolerance and preventing pregnancy complications.
Purpose of the Study:
- To isolate and characterize an immunosuppressive factor from early human decidual cells.
- To investigate the factor's effects on lymphokine production and lymphocyte activation.
Main Methods:
- Gel filtration and anion exchange chromatography were used for purification.
- Lentil-lectin affinity chromatography and isoelectric focusing were employed for characterization.
- The factor's impact on phytohemagglutinin (PHA)-stimulated peripheral blood lymphocytes (PBL) was assessed.
Main Results:
- An immunosuppressive protein with a molecular weight of 43,000–67,000 daltons was purified.
- The protein's isoelectric point (PI) ranged from 6.85 to 7.50, indicating it is not a glycoprotein.
- The purified factor suppressed Interleukin-2 (IL-2), Interferon-gamma (INF-γ), and B-cell stimulating factor-2 (BSF-2) production.
- It also inhibited IL-2 receptor and transferrin receptor expression on PHA-stimulated PBL.
Conclusions:
- A novel immunosuppressive protein derived from human decidual cells has been identified.
- This protein effectively inhibits lymphokine production and key aspects of lymphocyte activation.
- The findings contribute to understanding the immunomodulatory mechanisms at the maternal-fetal interface.
Abstract:
An immunosuppressive factor was obtained from culture supernatants of early human decidual cells. The suppressor factor was concentrated by gel filtration in a fraction with a molecular weight between 43,000 and 67,000 daltons. It was further purified by biochemical methods. Four peaks were obtained in the fraction with molecular weight between 43,000 and 67,000 daltons by anion exchange chromatography. Only the second peak had immunosuppressive activity in MLR. Lentil-lectin affinity chromatography of this suppressor factor showed that the suppressor factor had no affinity for lentil-lectin sepharose. Isoelectric focusing of the suppressor factor demonstrated four bands. The protein isoelectric (PI) point was approximately 7.50 in one band and between 6.85 and 7.35 in the other three bands. These results demonstrate that the suppressor factor is not glycoprotein but protein, whose PI is between 6.85 and 7.50. The suppressive effect of this purified factor on lymphokine production and lymphocyte activation was investigated. The addition of the purified suppressor factor to a culture of PBL stimulated with PHA suppressed not only IL-2 production and gamma-INF production, but also BSF-2 production. IL-2 receptor expression and transferrin receptor expression of PBL stimulated with PHA were also suppressed by addition of the suppressor factor. These results demonstrate that this suppressor factor inhibits lymphokine production and lymphocyte activation.
