Immunosuppression by Conditioned Media Derived From a Cloned Choriocarcinoma Cell Line in Serum-Supplemented and Defined Media
Article first published online: 9 MAY 2013
American Journal of Reproductive Immunology
Volume 33, Issue 1, pages 108–113, January 1995
How to Cite
Bennett, W. A., Brackin, M. N., Long, C. A. and Cowan, B. D. (1995), Immunosuppression by Conditioned Media Derived From a Cloned Choriocarcinoma Cell Line in Serum-Supplemented and Defined Media. American Journal of Reproductive Immunology, 33: 108–113. doi: 10.1111/j.1600-0897.1995.tb01146.x
- Issue published online: 9 MAY 2013
- Article first published online: 9 MAY 2013
- Accepted September 12, 1994
PROBLEM: Immunosuppressive factor(s) of trophoblast origin may contribute to the immunological privilege afforded the fetal allograft. Characterization of these immunoregulators in humans has been impeded by a lack of sufficient quantities of early gestational trophoblast for experimentation.
METHOD: In this study, a cloned choriocarcinoma cell line (BeWo) was evaluated as an experimental model of trophoblast-derived immunoregulation. BeWo cells were cultured in both serum-supplemented (15% fetal bovine serum; FCS-CM) and serum-free (10% bovine serum albumin, BSA-CM; 0.01% gelatin, Gel-CM) media. Immunosuppressive activity was determined through the use of interleukin-2-dependent (CTLL-2) and -independent (LBRM) cell lines. Human chorionic gonadotropin (hCG) levels were determined by an immunoradiometric assay, and cellular morphology was assessed by light microscopy.
RESULTS: In the serum-supplemented cultures, a portion of cells underwent transformation from single nucleated cytotrophoblast to multinucleated syncytiotrophoblast during days 1 to 5 of culture and was accompanied by a rise in hCG. Serum-free cultures were characterized as islands of cytotrophoblast and did not exhibit differentiation. FCS-CM suppressed CTLL-2 and LBRM proliferation with estimated EC50 values of 415 and 280 μg protein/ mL, respectively. Gel-CM suppressed CTLL-2 and LBRM proliferation with EC50 values of 12 and 7 μg protein/mL, respectively. BSA-CM suppressed CTLL-2 proliferation with an EC50 of 132 μg protein/mL, but failed to suppress LBRM proliferation below 50% of control.
CONCLUSION: These results suggest that the BeWo cell line is a promising model for the study of trophoblast-derived suppressive factors and that these factors can be generated in serum-free medium.