Biology of Reproduction, Vol 40, 1109-1118, Copyright © 1989 by Society for the Study of Reproduction

ARTICLES

Porcine conceptuses secrete an interferon during the preattachment period of early pregnancy

JC Cross and RM Roberts
Department of Animal Sciences, University of Missouri-Columbia 65211.

Maternal recognition of pregnancy in sheep and cattle is thought to be initiated by the conceptus secretory proteins ovine trophoblast protein- 1 (oTP-1) and bovine trophoblast protein-1 (bTP-1), respectively. Recently, these proteins have been shown to be members of the interferon-alpha (IFN-alpha) family. In this study, we have examined whether pig conceptuses also produce IFN during early pregnancy. conceptuses were collected at Days 8, 10, 11, 12, 13, 15, and 17 of pregnancy and cultured in serum-free medium for 24 h. Day 11 conceptuses secreted a dominant 22,000-24,000 Mr cluster of acidic proteins (pI 5.2-5.4), that appeared to cross-react on immunoblots with antiserum against human IFN-alpha but not against oTP-1. Antiviral activity characteristic of an IFN was present in conceptus culture medium and uterine flushings from Day 11 through Day 17 of pregnancy, but was absent in flushings prior to Day 11 of pregnancy and in flushings from Day 12 nonpregnant gilts. The antiviral activity coeluted with a 22,000-24,000 Mr protein during partial purification through a gel filtration column. The activity was extremely labile, but could be restored by sequential protein denaturation, reduction, and renaturation. We conclude that production of IFN by early conceptuses is not restricted to ruminant species, and may therefore represent a more general phenomenon.

This article has been cited by other articles:

				M. M. Joyce, R. C. Burghardt, R. D. Geisert, J. R. Burghardt, R. N. Hooper, J. W. Ross, M. D. Ashworth, and G. A. Johnson Pig Conceptuses Secrete Estrogen and Interferons to Differentially Regulate Uterine STAT1 in a Temporal and Cell Type-Specific Manner Endocrinology, September 1, 2007; 148(9): 4420 - 4431. [Abstract] [Full Text] [PDF]

				M. M. Joyce, J. R. Burghardt, R. C. Burghardt, R. N. Hooper, L. A. Jaeger, T. E. Spencer, F. W. Bazer, and G. A. Johnson Pig Conceptuses Increase Uterine Interferon-Regulatory Factor 1 (IRF1), but Restrict Expression to Stroma Through Estrogen-Induced IRF2 in Luminal Epithelium Biol Reprod, August 1, 2007; 77(2): 292 - 302. [Abstract] [Full Text] [PDF]

				V. Emond, E. Asselin, M. A. Fortier, B. D. Murphy, and R. D. Lambert Interferon-Tau Stimulates Granulocyte-Macrophage Colony-Stimulating Factor Gene Expression in Bovine Lymphocytes and Endometrial Stromal Cells Biol Reprod, June 1, 2000; 62(6): 1728 - 1737. [Abstract] [Full Text]

				J L Rothstein, D Johnson, J A DeLoia, J Skowronski, D Solter, and B Knowles Gene expression during preimplantation mouse development. Genes & Dev., July 1, 1992; 6(7): 1190 - 1201. [Abstract] [PDF]