Expression of antiviral activity and induction of 2',5'-oligoadenylate synthetase by conceptus secretory proteins enriched in bovine trophoblast protein-1.
Establishment of pregnancy in cattle has been proposed to depend on production of a conceptus protein, bovine trophoblast protein-1 (bTP-1), which has a high degree of sequence homology with bovine interferon-alpha (bIFN-alpha), especially the alpha II subfamily. A preparation of bovine conceptus secretory proteins enriched for bTP-1 has antiviral and physico-chemical properties similar to other bIFN-alpha. Antiviral activity is initially detectable in uterine flushings on Day 14 of pregnancy, when the conceptus measures 4-5 mm in length, and increases as the conceptus elongates through Day 18. Day 17 conceptuses produce more than 10(6) U antiviral activity during 24 h of culture. All IFNs induce the enzyme 2',5'-oligoadenylate synthetase, which catalyzes production of 2',5'-oligo(A), which in turn is involved in antiviral and growth inhibitory effects of IFNs. This enzyme activity is induced in Madin-Darby bovine kidney cells by the partially purified bTP-1 preparation similarly to IFN-alpha, -beta, and -gamma. Likewise, the partially purified bTP-1 and bIFN-alpha 1 induce 2',5'-oligo(A) synthetase activity in monolayers of endometrial epithelial and stromal cells. Compared to epithelial cells, stromal cells have higher baseline activity of 2'-5'-oligo(A) synthetase activity (p less than 0.01) and show a greater degree of induction in the presence of either the partially purified bTP-1 or bIFN-alpha 1 (p less than 0.01). Also, 2',5'-oligo(A) synthetase of endometrial stromal cells is induced to a greater degree by our enriched bTP-1 preparation than by bIFN-alpha 1 (p less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)
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Department of Physiological Sciences, Oklahoma State University, Stillwater 74078.
Geisert
R D
RD
Helmer
S D
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Zavy
M T
MT
Fulton
R W
RW
D015088:2',5'-Oligoadenylate Synthetase / Q000096:biosynthesis*; D000818:Animals; D000998:Antiviral Agents / Q000378:metabolism*; D002417:Cattle; D004717:Endometrium / Q000378:metabolism; D004971:Estrus / Q000378:metabolism; D005260:Female; D007370:Interferon Type I / Q000378:metabolism; D011247:Pregnancy; D011257:Pregnancy Proteins / Q000378:metabolism*
D000998:Antiviral Agents; D007370:Interferon Type I; D011257:Pregnancy Proteins; C020947:interferon tau; D015088:2',5'-Oligoadenylate Synthetase