Antiviral and Antiproliferative Assays
The ability of ovIFN-ts to protect cells from lysis after vesicular stomatitis virus infection was examined in Madin-Darby bovine kidney cells (MDBK; ATCC-CCL22). Antiviral activity was computed by comparison with a laboratory standard (recombinant boIFN-Tl; 5.4 X 107 IU/mg) that had been standardized against a human IFN-a reference reagent provided by the Antiviral Substance Program, NIAID, NIH (Bethesda, MD). buy ampicillin
Antiproliferative activity was assessed on the human lymphoma cell line Daudi (ATCC-CCL 213) by determining cell number after a 4-day incubation of cells with 2fold serial dilutions of each ovIFN-t.
Intrauterine Injection of Recombinant ovIFN-t Preparations
Estrous cycles of 35 Romanov and Dorset crossbred ewes were synchronized by two i.m. injections of 15 mg PGF2„ given 9 days apart. Twenty-three ewes exhibiting estrus in the presence of vasectomized rams after the second PGF2a treatment were fitted with indwelling uterine catheters on Day 8 postestrus, and CLs were marked with India ink, as described elsewhere. Ewes were assigned randomly (n = 4 to 5) to receive either intrauterine treatment of p3 or рЗТтб, injected at doses of either 60 or 300 jig/day, or no ovEFN-t treatment (see for procedure). All proteins were introduced into the uterus as a sterile solution in 0.01 M PBS (pH 7.2) containing 0.1% (w:v) BSA. Controls received injections of PBS containing 0.1% (w:v) BSA. Uterine injections were given with equal amounts of proteins administered at 0700 and 1900 h from Day 10 to Day 18 postestrus. On Day 20 postestrus, uterine cannulae were removed, and the status of marked CLs was assessed visually.