Induction and measurement of 2',5'-oligoadenylate synthetase in Madin-Darby bovine kidney cells and in cattle

Abstract

2',5'-Oligoadenylate [2',5'-oligo(A)] was separated from 14C-labeled nucleosides produced in the 2',5'-oligo(A) synthetase assay by using 100-microliters columns of Dowex 1. No detectable nucleoside remained on the column after elution with 20 column volumes of water, whereas less than 1% of oligonucleotides were eluted from the column. At least 99% of oligonucleotides were eluted from the column with 1 M NaCl, pH 2. The major product had properties consistent with 2',5'-oligo(A). Exposure to alpha-1 bovine interferon (IFN) caused an increase in cellular 2',5'-oligo(A) synthetase activity which was proportional to the concentration of IFN in the medium up to 10(4) U of IFN per ml and then leveled off at about 15 X control activity. Under the assay conditions used, 2',5'-oligo(A) synthetase activity was directly proportional to the amount of cell extract over a 10-fold range. Cattle inoculated with IBR/BVD/PI-3 modified live virus vaccine showed an increase in 2',5'-oligo(A) synthetase activity in peripheral blood mononuclear leukocytes which persisted for at least 3 days postvaccination. Intramuscular injection of cattle with IFN caused a similar increase in 2',5'-oligo(A) synthetase activity. Changes in 2',5'-oligo(A) synthetase activity should be of value in (i) assessing the response of cattle to experimental viral infections or inoculations with viral vaccines or IFN or (ii) indicating a possible viral etiology in disease.

Stimulation of 2',5'-oligoadenylate synthetase activity in sheep endometrium during pregnancy, by intrauterine infusion of ovine trophoblast protein-1, and by intramuscular administration of recombinant bovine interferon- I1

“…The suspension was mixed and subjected to one freeze-thaw cycle. Supernatant obtained after centrifugation at 12 000 g for 5 min was used to assay the enzyme which catalyses conversion of [14C]ATP to [14C]2',5'oligoadenylate products (Short & Fulton, 1987). Activity of 2',5'-A synthetase in endometrium collected during the second breeding season in Expt 4 was quantified after further modification of the assay.…”

Differential Loss of OAS Genes Indicates Diversification of Antiviral Immunity in Mammals

“…Therefore, it is of special clinical interest to transfer basic immunological knowledge into the development of highly effective vaccines. OAS proteins are involved in early immune responses against RNA viruses and perhaps also against modified-live RNA virus vaccines [ 10 , 53 ]. Yellow fever vaccination induced upregulation of OAS1 among other innate antiviral molecules and also a strong acquired serological and cellular immune response [ 54 ].…”