BLOOD FROM BOVINE LEUKEMIA VIRUS-INFECTED CATTLE - ANTIGEN PRODUCTION CORRELATED WITH INFECTIVITY

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  • 1 January 1985
    • journal article
    • research article
    • Vol. 46  (4) , 808-810
Abstract
Leukocytes from 1 ml of blood from cattle seropositive to the bovine leukemia virus were cultured for 3 days and then tested by radioimmunoassay for antigen production. Infectivity of blood from each animal was also tested by calf inoculation and subsequent serologic detection of bovine leukemia virus transmission by agar-gel immunodiffusion. In a preliminary experiment, blood from each of 3 antigen-positive cattle was inoculated intracutaneously into 2 calves in volumes of 20 or 100 .mu.l. Blood from each of 4 antigen-negative cattle was similarly inoculated into 3 calves in volumes of 20, 100 or 500 .mu.l. At the termination of the experiment (8 wk after inoculation), all 6 calves given blood from antigen-positive cattle had seroconverted, and 11 or 12 calves given blood from antigen-negative cattle had seroconverted. In a 2nd experiment, blood from each of 2 antigen-positive and 2 antigen-negative cattle was inoculated into pairs of calves in volumes of 1, 10 or 20 .mu.l. At the end of the experiment (12 wk after inoculation), all calves inoculated with blood from antigen-positive cattle had seroconverted, but only 6 of 12 calves that had been given blood from antigen-negative cattle had seroconverted. The relative infectivity of blood was best illustrated by comparing results from the 1-.mu.l inoculations. At that volume, the 4 calves given blood from antigen-positive cattle were infected; none of 4 calves given blood from antigen-negative cattle was infected.