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Injection into Xenopus oocytes of polyadenylated cytoplasmic RNA from mouse C-243-3 cells induced with poly(rI) · poly(rC) and DEAE-dextran resulted in the production of biologically active interferon. The synthesis of interferon by oocytes is linearly related to the amount of mRNA injected. Thus a titre of 160 reference units/oocyte was obtained by injecting 250 ng of total cytoplasmic poly(A)-containing RNA. The kinetics of interferon production in mouse C-243-3 cells induced with poly(rI)-poly(rC) and DEAE-dextran are characterized by an initial lag of 3–4 h and a burst of interferon secretion between 5–8 h with a maximum accumulation at 7 h. Comparison of the relative amount of interferon mRNA at various time intervals of induction with the cellular synthesis of interferon showed a general correlation. At 9 h after induction, i.e. during the shut off phase of interferon production, the cells contained no detectable amount of interferon mRNA (< 20 units/ml). Attempts to superinduce interferon production in mouse C-243-3 cells by using the cycloheximide/ actinomycin D protocol as in human fibroblast cells were not successful α-Amanitin at concentrations similar to those required to inhibit cellular DNA-dependent RNA polymerase form II completely inhibited the interferon production when applied during the first 3 h of induction. Addition of α-amanitin at 3, 5 or 7 h after induction stimulated the subsequent interferon production by 2–4-fold. [ABSTRACT FROM AUTHOR]

The safety and immunogenicity of a human immunodeficiency virus type 1 (HIV-l) gp160 recombinant vaccinia virus (HIVAC-le) vaccine was evaluated in vaccinia-naive, healthy adults at low risk for acquiring HIV-l infection. Volunteers (n = 36) were randomized to receive HIVAC- l e or control vaccinia virus at two dosages by bifurcated needle puncture at 0 and 2 months; 12 HIVAC-le and 6 control vaccinia virus recipients received either 106 or 107 pfu/mL at each inoculation. There was no significant difference in lesion size, level of viral replication, or systemic symptoms after vaccination with HIVAC-le or control vaccinia virus. Of 22 HIVAC-le recipients with lesion formation, 16 developed low-titer gp 160-specific antibody responses detectable by Western blot. The peak response occurred between days 70 and 120 and was still detectable at day 365 in 9 of 18 vaccinees. gp 160-specific Iymphoproliferative responses were detected in 5 of 10 vaccinees. Vaccination with HIVAC-le was safe in vaccinia-naive, healthy adults and could induce both humoral and cell-mediated gp160-specific immune responses. [ABSTRACT FROM PUBLISHER]