Production and characterization of human T leukemic lymphoblastoid cell interferon

Although human lymphoblastoid cells (Namalva and BALL-1 cells) which have the characteristics of B lymphocytes are known to be good producers of human lymphoblastoid interferon (Hu IFN-alpha (Ly) ), there is only one report on IFN production by human T lymphoblastoid cells. The present study showed that Sendai virus could induce human T lymphoblastoid cells (RPMI 8402 cells) to produce IFN. On incubation with virus, IFN was detected after 9 h, and increased until 24 h. The IFN yield depended on the dose of Sendai virus. No superinduction was observed on treatment with BUdR or antimetabolites or on irradiation with ultraviolet light. The T cell line produced IFN even in serum-free medium. The IFN produced by RPMI 8402 cells (8402-IFN) was as stable at pH 2 and on heating at 60 C for 30 min as Hu IFN-alpha and Hu IFN-beta. 8402-IFN, Hu IFN-alpha and Hu IFN-beta showed the same kinetics of induction of the antiviral state of FL cells. The 8402-IFN was neutralized by anti-Hu IFN-beta serum, but not anti-Hu IFN-alpha serum, indicating that it was antigenically identical with Hu IFN-beta. MDBK cells were very sensitive to Hu IFN-alpha, but not to this IFN or Hu IFN-beta, but L929 and RK-13 cells were equally sensitive to 8402-IFN, Hu IFN-alpha and Hu IFN-beta. The molecular weight of this IFN was estimated as 21,000 and 16,500 daltons by SDS-PAGE and Sephadex G-100 gel chromatography, respectively.