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D S Milstone

Publications and source records attributed to D S Milstone.

21 records · Page 2Linked to original sources

Interleukin 2-mediated induction of lytic activity in a cloned murine CTL line.

We have analyzed the ability of interleukin 2 (IL 2) to induce lytic activity within a cloned murine H-2Dd-specific CTL line. Weakly lytic CTL harvested 6 to 7 days after previous stimulation with irradiated DBA/2J spleen cells and conditioned medium from secondary MLC (MLC SN) could be reactivated to high antigen-specific lytic activity with highly purified gibbon IL 2 or E. coli-produced human recombinant DNA IL 2. Dose-response curves with IL 2 and MLC SN suggest that IL 2 may be the principal detectable activity in MLC SN that is active on these CTL. Doses of IL 2 or MLC SN that were saturating for the induction of lytic activity were suboptimal for the expression of DNA synthesis measured by 3HTdR incorporation. This is consistent with a mechanism in which different threshold IL 2 concentrations are required to induce these two biologic responses. Finally, we show that IFN-gamma has little effect on the expression of lytic activity either alone or in combination with IL 2 in this bioassay.

Absorption↗

Purification of primate T cell growth factor to apparent homogeneity by reverse phase high pressure liquid chromatography: evidence for two highly active molecularly distinct species.

T cell growth factor produced by the MLA144 gibbon ape lymphosarcoma T lymphocyte line was separated into two molecular forms of Mr 16,300 and Mr 14,300 which were purified 32,000-fold and 82,000-fold, respectively, and which in combination constitute the majority of biological activity of the starting material. The overall recovery of biological activity was 50%. This was accomplished with a series of chromatographic steps including reverse-phase high pressure liquid chromatography. The purified proteins are of comparable specific activities and each maintains the DNA synthesis of T cell growth factor-dependent human T cell lines at concentrations of less than approximately 18 pM (300 fg/ml).

Animals↗

Antibodies to N6-(delta2-isopentenyl) adenosine and its nucleotide: interaction with purified tRNAs and with bases, nucleosides and nucleotides of the isopentenyladenosine family.

The interaction of antibodies directed toward N6-(delta2-isopentenyl)adenosine, i6Ado, or its nucleotide with related bases, nucleosides, nucleotides and purified tRNAs is described. The selectivity of the antibody preparation was tested in inhibition experiments utilizing a sensitive radioimmunoassay to quantitate the binding of [3H]i6Ado to the antibody. Purified tRNAs containing various modified nucleosides adjacent to the 3'-end of the anticodon were tested to provide information about the selectivity of the antibody preparation toward nucleotides in this position of the tRNA chain. Antibodies directed against the nucleotide hapten were used to purify tRNAs which contain i6Ado and to quantitate the amount of that nucleotide. The same order of selectivity was expressed whether the nucleotides were free or in a tRNA molecule. Interaction of the antibody with compounds from the i6Ado family demonstrated dominance of the hydrophobic isopentenyl group and the importance of positional differences of modifications.

Adenosine↗