Biomedical subjects

R C Bleackley

Publications and source records attributed to R C Bleackley.

111 records · Page 7Linked to original sources

PubMed1982

Cellular and molecular properties of an antigen-specific cytotoxic T lymphocyte line.

Two cytotoxic T cell lines of CBA/J mouse origin have been generated, cloned, and characterized. One of these, MTL2, is cytotoxic for cells carrying the H-2(d) haplotype, the other MTL3, for H-2(b). Two clones of MTL2 differ significantly from each other in the morphology of the cells, although not in cytotoxicity. One has a higher number of intracellular vacuoles, or vesicles, and shows more of the typical attaching structures to the growth surface ("spikes") compared with the other. Cross-reactivity with a third-party alloantigen is enhanced by adding Con A to the cytotoxicity assay, but there is no self-killing either with or without Con A. The T cell lines show no rearrangement in their immunoglobulin heavy chain J and C(mu) genes. Normal T cells are also not rearranged, apparently, but normal B lymphocytes have both of their heavy chain alleles altered. Finally, cloned MTL2 cells contain less than five molecules of mu (IgM heavy chain constant region) mRNA per cell.

Alleles↗

PubMed1981

Translation of lymphocyte mRNA into biologically-active Interleukin 2 in oocytes.

A variant line of murine T lymphoma EL4 produces high levels of the lymphokine Interleukin 2 (IL 2) when it is stimulated with phorbol myristate acetate. We have extracted poly A+ RNA from the stimulated cells and injected it into Xenopus laevis oocytes. The injected oocytes synthesize a material with biologic and biochemical properties of murine IL 2. Namely, it stimulates the continued growth of a cloned, cytotoxic T cell line (the T cell growth factor assay) and it chromatographs on a gel filtration column (G-100) with IL 2 produced by the stimulated EL4 line. The RNA responsible for the biologic activity sediments with markers of 11 to 12S in a sucrose gradient. The IL 2 produced by injected oocytes from a given preparation of mRNA is about 1% of the amount produced by the EL4 cells stimulated originally with phorbol myristate acetate. When RNA is extracted and purified from unstimulated EL4 cells it does not induce IL 2 production in oocytes. We conclude that IL 2 is essentially protein in nature, that the protein is coded for by poly A+ mRNA, and that the amount of this mRNA increases significantly after stimulation of the variant EL4 cells with the inducer phorbol myristate acetate.

Animals↗

PubMed1975

The preparation of 5-cyanouracil and 5-cyano-2'-deoxyuridine from the corresponding 5-iodo derivative and cuprous cyanide.

5-Cyanouracil has been prepared in high yield from cuprous cyanide and 5-iodouracil. The deoxynucleoside has been similarly prepared form 5-iodo-2'-deoxyuridine and this has enabled these compounds to be labelled with (14-C) cyanide. Attempts have been made to incorporate 5-cyanouracil into Escherichia coli 15T and into Mycoplasma mycoides var. capri DNA under conditions in which several other 5-substituted uracils have been incorporated, but without success. Similarly 5-cyano-2'-deoxyuridine could not be incorporated into the DNA of T3 phage under conditions in which 5-bromo-2'-deoxyuridine is easily incorporated. These results suggest that the criteria for a 5-substituted uracil to be incorporated into DNA in vivo depends on some factor other than the size of the substituent.

Chemical Phenomena↗