Search

Two human hematopoietic cell lines (TYS and TYH) with monocytic characteristics were derived from the peripheral blood of a patient with acute myelomonocytic leukemia and of another with a follicular large-cell type of malignant lymphoma. The TYS cells, derived from the leukemia patient, revealed a monocytic appearance with microvilli at one side and had many granules and vacuoles. They showed strongly positive reactions with alpha-NBE, NASDAE, and AcP, and were reactive with monoclonal antibodies such as OKlal, 12 and Bl. The TYS cells, which phagocytized carbon particles and antibody-coated SRBC but not latex particles, released lysosomal enzymes and tumoricidal factor into the supernatant. The TYH cells, derived from the malignant lymphoma patient, had abundant cytoplasm and pseudopods detectable by electron microscopy with a monocytoid appearance and virus-like particles in the cytoplasm. They showed strongly positive reactions with alpha-NBE, NASDAE and beta-Gase, but no reactivity with monoclonal antibodies or with surface markers except Fc gamma-R. TYH cells phagocytized latex particles very well. Two different human monocyte-histiocyte lineages were thus established. During culture, the TYS and TYH cells maintained their characteristics over 28 and 16 months of passage, respectively.

Effects of a water soluble fraction of Corynebacterium equi (CEF) on the histamine release from rat peritoneal mast cells (RPMC) were investigated. The treatment of RPMC with CEF resulted in a significant inhibition of the histamine release from RPMC which was induced by IgE antibody-antigen interaction as well as nonimmunological histamine liberators. CEF was much more effective in inhibition of IgE-mediated histamine release and compound 48/80 or polymyxin B-induced histamine release when the mast cells were treated with CEF prior to the incubation with the antigen or the liberators. In contrast, CEF was equally effective in inhibition of the histamine release by concanavalin A with phosphatidyl serine when the mast cells were treated with CEF prior to or simultaneously with the liberator. Evidence was also presented that CEF inhibits degranulation of mesenteric mast cells induced by immunological as well as nonimmunological mechanisms.

A procedure for separating Escherichia coli aminoacyl-tRNA from unacylated tRNA or components of the aminoacylation reaction, thereby achieving an aminoacyl-tRNA product with a very high specific activity, is described. The method utilizes the specific recognition of aminoacyl-tRNA for E. coli protein synthesis elongation factor Tu which has been immobilized on an affinity matrix. The application of the affinity procedure as a means of purifying a single aminoacyl-tRNA from an unfractionated mixture of tRNAs is also discussed.