Inhibition of human natural killer activity by monolayers of primary cell cultures

Some primary and continuous cell cultures were tested for their capacity to regulate human natural killer (NK) activity. Primary cultures of endothelial cells, fetal fibroblasts, adult fibroblasts, amnion epithelial cells, renal parenchymal cells, and ovarian carcinoma cells inhibited NK activity when peripheral blood lymphocytes were preincubated on target cell monolayers for 18 h before testing the cytotoxicity against K-562. The supernatants of the inhibiting cell cultures were not suppressive. Prostaglandins or suppressive lymphocytes were not involved in the phenomenon. The binding capacity of the effector cells was not changed, suggesting that the suppressive signal was targeted at the cytolytic machinery of NK cells. The down-regulating capacity of the cell cultures weakened significantly during subculturing in vitro, and continuous cell lines were not inhibitory. The inactivation of NK cells may be one of the mechanisms by which target cells are protected from NK activity.     

Mass Spectrometric Analyses of Brain Synaptic Peptides Containing Taurine

The structure of a number of low-molecular-weight acidic peptides containing taurine prepared from calf brain synaptosomes and their subcellular vesicles was studied using electron impact mass spectrometry. At least seven sequences could be identified: N-acetylaspartyl-glutamyl-taurine, N-acetylaspartyl-taurine, N-acetylglutamyl-taurine, glutamyl-taurine, aspartyl-taurine, seryl-glutamyl-seryl-taurine, and seryl-taurine.     

Prognostic value of non-MHC-restricted killer cell activity in lung cancer

The prognostic value of peripheral blood non-MHC-restricted cytotoxicity against the myeloid leukaemic line K562 in lung cancer patients was studied. At the time of diagnosis and before operation, 57 patients with lung cancer were tested for cytotoxicity and subsequently followed for up to 4 years. In addition, 145 lung cancer patients, 30 patients with non-neoplastic lung diseases and 76 healthy donors were tested for cytotoxicity without the follow-up, in order to correlate the stage of lung cancer and the growth rate of tumours to the level of non-MHC-restricted cytotoxicity. On average, lung cancer patients had similar non-MHC-restricted cytotoxicity to the controls. However, patients with stage II–IV diseases showed an impaired activity, stages III and IV differing significantly from the controls. This result shows that the decline in natural killer (NK) activity is associated with tumour burden. Patients with slowly growing neoplasms had stronger cytotoxic activity than patients with fast or moderately progressing disease. In the follow-up study, the whole material of 57 patients showed only a slight correlation between cytotoxicity and survival: 42% of the patients with strong activity survived for more than 2.5 years, whereas 6% of the patients with weak activity did so. In stage I patients there was no correlation between cytotoxicity and survival, nor was there a correlation in patients with stages II–IV of the disease. Hence, in our group of patients the determination of cytotoxicity preoperatively yielded no prognostic information beyound that already available from staging. However, those stage II–IV patients that survived for 1 year or more after the diagnosis and cytotoxicity tests, showed a significant correlation between cytotoxicity and survival.     

Cultures of purified human natural killer cells: Growth in the presence of interleukin 2

We have isolated highly enriched populations of LGL, which are virtually devoid of mature typical lymphocytes (as enumerated by morphological and surface antigen analysis using monoclonal antibodies e.g., OKT3) in comparison to T cells which contain greater than 95% sheep erythrocyte-forming cells and are devoid of LGL and $\text{NK}\text{K}$ activities. Both types of cells grew in the presence of crude or partially purified IL-2. Cultures of LGL could be initiated consistently even in the absence of lectins and the cultured LGL retained their characteristic morphology and cytotoxic activity. However, within 7–10 days after initiation, the cultured LGL changed in surface phenotype to become antigenically indistinguishable from cultured T cells.     

Recognition of chromosome 6-associated target structures by human lymphokine-activated killer cells

Different populations of unstimulated and IL-2-activated PBL were used in binding and killing assays against somatic mouse/human lymphocyte cell hybrids containing different human chromosomes. Unstimulated PBL effector cells showed low binding and killing activity to both cell hybrids and mouse parental cell lines. However, IL-2-activated killer (LAK) cells bound strongly to, and effectively killed, cell hybrids carrying human chromosome 6, but were inefficient in both assays to mouse parental cells and to cell hybrids not carrying human chromosome 6. These results show that human LAK cells but not endogenous NK cells bind and kill mouse/human lymphocyte hybrids containing human chromosome 6. We thus suggest that LAK cells recognize ligands encoded by genes on chromosome 6.     

Fractionation, morphological and functional characterization of effector cells responsible for human natural killer activity against cell-line targets

Human natural killer cells cytotoxic against cell-line target cells (NK-CLT) were isolated and characterized by utilizing adsorption-elution of the effector cells from the K-562 target cells. The cell associated with the cytotoxicity was a large lymphocyte with pale and characteristically granular cytoplasm. Thus, its morphology was identical with that of the large granular lymphocyte (LGL) previously shown to be the principal cytotoxic NK cell against fetal fibroblasts (NK-FF). The association of LGL with natural killer activity was verified with contact analysis from mixtures of unfractionated effector cells and target cells, which revealed that the number of contact of LGL with K-562 was correlated to the level of the individually expressed intensity of natural cytotoxicity. The ANAE-staining distribution of LGL was intensively positive with granular or diffuse staining pattern. In direct surface marker analysis LGL were E-rosette forming but, in contrast to NK-FF, heterogenous in regard to the Fc receptors. During in vitro incubation after elution from the target cells, the cytotoxic activity of LGL increased several fold. Also, the presence of K-562 among unfractionated effector cells caused an augmentation of cytotoxicity. This phenomenon was not observed as a result of effector cell-fetal fibroblast coculturing. Evidence from fetal fibroblast adsorption-elution and aggregated IgG blocking experiments suggested that the LGL with strong expression of Fc receptors were initially cytotoxic “mature” NK-cells, whereas the LGL with a weak expression of Fc receptors were initially noncytotoxic, but contact with K-562 “augmented” or “recruited” them to nonselective cytotoxicity.     

Human natural cell-mediated cytotoxicity against fetal fibroblasts. III. Morphological and functional characterization of the effector cells

We have isolated and characterized human natural killer cells cytotoxic to human fetal fibroblasts utilizing adsorption-elution of the effector cells from target cell-coated beads. The cell associated with enriched cytotoxicity was slightly larger than small- to medium-sized lymphocytes, the cytoplasm was pale and characteristically granular. In direct surface marker analysis the cell was Fc-receptor-positive, formed E-rosettes, and displayed strong either diffuse or granular ANAE reactivity in the cytoplasm. The ANAE reactivity could not be inhibited with sodium fluoride and in mitogen and antigen stimulation experiments the cell had T-cell characteristicis. The cell type was termed large granular lymphocyte and we suggest that it is the main direct effector cell for natural killer activity against human fetal fibroblasts.     

The impact of generic substitution on the activities of pharmaceutical companies - a survey from the companies' perspective one year and five years after the introduction of generic substitution in finland

Background  

Mandatory generic substitution (GS) was introduced in Finland on 1 April 2003. The aim of this study was to explore and compare the impacts of GS on the activities of pharmaceutical companies representing mainly original or generic pharmaceutical products in Finland. The self-reported impact of GS from pharmaceutical companies' perspective was explored with a focus on the number of employees, the range of sales packages on the market, the marketing activities, the research and development of new pharmaceutical products and storage of pharmaceuticals.     

Characterization of culturable bacterial populations associating with Pinus sylvestris--Suillus bovinus mycorrhizospheres

Bacterial isolations were carried out on Pinus sylvestris--Suillus bovinus mycorrhizospheres obtained directly from boreal pine forest. When samples were taken during dry weather, the numbers of bacterial colony-forming units were significantly higher in uncolonized short roots and external mycelia than in mycorrhizal roots and soil outside the mycorrhizosphere. In contrast, the colony-forming unit counts were similar in all hypogeous samples after rainy weather. Culturable bacteria were absent from most Suillus bovinus sporocarps. The bacteria isolated from all types of mycorr hizo sphere samples, i.e. short roots, mycorrhizal roots, and external mycelia, consisted primarily of Burkholderia spp., whereas most isolates from soil outside the mycorrhizosphere were identified as Paenibacillus spp. This study shows that mycorrhizal external mycelia can expand the habitat favourable for common rhizosphere bacteria into the soil far from the immediate rhizosphere. Some of these bacteria may help the trees with nitrogen acquisition, since potentially diazotrophic bacteria harbouring nitrogenase reductase (nifH) genes were isolated from mycorrhizal root tips.