Effects of glutathione depletion on the cytotoxicity of agents toward a human colonic tumour cell line

Testicular leukocytes are assumed to be involved in immunological surveillance against infection and tumours as well as regulation of local immune responses. They are implicated in mechanisms that make the testis a successful site for tissue transplantation in both rats and mice. Our previous studies using multi-colour fluorescence flow cytometric analysis to examine isolated testicular leukocytes in the rat testis have established the existence of a significant population of predominantly CD8+ T cells and a comparable number of lymphocytes expressing natural killer (NK) cell markers (NK and NKT cells). The functional activity of these testicular NK and NKT cells subsequently has been confirmed by a standard flow cytometric cytotoxicity assay using an NK-sensitive tumour cell line (YAC-1) and an NKT-sensitive tumour cell line (U937). Similar analyses of mouse testicular leukocytes have shown a slightly different pattern. The data indicate that mouse testicular lymphocytes comprise T cells, NK cells, and NKT cells, similar to the rat testis. However, while the apparent numerical densities of T cells in rat and mouse testes were similar, the numbers of NK and NKT cells were considerably lower in the mouse. Mouse testicular NKT cells were positive for staining with the tetramer CD1d/αGC, which is used to identify classical NKT cells, whereas rat NKT cells did not stain for this marker. Moreover, the CD8/CD4 T cell ratio in the mouse testis displayed a skewing towards the CD4+ subset. These data highlight the possibility that the immunological environment, and hence the course of immunological events, might be quite different in the testes of the two species. The reasons for these differences are not clear, however they should be taken into account when considering studies of testicular immune processes. Finally, comparative studies of immunological process in the testes of rats and mice may be very informative.

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Changes accompanying long term tissue culture of an adenovirus type 12 tumour cell line

British Journal of Cancer ◽

10.1038/bjc.1968.94 ◽

1968 ◽

Vol 22 (4) ◽

pp. 798-807 ◽

Cited By ~ 6

Author(s):

G C Schild ◽

J S Oxford ◽

C W Potter

Keyword(s):

Tissue Culture ◽

Cell Line ◽

Tumour Cell ◽

Adenovirus Type ◽

Tumour Cell Line

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Synthesis and secretion of mucin by the human colonic tumour cell line LS180

Biochemical Journal ◽

10.1042/bj3020111 ◽

1994 ◽

Vol 302 (1) ◽

pp. 111-118 ◽

Cited By ~ 38

Author(s):

D J McCool ◽

J F Forstner ◽

G G Forstner

Keyword(s):

Cell Line ◽

Carcinoma Cell ◽

Tumour Cell Line ◽

Mucin Secretion ◽

Vicia Villosa ◽

Golgi Transport ◽

Sds Page ◽

Colonic Tumour ◽

Isolectin B4 ◽

Time Point

Pulse-chase labelling experiments were performed using the mucin-producing colonic carcinoma cell line LS180. Cells were pulsed with [3H]threonine or [3H]glucosamine and chased in complete media without radiolabel for various lengths of time. From cell and media extracts obtained at each time point, mucin proteins were immunoprecipitated with specific anti-mucin antibodies and analysed by SDS/PAGE and fluorography. At short labelling times with [3H]threonine, without chase, a monomeric thiol-reduction-resistant mucin precursor of apparent molecular mass > 670 kDa was identified. The precursor, in contrast to oligomeric species, was not labelled by [3H]glucosamine but exhibited binding to Vicia villosa isolectin B4, suggesting the presence of some core GalNAc residues. Treatment with tunicamycin to inhibit N-glycosylation had no effect on the apparent mass of the precursor. Identity of the mucin antigen with MUC2 mucin was established by immunoprecipitation with antibodies specific for a MUC2 tandem repeat and C-terminal regions. With increasing chase time the precursor was replaced by thiol-reduction-sensitive mucin oligomers that reached peak intracellular radiolabelling with [3H]threonine by 2 h of chase, and then declined. Only oligomeric mucin was secreted into the medium. Secretion of [3H]threonine-labelled mucin was detectable after 2 h of chase and increased as the cytoplasmic mucin label declined. Monensin inhibited [3H]glucosamine incorporation, sialylation and baseline (non-regulated) mucin secretion without affecting initial [3H]threonine incorporation or oligomerization. Oligomerization and Golgi transport are therefore essential early steps in MUC2 mucin secretion. Oligomerization may follow some core O-glycosylation with GalNAc, but precedes elongation of oligosaccharide chains.

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Interleukin-1β induces nitric oxide production by a mouse pituitary tumour cell line (AtT20/D16)

Journal of Endocrinology ◽

10.1677/joe.0.1380429 ◽

1993 ◽

Vol 138 (3) ◽

pp. 429-435 ◽

Cited By ~ 12

Author(s):

K. Ohta ◽

Y. Hirata ◽

T. Imai ◽

F. Marumo

Keyword(s):

Cell Line ◽

Tumour Cell ◽

Pituitary Tumour ◽

No Synthase ◽

Tumour Cell Line ◽

Dependent Manner ◽

Mouse Pituitary ◽

Dose Dependent ◽

Inducible Nos ◽

Acth Release

ABSTRACT To elucidate whether anterior pituitary cells express the nitric oxide (NO) synthase gene, we studied the synthesis of NO and the expression of NO synthase (NOS) mRNA by a mouse pituitary tumour cell line (AtT20/D16). Interleukin-1β (IL-1β) stimulated production of NO2−/NO3− (NOx) in a time-dependent manner and both NOx and cyclic GMP formation were stimulated in a dose-dependent manner by IL-1β. IL-1β-induced NOx production and intracellular cyclic GMP formation were similarly blocked by an NO synthase inhibitor, NG-monomethyl-l-arginine (LNMMA), whose effect was reversed by l-arginine, but not by d-arginine. Dexamethasone inhibited IL-1β-induced NOx production in a dose-dependent manner. A calmodulin inhibitor (W-7) showed no effect on IL-1β-induced NOx production, whereas cycloheximide and the actinomycin D completely inhibited NOx production. Northern blot analysis using cDNA for mouse macrophage-inducible NOS as a probe revealed the expression of inducible NOS mRNA in the cells only after exposure to IL-1β. Although IL-1β stimulated ACTH release from tumour cells, LNMMA failed to affect ACTH release stimulated by IL-1β. These results demonstrate for the first time that a pituitary tumour cell line (AtT20/D16) possesses cytokine-inducible and Ca2+/calmodulin-independent NOS, although NO may not be involved in ACTH release. Journal of Endocrinology (1993) 138, 429–435

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