A humoral cytotoxic substance produced by a human killer cell line

Karpas, Abraham

doi:10.1038/bjc.1977.212

Cited by 13 publications

(6 citation statements)

References 7 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…It is therefore not possible to make a meaningful comparison with the legion of cytotoxic factors reported previously in the literature. However, it is worth noting that a malignant cell isolated from human peripheral blood, which had characteristics similar to those of NK cells, released a cytotoxic factor into the culture medium which was claimed to have anti-tumour activity in vivo (Karpas, 1978). Whether the factor described in the present study is also active in vivo remains to be determined.…”

Section: Resultsmentioning

confidence: 72%

Spontaneous development of cytotoxic activity in cultured lymphnode cells from tumour-bearing rats

Robins¹,

Rees²,

Brooks³

et al. 1979

Br J Cancer

View full text Add to dashboard Cite

Section: Resultsmentioning

confidence: 72%

Spontaneous development of cytotoxic activity in cultured lymphnode cells from tumour-bearing rats

Robins¹,

Rees²,

Brooks³

et al. 1979

Br J Cancer

View full text Add to dashboard Cite

“…The spontaneous production of a cytotoxic activity by K160, a human B-lymphoblastoid cell line, has been described (15,23). Using sucrose density gradient centrifugation, the cytotoxic factor was shown to have an approximate molecular mass of 70 kDa (15).…”

Section: Discussionmentioning

confidence: 99%

Identity of human B-cell line cytotoxic lymphokine with tumor necrosis factor type beta.

Yamanaka¹,

Karpas²

1989

Proc. Natl. Acad. Sci. U.S.A.

Self Cite

View full text Add to dashboard Cite

A humoral cytotoxic protein that is spontaneously produced by a cloned human lymphoblastoid cell line (K160b) was partially purified by a simple three-step column chromatography procedure and NaDodS04/polyacrylamide gel electrophoresis. Proteins were electrically blotted onto a polyvinylidene difluoride membrane, and a band of the cytotoxic protein was excised after staining with Coomassie brilliant blue. Direct analysis ofthe amino acid sequence of this protein showed the primary structure of its N-terminal region was identical to that of natural tumor necrosis factor type 13 (TNF-fi). The 24-kDa molecular mass of the cytotoxic protein, determined by NaDodSO4/PAGE, and its elution profiles from various types of columns correlated with those of natural TNF-.8. Specific activity of the cytotoxicity, standardized with recombinant TNF-fi, was comparable to that of the purified factor. However, polyclonal antiserum to recombinant TNF-.3 failed to react with the purified factor. Since recombinant TNF-fi, when used in patients, causes unacceptable side effects, which may be due to absence of glycosylation, the cell line K160b could be a useful source of natural TNF-(3 for clinical trials.Early studies of cytotoxic lymphokines were performed on material obtained from mixed cultures of animal and human white blood cells stimulated by mitogens such as phytohemagglutinin (1). It was not possible to determine which cell types produced cytotoxic lymphokines or whether the test material contained a single factor or several. In the past decade there has been an increased interest in the study of cytotoxic lymphokines produced by human white blood cells. It is claimed that macrophage cytotoxicity is mediated by tumor necrosis factor type a (TNF-a) (2-4), whereas Tlymphocyte cytotoxicity is mainly mediated by tumor necrosis factor type 8 (TNF-,B) (5). Both have been purified and sequenced (6,7). Natural killer cells are reported to release a third cytotoxic factor, termed NK-CF (8). Besides these well-characterized cytotoxins, interferons are known to have cytostatic as well as cytolytic activity (9). Interleukin 1 has also been reported to have cytolytic activity (10). Furthermore, there have been several reports of other cytotoxic factors, whose relationship to characterized lymphokines is still uncertain (6,(11)(12)(13)(14). Karpas (15) described the production of a humoral cytotoxic factor by a human B-cell line, Karpas 160. The cell line consisted of a homogeneous population of Epstein-Barr virus-infected B lymphoblasts. This line was cocultured with a wide range of adherent cell lines and found to kill spontaneously most of the target cells, even at a target/effector cell ratio of 1:1. Malignant cells were more susceptible to killing than normal cells. Subsequently, it was established that cell killing was mediated by two distinct humoral cytotoxic factors, named factors 1 and 2 (16). It was the first report that cloned Epstein-Barr virus-infected B lymphoblasts produce a cytotoxic lymphokine (17), which was subs...

show abstract

“…The concentration of the cytotoxic factor was assayed by the method described in detail previously (Karpas, 1977b). Samples, with known protein concentrations, were dialysed at 40C for at least 20h against several changes of 20ml or larger volume of fresh growth medium (Dulbecco's modified Eagle's medium; Flow Laboratories, Irvine, Ayrshire, Scotland, U.K.), filtered through Millipore filters (0.45,um pore size).…”

Section: Assay Ofthe Cytotoxicfactormentioning

confidence: 99%

“…When the cytotoxic factor was injected into fibrosarcoma-bearing mice, approx. 50% survived, whereas all control animals died (Karpas, 1977b).…”

mentioning

confidence: 95%

Purification and physicochemical characterization of a human cytotoxic factor produced by a human haemic cell line

Neumann¹,

Karpas²

1981

Biochemical Journal

Self Cite

View full text Add to dashboard Cite

A cytotoxic factor, produced by a human lymphoblastoid cell line [Karpas (1977) Br. J. Cancer 35, 152--160; Karpas (1977) Br. J. Cancer 36, 437--445], was purified both from the cell extracts and from the culture medium containing the cell lysate, by using ammonium sulphate precipitation, DEAE-cellulose chromatography, gel filtration and affinity chromatography on concanavalin A--Sepharose and on [3H]amino-ethanol--glass beads. Two factors, Factor I and Factor II, were separated by DEAE-cellulose chromatography. Factor I was eluted from this column at 30 mM-aminoethanol/HCl buffer, pH 8.0, whereas Factor II was bound strongly to DEAE-cellulose and was eluted only at 325 mM-aminoethanol/HCl buffer, pH 8.0. The purified Factor I migrated as a single band on polyacrylamide-gel electrophoresis. Its isoelectric point, pI, was 8.0 +/- 0.3. Its sedimentation coefficient, S20,w, was 3.5 +/- 0.1 S and its apparent molecular weight, Mr, was 65 000 +/- 1000 as determined by sedimentation-velocity and sedimentation-equilibrium measurements. A linear relationship between molecular weight and concentration was found in equilibrium runs, suggesting a non-spherical shape of the molecule. Factor I is not a glycoprotein, inasmuch as it does not bind to concanavalin A--Sepharose. It consists of two subunits (Mr 32 000 +/- 4000), migrating on sodium dodecyl sulphate/polyacrylamide-gel electrophoresis as a single band. Factor II had pI 6.0 +/- 0.4 and Mr 75 000 +/- 3000. Factors I and II are thus different proteins.

show abstract

A humoral cytotoxic substance produced by a human killer cell line

Cited by 13 publications

References 7 publications

Spontaneous development of cytotoxic activity in cultured lymphnode cells from tumour-bearing rats

Spontaneous development of cytotoxic activity in cultured lymphnode cells from tumour-bearing rats

Identity of human B-cell line cytotoxic lymphokine with tumor necrosis factor type beta.

Purification and physicochemical characterization of a human cytotoxic factor produced by a human haemic cell line

Contact Info

Product

Resources

About