Cancer and Subversion of Host Defences

Booth

1982

Aust J Exp Biol Med

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Summary The following enzyme activities were measured in cell lysates and supernatants from mouse peritoneal macrophages incubated with products of cultured tumour and other cells: acid phosphatase, β‐D‐glucuronidase, N‐acetyl‐D‐glucosaminidase, muramidase (lysozyme), lactic dehydrogenase (supernatant only) and plasminogen activator (supernatant only). There were no noteworthy changes in enzyme activities. Hydrogen peroxide production by appropriately stimulated mouse and/or guinea‐pig peritoneal exudate macrophages was variably inhibited by supernatants from some tumour cells and some normal cells. Changes in these biochemical activities of macrophages do not appear to be closely related to the anti‐inflammatory activity of tumour cell products.

Section: Resultsmentioning

confidence: 99%

“…Macrophage function and inflammatory responses may be depressed in tumour-bearing human and experimental animal hosts, the depression being largely due to soluble products of tumour cells (reviewed by Nelson et al, 1981). In this laboratory cultured tumour cells have been found to produce three factors or groups of factors.…”

Section: Introductionmentioning

confidence: 99%

Effects of Tumour Cell Culture Supernatants on Some Biochemical Activities of Macrophages

Booth

1982

Aust J Exp Biol Med

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“…Among the ways in which tumour cells can evade or subvert host defences is the production of soluble factors which interfere with the expression of cell-mediated immunity (CMI), including macrophage function (7)(8)(9)(10)(11)(12). In studies in this laboratory, all tumours tested, regardless of type or Abbreviations used in this paper: CMI, cell-mediated immunity; con-A.…”

Section: Introductionmentioning

confidence: 99%

Festschrift Inhibition of cell‐mediated immunity by tumour cell products: Depression of interleukin‐2 production and responses to interleukin‐2 by mouse spleen cells

Nelson²

1988

Immunol Cell Biol

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Summary Supernatants from cultures of mouse and human tumour cells inhibited the production of interleukin‐2 (IL‐2) by stimulated mouse spleen cells. The tumour cells tested, all of which were active, included a mouse and a human melanoma, three methylcholanthrene‐induced fibrosarcomas of mice, and human HeLa cells. Supernatants from normal mouse and human fibroblasts were inactive. Inhibition was dose‐dependent. Spleen cells from aged mice were more susceptible to inhibition than spleen cells from young mice. When tumour cell culture supernatants were fractionated on Sephacryl S‐300, two peaks of activity were found, with apparent molecular weights of approximately 50 and 18 kD. Supernatants from tumour cell and fibroblast cultures caused variable, but generally weak, inhibition of responses of lymphoblasts to IL‐2. It is suggested that inhibition of IL‐2 production may be an important mode of action of tumour cell products that inhibit cell‐mediated immunity.

“…Many abnormalities in immune function, including suppression in macrophage fuinction, occur in mice infected iHNBITIO(N OF THE GRANULOM)AATOUS RESPONSE BY TUMAlOUR with viruses (Specter & Friedmain, 1978;Nelson et al, 1981). In particular lactatedehydrogenase-elevating virus (LDV) is known to be widely distributed in laboratory mice (Riley et al, 1978) and is associated with a nuimber of transplantable murine tumours (Riley, 1968).…”

Section: Methodsmentioning

confidence: 99%

“…There was no significant difference between the plasma and serum levels of LDH activity found in control animals, so the levels in experimental animals were expressed in terms of serum activity (Table V) (James, 1977;North et al, 1978: Nelson et al, 1981 (Milas & Scott, 1978). These tissues then show a characteristic granulomatous response (see e.g.…”

Section: Methodsmentioning

confidence: 99%

Inhibition by the Landschütz ascites carcinoma of the granulomatous inflammatory response to C. parvum

McIntosh¹,

Pugh-Humphreys²,

Fraser³

et al. 1982

Br J Cancer

Summary.-I.p. or i.v. administration of Corynebacterium parvum (CP) to MF1 mice induces a generalized inflammatory response, associated with marked hepatosplenomegaly and accompanied by a pronounced granulomatous response in the liver. Injection of the Landschutz ascites carcinoma (LAC) 24 h after CP substantially reduced the intensity of the inflammatory response, and decreased both the frequency and size of the hepatic granulomas, as revealed by morphometric analysis of histological sections.The difference in cellular composition of the granulomas between the experimental groups, as revealed by light microscopy, was further emphasized and characterized by ultrastructural studies. These revealed the predominance of macrophages within the granulomas in tumour-bearing mice, in contrast to the predominance of epithelioid cells in the lesions which developed in mice given CP alone.Our experimental findings show that the inhibitory effect of the growing LAC on granuloma formation in response to CP cannot be ascribed to (a) sequestration of the microorganism within the growing tumour, (b) a nonspecific inflammatory stimulus, (c) diversion and seqestration of mononuclear phagocytes in the growing tumour or (d) the presence of lactate dehydrogenase-elevating virus in either the host or tumour cells. The inhibition of liver granuloma formation is consistent with an effect mediated by soluble, heat-stable tumour-associated factor(s).