Endotoxin as Adjuvator to the Transplantation of a Mouse Mammary Tumor

Abstract

Tumor cells, if they are to survive transplantation, depend for some time solely on the nutritional and other favorable influences of the tissue fluid surrounding them. The tissue fluid is enriched meanwhile by products of the transplanted cells themselves. Such mutual aid becomes attenuated as the transplanted cells are made to lie farther from each other. Other adjuvators to their successful transplantation are then uncovered (1).In the work already reported, tumor cells from the breast of a Balb C mouse were transplanted in degrees of isolation by spraying them in single cell suspensions onto the broad subcutaneous expanses of mice of the same inbred stock. With the intrinsic adjuvators thus reduced, extrinsic adjuvators could be assayed. One strong adjuvator, derived from liver, was thought to act by enhancing the general nutritiousness of the fluid supplying the tumor cells as they awaited the restoration of vascular support. Further analysis of the liver adjuvator showed that it was not ether soluble, that it was heat stable, and that it resisted mild hydrolysis with acids and alkalis. Since some properties of endotoxin exhibit similar resistance (2-4), and since the liver stores bacterial endotoxin (5), it seemed worthwhile to test the effects of lipopolysaccharide from Salmonella typhosa on descendants of the same cells.The present paper is to report the adjuvator effects of this endotoxin, and some experiments to illustrate the nature of endotoxin's adjuvator effect. Materials and MethodsEndotoxln.--A lipopolysaccharide, 1 prepared commercially from S. typkosa by Boivin's aceto-acefic acid extraction method, was suspended by shaking it in one or other of the balanced salt solutions appropriate to the experiments.Mice.--All were young adult females from the notably homogeneous C strain colony maintained for many years in this laboratory. The colony was bedded in autoclaved wood shavings and sustained with tap water and mouse breeder pellets. ~ The weanlings were fed a daily ration of bread and milk mash and kept in equable conditions of temperature and humidity. The mice were prepared, when the experiment called for it, by the splitting of their dorsal subcutaneous tissues with 5 cc of air and 1 ce of modified Earle's solution (E soln) with or without (1), except that the air was withdrawn at once.Tum~.--The mouse mammary cancer MT 296 (1) was used, from its 42nd to its 48th plated generations, in this series of experiments. It remained a complex of several neoplastic components persisting in apparent equilibrium with one another (see Fig. 4).Plating.--Tumor cell suspensions were prepared by alternately stirring and sieving the tumor fragments in 0.25°/o trypsin 3 in E soln, centrifuging and resuspending the loosened cells and cell clumps in 0.04~ DNasc 4 in spinner salt solution (SS seln) and by finally filtering this through the 5/z pores of porous steel sieves (see Fig. 2). Such suspensions contained exclusively cells which were both viable and individual. They were suitably diluted in SS soin, with ...

Interference by cortisone with endotoxin's adjuvator action on transplantation of a mouse tumour

“…subcutaneous expanses forming the plane for them have been prepared with endotoxin. This was first inferred from the growth of a grossly similar harvest of tumour from sparser platings of tumour cells (Henderson, 1969). The same inference can be made more confidently from the present study in which tumour takes were counted while still discrete.…”

“…Tumour.-The mouse mammary cancer MT296 (Henderson, 1967(Henderson, , 1969 was used from its 79th to 110th generations.…”

“…It was freshly suspended in E soln and injected, 50 ,ug per mouse, as described before (Henderson, 1969 …”

“…Endotoxin is one of these factors. It has been found to increase tumour harvests more thain a hundredfold (Henderson, 1969). The events in the connective tissues which accompany or permit this increased plating efficiency inliclude hyperaemia, leucocyte migration and venular thrombosis.…”

“…This paper describes how the overlapping spectra of effects from cortisone and irradiation were set against the adjuvator effect of endotoxin on tumour transplantation (Henderson, 1969).…”