Metastasis in the nude rat associated with lack of immune response

Effect of cyclosporin A on the growth and spontaneous metastasis of syngeneic animal tumours

“…It has been shown also that animals receiving continuous daily doses of Cy A recovered rapidly from the effects once treatment was terminated (Denham et al, 1980 (1) Doses similar to those used in this study have been shown to permit the L survival of skin allografts in our rat LN LN colony (Denham et al, 1980). (2) Production of specific antibody to tumour antigens estimated by a direct binding assay was totally inhibited, as l,N+L described previously in athymic animals L (Eccles et al, 1979). This effect is also found in athymic or LN + L thymectomized/irradiated hosts (Eccles et al, 1979;Eccles & Alexander, 1976 Eccles, 1978).…”

“…(2) Production of specific antibody to tumour antigens estimated by a direct binding assay was totally inhibited, as l,N+L described previously in athymic animals L (Eccles et al, 1979). This effect is also found in athymic or LN + L thymectomized/irradiated hosts (Eccles et al, 1979;Eccles & Alexander, 1976 Eccles, 1978). Treatment with high i.m.…”

“…Although these effects could be reversed by reconstitution of the animals with lymphoid cells before tumour implantation (Eccles, 1978) the possibility that surgical stress or radiation damage had contributed to the increased incidence of metastases could not be discounted entirely. Subsequently, it was shown that similar tumours grown in congenitally athymic "nude" rats also exhibited enhanced metastasis over immunecompetent hosts (Eccles et al, 1979;Eccles, 1980) although the athymic rats were of mixed genetic background, and not syngeneic with the Lister Hooded/ Cbi tumours under investigation. Cyclosporin A offered the possibility of studying the growth and metastasis ofa wide variety of rat and mouse tumours in strictly syngeneic hosts, subjected to specific immune suppression not requiring surgery, the use of antibiotics or filterbox housing as had all previous experimental systems used.…”

Effect of host immune status on the spontaneous metastasis of cloned cell lines of the 13762NF rat mammary adenocarcinoma

“…Another approach to testing the influence of T cell immunity in this system has been to grow the tumours in congenitally athymic nude rats (Eccles et al, 1979). One potential problem with this approach, however, is that the nude rats used were histoincompatible with Fischer F344 rats, and recent reports have indicated that Rowett nude rats possess some residual T cell activity that may be sufficient for mounting a weak allo-response to the 1 3762NF tumour.…”

Syngeneic antitumour antibodies in rats: clearance of cell-bound antibody in vivo and in vitro

“…Tumours that show a low rate of spontaneous metastasis in the immunocompetent host, have been found to exhibit rapid and widespread dissemination in animals that (a) are congenitally athymic (Eccles et al, 1979) (b) have been T-celldeprived by thymectomy and sub-lethal irradiation (Eccles & Alexander, 1974) or (c) have been immunosuppressed by treatment with cyclosporin A (Eccles et al, 1980). In one such model system (the HSN.TC fibrosarcoma grown in syngeneic Hooded rats) we have found (Eccles et al, 1979) that when this tumour was grown in athymic rats, they failed to produce the specific serum antibody normally found in immunocompetent animals, and were also defective in the recruitment of mononuclear phagocytic cells. Currently we are attempting to define the role of humoral factors in metastatic disease, and in this communication report further on the specific antibodies that are produced in Hooded rats during the growth of the HSN.TC fibrosarcoma.…”