Enhancement of tumour growth in two syngeneic C3H murine systems by immunization via the intracaecal route

Abstract

Over the past 70 years many experiments have been designed to promote tumour growth. These studies were all carried out in allogeneic tumour systems or by artificially influencing the immunization process. In the present study, the growth of syngeneic mammary tumour cells was enhanced by prior immunization via the intracaecal route. Such induced enhancement could be transferred to untreated animals by serum or by spleen cells. Tumour growth was also enhanced in another syngeneic system by immunization via the intestinal route with frozen-thawed ascites tumour cells. The result is in direct contrast to that obtained by similar immunization with live cells, which affords protection against a later challenge.

Serological response to intracaecal injections of antigenic mouse tumour cells

“…route have been described elsewhere (Laursen & Laursen, 1978 The fluotescent index wNas calculated as (a-b)/a, where a = the percentage of fluor escent-negative cells treated with normal control serum, and b = the percentage of fluorescent-negative cells treated w,Nith the seirum to be tested (Klein & Klein, 1964).…”

“…In a previous publication, Laursen and Laursen (1978) have described enhanced growth of tumour grafts after two prior intracaecal inoculations of either frozen-thawed C3H mouse ascites tumour cells or live C3H mammary tumour cells. The induced enhancement was transferable to untreated animals by serum and by spleen cells.…”