Rejection of mammary adenocarcinoma cell tumors in DBA/2 mice immunocompromised by thymectomy and treatment with antithymocyte serum
Likhite, V.V.
Journal of Immunology 114(6): 1736-1742
1975
ISSN/ISBN: 0022-1767 PMID: 1092759 Document Number: 84463
Syngeneic mammary adenocarcinoma cells were mixed with killed Corynebacterium parvum organisms and were then transplanted subcutaneously into groups of normal and immunocompromised mice. The tumors formed at the site of injection exhibited normal growth for approximately 12 days followed by rapid and lasting rejection in both normal and immunocompromised animals. The control mice were protected against reinjections of 10-4 to 10-8 cells of the same line of tumor cells. The immunocompromised mice exhibited protection to reinjection of 10-4 cells of the tumor line initially employed. Microscopic examination of histologic sections of 10-day-old tumors in immunocompromised mice arising from administration of tumor cells and C.parvum mixtures revealed infiltration of only macrophages whereas those from normal animals exhibited both macrophages and lymphocytes. The data suggested that primary rejection of these tumors in immunocompromised mice may be the result of macrophage activity together with humoral immunity. These studies also revealed that 59 to 75% of immunocompromised mice exhibit protection against reinjection of the same line of tumor cells if twice-weekly treatment (i.p.) with killed C. parvum was included after inoculation of tumor cells mixed with C. parvum vaccine. These mice, unlike their saline-treated peers, exhibit delayed hypersensitivity reactions which are associated with proliferation of theta antigen-bearing lymphocytes. They also have intact tumor-directed humoral immune reactions.