Cell-mediated "immunostimulation" induced by mammary tumour virus-free Balb-c mammary tumours

Treating medical data as a durable asset

Access to medical data is central for conducting research on genomics. However, to tap these metadata (observable traits and phenotypes, diagnoses and medication, and labels), researchers must grapple with the complex and sensitive nature of the information. In this Perspective, we argue that, at this exciting time for genomics and artificial intelligence, several critical aspects of data generation, infrastructure and management are pillars of a modern data ecosystem. Many risks to privacy and many obstacles to medical research can be eliminated or mitigated by new secure data analytics. Finally, we discuss the potential consequences of medical data exiting the institutions and being managed by individuals. These shifts in data ownership have the potential for profound disruption and opportunity across many fields.

The flip side of immune surveillance: immune dependency

The growths of many and perhaps all tumors may be stimulated rather than inhibited by a quantitatively low level of immunity. The reason tumors have antigens may be that tumors do not develop in vivo in the absence of at least a minimal immune reaction; in this sense, cancer may be considered an autoimmune disease. This review, based largely on the work of our own laboratory, outlines the data showing that the titration of anti-tumor immunity exhibits the phenomenon of hormesis, i.e. the dose-response curve is non-linear such that low levels of immunity are generally stimulatory but larger quantities of the same immune reactants may inhibit tumor growth. Evidence is also reviewed that suggests that the immune response may vary qualitatively and quantitatively during progression, such that there seems to be, during oncogenesis, a very low level of immune reaction that aids initial tumor growth, followed by a larger reaction that may cause remission of early neoplasms, followed, if the neoplasm survives, by a relative immunologic tolerance to the tumor that may be dependent, at least in part, on suppressor cells. This knowledge may help to explain some clinical observations concerning the relationships among tumor types and the organ distribution of metastases.

Immune response to polyoma tumor cells in mice--III. Stimulation of tumor cell growth in vitro by spleen cells from immunized animals

We have evaluated the stimulation of target cell growth in vitro by spleen cells from mice which were immunized with polyoma-transformed cells and other tumor and non-tumor antigens. Stimulation was particularly seen under conditions of immunization that were suboptimal for the production of specific cytotoxicity. Significant stimulation of polyoma target cell growth was observed by lymphocytes from mice immunized against 10(5) Py 4198 tumor cells. This stimulation of target cell growth was not confined to polyoma-transformed cells only. Cells transformed by SV40, H-MuSV and non-transformed cells like 3T3 and embryo fibroblasts were also stimulated. Immunization of mice with syngeneic embryo fibroblasts also resulted in stimulation of tumor cell growth by the spleen cells from the immunized mice. However, the growth stimulation was less consistent and did not occur in all target cells tested. The specificity of immunostimulation was further studied with the Moloney sarcoma virus (M-MuSV) system; an antigenically distinct tumor system. Spleen cells from M-MuSV tumor-bearing mice stimulated cell growth in vitro not only against MuSV-transformed cells but also with SV40-transformed and polyoma-transformed cells as targets. Significant stimulation of target cell growth was also observed by spleen cells from mice that were immunized against 'non-pertinent' antigens, e.g. sheep red blood cells and allogeneic (C57B 1/6) spleen cells.

Inhibitory and stimulatory effect of spleen cells from tumour bearing animals on the growth of syngeneic tumour cells

When spleen cells from C3H mice inoculated with a primary spontaneously arisen C3H mammary carcinoma were added to tumour target cells of the same type in vitro, both an inhibitory and a stimulatory effect on target cell growth were seen, when compared with the effect of adding normal syngeneic spleen cells. The inhibitory effect was seen regularly when high concentrations of spleen cells were added, while there was a stimulatory effect when low concentrations were added to the tumour target cells. When transferring spleen cells from tumour bearing mice together with a tumour inoculum to groups of normal syngeneic recipients, the resultant tumour growth was enhanced, as compared with recipients given tumour plus normal spleen cells and those given tumour cells only. It was found that the spleen cells which caused the greastest enhancement in vitro caused the greatest inhibition in vitro. This relationship could be explained by assuming the occurrence in spleens of tumour bearers of a population of reactive cells which when added in high concentrations to tumour target cells in vitro cause inhibition, while they cause stimulation of tumour growth in vivo because of being transferred to recipients in relatively low concentrations.

Stimulation of transplanted 3-methylcholanthrene-induced sarcomas in mice by specific immune ahd by normal serum

Serum from Bl x C3H mice carrying syngeneic, progressively growing, highly immunogenic 3-methylcholanthrene-induced tumors when admixed with the specific tumor and inoculated into immunologically crippled syngeneic recipients, stimulated growth as compared with serum from control normal mice. It appears that this acceleration of tumor growth is an immune effect since it is not present when a non-immunogenic (spontaneous tissue culture) tumor is used; and the active factor can be absorbed from the serum by the specific tumor but not by an immunologically unrelated tumor. Normal serum per se also stimulated tumor growth, but to a smaller extent.

Induction of pulmonary metastases in both immune and nonimmune mice. Effect of the removal of a transplanted primary tumor

In mice bearing a benzypyrene-induced fibrosarcoma tumor, the survival was determined of intravenously injected tumor cells at various intervals after previous immunization of experimental animals by induction and subsequent excision of a transplanted primary tumor in the soft tissues of the leg. Seven days after induction of a transplanted primary tumor, I.V. tumor cells produced fewer pulmonary metastases in immunized mice than in nonimmunized mice. When tumor cells were inoculated I.V. immediately following amputation of the transplanted primary tumor, the number of pulmonary metastases in the immunized and nonimmunized animals were similar; however, 6 hours, 7 days and 14 days after primary tumor excision, I.V. inoculated tumor cells produced a higher incidence of lung metastases in the immunized than in the nonimmunized mice. This increased survival of I.V. tumor cells following excision of the transplanted primary tumor may have relevance to the development of metastases after eradication of certain primary tumors in humans.

Different responses of lymphoid cells from tumor-bearing as compared to tumor-immunized mice when sensitized to tumor specific antigens in vitro

Lymphoid cells from spleen and lymph nodes of BALB/c mice were sensitized in vitro by cocultivation with cells from syngeneic methylcholanthrene-induced sarcomas. The donor mice were either immunized in vivo by tumor transplantation followed by excision ("tumor-excised mice") or were carrying a progressively growing tumor ("tumor-bearing mice"). The cell-mediated immune response of the sensitized cells was compared by a 36-hr microcytotoxicity assay. Lymphoid cells from tumor-excised mice were cytotoxic when tested after 3 days and also after 6 days of sensitization in vitro. Lymphoid cells from tumor-bearing mice were cytotoxic to cells of the tumor borne when tested after 3 days in culture. However, the cytotoxic effect was lost after 6 days of contact with the sensitizing tumor in vitro. Preliminary data suggest that the cultured lymphoid cells of tumor-bearing mice which have lost cytotoxicity, can suppress the reactivity of in vitro sensitized lymphoid cells from tumor-excised mice.

Changes in host immunity following excision of a murine melanoma

Changes in cell mediated and humoral immunity following the excision of a transplantable melanoma growing in the footpad of its syngeneic host, as measured by an in vitro cytotoxicity test, were assessed. Spleen cell cytotoxicity did not change significantly. Cells from the regional lymph nodes stimulated tumour growth before tumour excision. Three days following tumour excision this stimulatory effect was undetectable. Loss of serum factors capable of blocking the cytotoxicity of spleen cells occurred 24 h after tumour excision. Serum cytotoxicity increased after tumour excision to a maximum of the third day. Following tumour excision the rise in serum cytotoxicity and loss of regional lymph node tumour stimulation were concomitant with the loss of blocking activity.