The immune reaction as a stimulator of tumor growth

Rank order of sarcoma susceptibility among mouse strains reverses with low concentrations of carcinogen

Ten mouse strains in which aryl hydrocarbon hydroxylase can be induced, or F1 hybrids of these strains, were ranked according to their sarcoma susceptibility when exposed to a high concentration (5 percent) of the chemical carcinogen 3-methylcholanthrene. This rank order was reversed when the concentration of 3-methylcholanthrene was reduced to 0.05 percent.

Reproducibility and relation to specific and non-specific anti-tumor resistance of the tumor "sneaking through" phenomenon

The reproducibility and immunological specificity of the tumor "sneaking through" phenomenon and enhancement of tumor growth were studied in syngeneic and random-bred Syrian hamsters by means of a quantitative modification of the transplantation test. After primary challenge the phenomenon was neither observed in normal animals nor in animals effectively immunized against tumor. However, it was regularly observed in some "immune" animals after secondary challenge. In primary challenge of animals "sneaking through" phenomenon was most often observed in animals pretreated with large doses of heat-inactivated tumor cells. This characteristic could not be transferred with serum of pretreated animals. In contrast to specific tumor immunity, the "sneaking through" pbenomenon appeared to be immunologically non-specific. This was observed in cross-transplantation tests with tumor cells bearing different TSTAs. Thus, TSTA is not an inducer and apparently not a target for a response leading to enhancement of tumor growth in pretreated hamsters. Experiments demonstrating enhanced tumor growth in pretreated animals at the same time demonstrate two other possibly more essential findings: (1) normal animals are naturally resistant to transplantation of 1 to about 1 x 10(3) (or more) tumor cells; and (2) this resistance can be totally abrogated by the pretreatment of normal animals with tumor cell preparations. The preliminary data demonstrate that abrogation of natural anti-tumor resistance in adult hamsters subsequently inoculated with SV40 leads to rapid development of primary tumors in such animals. The development of specific anti-tumor immune response in animals treated with inactivated tumor cell preparations was also studied. Significant non-specific inhibition of sponse in Syrian hamsters treated with inactivated syngeneic tumor cells was observed. The data obtained are considered to demonstrate two anti-tumor defense systems in the animal, i.e., non-specific natural resistance and specific anti-tumor immunity. The first seems to be responsible for elimination of low numbers of tumor cells in the normal organism and also to be esseitial for effective induction and functioning of the specific anti-tumor immunity.

Dissociation of anti-tumor immune responses in rats immunized with solubilized tumor-associated antigens from a methylcholanthrene-induced fibrosarcoma

Soluble tumor antigens were prepared from chemically-induced rat fibrosarcoma KMT-17 cells by various methods [Na-deoxycholate (DOC), 3 M-KCI extraction, and crude membrane preparations by mechanical disruption]. Soluble tumor antigens prepared by DOC extraction (DOC-STA) could be detected by a radioisotopic footpad assay (FPA) and they showed the strongest antigenic activity in KMT-17 immune rats. Anti-tumor immune responses in rats previously immunized with DOC-STA were measured by FPA, Winn assay, and transplantation resistance. Significant responses detected by the FPA and Winn assay were demonstrated in rats immunized with DOC-STA. However, rats previously immunized with DOC-STA showed a significant enhancement of tumor growth when challenged with KMT-17 cells. This enhancement was specific for the tumor line used. Normal rats which received adoptive transfer of thymus and spleen cells from rats immunized with DOC-STA produced specific enhancement of tumor growth as compared with non-treated rats. Administration of cyclophosphamide before immunization with DOC-STA abrogated the enhanced tumor growth in the host. These results suggest that immunization with soluble tumor antigens specifically enhanced tumor grwoth by the induction of immunosuppressor cells. Dissociation between the anti-tumor immunity detected by the FPA and Winn assay and the enhanced tumor growth detected by transplantation resistance in rats immunized with DOC-STA is discussed.

[Cell mediated immunity in cervical cancer patients: evaluation by in vitro leukocyte-migration-inhibition-assay (author's transl)]

Cellular mediated immune reactions (CMI) against tumour associated antigens are the demonstration of an interrelationship between tumour and tumour host. They are related to the stage and prognosis of the disease. 41 patients with cervical cancer were tested by leukocyte-migration-inhibition test. Cryostat sections of 10 micron of the tumour-tissue, gained by excision or curettage and histologically defined, were taken as tumour antigens. The test was performed in Sykes-Moore-Chamber as so-called one-way-test with the lymphocytes/leukocytes and macrophagen of the tumour patient. Reactions against autologous and homologous tumour tissue and against recall antigens (tuberculin and varidase) were tested. There was no overall diminution of cellular mediated immune reactions. CMI was demonstrated in 69.7% (inhibition in 30.3%, stimulation in 39.4%) in the autologous and in 51.3% in the homologous system (21.6% inhibition, 29.7% stimulation).

Influence of micrococcus, BCG and related polysaccharides on the proliferation of the L1210 leukaemia

A comparative study of the effects of BCG, Micrococcus lysodeikticus, and a series of structurally related polysaccharides (complement triggers) on the non-specific and specific immune resistance against L1210 lymphoid leukaemia was carried out and commented on. In contrast with authors of earlier reports, we were unable to generate any effective non-specific or specific immunotherapy after the graft of 10(4) leukaemic cells to 8--10-week-old CDF1 mice. However, when mice were prevaccinated with irradiated (8 krad X-rays) cultured cells combined with 1 mg of bacterium or polysaccharide one month before grafting 10(4) cells, they were given an immunoprotection that was more pronounced with the i.p. than with the i.v. route. Prevaccinated mice were afforded a stronger immunoprotection when boosted repeatedly with 1mg injections of bacterium or polysaccharide after tumour challenge.

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.

Suppressive effects of regional lymph node cells and extracts of antibody-dependent cellular cytotoxicity

Lymphocytes from regional lymph nodes that drain tumors and extracts of such lymphocytes suppress antibody-dependent cell-mediated target cell lysis by effector cells from cancer patients and controls. In contrast, lymph node cells from control patients are not suppressive. Control extracts from normal lymphocytes and 2 immunologically inert tissues, muscle and kidney, exhibit some suppressive activity but significantly less than extracts from lymph nodes that drain tumors.

Progression of the immune response to solubilized tumor antigens

Local adoptive transfer assays (LATA) were used to analyze and compare the progression of the immune response in C3H/HeJ mice to irradiated tumor cell vaccine and to crude 3M KCl solubilized antigens extracted from a syngeneic methylcholanthrene-induced fibrosarcoma. Sequential LATA performed 2, 6, 9, 12 and 15 days after soluble antigen pretreatment of spleen cell donors revealed a sinusoidal evolution of lymphoid cell activity. An initial brief period of potent tumor facilitation (days 6-9) was followed by a phase of tumor neutralization (days 9-12) which decayed by day 15. On the other hand, spleen cells from donors sensitized with irradiated tumor cells exhibited consistent tumor neutralization which was sustained throughout 15 days. Thus the tumor growth facilitation observed only in CSA-treated donors may represent a qualitative difference in the immune state induced by soluble, as opposed to cellular, forms of tumor antigen.

Immunobiology of primary intracranial tumors. Part 3: Microcytotoxicity assays of specific immune responses of brain tumor patients

Fifty-six in vitro microcytotoxicity assays were conducted on 30 patients with intracranial tumors at various times during the postoperative course. Significant specific cellular cytotoxic responses were found in nine of 56 assays, humoral cytotoxic responses in nine of 54 assays, and host effector cell-dependent, antibody-dependent cytotoxic responses in four of 28 assays. Variables that might influence the occurrence of cytotoxicity were studied, and the relationship of these findings to other immune parameters was discussed.

Immunotherapy in the treatment of cancer

This article is a review of immunotherapy in the treatment of cancer incorporating the history of immunotherapy in the nineteenth and twentieth centuries, assessment of the techniques currently in use and of possible future developments. Although immunotherapy is not established as a therapeutic technique, evidence suggests that the immune response does influence the development of neoplastic cells. A better understanding of the immune response and its control may lead to the production of efficacious immunological treatment of certain cancers.

Transplantability and metastasibility of an MCA-induced sarcoma in nude mice. Influence of transfer of thymus cells and adoptive immunity

Challenge of C57(nu/nu) mice with an MCA-induced sarcoma, MCG101, induced in C57BL/6J mice, disclosed a higher resistence subcutaneously and intravenously than in syngenic C57/(+/+) mice. Transfer of 5 X 10(7) thymus cells to the nude mice brought their resistance to subcutaneously injected tumour cells back to the level of the C57/(+/+) mice, but only with the highest tumour cell doses tested, i.e. 5 X 10(4) and 10(5) cells. Against intravenously injected tumour cells a similar effect by the thymus cells was only suggested. Spontaneous metastases from the same tumour transplanted to the tail did occur in the nude mice and were possibly facilitated by specifically sensitized spleen cells. The results indicate that the resistance to subcutaneously injected tumour cells in nude mice may well be dependent on their incapability to develop thymus-dependent immuno-responses and that spontaneous metastases can be facilitated by a weak immuno-response.

Inhibition of the growth of lymphoid tumours in syngeneic athymic (nude) mice

A comparison of the growth of a number of BALB/c tumours in BALB/c, BALB/c.nu/ + (heterozygous nude) and BALB/c.nu (homozygous) nude mice has shown that a majority of BALB/c lymphoid tumours grow at a significantly reduced rate in BALB/c.nu mice. The three non-lymphoid BALB/c tumours (carcinomas and sarcomas) tested and a minority of lymphoid tumours, however, grew as well, or better, in the BALB/c.nu mice. Furthermore a correlation, without exception to date, has emerged from a comparison between the susceptibility of a tumour cell line to in vitro lysis by spleen cells from syngeneic nude mice and its growth in vivo in syngeneic nude mice. Only those lymphoid tumour cell lines lysed in vitro show the reduced growth rate in syngeneic nude as compared to syngeneic normal mice. Tumour cell lines, both lymphoid and non-lymphoid, which are resistant to in vitro lysis do not show the reduced in vivo growth rate in syngeneic nude mice. Both the in vivo and in vitro effect can be partially abolished by irradiating the nude mice prior to use, suggesting that a radiation-sensitive non-T-cell surveillance of lymphoid tumours is operating in nude mice. While the identity of the antigens is still unknown, the specificity of the phenomena suggest that C-type RNA oncogenic viral determined antigens are involved.

In vitro induction of cell-mediated immunity to murine leukemia cells. II. cytotoxic activity in vitro and tumor-neutralizing capacity in vivo of anti-leukemia cytotoxic lymphocytes generated in macrocultures

The main findings of the present study are: (a) highly reactive cytotoxic lymphocytes (CTL) against syngeneic and allogeneic murine leukemia cells were generated in vitro in macro 'one-way' mixed leukocyte-tumor cultures (MLTC). Cultures set up in large tissue culture flasks contained up to 400 X 10(6) normal spleen cells (responder cells) and 20--40 X (10(6) mitomycin C-treated leukemia cells (stimulator cells). Successful sensitization in macrocultures was greatly dependent upon the responder cell density and the responder/stimulator cell ratio. Cytotoxic activity, as measured by the 51Cr-release assay, peaked on day 5--7. (b) Sensitized 'memory' lymphocytes produced in primary MLTC could be restimulated with the original tumor cells to give a more rapid and stronger secondary cytotoxic response. (c) lymphocytes sensitized to allogeneic leukemia cells reacted equally well with sensitizing leukemia cells and with the corresponding normal lymphoid target cells, whereas lymphocytes sensitized to syngeneic leukemia cells did not react with the homologous normal lymphocytes. (d) Cryopreserved normal splenocytes and leukemia cells were as efficient as fresh cells in generating allogeneic and syngeneic CTL. (e) Using a Winn-type tumor neutralization assay, it was shown that both allogeneic and syngeneic splenocytes sensitized in vitro to EL4 leukemia (of C57BL/6 mice) and to YAC leukemia (of A mice) were capable of preventing tumor growth in the syngeneic host, whereas cultured normal splenocytes frequently showed a tumor-enhancing effect. Long-term survivors, remaining after inoculation of leukemia cells and sensitized lymphocytes, also became resistant to a tumor challenge that was up to 10,000 greater than the minimum lethal dose.

Cellular immune responses in familial medullary thyroid carcinoma

We studied prospectively 46 members of a kindred with familial medullary thyroid carcinoma to determine the importance of possible cellular immune reactivity to tumor antigen. We evaluated in vitro production of macrophage-migration-inhibitory factor and 3H-thymidine uptake by lymphocytes from patients, family members and normal subjects in response to extracts of medullary thyroid carcinoma and normal thyroid tissue. Lymphocytes from 12 of 18 patients with medullary thyroid carcinoma and four of seven patients with C-cell hyperplasia produced migration inhibitory factor or proliferated (or both) in response to tumor antigen. In contrast, cells from only two of 25 normal subjects and two of nine family members not genetically at risk for medullary thyroid carcinoma made migration inhibitory factor and proliferated to tumor antigen. Of particular interest, lymphocytes from six of 12 clinically normal family members genetically at risk for medullary thyroid carcinoma exhibited cellular immune reactivity to tumor antigen.

The treatment of lung cancer: perspectives and critique

Future improvements in the therapy of lung cancer most probably will result from new treatment approaches that combine all existing modalities. This paper discusses the applications and, in particular, the shortcomings of present knowledge in surgery, radiotherapy, chemotherapy, immunotherapy, and combinations of these modalities as they relate to the growing problem of treatment in lung cancer.

Immunogenicity of modified tumor cells in syngenic hosts

Modified tumor cells were used to immunize three murine hosts against syngenic ascitic lymphomas: C3H-6C3HED, BALB/c-P1798, and DBA/2-L1210. When the host was capable of a significant immune response against the malignant cells during progressive tumor growth (e.g., C3H vs. 6C3HED), protective immunization against a larger challenge tumor dose was achieved after fewer vaccinations. Lipopolysaccharide (LPS) enhanced host response to iodoacetamide (IAd) modified P1798 and L1210 so as to confer resistance after fewer immunizations with these weakly antigenic tumors. Similarities among the three systems were also seen. Modified cells may be stored at 4 degrees C several weeks and are effective when 107-108 are given i.p.; resistance appears maximal about one week after vaccination. In immunotherapy trials, C3H mice implanted with 5 x 104 6C3HED cells and treated at least four times with IAd-6C3HED demonstrated a 25% cure rate. A model was presented for evaluating parameters of response to immunotherapy in conjunction with chemotherapy. Cell-mediated immunity in resistant mice was demonstrated by inhibition of DNA synthesis in cultures of lymphoma cells and sensitized peritoneal cells (PEC) compared to that with nonimmune PEC. This assay system may also provide an opportunity for examining the hypothesis of immunostimulation of tumor growth in vitro. Humoral response to modified cells was established by membrane immunofluorescence. Although anti-6C3HED and anti-L1210 appear specific, anti-P1798 antiserum reacts with BALB/c thymocytes and murine fetal antigen.

Induction of resistance or enhancement to a transplantable murine plasmacytoma by transfer of non-immune leucocytes

Newborn mice have a lower spontaneous resistance to the growth of a syngeneic plasmacytoma (MOPC-460) as compared to adult mice. The transfer of different leucocyte populations from non-immunized adult donors to newborn mice influence in a dual way the resistance to MOPC-460 growth, depending on the number of cells transferred. The transfer of a low number of neutrophils, thymus or spleen cells enhances the MOPC-460 takes. Higher numbers of neutrophils, thymus or bone marrow cells induce an effective protenction. By contrast, macrophages over a dose of 1 X 10(4) constantly produce a reduction of tumour growth.

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.

Hyperplasia of donor cells in rejecting weakly antigenic skin grafts

Proliferation of epidermal cells and fibroblasts in the upper part of the dermis characterized the rejection of weakly histoincompatible male skin grafts by otherwise syngeneic females of an inbred rat strain. Quinacrine dihydrochloride staining of the Y chromosome established that the hyperplastic cells were of donor origin. Proliferation of graft cells was apparently a consequence of the immune response. If the analogy between weak histoincompatibility and the tumour-host relationship is valid, the hazards of attempting to heighten anti-tumour immunity could include increased proliferation of neoplastic cells.

Failure of BCG immunostimulation to affect the clinical course of Burkitt's lymphoma

A controlled randomised trial was carried out to evaluate the efficacy of BCG immunotherapy in preventing relapse in patients with Burkitt's lymphoma in whom remission had been induced with cyclophosphamide. Twenty-one patients were treated with BCG, and 19 were controls. Eleven patients in each group relapsed during a follow-up period long enough to make it unlikely that further relapses would occur. There were no significant differences in the length of remission or the site of relapse that could be attributed to treatment. Eleven patients died: of these none of the six patients in the BCG group but all of the five in the control group had stage D lymphomas. BCG treatment increased the rate of recovery from tumour-induced immunosuppression, but within the BCG group immunocompetence improved most rapidly in the patients who relapsed-a finding that appears to contradict the tenet retionalising the use of immunological adjuvants as treatment.

Temporal analysis of cellular cytotoxicity and humoral factors during progession and regression of Rous sarcomas in Japanese quails

Temporal appearance of cellular cytotoxicity and humoral activities including blocking and arming activities during the entire course of Rous sarcoma development in Japanese quails was examined by microcytotoxicity assay with comparison of animals bearing regressing tumors induced by a moderate dose of virus (regressors) and animals bearing growing tumors induced by a large dose of virus (progressors). Cellular cytotoxicity of the spleen cells in regressors was detected in a biphasic pattern; the first phase being observed as early as 3-5 days post inoculation (p.i.), followed by an eclipse period between 7-10 days p.i. which was the time of active tumor growth, and the second phase occurring after 12 days p.i. when the tumor had attained the maximum size. In progressors, only the first phase was observed. Instead, a stimulatory effect of the spleen cells on growth of target cells was noticed. Arming activity which confers cytotoxic activity on the normal spleen cells was demonstrated in the sera of regressors in the similar biphasic pattern as the cellular cytotoxicity; the early activity being present at 3 days p.i., and the late one after 19 days p.i. The former was detected by pre-incubation of serum with effector cells in microcytotoxicity assay and the latter by pre-incubation with target cells. In progressors, only the early arming activity which reacts with effector cells was demonstrated. Blocking activity which abrogates cellular cytotoxicity was demonstrated in both regressors and progressors but in different patterns of appearance, that is, blocking activity in regressors was only transiently demonstrated only by pre-incubation with effector cells at the time of maximum tumor growth, while the activity in progressors seemed to persist after the tumor reached the maximum size. Since the earlier activity was found to be effective at effector cell level, and the later one at both effector and target cell levels, participation of blocking factors of different types in progressors was also suggested.

Intralesional BCG in the treatment of metastatic malignant melanoma

The therapeutic efficacy of intralesional BCG (Bacillus Calmette-Guerin; one immunizing dose every 2 weeks for a minimum of five treatments) was studied in 19 melanoma patients. Of 15 patients evaluable for response, five experienced significant objective improvement (two complete and three partial remissions). Objective improvement was limited to those patients with dermal metastatic disease. In vitro cytotoxicity in the presence of patient's serum bore, on average, a relationship to the clinical disease. In certain individual cases, serum blocking and/or lymphocyte stimulation may have had prognostic significance.