Cellular immunity against tumor-associated antigens in humans: lymphocyte stimulation and skin reaction

Immunogenicity and immunosensitivity of ex vivo human carcinomas: interferon gamma and tumour necrosis factor alpha treatment of tumour cells potentiates their interaction with autologous blood lymphocytes

Human carcinoma cells vary appreciably in the expression of MHC class I, class II, ICAM-1 (CD54) and B7 (CD80) molecules. Short-term in vitro exposure of ex vivo carcinoma cells to interferon gamma and tumour necrosis factor alpha elevated/induced the surface expression of MHC class I, class II and ICAM-1, but only rarely of B7. We found that cytokine treatment elevated the cytotoxic susceptibility and the stimulatory potential of ex vivo tumour cells. This was demonstrated (a) by the increased frequency and elevated level of auto-tumour lysis and (b) by induction of DNA synthesis and generation of cytotoxic lymphocytes in autologous mixed lymphocyte/tumour cell culture (MLTC). The MHC class I and ICAM-1 molecules on the tumour cells were required for interaction with the lymphocytes as indicated by the inhibitory effect of specific mAb both in the stimulation and in the cytotoxic tests. While the cytokine-induced increases in MHC and ICAM-1 on the low-expression tumours were probably important for the modification of functional interaction with the autologous lymphocytes, it is likely that alterations in other properties of tumour cells were also induced which contributed to the phenomenon. This was indicated by the results obtained with several tumours, which expressed indigenously high levels of these molecules but activated the autologous lymphocytes only after cytokine treatment. In several experiments the untreated targets that did not activate the lymphocytes were sensitive to the cytotoxicity of the effectors activated in MLTC. The results show that the afferent and efferent arms of the immune response have different requirements for functional interactions between lymphocytes and tumour cells.

Expression of interleukin-2 receptor on blood lymphocytes stimulated with allogeneic lymphocytes or autologous tumor cells. The mixed lymphocyte culture of allo-sensitized individuals and the auto-tumor stimulation show similar kinetics of activation

The kinetics of interleukin-2 receptor (IL-2R) expression and the [3H]dT incorporation of blood lymphocytes after the first and the second stimulation with allogeneic leukocytes (primary and secondary MLC) or with the autologous tumor cells (primary and secondary MLTC) were compared. The expression of IL-2R paralleled the induction of DNA synthesis. The proportion of IL-2R+ cells of the unprimed donors peaked earlier in the secondary MLC as compared to the primary MLC (on days 3 and 5 respectively). In MLC of alloimmunized healthy individuals and in the MLTC of cancer patients the highest proportions of IL-2R+ cells were detected between days 2 and 3 after both the first and second stimulations. Thus the first in vitro stimulation in the MLTC showed similar kinetics to those of the secondary MLC of unprimed individuals and to the primary MLC response of the allo-immunized individuals. The findings in the MLTC substantiate the hypothesis that cancer patients can be sensitized to their own tumors. The kinetics of the appearance of the IL-2R together with the characteristics of the IL-2-propagated cultures provide useful information for the strategy of expansion of auto-tumor reactive lymphocyte populations.

Difference between young and old patients in characteristics of leukemic cells: older patients have cells growing excessively in vitro, with low antigenicity despite high HLA-DR antigens

Fifty-six patients with acute, non-lymphatic leukemia in the initial phase were studied. The poor prognostic signs were excessive in vitro growth, many HLA-DR-positive cells, or a low ratio of leukemic cell antigenicity to HLA-DR positivity and age. The cells from older patients formed more clusters (P less than 0.05), and they had less capacity to stimulate normal allogeneic lymphocytes (P less than 0.05) than those from younger patients. Cells forming many clusters also were more often (P less than 0.01) HLA-DR-positive than those forming few clusters. It is suggested that the prognosis in old patients with acute leukemia is poor in part because their leukemic cells have characteristics different from those of young patients.

The human mixed lymphocyte-tumor cell interaction test. I. Positive autologous lymphocyte proliferative responses can be stimulated by tumor cells as well as by cells from normal tissues

Co-culture of cancer patients' nonadherent peripheral blood lymphocytes with irradiated autologous fresh tumor cells, termed the mixed lymphocyte-tumor interaction (MLTI) test, resulted in significant stimulation of 3H-Tdr in corporation on day 6 in 19 of 37 autologous combinations. The MLTI test was performed in a microtiter wells (0.2 ml) and a variety of solid tumor cells (sarcomas and carcinomas) were used. Tumor cells were dissociated from the fresh biopsy tissue by nontrypsin enzymatic digestion (deoxyribonuclease, hyaluronidase, and collagenase) and the tumor cells enriched by depletion of macrophages using adherence procedures. Occasionally, further tumor cell purification was achieved by separation of cells on the basis of size on dis-continuous gradients. Positive MLTI resulted in stimulation as high as 20-fold over the backgrounds of PBL and tumor cells cultured alone. Mean positive MLTI was SI of 7.7. The negative MLTI were not a reflection of generalized immunosuppression, because tumor cell preparations that did not stimulate autologous PBL did stimulate allogeneic PBL. In an additional patient, PBL not responding in the autologous MLTI did respond to allogeneic tumors. MLTI using cryopreserved cells reproduced the MLTI results using fresh cells in 11 of 16 tests; the other five tests were all positive in the fresh MLTI and negative when using cryopreserved cells. Despite reports from many other groups it appears that positive MLTI were not tumor-specific. In 14 experiments we were able to simultaneously test the proliferative response to autologous tumor as well as to an autologous normal tissue (lung, liver, colon, and bowel). In eight of these experiments positive responses were obtained with tumor stimulators and in seven of these, positive proliferation was also obtained with normal tissue.

Immune response to chemically induced tumours: correlation of responding cell class with in vivo inhibition of tumour growth

Lymphoid cells stimulated by soluble tumour antigens in the MCA-induced murine fibrosarcoma system have been identified by subclass and protective capacity in adoptive syngeneic hosts. Lymph-node or spleen cells taken at weekly intervals after inoculation of syngeneic chemically induced fibrosarcomas were enriched by 3 methods in T, B, and "null" cell subclasses, and assayed for proliferative kinetics in response to soluble membrane antigens. The stimulated subpopulations were found to be heterogeneous, their composition varying with time and tumour burden. Initial proliferative responses after tumour inoculation were limited to the T-enriched subpopulation. Later during tumour growth, T, B and null cell fractions were vigorously and equally stimulated by tumour antigen. The ability of the same T, B or null-cell subpopulations to inhibit tumour growth was measured in adoptive hosts by a modified Winn assay. Only the T-cell subpopulation responding to tumour antigen in vitro effectively and consistently retarded tumour growth in vivo. In contrast to the shared specificities on syngeneic tumours identified by the proliferative assay, tumour-growth inhibition was limited to the specific tumour borne by the cell donor.

Specific and aspecific immune responsiveness in lung cancer patients: cutaneous delayed hypersensitivity reactions to a lung cancer-associated antigen

The ability of a lung cancer-associated antigen (LCAA) to provoke specific cutaneous delayed-hypersensitivity reactions has been studied on a group of 59 lung cancer patients. Biological activity of LCAA, monitored by skin testing, was demonstrated in 32% (17 of 53) of lung cancer patients, in 48.0% with limited disease, and in 17.2% with extensive disease. All the responders were in the group of normal reactors to standard recall antigens, if three antigens were used (PPDSK-SD, candida). No correlation was found between biological activity of LCAA and level of immunocompetence evaluated by lymphocyte-blastic transformation with PHA and count of rosette E-forming cells. These studies on the capacity to evoke specific DTH reactions in lung-cancer patients will be extended to the use of assays in vitro in the perspective of a more significant evaluation of immunocompetence levels.

Evaluation of the humoral response of glioma patients to a possible common tumor-associated antigen(s)

Cytotoxic antibodies against glioblastoma-associated antigen(s) have been sought for in glioma patient sera. Complement-dependent cytotoxicity (CDC) I and antibody-dependent cell-mediated cytotoxicity (ADCC) assays were used to test sera from 80 patients using 51 Cr labelled target cells derived from eight different glioblastoma lines. As more positive sera were detected with ADCC than with CDC, ADCC assay was used for the remainder of the study. Cytotoxic antibodies were detected in the sera from 8 of 80 glioma patients (10%) by CDC and in 20 of 143 (14%) by ADCC. Fourteen percent of 27 meningioma patients and 16% of 25 normal donors used as controls were found to react in ADCC against the same glioblastoma cell lines. The positive serum samples showed extensive cross-reactions with the different glioblastoma cells, but the pattern of reactivity was different for each serum tested. The antibodies detected did not seem to be directed against tumor-associated antigen(s), since the positive sera were found to have a similar ADCC reactivity against unrelated tumor cells and normal fibroblasts. Moreover, their antiglioma reactivity was absorbed by cells of unrelated tumors and by normal platelets. These results do not support previous reports of specific humoral responses in glioma patients against common tumor-associated antigen(s).

Circulating immune complexes and prognosis in human malignant lymphoma, a prospective study

Sera from 53 patients with Hodgkin's disease (HD) and 56 patients with non-Hodgkin malignant lymphoma (NH) were investigated, prior to treatment, for the presence of circulating immune complexes (CIC) by the 125I-C1q-binding radioassay. The patients were then followed for 14-31 months. No significant association was found between the presence of CIC and achievement of complete remission in any of the groups. In none of the groups could a difference be found between the survival rates of patients with and without CIC in their sera prior to treatment. About half of the patients were retested for the presence of CIC after completion of initial therapy. No significant association was found between the presence of post-treatment CIC and lack of complete remission in any of the patient groups. In the HD group, both pre- and post-treatment CIC appeared to be most frequent among patients over 50 years. No such association was found in the NH group.

Human malignant melanoma antigenic properties of phenol water extracts

Tumor-associated antigens were demonstrated in phenol water extracts of human malignant melanoma by migration tests with leukocytes from melanoma patients and controls: in 25 out of 60 melanoma patients weak reactivity was observed, usually stimulation of leukocyte migration, while leukocytes from 37 controls were negative in 100 tests. The frequency of positive reactions did not differ significantly in patients with and without metastases. Humoral antibodies against antigens of phenol water extracts were not detectable in melanoma patients. Rabbits did not produce antibodies against tumor typical substances after immunization with phenol water extracts. Tumor associated antigens of phenol water extracts are presumably not targets of antitumor immune reactions that can influence the clinical course.

Human tumor-lymphocyte interaction in vitro. III. T lymphocytes in autologous tumor stimulation (ATS)

The T-cell nature of the responding cells in autologous tumor stimulation (ATS) was proven by (1) E-rosette formation of lymphocytes attached to tumor cells during the early period of co-cultivation; (2) blast-transformed E-rosetting cells detectable at the end of the test period (day 6) and (3) the reactivity of T-enriched lymphocyte subset and unresponsiveness of T-depleted fractions. Preparation of tumor suspensions devoid of lymphocytes made it possible to carry out cross-tests between patients. Blastogenesis with allogeneic tumors was rare. The restricted autologous nature of the reaction is a strong indication for genuine tumor-relatedness.

Demonstration of specific cell-mediated anti-tumor immunity in lung cancer to autologous tissue extracts

Cell-mediated immunity (CMI) of lung cancer patients to autologous tumor antigens was assessed by mixed lymphocyte tumor interactions (MLTI) as measured in a microculture (200 microliter) lymphocyte proliferation (LP) assay. Positive lymphoproleferative responses were observed with cryopreserved intact mitomycin-C-treated autologous tumor cells (8/12 or 67% patients reactive) and with hypotonic membrane extracts (HMP) of tumor cells (28/40 or 70%). Good correlation was found between reactivity to tumor cells and extracts in parallel testing. In contrast, HMP of autologous normal lung tissue elicited very little LP reactivity, with only one patient giving a weak response by the SI criterion and low level of n cpm. Upon repeat testing, many patients gave reproducibly positive LP responses to tumor HMP. Patients at all clinical stages of disease and with different histologic tumor types had a similar proportion of HMP reactivity. Most reactive patients responded to a broad range of protein concentrations of tumor HMP, and LP responses were frequently elicited with 1 microgram or less of HMP. Thus, HMP appear to afford a convenient source of reactive tumor antigen for assessing anti-tumor immunity.

Wilms' tumor--model of a curable pediatric malignant solid tumor

Wilms' tumor is the model of the treatment of a pediatric solid tumor. Initially it appeared that multi-modality therapy, consisting of transabodominal nephrectomy, post-operative radiation therapy to the tumor bed and adjuvant, single agent chemotherapy provided the highest likelihood of disease-free survival. The identification of important prognostic factors, such as histology, tumor weight, lymph node involvement and age at diagnosis has led to a re-examination of the treatment of Wilms' tumor. Future therapeutic developments will include the administration of less therapy to some well defined groups of patients, and the exploration of new programs for patients who have been demonstrated to have a poor prognosis using currently accepted treatment techniques.

In vitro generation of cytotoxicity against autologous human tumour biopsy cells

Blood lymphocytes from 22 cancer patients were examined for cytotoxicity against autologous tumour cells in a short-term 51Cr release assay. Only three showed reactivity. In an attempt to increase cytotoxic potential in these and induce reactivity in non-reactive cases, the lymphocytes were cultured alone or with autologous tumour cells for 6 days. Upon subsequent testing against frozen, stored targets, nine samples reacted, including two of those with primary reactivity. In seven cases augmented cytotoxicity was evident in mixed cultures compared with lymphocytes cultured alone. Two of 10 cases showed cytotoxicity against the K562 cell line after culture and, in two of 13 tests in which allogeneic tumour biopsy targets were used, weak reactivity was bound. Cytotoxicity for autologous tumour biopsy cells was uniformly accompanied by positive blastogenesis in MLTI assays. In four cases blastogenesis occurred without the induction of cytotoxicity.

Human tumour--lymphocyte interaction in vitro. V. Comparison of the reactivity of tumour-infiltrating, blood and lymph-node lymphocytes with autologous tumour cells

Lymphocytes prepared from the blood, tumour-draining lymph node and tumour were tested for immune reactivity with freshly isolated autologous tumour cells from biopsies. Reactivity was assessed by the autologous tumour stimulation assay and by lymphocytotoxicity. Activity was found in 6/11 blood preparations, 7/10 lymph nodes and 1/7 tumour-infiltrating lymphocytes in tumour stimulation assays and in 6/19 blood, 8/18 lymph-node and 5/20 tumour-infiltrating lymphocytes in cytotoxicity assays. Tests with material from patients with nasopharyngeal carcinoma showed a higher frequency of cytotoxicity in the tumour-infiltrating lymphocytes than in other solid tumours. There was a correlation between results of the two assays when performed on the same preparations and between the levels of reactivity in lymph node and blood from the same patient. Cytotoxicity in the lymph nodes showed specificity in that cells from a long-term culture (K562) known to be sensitive to natural killer activity and from allogeneic tumour biopsies were only rarely damaged. Cytotoxicity against K562 was more frequently determined in blood lymphocytes. Tumour-infiltrating lymphocytes were non-reactive in patients when the blood and lymph-node lymphocytes were active.

Natural cytotoxicity in man: activity of lymph node and tumor-infiltrating lymphocytes

Lymphocytes from blood, lymph node and tumor have been tested for cytotoxicity against the K562 cell line which is known to be highly sensitive to lysis by spontaneously reactive cells. Cytotoxicity was found in all 13 samples from healthy donors and in 17/32 cancer patients. By contrast, activity was determined in only 1/18 lymph node and 1/14 preparations of tumor-infiltrating lymphocytes. Lymph node cells were similarly nonreactive against 3 other cell lines known to be sensitive to natural cytotoxicity. Studies of the composition of the effector populations revealed no absolute deficit of a particular cell type although there were differences between them resulting from the different isolation procedures used. Enrichment of the lymph node population for non-T, non-B lymphocyte was ineffective in inducing cytotoxicity in previously nonreactive samples although this procedure uniformly increased the cytotoxic potential of blood lymphocytes. Tests with blood taken during operation showed that the lack of reactivity in these preparations was unlikely to be a result of the effects of anesthesia or surgery. The reason for the low cytotoxicity in the lymph node and tumor-infiltrating lymphocytes is as yet undefined.

Use of a permanent cell line extracts to study the tumor associated immune reactions in colorectal cancer patients by leucocyte migration inhibition test

Crude extracts of colorectal surgical tumors, either individual or pooled, and HT29 line cells were compared in leucocyte migration inhibition test. HT29 cell extract gave more positive reactions with leucocytes of colorectal cancer patients than the other ones, and less with control leucocytes. It was thus used for all the subsequent experiments. As a whole, we obtained 44% (30/68) of positive inhibitions in patients afflicted with a colorectal carcinoma, against 9% (3/31e in normal controls and 20% (8/40) in patients bearing a carcinoma from another organ. Among the latest patients, those having a gynecological carcinoma were rarely positive, contrasting with those suffering from a carcinoma from the aerodigestive organs. It seemed that the antigen(s) involved in the reaction had no organ specificity, but rather a broad tissue specificity.

Immunological monitoring and immunotherapy in carcinoma of the lung

One hundred and seven patients with carcinoma of the lung underwent immunologic testing, and 62 of these patients were randomized to an immunotherapy protocol comparing the effects of Pasteur strain BCG, either alone or combined with allogeneic tumor cells, to the effects of no immunotherapy. Patients with residual disease left at the time of surgery or with metastatic disease at the time of diagnosis showed no increase in survival as a result of this form of immunotherapy. An insufficient number of patients with less advanced disease, in whom we would expect the most beneficial effect, have been entered in this study. In general, we were unable to document substantial effects of immunotherapy on the immunologic parameters tested. Only in recall antigen skin testing was there a statistically significant increase in reactivity in the immunotherapy groups. Tests of general immune status appeared to have a predictive value in monitoring lung cancer patients. Anergic patients had a poorer prognosis than did patients who demonstrated skin test reactivity. Patients with normal percentages of lymphocytes (T cells) forming rosettes with sheep erythrocytes at 29 degrees C were generally normal in other tests of immune competence. In serial studies of rosette formation, all patients who developed recurrent disease had a pattern of depressed or falling rosette values, and these abnormalities occurred an average of 3.1 months prior to clinical detection of recurrence. Patients with large-cell anaplastic carcinoma were found to have a significantly higher incidence of depressed rosette levels than the other histologic types. Both large and small-cell anaplastic patients had significantly depressed lymphocyte proliferation by mitogens and allogeneic cells. Although lung cancer patients have been described as immunologically depressed, they are capable of recognizing tumor-associated antigens. When tested in leukocyte migration inhibition assays with tumor-associated antigens, the majority of the patients in our study were found to be reactive. The use of a 3 M KCl extract of pleural effusion cells from a patient with pulmonary adenocarcinoma has given good reactivity and specificity in lung cancer patients of all histologic types. In addition, these patients have been shown to respond in a mixed lymphocyte/tumor interaction to tumor-associated antigens (Dean, 1976b).

Stimulation of autologous blood lymphocytes by malignant lymphoma cells and homogenates

The blastogenic response to autologous blood lymphocytes to whole-cell suspensions and to homogenates obtained from malignant lymphoma tissue has been investigated. Spleens were obtained from patients in whom laparotomy was performed for staging of malignant lymphoma. Cell suspensions prepared from tumour nodules were treated with mitomycin C and allowed to react with separated autologous blood lymphocytes for 6 days. Lymphocyte stimulation was measured by liquid scintillation counting after exposure to 3H-TdR. Cultures were also prepared in which autologous lymphocytes were treated with spleen tumour homogenate. Control experiments used spleens from staging procedures in which no tumour deposits were present, and normal spleens removed incidentally during other operations. In the controls, the uptake of TdR was never more than twice that of unstimulated lymphocytes. Greater degrees of lymphocyte stimulation were seen in 6 out of 14 patients, using whole tumour cells, and in 7 out of 16 patients, using tumour homogenates. The results indicate an antigenic difference between tumour and host cells, and suggest that lymphocytes can react to a tumour-associated antigen.

Inhibition of leukocyte migration by human breast-cancer-associated antigens

The existence of CMI to tumor-associated antigens present in 3 M KCl extracts of breast carcinomas was demonstrated in a group of breast cancer patients by the leukocyte migration inhibition (LMI) assay. When crude KCl extracts were tested, 3 of 5 breast cancer patients gave a positive response to autologous tumor extracts. Eleven of 20 gave a positive response to allogeneic extracts as compared to 3 of 22 controls (including 6 patients with benign breast disease, 7 with non-mammary cancers and 9 normal controls). Extracts of fibrocystic disease tissue gave positive LMI tests in 2 of 5 breast cancer patients, suggesting the presence of antigenic cross-reactivity between benign and malignant breast disease. An extract of a medullary carcinoma of breast was fractionated on Sephadex G-200 and the effluent pooled into three fractions. The high molecular weight fraction produced LMI in 11 of 22 breast cancer patients and in 1 of 19 controls, including patients with benign breast disease, other cancers and normal individuals. The low molecular weight fraction produced LMI in both the benign (4 of 6) and the malignant breast disease (6 of 20) patients, but not in the controls (0 of 12). A simple fractionation technique has thus separated "cancer-specific" from "organ-specific" activity. Sephadex G-200 fractions were active at a much lower protein concentration than the crude 3 M KCl extracts.

Properties of the K562 cell line, derived from a patient with chronic myeloid leukemia

The K562 cell line derived from a CML patient in blast crisis was examined for properties of B and T lymphocytes and cell lines. K562 lacks the B markers of immunoglobulins, Epstein-Barr virus (EBV) genome and associated nuclear antigen, and receptors for EBV. A low proportion of cells from rosettes with sheep erythrocytes, the frequency of which is considerably increased after neuraminidase treatment. Unlike B lines but like T lines, K562 cells are lysed rapidly by C'/Fc receptor-positive human blood leukocytes and do not stimulate MLC reactions. On the other hand, K562 lacks T antigen, high radiosensitivity and sensitivity to growth inhibition by thymidine. The cells do not contain N-APase, an enzyme found in all lines derived from lymphoid cells and in lymphoproliferative diseases. By scanning electron microscopy, K562 cells were seen to be rounded and relatively smooth, with small numbers of short microvilli resembling undifferentiated leukemic cells. A few cells had narrow ridge-like profiles and small ruffles similar to granulocytic leukemic cells. K562 is strongly positive for immunoglobuln Fc receptors and pinocytosis, but does not phagocytose or mediate antibody-dependent phagocytosis or cytolysis. Among histochemical stains, K562 is positive for esterase, lipid, and acid phosphatase. There seems to be no doubt that K562 is not a B cell line. While it has some T cell properties, these are not exclusive. Some of its characteristics indicate that it is probably not lymphoid. Due to its low level of differentiation, its nature cannot be stated with certainty. On the basis of the possible presence of the cellular marker of chronic myeloid leukemia, the Ph chromosome, it may be regarded as belonging to the granulocytic series of cells.

Search for anti-tumor response in a bone tumor patient with a long clinical history

Immunological studies are presented on a patient with a long clinical history suggesting the existence of a tumor-specific immune response. His tumor, first considered benign, progressed to a highly malignant osteosarcoma. Cell-mediated immune reactivity against biopsy cells and against tumor extract was detected in vitro by the autologous tumor stimulation test (ATS) and in vivo by the skin test. In one ATS-test with tumor extract, blastogenesis of T-cells was demonstrated. The amount of Ig(s) in consecutive biopsies increased. Biopsies taken in the later period of the disease stimulated only after trypsin treatment. This stimulation was inhibited by autologous serum or acid eluate of the biopsy. The inhibitory factor in the serum was not intact immunoglobin. Blood lymphocytes did not show a discriminatory or disease-related cytotoxicity, either directly or after co-cultivation with the tumor material. Lymphocytes isolated from one biopsy were non-reactive in both the ATS and the cytotoxicity test.

Specific antigen stimulated lymphocyte proliferation in osteosarcoma

A lymphocyte proliferation assay (LPA) for cellular immune responses to osteosarcoma antigens is described and applied to an examination of peripheral blood lymphocytes (PBL) taken from osteosarcoma patients. The antigen preparations were derived from 3 M KC1 solubilized osteosarcoma, taken from a limited number of patients. Lymphocytes from most tumor-bearing patients were stimulated to significant proliferation when cultured in normal human serum. Such stimulation was observed whether or not the lymphoid cells were preincubated 24 hours at 37 degrees C prior to addition of antigen. Patients whose lesion had been resected and who were without evidence of disease for 5-70 months had diminished proliferative responses. Lymphocytes from normal subjects, from patients having other types of sarcoma, and patients having carcinomas rarely responded to the soluble osteosarcoma antigens. When responsive PBL taken from tumor-bearing patients were cultured in autologous serum, the proliferative responses were abrogated or blocked. Serial assays made in the course of bearing this tumor under a variety of therapeutic regimens, including an immunotherapy protocol, suggest that the LPA may be useful in monitoring clinical progress of the disease and possibly in other immunotherapy protocols for osteosarcoma.

Lymphocyte stimulation by autologous tumor cells in the presence of serum from the same patient or from healthy donors

Lymphocyte blastogenesis induced by autologous tumor biopsy cells, by allogeneic lymphocytes and by PHA, was performed in the presence of autologous or allogeneic serum collected from normal blood donors. In 13 of the 15 cases lymphocyte stimulation by autologous tumor cells was inhibited in the presence of autologous serum. In contrast, autologous serum somewhat enhanced the blastogenic effect of PHA and allogeneic lymphocytes.

Human tumor--lymphocyte interaction in vitro: blastogenesis correlated to detectable immunoglobulin in the biopsy

Binding of radioiodinated anti-immunoglobulin (Ig) reagent assayed by acid elutable radioactivity was shown in 18 of 44 cell suspensions (41%) prepared from surgical specimens of human tumors. Aliquots of these biopsies were admixed to autologous lymphocytes and in 13 cases they induced stimulation of DNA synthesis. In only one of these 13 cases was the anti-Ig reagent bound, while among the 26 biopsies with low or no binding capacity 12 (46%) were stimulatory, indicating that immunoglobulin-containing biopsies are not stimulatory. Experiments on 32 lymphocyte preparations from different lymphoid organs suggest that the immunoglobulin detected in the tumor-cell suspension is not derived from the infiltrating lymphoid cells.