Immunobiology of primary intracranial tumors. Part 1: studies of the cellular and humoral general immune competence of brain-tumor patients

Immunocytochemical study of the cellular immune response in meningiomas

Twenty four meningiomas (17 benign and seven "atypical" were reacted with a panel of monoclonal antibodies to macrophages, lymphocytes, and HLA DR antigens. All the tumours contained macrophages but these cells were more numerous in the atypical meningiomas. Lymphocytes, almost exclusively of the CD8 subtype, were also present in 70% of benign meningiomas and in all atypical meningiomas and were more abundant in the latter. B lymphocytes were present in minimal numbers in three atypical meningiomas and in one benign meningioma. CD4 positive T lymphocytes were present in small numbers in one benign meningioma and in moderate numbers in one atypical meningioma. HLA DR antigen expression on tumour cells was present in about 60% of both tumour groups. The numbers of macrophages and T and CD8 lymphocytes in meningiomas seem to be related to atypical histological features, and the presence of these cells raises questions about host immune response and the relation of this to prognosis.

Mononuclear cell infiltration in central portions of human astrocytomas

The mononuclear cell infiltration in the central portion of human low- and high-grade astrocytomas has been examined using monoclonal antibodies to cell surface differentiation antigens. There was no significant difference between the number of T cells, B cells, or macrophages. The OKT8+ (suppressor/cytotoxic) T cell population was the major lymphocyte subset in the infiltrates. There was, however, indirect evidence for a proportion of the total OKT8+ cells being natural killer cells. Overall, there was a significant difference in the number of macrophages compared to the total lymphoid cell population. Several cell types seem to play an equal role in the cellular and humoral immune response within the center of the tumors, as distinct from that occurring at the periphery.

The response of peripheral blood mononuclear cells of glioma-bearing patients to stimulation with microbial antigen and IL-2: proliferation and IFN-gamma production

Peripheral blood mononuclear cells (PBMC) of malignant glioma-bearing patients were stimulated in vitro with a glucomannan-protein antigen of Candida albicans (GMP) or Interleukin-2 (IL-2), then assayed for proliferation and production of Interferon gamma. PBMC of healthy, age and sex matched subjects were the controls. PBMC from glioma-bearing patients did not differ, as a whole, from PBMC of healthy donors in IL-2 or GMP-induced proliferation. However, they showed a definitely lesser ability to produce IFN. The results are discussed in the framework of the impairment of immune responses known to affect glioma-bearing patients.

Inhibition of lymphocyte responsiveness by a glial tumor cell-derived suppressive factor

The results of this study demonstrate the presence of suppressive factor(s) in the tissue culture supernatants of cloned and freshly explanted malignant glioma cells. Culture supernatants obtained from these glial cell lines were demonstrated to have potent suppressive activity as evidenced by their ability to inhibit the proliferative response of normal human peripheral blood lymphocytes induced by phytohemagglutinin and anti-OKT3 monoclonal antibodies. The results further demonstrate the existence of a dose-response relationship between these supernatants and inhibition of mitogen-induced lymphocyte activation. Maximum production of suppressive activity by glial tumor cells was dependent on: 1) the number of tumor cells seeded in culture, 2) whether fetal calf serum was present, and 3) the duration of culture. The production of the suppressive factor(s) was not inhibited by the addition of inhibitors of prostaglandin E synthesis. Experiments designed to determine at what time during lymphocyte activation the suppressive factor was most effective demonstrated that the culture supernatants must be added during the first 24 hours of culture to exhibit inhibitory properties. Finally, proliferation of both the T-helper and T-suppressor/cytotoxic subsets was equally well inhibited by the glial tumor cell culture supernatants.

Activation of immunoregulatory lymphocytes obtained from patients with malignant gliomas

The responsiveness of T cells and their subsets (T-helper cells and T-suppressor cells) obtained from patients with malignant gliomas was evaluated in an effort to further define the mechanism of their impaired host immunocompetence. This study demonstrates that peripheral blood lymphocytes obtained from these patients have impaired responsiveness to a variety of mitogens including phytohemagglutinin, concanavalin A, pokeweed mitogen, and anti-T3 monoclonal antibody. The impaired lymphocyte responsiveness does not result from the inability of these cells to express receptors for a specific mitogen or antibody. The mitogenic responsiveness of purified T cells is markedly reduced when compared to values obtained from control subjects. Therefore, the decreased T cell reactivity of patients with malignant gliomas does not result simply from a diminution in the absolute number of potentially responding lymphocytes. The mitogen reactivity of the T cell subsets, CD4+ helper cells, and CD8+ cytotoxic/suppressor cells was also investigated. These results demonstrate that the responsiveness of the CD4+ T-helper cell subset obtained from these patients is consistently diminished as compared to control values. In contrast, the reactivity of the CD8+ T cell subset was not nearly as dramatically impaired. Thus, these results indicate that the proliferative defect observed in T cells obtained from patients is located predominantly in the T-helper cell subset. Functional deficiencies in this important subpopulation of T lymphocytes may explain, in part, the presence of depressed immune responsiveness in patients with malignant glial tumors.

Immunological studies in patients with central nervous system tumors

Impairment of cell-mediated immunity in patients with primary central nervous system (CNS) tumors has repeatedly been reported but data to demonstrate the underlying immunological defect are not univocal. This report concerns a series of 31 patients harboring a glioma in which we studied: peripheral blood T-lymphocyte subpopulations by monoclonal antibody analysis; cellular responsiveness to mitogens; serum immunoglobulin values. The same parameters were also evaluated in 7 cases of intracranial meningioma and in 8 patients affected by non-proliferative, non-inflammatory CNS diseases. Thirty age-matched healthy volunteers formed the control group. Neither impairment of T-cells as regard to number, responsiveness and subsets, nor abnormal Ig values were found in these groups. However two patients, harboring respectively a third ventricle low grade astrocytoma and an anterior callosal glioblastoma, presented a striking T-cells impairment. These findings might suggest a correlation between hypothalamus and immune system, as already postulated by several previous experimental and clinical studies.

Natural killer activity of blood lymphocytes in patients with primary intracranial tumors. Correlation to histological tumor type and anatomical site

The possible relationship between the natural killer (NK) activity of blood lymphocytes and the histological tumor type or anatomical location of the lesions was examined in 116 patients with primary intracranial tumors. The patients had not undergone any surgical intervention or received any treatment with ionizing radiation or cytotoxic drugs. However, some of them had received corticosteroid medication. Regardless of the histological type of tumor, there was no significant difference in the NK activity of the non-corticosteroid treated patients and the healthy control subjects. However, there was a trend towards an increased NK-activity in patients with low-grade gliomas, in particular oligodendrogliomas. The NK-activity was reduced in patients who were treated with corticosteroids. There was no relationship between the NK-activity in non-steroid treated patients and the anatomical location of the tumor. The latter finding contrasts to a recent observation showing a strong relationship between tumor site and PPD-reactivity of blood lymphocytes in patients with intracranial tumors.

Malignant gliomas of the brain. A retrospective study

A retrospective study of 72 consecutive and nonrandomized patients with malignant glial tumors is presented. The influence of age, sex, location of tumor, initial presenting symptoms, symptomatic preoperative interval, reoperation, extent of tumor removal, histological subtype of tumor, lymphocyte infiltration, and different treatments upon survival time has been evaluated and statistically analyzed. Age was inversely associated with survival with a strong statistical significance (p = 0.0001). Headache was the most common (67%) initial symptom; aphasia and seizure were both present in 45.3% of patients. Initial presenting symptoms had no effect upon survival. Parietal lobe and lymphocyte infiltration had marginally negative effects upon survival (p = 0.097 and p = 0.10 respectively). The amount of tumor removal was marginally associated with an improved survival (p = 0.07). Radiation therapy was strongly associated with an improved survival time (p = 0.0007). The addition of chemotherapy did not affect the survival (perhaps reflecting the small number of patients and inadequate chemotherapy). There was an obvious beneficial effect of reoperation upon survival time, if the patient lived and underwent reoperation later than 16 months after the initial operation (slow-growing tumor). Although median and mean survival times (10 and 20.34 months respectively, SD 7.45 months) were similar to most series reported, our rates of survival (20%, 12.5%, and 7.5% at 2, 3, and 5 years, respectively) were notably higher.

Blood lymphocyte subsets in patients with primary intracranial tumours. Correlation to histological tumour type and anatomical site

The blood lymphocyte population of 118 patients with primary intracranial tumours and healthy volunteers was examined with respect to its size and cellular composition using various rosette tests. The patients had not undergone any surgical intervention or received any treatment with ionizing irradiation or cytotoxic drugs. However, some of them were treated with corticosteroids. It was observed that non-steroid treated patients with oligodendrogliomas, but not patients with other histological types of tumours, had a significantly reduced proportion of "active" T-lymphocytes forming rosettes with sheep erythrocytes (a type of T-lymphocyte which is activated by foetal calf serum). These patients as well as those with astrocytomas, malignant gliomas (anaplastic astrocytomas and glioblastomas) or miscellaneous tumours (mainly meningiomas) had normal proportions of lymphocytes with receptors for the Fc-part of IgG or C'3 and cells forming rosettes with sheep erythrocytes under more conventional conditions. Patients who were treated with corticosteroids had an increased frequency of lymphocytes with the above Fc-receptor. An association between site of the lesions and cellular composition of the blood lymphocyte population was not detected. The results give further support for the view that the immunological system may be changed in patients with oligodendrogliomas.

Mitogen-activated lymphocytes of normals and glioma patients produce factors with anti-glioblastoma activity in vitro

Human glioblastoma cell lines showed profound suppression of both DNA and RNA synthesis when exposed to supernatants (SNs) of mitogen-activated blood mononuclear cells. Cloning efficiency of these glioma cells also decreased 10- to 500-fold. In monolayer cultures, growth inhibition was evident within 12 h of adding SN and peaked at 24 h. A decrease in absolute cell number was evident by 72 h. The inhibitory effect of SNs, however, was not permanent as more cells entered S-phase when SN-treated cultures were refed with fresh medium (without SN). The factor(s) responsible for this inhibitory activity was a product of lymphocytes and was produced in comparable amounts by cells of normal blood donors and patients with glioma. The compromised immunological status of glioblastoma patients did not influence their capacity to produce cytostatic lymphokines.

Prognostic value of round cell (lymphocyte) infiltration in malignant gliomas

The biopsy specimens of 342 patients with malignant glioma were evaluated to determine the extent and prognostic significance of round cell infiltration within these representative tissues: (a) tumor, (b) peritumoral, (c) hypervascular, (d) necrotic, and (e) normal tissue. Thirty-six percent of all biopsy specimens showed at least one tissue area with round cell infiltration. Patients in age groups 0 to 25 years and 71 years and older tended to show less round cell infiltration than did patients 41 to 55 years old. The presence of round cell infiltration in tissue was associated with a poor prognosis. Patients showing any infiltration had mean survival times of 8.4 months as opposed to 11.9 months for those showing no infiltration. The relationship between round cell infiltration and poor prognosis is true, irrespective of postoperative therapy, sex, and age.

Natural killer activity against cultured human neural tumor and fetal brain cells

Ten human neural tumor lines and three established from normal human brain were analyzed for sensitivities to natural killer (NK) cytolysis. Compared to MOLT-4, fetal brain cells were sensitive, but those from adult brain and eight of ten neural tumor cell lines demonstrated marked NK resistance. The frequencies of target-binding cells (TBC) and single-cell lysis of glioma cells bound within tumor cell conjugates demonstrated that the resistance of two lines was explained either by a decrease in the frequencies of TBC or reduced ability of bound NK cells to lyse the tumor cell conjugates. A third resistant line demonstrated decreases in both TBC and tumor cell conjugate lysis. Two glioma lines with less NK resistance had greater frequencies of TBC or conjugate lysis than the resistant lines. Thus, NK resistance can result from decreased recognition of targets, diminished NK lysis of bound targets, or a combination of both.

Immunosuppression by phenytoin: implication for altered immune competence in brain-tumor patients

This investigation was conducted to examine the immunosuppressive potential of phenytoin in vivo and to document a correlation between phenytoin therapy and depressed lymphocyte responsiveness to mitogens. It was thought that phenytoin, the most widely used anticonvulsant agent, may play some role in the immunosuppression seen in brain-tumor patients. The effect of phenytoin on mitogen-stimulated lymphocyte function was evaluated by tritiated (3H)-thymidine incorporation and lymphocyte nuclear size distribution. Lymphocytes from either phenytoin-treated or normal rabbits were incubated for 90 hours in culture medium in the presence of three mitogens: phytohemagglutinin (PHA), concanavalin A (Con A), and pokeweed mitogen (PWM). Significant suppression of mitogen-induced activation of the lymphocytes from treated animals was demonstrated. The present studies suggest a possible connection between phenytoin therapy and altered immune competence in brain-tumor patients.

Intracerebral transplantation of a human glioma line in immunosuppressed rats

A model was developed for in vivo study of the human glioma-derived D-54 MG cell line in the brains of immunosuppressed Fischer 344 rats. The rats were injected with horse anti-rat thymocyte serum before and after intracerebral inoculation with 5 or 10 microliters of a D-54 MG tumor cell suspension. Reproducible mortality distributions were obtained, with deaths occurring 18 to 34 days after intracerebral inoculation. Tumors grew as well circumscribed intracerebral masses with sheets of anaplastic cells, areas of necrosis bordered by concentrated nuclei, and minimal lymphocytic infiltration. Cytogenetic analysis revealed the same general chromosome distribution and markers in the heterotransplanted glioma cells as in the cultured line. Blood-brain barrier disruption was demonstrated by intracerebral tumor staining after intravenous injection of Evans blue dye. The in vivo growth of D-54 MG in immunosuppressed rats provides a reliable experimental model for the study of chemotherapy, immunodiagnosis, and immunotherapy of a human glioma-derived tumor in an animal sufficiently large to evaluate intracarotid or intratumoral injection of therapeutic agents.

Autologous serologic responses in glioma patients. Correlation with tumor grade and survival

The serologic responses of 42 patients with gliomas have been evaluated in a quantitative microcytotoxicity assay utilizing autologous cultured glioma cells. Forty-five percent of patients had detectable cytotoxic antibody apparently directed to their own cultured cells. When tumor grade was correlated with immune response, 15/20 patients with Grade I, II and III astrocytomas had antigens detectable in autologous sera whereas only 5/22 patients with Grade IV astrocytomas had such responses. None of the autologous fibroblasts from the 15 patients with paired gliomas and fibroblast lines had membrane antigens detectable using autologous sera and fibroblast absorption did not reduce antiglioma activity. Thus, the cytotoxicity observed in this assay appears to be restricted to tumor cells, suggesting reactivity against tumor-associated antigen. In addition, it appears that these immune responses are highly correlated with survival in primary malignant brain tumor patients.

Presence of immunosuppressive factors in brain-tumor cyst fluid

The present investigation was conducted to examine the effects upon normal lymphocyte activation of the addition of brain-tumor cyst fluid or cerebrospinal fluid (CSF) to an in vitro culture system. It was believed that factors present in these fluids may play a role in local and systemic immunosuppression in brain-tumor patients. The authors evaluated the effect of the cyst fluid, CSF, and serum from eight patients with brain tumors (one astrocytoma, five glioblastoma multiforme, one medulloblastoma, and one microglioma) on mitogen-stimulated lymphocyte function as measured by 3H-thymidine incorporation, cell size distribution, and cellular proliferation. Lymphocytes from normal volunteers were incubated for 90 hours in culture medium with 10% pooled human serum, mitogens (phytohemagglutinin, concanavalin A, and pokeweed mitogen), and a range of volumes of cyst fluid or CSF from the tumor patients. Significant suppression of mitogen-induced activation of the lymphocytes was demonstrated in the presence of cyst fluid from five out of six patients, but the mitogen response was only minimally affected by the addition of the CSF from these patients to the culture medium. The suppression of lymphocyte activation by cyst fluid was directly proportional in several cases to the concentration of the cyst fluid. The total protein, albumin, and immunoglobulin (Ig) concentrations in the cyst fluids were observed to roughly correspond to the serum levels and were much higher than in CSF. These studies suggest that brain-tumor cells locally produce lymphocyte-suppressive factors which may then be released into blood. Preliminary characterization of the suppressive factor(s) responsible for the inhibition of lymphocyte function indicates that they are non-dialyzable and do not appear to be an IgG.

Immunobiology of primary intracranial tumors. Part 7: Active immunization of patients with anaplastic human glioma cells: a pilot study

Twenty patients with malignant gliomas were selected for active immunization within 4 weeks following surgery. Each patient had a Karnofsky Functional Rating equal to or greater than 70, a peripheral blood lymphocyte count equal to or greater than 1000 cells/cu mm, skin test responses to one or more of four recall antigens, peripheral blood T-cells equal to or greater than half that of control, and was not receiving steroid therapy at the time of entry into the study. Each patient received subcutaneous inoculations with one of two human glioma tissue culture cell lines (D-54MG or U-251MG) monthly, with 500 micrograms of bacillus Calmette-Guérin cell wall (BCG-CW) being included with the first inoculation. Each patient also received levamisole, 2.5 mg/kg 3 days per week every other week. Radiotherapy and chemotherapy with BCNU were begun after the first month of immunization. Follow-up evaluations included computerized tomography brain scans, neurological examinations, Karnofsky Functional Ratings, and studies of general immune competence. No evidence of allergic encephalomyelitis was noted clinically, nor was any gross or microscopic evidence of such pathology obtained upon autopsy of three of these patients. Serial studies of general immune competence showed no alterations from those previously described with non-immunized patients. Patients who were inoculated with the U-251MG cell line have had a longer survival time compared to those inoculated with the D-54MG cell line (p less than 0.0590) or compared to 58 historical cases of glioma patients treated with levamisole, radiation therapy, and chemotherapy alone (p less than 0.02).

Immunobiology of primary intracranial tumors. Part 8: Serological responses to active immunization of patients with anaplastic gliomas

Serial serological studies were carried out on 19 of 20 patients with malignant gliomas who were actively immunized with one of two human glioma tissue culture cell lines (D-54MG or U-251MG). Most patients mounted a significant serum reaction to histocompatibility antigens (HLA's), as well as an antibody response to fetal bovine serum (FBS) which was added to the glioma-cell inoculum. These two sources of antibody accounted for greater than 90% of the antibody induced by these inoculations. Two patients continued to have significant amounts of binding antibody to the original immunizing cell line following exhaustive absorptions of FBS and these two had all remaining significant antibody removed by further absorption of the serum against the 2-T osteogenic sarcoma tissue culture cell line known to possess antigens cross-reactive with human gliomas. One single patient continued to show significant antibody binding to the original glioma cell line following absorption against FBS, human platelets, and the 2-T cell line, and therefore seems to have produced glioma-distinctive antibodies in response to immunization. The antibody preparation from this patient was also cytotoxic against the original glioma cell line, as well as another recently cultured human glioblastoma cell line. The significance of these serological studies is discussed as it relates to immunological responses patients with gliomas may make to active immunization.

Electron-microscopic visualization of binding of antibodies from sera of glioma patients on cultured glioma cells

Several human cell lines (normal and neoplastic glia, cerebral metastases from adenocarcinoma, fibroblasts) were incubated with sera from patients with well and poorly differentiated glioma and with sera from healthy donors and then stained with PAP complex to define and localize the antibody reaction with cell surface antigens by means of electron microscopy. The sera of glioma patients proved to contain antibodies which bound the tumor-associated antigenic determinants on the cell membranes of gliomas and of cerebral metastases from adenocarcinoma in tissue cultures. Further, absorption testing of the reactive sera on normal brain, well-differentiated astrocytoma and cultured glioblastoma cells, together with cross-reactivity experiments suggests that at least two antigens or groups of antigens are expressed on the glioma cell surface: one shared by well and poorly differentiated glioma cells and the other by poorly differentiated glioma cells and the cells of cerebral metastases from adenocarcinoma.

Immune responses in patients with brain tumors. Factors such as anti-convulsants that may contribute to impaired cell-mediated immunity

The responsiveness of lymphocytes obtained from patients with brain tumors to in vitro stimulation with mitogenic lectins was examined. The previously reported finding of decreased responsiveness was confirmed. To investigate the factors responsible for the hyporesponsiveness, mitogen (phytohemagglutinin and pokeweed mitogen) induced lymphocyte activation was evaluated using lymphocytes from 22 patients with brain tumors and 22 normal individuals. Lymphocytes from 13 patients with brain tumors, showed depressed responsiveness when cultured in autologous serum; in eight this was marked and in five moderate. Normal, rather than autologous, serum corrected lymphocyte function from only one of the markedly hyporesponsive patients, suggesting the existence of an intrinsic lymphocyte abnormality in some patients with brain tumors. However, serum from the hyporesponsive patients depressed mitogen-induced activation of lymphocytes from both tumor patients and normals. The presence of suppressive serum factors could not be related to the nature of the tumor (benign versus malignant, site, cell type or degree of anaplasia). The present studies showed that significant depression of in vitro lymphocyte responsiveness occurred with exposure to two anti-convulsant agents (phenytoin and phenobarbital) and dexamethasone. Thus, impaired lymphocyte function in patients with brain tumors may have a complex explanation with drug (corticosteroids, anticonvulsants) induced suppression playing a significant role.

Serial immune testing in surgically resected lung cancer patients

Immunoregulation of phytohemagglutinin (PHA) responsiveness by glass-adherent cells and prostaglandin-synthesizing cells was serially monitored in the peripheral blood mononuclear cells (PBMC) of surgically resected stage I and stage II lung cancer patients entered on a trial of adjuvant immunotherapy. The relationship between immunoregulatory cell function, immunocompetence, and disease relapse was determined. Immunoregulatory activity was measured in PHA-stimulated cultures in the presence and absence of 2 micrograms/ml indomethacin and in the presence and absence of glass-adherent cells. In each instance of disease relapse seen, an increase in immunoregulatory cell function to a level significantly different from normal was observed 3 months prior to or coincident with clinical confirmation of disease recurrence. This was usually associated with a decline in PHA responsiveness. In the patients who did not relapse, the levels of PHA responsiveness and immunoregulatory function persisted within normal limits throughout the course of study. Percentages and numbers of leukocytes and leukocyte subsets and delayed cutaneous hypersensitivity were also monitored in this study, but could not be consistently correlated with early changes in clinical disease status. These data suggest that the development of indomethacin-sensitive and glass-adherent suppressor cells may precede and predict for tumor recurrence in surgically resected lung cancer patients.

Particular features of cell-mediated immunity in patients with anaplastic gliomas. A comparison with kidney and bladder cancer patients

The authors studied 24 patients affected by anaplastic gliomas in regard to the killer (Antibody-Dependent Cellular Cytotoxicity) and natural killer (Spontaneous Lymphocyte-Mediated Cytotoxicity) immunological functions, by counting the Cr51 release in Change liver and K 562 cell cultures, respectively. These parameters were also evaluated in 24 healthy donors as control, in 24 patients affected by bladder cancer and in nine cases of kidney cancer. Our data show, pre-operatively, a statistically significant impairment of ADCC and SLMC activity in glioma patients as compared both with controls, bladder and kidney cancer patients. The particular impairment of K and NK functions in gliomas is discussed with regard to the specific features of Central Nervous System malignancies. An improvement of ADCC activity was also found in the post-operative samples. This finding confirms other reports about partial restoring of altered immunocompetence after surgery, suggesting a link between extention of tumor mass and impaired immunological reactions.

Immunobiology of primary intracranial tumors. VI. Suppressor cell function and lectin-binding lymphocyte subpopulations in patients with cerebral tumors

Peripheral blood lymphocytes obtained from patients with primary intracranial tumors were assessed for the presence of Concanavalin-A-activated, glass-adherent, and spontaneous, nonspecific suppressor cells. Additionally, the effect of indomethacin on phytohemagglutinin (PHA)-induced blastogenesis was determined. No significant differences in cellular suppressor mechanisms in these patients and normal controls were observed. However, shifts in lymphocyte populations were demonstrable when cells were separated according to quantification of PHA-L surface binding sites by flow microfluorometry. Therefore, although impaired cellular responsiveness in patients with cerebral neoplasms does not appear to be due to alterations in suppressor-cell function, changes in lymphocyte subpopulations occur that may be induced as an immunobiological consequence of primary central nervous system neoplasia and contribute to suppressed host immunocompetence.

Immunological monitoring of patients affected by anaplastic glioma concerning in effects of surgery, radio-, and chemotherapy. A preliminary report

The authors studied 24 patients affected by anaplastic gliomas, as regards immunology. In all of them the authors evaluated the lymphocyte subpopulation (B and T), firstly by simple lymphocyte count, secondly by studying the rosettes E-total and EAC, thirdly by stimulating the lymphocytes with mitogens phyto-haemoagglutinin-P (PHA), concanavalin A (Con A), and pokeweed mitogen (PWM), and lastly by counting the release of Cr51 in Chang liver cells culture in order to obtain antibody dependent cellular cytotoxicity (ADCC). The parameters were also evaluated after surgery and during conventional radio-chemotherapy with BCNU. Whereas the so-called B-pool seems to be unaffected, the preliminary results show that the T-pool (identified by the E-t rosettes and by responses to PHA, PWM, and ConA) is depressed to a statistically significant degree, if compared with a control group. This depression seems to be related to the tumoral mass, and it is not increased by radio-chemotherapy. In addition, ADCC also seems to be depressed in our glioma patients in comparison with a control group and witha group of bladder cancer patients.

Human hybridomas from malignant gliomas

Intratumoral lymphocytes from 12 patients undergoing craniotomy for malignant glioma were fused with a specially derived human myeloma line LICR-LON-HMy2. 71 stable hybridomas were obtained from 5 of the 12 patients. Such hybridomas had a DNA content equal to the sum of that present in lymphocytes and the parent myeloma. The hybridoma supernatants contained human monoclonal immunoglobulins. Glioma-binding activity was detected in 7 out of the 71 supernatants. These results suggest that malignant gliomas contain a population of B lymphocytes which may be involved in host defence against the tumour.

The utilization of native glioma antigens in the assessment of cellular and humoral immune responses in malignant glioma patients

Cellular and humoral components of the immune response have been studied preoperatively, concurrently, and serially in patients with malignant glial neoplasms. In order to assess titres of circulating antibodies to tumour cell constituents an indirect immunofluorescent technique was applied to single cell suspensions and snap frozen cell smears. In an allogeneic system, 49% of 47 test and 7% of 124 control sera gave a positive response to cytoplasmic components. The leucocyte adherence inhibition assay was applied to study 39 test and 64 control patients. Significant non-adherence of leukocytes was observed in 77% of test cases. Control parameters indicated specificity of the response. Simultaneous assessment in 28 test patients yielded a positive response for one or both assays in 89% of cases..

Immunological aspects of intrinsic glial tumors

✓ Fundamental concepts of general tumor immunology and modes of immunotherapy are presented. Significant work dealing with the relationship of the immune system to intrinsic glial neoplasms is reviewed in relation to therapeutic applications and future investigative efforts.

Long-term immunological investigation of malignant intracranial gliomas

In this study, 118 consecutive adult patients with supratentorial gliomas underwent preoperative immunological monitoring, with particular regard to B-lymphocyte and T-lymphocyte markers. Most patients were treated surgically and with radiotherapy. Three months later, they were readmitted for postoperative immunological investigation and follow-up control. A total of 76 cases could thus be completely investigated and were statistically eligible for evaluation. A pronounced failure of T-cell-mediated immunity was observed: "E-active" rosette-forming cells and mitogen-induced blastogenesis tests turned out to be markedly depressed, with a slight postoperative recovery. Spontaneous cell-mediated cytotoxicity was significantly (p less than 0.01) increased both in preoperative and postoperative findings. The main immunodiagnostic patterns (immunoglobulins assay, surface immunoglobulins, "mouse" rosettes) concerning the B-cell-dependent "pool" were found to be within normal limits.

Immunobiology of primary intracranial tumors. Part 5: Correlation of a lymphocyte index and clinical status

Long-term assessment of general host immunocompetence of patients with primary malignant brain tumors indicates that although isolated determinations of nonspecific responsiveness are not clinically useful, sequential analyses utilizing a linear combination of in vitro lymphocyte probes are capable of predicting tumor recurrence prior to clinical deterioration.

Immunobiology of primary intracranial tumors. Part 4: levamisole as an immune stimulant in patients and in the ASV glioma model

Levamisole was evaluated as an immune stimulant in a randomized controlled study of patients with anaplastic gliomas, who had undergone surgical resection and who were also treated with radiotherapy and BCNU chemotherapy. Of 102 patients placed into the study, 85 were determined to comprise the adequately treated group (ATG): a full course of radiotherapy and two cycles of BCNU chemotherapy. Within the ATG, those patients who received levamisole did not demonstrate significantly different serial delayed hypersensitivity reactions, peripheral blood lymphocyte and T-cell counts, or serum IgM levels, compared to those patients not receiving levamisole. There was no significant difference in survival times of the two groups. Studies utilizing the avian sarcoma virus-induced glioma in rats also showed no improvement in survival with levamisole stimulation as the only immune agent, but the combination of active immunization and adjuvant stimulation with bacillus Calmette-Guerin plus levamisole was found to be therapeutically effective in this model and will be used in future pilot studies of active immunization in patients.

Impaired thymus-derived lymphocyte function in patients with malignant brain tumour

Cell-mediated immunity was evaluated in 28 patients with malignant glioma, using in vivo and in vitro tests of lymphocyte function. The results were compared to those found in patients with carcinomatosis (11 subjects), benign brain tumours (9), other neurological disorders (20) and normal, healthy controls (21). Significant impairments of delayed hypersensitivity responses to common antigens was found in patients with malignant glioma and in those with generalised malignancy. A less significant depression of lymphocyte responses was also detected in patients with meningioma. The impairment in cell-mediated immunity was shown not be due to a serum blocking factor. Our data indicate that there is defective T cell function in patients with glioma, similar to that reported in cases with malignancies outside the central nervous system. This impaired immunity may have clinical significance.

Macrophages in experimental and human brain tumors. Part 2: studies of the macrophage content of human brain tumors

The authors have analyzed 47 tumors of the central nervous system (11 glioblastomas, nine meningiomas, three medulloblastomas, 12 assorted primary neural tumors, and 12 brain metastases) for their content of macrophages. Cell suspensions were prepared by enzymatic digestion and macrophages were quantitated by IgGEAC rosette formation. Adsorption of sensitized indicator cells (EA) to sections of tumor was used as a measure to determine the distribution of IgGFc receptor-positive cells within the tumors and to serve as a control for selective release of IgGFc receptor-positive cells by enzyme digestion. The 11 glioblastomas had a mean macrophage content of 45% (range: 8% to 78%), the nine meningiomas had a mean of 44% (range: 5% to 81%), the three medulloblastomas a mean of 6% (range 2% to 15%), and the metastatic tumors a mean of 24% (range: 4% to 70%). Adsorption of EA demonstrated that IgGFc receptor-positive cells were distributed throughout the tumor mass, although different types of patterns were observed. There was an excellent correlation between the percent of IgGEAC positive cells in suspensions and the extent of EA adsorption to the tumor sections. Compared to systemic neoplasms, most nervous system tumors have a high macrophage content. It is possible that the high macrophage content of brain tumors is related to their immunogenicity, and may be a partial explanation for tha rarity of brain-tumor metastases.

T lymphocytes in peripheral blood from patients with neurological diseases

Absolute and relative numbers of T lymphocytes in peripheral blood were determined in 19 different groups of patients with neurological diseases, using the E-rosette test. A significantly decreased total number of T lymphocytes was found in the following groups: acute Guillain-Barré syndrome (GBS), active multiple sclerosis (MS), and malignant cerebral tumor. A less pronounced and not significant reduction was observed in patients with amyotrophic lateral sclerosis (ALS). In all other groups of patients normal total numbers of T lymphocytes were found, thus indicating that the decrease in T lymphocyte counts in GBS, MS and malignant cerebral tumors is not due to nonspecific injury of nerve tissue.

Tumor specific fluorescent and complement-dependent cytotoxic antibodies in the serum of rats with chemically induced brain gliomas

Brain tumors were induced in Sprague-Dawley and Long-Evans rats by administration of N-methyl-N-nitrosourea in the drinking water. Of these tumors, a grade 2 mixed glioma, a grade 2 to 3 astrocytoma and a grade 1 to 2 oligodendroglioma were established in vitro, maintained in culture and designated 75SD-G-376, 75SD-G-420 and 77LE-G-180, respectively. Of these mass cultures, two were successfully cloned and are currently available as 75SD-G-376C and 75SD-G-420C cell lines. Clonal lines produce S-100 protein and grow as tumors when isografted in young rats. Using the cultured cells as target cells , specific antibodies were searched for in the sera of the rats with the primary tumors by means of an indirect fluorescent antibody staining method and a complement-dependent antibody-mediated microcytotoxicity assay. Fluorescent and cytotoxic antibodies were demonstrated in the sera of the mixed glioma- and astrocytoma-bearing animals. However, a variable proportion of cells of the 75SD-G-376 and 75SD-G-420 lines showed no reaction with the corresponding sera. Furthermore, cytotoxic antibodies had a lytic effect on the autologous glioma cells only in the presence of rabbit complement.

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.