The mononuclear cell infiltrate compared with survival in high-grade astrocytomas

Frozen samples from 92 malignant astrocytomas were stained with a panel of monoclonal antibodies directed against macrophages and lymphocytes. A follow-up to death was available on 68 cases which form the basis of this study. Large numbers of macrophages were found in all cases; T lymphocytes, mostly of the CD8 phenotype were also seen in moderate numbers in 70% of cases. CD4-positive cells were present in small numbers in 32% and B cells were seen in only 8% of cases. Analysis of the survival showed no demonstrable correlation between the numbers of macrophages or CD4 lymphocytes and survival. The survival curves for parenchymal CD8 infiltration diverged after 9 months suggesting increased survival for those patients without such an infiltration but the difference failed to reach statistical significance (P = 0.37). No correlation between lymphocytic cuffing and survival was seen after studying all paraffin-embedded material. We conclude that there is no significant statistical correlation between survival and the various types of mononuclear cell infiltrating malignant astrocytomas.

Flow cytometric DNA and nuclear antigen content in astrocytic neoplasms

Simultaneous flow cytometric DNA content and proliferation-associated nuclear antigen (p105) quantitation was performed on 23 astrocytic tumors and the results correlated with histologic subtype. Three of nine anaplastic astrocytomas and one of ten glioblastomas had an identifiable aneuploid peak, while all four well differentiated astrocytomas were diploid. Cell cycle analysis of malignant gliomas revealed a higher mean percentage of S and G2M cells compared to well differentiated astrocytomas but there was considerable overlap between histologic subtypes. Nuclear antigen analysis of diploid tumors showed a higher mean p105 fluorescence of S + G2M cells than G0G1 cells from the same case but there were no apparent differences in p105 expression by histologic subtype. Aneuploid tumors showed enhanced expression of p105 relative to diploid cells. The findings suggest that the aggressive course of high grade glial tumors may be related to an abnormal DNA stemline or an increase in proliferative activity.

Three consecutive primary malignancies in one patient during childhood

Patients with a primary immunodeficiency syndrome have an increased risk of developing a malignancy. Lymphoreticular malignancies are the most common malignancies in these patients. Patients with ataxia telangiectasia (AT) also appear to be at a high risk for the development of nonlymphoid tumors--in particular, carcinomas of the gastrointestinal tract and central nervous system tumors. We describe a child with an immunodeficiency and slight neurological manifestations. During childhood she developed three consecutive primary malignancies.

Immunohistochemical diagnosis of central nervous system tumours on smear preparations

The successful application of immunostaining on smear preparations from 34 tumours of the central nervous system using the peroxidase-antiperoxidase technique and the avidin-biotin-peroxidase complex technique with commercially available antibodies is described. When combined with conventional smear preparations, the technique contributed to a rapid and accurate diagnosis in 79% of cases and is advocated to be a useful adjunct in neurosurgical diagnosis.

Simultaneous demonstration of glia- and glioma-associated antigens in human astrocytomas

Glial fibrillary acidic protein (GFAP) and glioma-associated antigens (GAA) defined by monoclonal antibodies (MAbs) were demonstrated simultaneously in human astrocytoma tissue. GFAP was stained by PAP-method, GAA were visualized by avidin-biotin-technique using alkaline phosphatase. In primary and secondary tumors as well as in tissue culture heterogeneity of GFAP- and GAA-expression is obvious. GFAP is mostly restricted to cell processes and less marked in the perinuclear space. Depending on the individual antibody, MAbs-positive material is located either in the tumor cell plasma (MUC 8-22) or on cell surface membranes (MUC 2-63). There is remarkable expression of GAA in cell clusters which fail to express GFAP. At higher magnification, 3 types of cellular reactivity are detectable: (a) cells which react only with anti-GFAP, (b) cells which react only with anti-GAA and (c) cells which express both, GFAP and GAA, especially those of protoplasmic astrocyte type. These cells also occur in subcutaneous tumor grafts, and may thus represent not only a reactive event, but be part of tumor cell populations.

Mononuclear cell infiltrate and HLA-DR expression in low grade astrocytomas. An immunohistological study of 23 cases

Frozen samples from 23 low grade (grade I and II) astrocytomas were studied by means of a panel of monoclonal antibodies to macrophages, lymphocytes (and their subsets) and HLA-DR antigens. Macrophages were present in low to moderate numbers in 38%-86% of cases, the variance in figures depending on the antibody used. T lymphocytes, the majority of CD8 phenotype, were detected in low numbers in 78% of tumours. B lymphocytes were scanty in 22% (5/22) and totally absent in the remaining cases. HLA-DR antigen was expressed by tumour cells in 35% (6/17) of cases. These findings indicate that in some low grade astrocytomas there is a mononuclear cell infiltrate with macrophages and secondarily CD8+ lymphocytes playing the major role. The significance of these findings remains speculative at present.

Pituicytoma (pilocytic astrocytoma). Case report

Tumors of the posterior pituitary are rare and the previous nomenclature has been confusing. A 40-year-old man presented with visual failure and disconnection hyperprolactinemia (830 mU/liter) due to a large invasive pituitary tumor shown to be a pituicytoma (pilocytic astrocytoma). Its astrocytic nature was confirmed by positive immunostaining for glial fibrillary acidic protein and the finding of cytoplasmic filaments on electron microscopy. This case report contains the pathological description of a pituicytoma and illustrates that a non-adenomatous pituitary lesion may masquerade as a pituitary adenoma. Large pituitary lesions associated with serum prolactin concentrations of less than 3000 mU/liter require early surgical biopsy.

Monoclonal antibodies against human astrocytomas and their reactivity pattern

The establishment of hybridomas after fusion of X63-Ag8.653 mouse myeloma cells and splenocytes from BALB/c mice hyperimmunized against human astrocytomas is presented. The animals were primed with 5 X 10(6) chemically modified uncultured or cultured glioma cells. Six weeks after the last immunization step an intrasplenal booster injection was administrated and 3 days later the spleen cells were prepared for fusion experiments. According to the specificity analysis of the generated antibodies 7 hybridoma products (MUC 7-22, MUC 8-22, MUC 10-22, MUC 11-22, MUC 14-22, MUC 15-22 and MUC 2-63) react with gliomas, neuroblastomas and melanomas as well as with embryonic and fetal cells but do not recognize non-neurogenic tumors. The selected monoclonal antibodies (McAbs) of IgG1 and IgG2a isotypes are not extensively characterized but these antibodies have been demonstrated to be reactive with a panel of glioma cell lines with varying patterns of antigen distribution. Using the McAbs described above and a series of cryosections of glioma biopsies and paraffin sections of the same material as well as glioma cultures established from these, variable antigenic profiles among glioma cell populations could be demonstrated. From these results it is evident that there is not only a distinct degree of antigenic heterogeneity among and within brain tumors, but also that the pattern of antigenic expression can change continuously. Some of the glioma associated antigens recognized by the selected antibodies persist after fixation with methanol/acetone and Karnovsky's fixative and probably are oncoembryonic/oncofetal antigen(s). The data suggest that the use of McAbs recognizing tumor associated oncofetal antigens in immunohistochemistry facilitates objective typing of intracranial malignancies and precise analysis of fine needle brain/tumor biopsies in a sensitive and reproducible manner.

Astrocytomas: old and newly recognized variants, their spectrum of morphology and antigen expression

The relationship between the morphology of astrocytomas and their prognosis is complex, with the localization of the tumour, the predominant cell type and the degree of anaplasia all playing an important part in determining the patient's future. Since many astrocytomas have a diversity of patterns, small needle biopsies taken from just one or a few areas may fail to elucidate the principal features of a given tumour. In addition to the astrocytoma subtypes listed in the WHO's International Histological Classification of brain tumours, new entities have been observed in the last few years. These include lipidized forms, such as the relatively benign pleomorphic xanthoastrocytoma and the highly malignant lipidized glioblastoma. Neoplastic astrocytes are capable of forming basal laminae and of phagocytosis, and often contain alpha-1-antitrypsin, features that may lead to confusing them with histiocytes. They may be arranged in a whorled pattern imitating meningiomas, their myxoid intercellular stroma may assume the morphology of cartilage and closely packed tumour cells in "epithelioid" astrocytomas come close to imitate metastatic carcinoma. Some astrocytomas contain cells indistinguishable from those of granular cell tumours of other tissues. The presence of reactive lymphocytes in astrocytomas and reactive astrocytes in malignant lymphomas can be the source of confusion between those two kinds of neoplasms.

Localisation on human chromosome 19 of three genes for cell surface antigens defined by monoclonal antibodies

Expression of three distinct human cell surface antigens defined by monoclonal antibodies (mAbs) was examined in a series of rodent-human somatic cell hybrids retaining different subsets of human chromosomes. Cell surface reactivity with mAbs F8 and G253, detecting a 95 kilodalton (kD) glycoprotein (gp95); with mAbs F10 and A103, detecting a 50 kD glycoprotein (gp50); and with mAb S7 was found to cosegregate with human chromosome 19. However, differential antigen expression was observed with hybrids containing fragments of the 19 and hybrids constructed with different human cell types. Comparison of results from the serological typing with the presence of a number of chromosome 19 DNA markers in hybrid cells and cytogenetic analysis suggests that MSK20, the gene coding for the F10/A103 antigen gp50, is located in chromosome region 19pter----19p13.2. The genes coding for the F8/G253 antigen, gp95 (gene symbol MSK19) and the S7 antigen (MSK37) are located in region 19p13.2----19q13.2. Thus, the cell surface antigens described in this study may be used as selectable markers for specific portions of human chromosome 19.

Epithelial properties of pleomorphic xanthoastrocytomas determined in ultrastructural and immunohistochemical studies

Three cases of pleomorphic xanthoastrocytoma (PXA), one of which showed anaplastic evolution, are described. In all three the PXA tumors were well circumscribed and could be totally removed. Light-microscopically, pleomorphic tumor cells clustered gregariously and often formed alveolar structures. Electron microscopy revealed various epithelial properties, such as junctions and interdigitations between apposing tumor cells, and prominent basal laminae surrounding tumor nests. The circumscribed growth of PXA, as contrasted with an infiltrative growth of usual astrocytoma, can be attributed to the cellular cohesion based on the epithelial properties of the tumor cells. In the third patient, tumor recurred 6 months postoperatively. Although the recurrent tumor retained the alveolar structures, pleomorphism and various degenerative features of the tumor cells diminished with advance in the proliferative activities.

Partial purification and characterization of a murine glioma-associated antigen defined by syngeneic rat monoclonal antibodies

A glioma-associated antigen was previously identified on an avian sarcoma virus-induced F-344 rat astrocytoma cell line S69-c15 by four rat monoclonal antibodies (7G4, 9F1, 10E3 and 10E7) produced after syngeneic immunization. Earlier data suggested all four antibodies reacted with a polypeptide-associated epitope. We report here that the antigen activity was detected in the supernatant of tumor homogenates and could pass through a 1000 Da molecular weight cut-off dialysis membrane, as determined by antibody binding inhibition in a cell surface radioimmunoassay. When the dialysate was fractionated by Bio-Gel P-2 chromatography, antibody inhibiting activity eluted in the range of 300-600 Da. A highly purified material was further isolated by ion exchange high pressure liquid chromatography. Parallel purification product from an antigen-negative cell line failed to demonstrate antibody inhibiting activity. We conclude that greater than 400-fold purification enrichment of antigen can be achieved. We postulate that the partially purified antigenic determinant is a glioma-associated determinant of highly restricted expression and is presented in hapten-carrier form by the glioma cells.

Differential expression of cell surface antigens and glial fibrillary acidic protein in human astrocytoma subsets

We have characterized five distinct cell surface antigens of human astrocytomas and correlated their expression with the expression of glial fibrillary acidic protein (GFAP) and four previously defined cell surface markers of astrocytomas. One of the newly studied antigens, A4, which was originally detected on rat central nervous system (but not peripheral nervous system) neurons, is expressed on GFAP+ human astrocytoma cells, but not on GFAP- astrocytomas or a wide range of other neuroectodermal, epithelial, and hematopoietic cells. Antigens F19 (Mr 140,000/90,000 glycoprotein) and F24 (Mr 90,000 glycoprotein) also show restricted distribution and are expressed on subsets of neuroectodermal and mesenchymal cells. Antigens G253 (Mr 95,000 glycoprotein) and S5 (Mr 120,000 glycoprotein) are more widely distributed on the cultured cell panel. The distribution of these antigens was determined on a series of 22 astrocytoma cell lines and in normal brain tissue and the results were compared with the distribution of 5 additional glial cell markers: GFAP and cell surface antigens A010 (Mr 110,000 glycoprotein); AJ8 (Mr 100,000 glycoprotein); LK26 (Mr 35,000 glycoprotein); and Thy-1. Distinct patterns of expression on cultured astrocytomas and in neural tissues were identified for all antigenic systems studied, and cell surface expression of antigen A4 was found to correlate closely with GFAP phenotype of cultured astrocytomas. The antigens described in this study provide new markers to study normal glial differentiation and to correlate the phenotypes and biological behavior of distinct subsets of astrocytomas.

Glioma-associated antigens defined by monoclonal antibodies against an avian sarcoma virus-induced rat astrocytoma

S69-c15 is a highly immunogenic cell line derived from an avian sarcoma virus (ASV)-induced astrocytoma in F-344 rats. Monoclonal antibody (Mab) production was attempted by fusing F-344 rat splenocytes and mouse P3 X 63/Ag8.653 myeloma cells after a syngeneic immunization protocol. 336 fusion clones were screened by cell surface radioimmunoassay (CS-RIA) against the immunizing line S69-c15, rat kidney fibroblast line S203-c11 and Walker rat carcinoma line. Mabs 7G4, 9F1, 10E3 and 10E7 which reacted only with S69-c15 were chosen. Further analysis demonstrated that these Mabs reacted only with rat (13/23 astrocytomas, 2/4 gliomas, 1/11 neurinomas) or mouse (2/10 astrocytomas) neurogenic tumor cells induced by both viral and chemical agents. Reciprocal competition assays suggested that 7G4, 9F1 and 10E3 recognized the same epitope and that 10E7 reacted with a spatially close determinant. Antigen activity could not be found in adult rat tissues (brain, heart, lung, liver, kidney, spleen, thymus, intestine, muscle and peripheral nerve) and fetal brain (8, 12, 20 days gestation) by either absorption analysis or tissue staining. Preliminary characterization indicated that the epitope may be polypeptide-associated. Further antigen purification and tumor localization can be attempted with these Mabs.

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.

Anaplastic astrocytoma mimicking metastatic carcinoma

A case of anaplastic astrocytoma mimicking a metastatic carcinoma is presented. This rare type of astrocytoma with epithelial features is compared to cases reported in the literature, and the importance of staining brain tumor biopsies for glial fibrillary acidic protein is emphasized.

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.

Monoclonal antibody to macrophages (EMB/11) labels macrophages and microglial cells in human brain

Normal and diseased human central nervous system (CNS) tissues were studied immunohistochemically by a monoclonal antibody to human macrophages (EBM/11), antisera to glial fibrillary acidic protein (anti-GFAP), and alpha-1-antichymotrypsin (alpha 1-ACT). EBM/11 reacted with brain macrophages located mainly around blood vessels in normal brain; it also reacted with resting microglia in normal brain and with numerous reactive microglia and macrophages in brain tumours and inflammatory lesions. Microglia did not react with anti-GFAP or alpha 1-ACT. An EBM/11 positive phenotype, therefore, is shared by microglia and macrophages and suggests that microglial cells form a specialised part of the mononuclear phagocyte system.

Mitogen stimulation of blood lymphocytes from patients with primary intracranial tumors. Correlation to histological tumor type

Blood lymphocytes from 125 patients with primary intracranial tumors were examined for proliferative responses to PHA and PPD in parallel with lymphocytes from sex- and age-matched controls. The tests were performed prior to surgery, radiotherapy, or chemotherapy and a histological diagnosis was obtained in all cases. Depending on tumor type, patients were divided into the following four histological groups: astrocytomas, oligodendrogliomas, malignant gliomas (anaplastic astrocytomas and glioblastomas), and miscellaneous tumors (mainly meningiomas). PHA-responses were approximately 10% lower in patients with malignant gliomas not receiving corticosteroids in comparison to corresponding controls. No significant differences were observed in the other groups of patients if not being treated with steroids. PPD-responses were largely similar in all groups of non-steroid treated patients. In the corticosteroid treated groups PHA-responses were significantly reduced in patients with oligodendrogliomas and malignant gliomas, but this was not true of those with astrocytomas or those in the group with miscellaneous tumors. The mean steroid doses given at the time of testing were similar in all four patient groups. The treatment period was longest in malignant gliomas but reasonably similar in the other three groups. It is speculated that PHA-responses of lymphocytes from patients with oligodendrogliomas may exhibit an increased steroid sensitivity.

Capacity of sera from patients with primary intracranial tumors to support mitogen stimulation of blood lymphocytes. Correlation to histological tumor type

Sera from 125 untreated patients with various histological types of primary intracranial tumors were examined for the capacity to support proliferative responses of lymphocytes to PHA and PPD in vitro. It was observed that sera obtained from groups of non-corticosteroid treated patients with astrocytomas, malignant gliomas (anaplastic astrocytomas and glioblastomas), and miscellaneous tumors (mainly meningiomas) did not differ significantly from sera obtained from a group of healthy subjects. However, sera from a group of patients with oligodendrogliomas exhibited a significantly reduced capacity to support PHA- and PPD-responses of both autologous and allogeneic lymphocytes. Corticosteroid treated patients seemed to have reduced serum activities regardless of histological tumor type. It is not known whether sera from patients with oligodendrogliomas contain increased amounts of factors which inhibit mitogen responses of lymphocytes, or whether they contain reduced amounts of factors which support stimulations in vitro.

Interferon-beta in patients with low-grade astrocytomas--a phase I study

In 3 patients with low-grade astrocytomas clinical pharmacology of interferon-beta (10(7) U/mg protein) was investigated. Interferon-beta with escalating dosage (2.3, 6.9, 23, 69 X 10(6) U/patient) was given to each patient in 4 infusions at weekly time intervals. In these patients dose-dependent plasma-levels of interferon-beta of up to 5800 IU/ml were achieved. Plasma concentrations showed a biphasic decline (T1 1/2:0.095-0.49 hrs and T2 1/2: 5-14.5 hrs). Side effects were: mild fatigue, myalgia, tachycardia, hypertension, and fever; the latter was well controlled by pretreatment application of paracetamol. Hematological changes included lymphopenia (2-6 hrs after infusion) and granulocytosis (3-6 hrs after infusion). Natural Killer cell activity was also monitored: 6 hours after infusion a drop of activity - not clearly dose dependent - was observed to a minimum of 1% pretreatment activity; 24 hrs after infusion activity increased up to a maximum of 400%. In this phase I study high biological activity of interferon-beta could be detected in plasma of astrocytoma patients - clinical tolerance was good and only mild toxicity was observed.

[Phase II study of recombinant leukocyte A interferon (Ro 22-8181) in malignant brain tumors]

A phase II study of recombinant interferon alpha A (Ro 22-8181) for malignant brain tumors was jointly conducted at 21 medical institutes in order to evaluate its clinical effects and side effects. Treatment started with exclusive administration of Ro 22-8181 at 3 X 10(6) U/day, which was increased appropriately after confirmation of its safety, until an optimum dose permitting long-term administration was achieved for each patient. The dose thus determined was intramuscularly administered daily. Among those treated, 39 patients were available for evaluation. The percentage of partial responses according to the "Criteria for the Evaluation of Clinical Effects of Cancer Chemotherapy on Solid Tumor" by Koyama and Saito was 10.3% (4/39). Histologically, this was 7.1% (1/14) for glioblastoma and 14.3% (3/21) for malignant astrocytoma. Side effects included fever (57.3%), anorexia (34.1%), general fatigue (31.7%), leukopenia (52.4%) and thrombocytopenia (30.5%), and increased GOT and GPT (40.2%). In view of the success even in previously treated patients, and the side effects observed, Ro 22-8181 may be accepted as a useful addition to the treatment of malignant brain tumors.

[Immunological monitoring of brain tumors--prognosis based on T-lymphocyte subpopulations and skin testing for delayed hypersensitivity]

We have already reported on the usefulness of the phytohemagglutinin (PHA) skin test and the purified protein derivative (PPD) skin test in predicting the prognosis of brain tumor patients. This paper outlines our investigation of T-lymphocyte subpopulations and analysis of their utilization. The cellular immunological states of brain tumor patients were examined by means of PHA and PPD skin tests, the blastogenic response of T-lymphocytes to PHA and the T-lymphocyte subpopulations. Our subjects consisted of 10 cases of glioma (8 astrocytoma, 2 ependymoma), 2 cases of meningioma, one of teratoma, one of hemangioblastoma and 4 of metastatic brain tumor. These were divided into 2 groups: the benign group, which included low grade astrocytoma, meningioma, teratoma and hamangioblstoma, and the malignant group which included malignant glioma and metastatic brain tumor. The T-lymphocytes were counted by monoclonal antibody assay using Ortho-mune T-lymphocyte monoclonal antibody (OK series). We then counted an analysis to determine metastatic brain tumor. The T-lymphocytes were counted by monoclonal antibody assay using Ortho-mune T-lymphocyte monoclonal antibody (OK series). We then conducted an analysis to determine whether or not the T-lymphocyte subpopulations could be of value in the prediction of the possible prognosis of patients. The results were as described below. Ratio of helper/inducer T-lymphocytes (OKT 4 positive cells: Th) to suppressor/cytotoxic T-lymphocytes (OKT 8 positive cells: Ts) were 1.78 +/- 0.18 in the benign group and 1.00 +/- 0.49 in the malignant group.(ABSTRACT TRUNCATED AT 250 WORDS)

Microcytotoxicity blocking assay for the detection and isolation of soluble astrocytoma association antigen

A blocking microcytotoxicity assay was used to detect soluble astrocytoma-associated antigen. The richest source of soluble antigen was found in spent culture media from an established glioblastoma (GF) tissue culture line. Also assayed were fractions of sonicated membrane antigen from another (GM) glioblastoma and pellets of GF and GM cultured glioblastoma tissue. Blocking by media conditioned by cultured normal human brain, breast cancer, neuroblastoma, meningioma, or 2-year-old astrocytoma cell lines was 41-82% lower. A monomer was isolated that blocked cytotoxicity and migrated in molecular exclusion chromatography with alpha-macroglobulins rather than the beta-2-microglobulins usually associated with histocompatibility antigens.

Surface antigens of melanoma and melanocytes. Specificity of induction of Ia antigens by human gamma-interferon

IFN-gamma is known to induce expression of Ia antigens on a variety of cell types. In the present study, this activity of IFN-gamma has been analyzed with a panel of 36 melanoma cell lines, normal melanocytes, and 97 cell lines representing a range of other differentiation lineages. 55% of the melanoma cell lines express Ia antigens in a constitutive manner without IFN-gamma induction. Of the 16 Ia-melanoma lines, 13 could be induced to express Ia antigens by IFN-gamma, whereas three were noninducible. Melanocytes, which do not normally express Ia antigens, are converted to Ia expression by IFN-gamma. Ia antigens expressed constitutively or after IFN-gamma induction were identified with antibodies detecting monomorphic and allomorphic products of DR and DC loci. IFN-gamma appeared to be unique in its ability to induce Ia expression on melanoma and melanocytes; 14 other agents (including IFN-alpha and IFN-beta) known to influence growth or differentiation did not have Ia-inducing activity. Equally striking is the restriction of antigenic changes following IFN-gamma induction to HLA-associated products; of the 38 systems of cell surface antigens examined, only HLA-A,B,C, beta 2m, and Ia antigens were affected. A variety of other Ia- cell types were shown to be Ia-inducible by IFN-gamma; these included established lines of breast, colon, pancreas, bladder, kidney, ovary, and brain cancers, and cultures of normal fibroblasts, kidney epithelia, and epidermal keratinocytes. In contrast, three tumor types, teratocarcinoma, choriocarcinoma, and neuroblastoma, were not inducible for Ia expression, even though IFN-gamma could induce expression of HLA-A,B,C products. The broad representation of Ia antigens on most somatic cell types expressed either constitutively or after IFN-gamma can be viewed in an immunological context (antigen presentation/immune regulatory signals) or could indicate that Ia products have functions other than those related to immune reactions.

Regulation of natural killer cell function by glass-adherent cells in patients with primary intracranial malignancies

Natural killer (NK) cell function against the NK cell-sensitive myeloid leukemia cell line, K562, was measured in the peripheral blood mononuclear cells (PBMCs) of 17 patients with primary brain tumors (4 diagnosed as having low grade tumors and 13 diagnosed as having high grade (malignant) tumors). The ability of monocytes to control the levels of NK cell function in PBMCs from these patients was assessed in glass-adherent cell depletion studies. Most patient assessments were performed before surgical biopsy and diagnosis; most but not all patients were receiving dexamethasone at the time of immunity assessment. The results demonstrate that patients with primary malignant brain tumors have depressed levels of NK cell function in their PBMCs due to the suppressive actions of glass-adherent monocytes, whereas patients with low grade tumors have normal levels of function shown by this assay.

Herpesvirus type 1 serum antibodies and brain tumors in humans

Sixty-five patients underwent craniotomy for brain tumors; of these 35 had glioblastoma multiforme (GM). The GM cases, as a group, showed significantly higher serum titers for herpesvirus type 1 (HSV-1) neutralizing antibodies (NT) than the non-glioblastoma cases. Both the GM group and the pituitary adenoma group had high levels of HSV-1 serum antibodies with the enzyme-linked immunosorbent assay (ELISA). These data, combined with other evidence, lead us to speculate that HSV-1 infections may be associated with certain brain tumors in humans. However, coincidental causes for these elevated HSV-1 titers must be ruled out.

Cytokinetic basis for the impaired activation of lymphocytes from patients with primary intracranial tumors

Patients with malignant brain tumors have a variety of immunologic abnormalities, including the impaired responsiveness of peripheral blood lymphocytes (PBL) to mitogens and alloantigens. We further investigated this impairment of lymphocyte reactivity by employing the techniques of limiting dilution analysis and cytokinetic analysis. PBL preparations from patients have approximately six times fewer phytohemagglutinin (PHA)-responsive cells than PBL from normal subjects. Similar results were obtained with purified T cell preparations. Cytokinetic analysis of PHA-induced [3H]thymidine incorporation employing colchicine blocking of mitosis demonstrated that the number of first generation cells entering the S-phase of mitosis for each 24-hr period was less for PBL from patients than for PBL from normal individuals. First generation responding cells from patients and normal subjects entered DNA synthesis at the same time (48 to 72 hr). Cytokinetic analysis over a period of 168 hr demonstrated that whereas PBL from normal individuals demonstrated second generation responding cells, PBL from the majority of patients did not, thus indicating a defect in their ability to undergo clonal expansion. Measurement of interleukin 2 (IL 2) activity in culture fluids from PHA-activated PBL from normal subjects and patients revealed significantly lower IL 2 levels in culture fluids from PBL from patients. The addition of various concentrations of lectin-free IL 2 to PBL from patients stimulated with PHA did not restore responsiveness to normal values. There was no difference between the levels of interleukin 1 (IL 1) produced by lipopolysaccharide-activated monocytes from normal subjects and patients. Overall, these results suggest that an intrinsic defect exists in T cells obtained from brain tumor patients that renders them unable to enter into normal mitogen-induced blastogenesis.

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.

A pigmentation-associated, differentiation antigen of human melanoma defined by a precipitating antibody in human serum

Antibodies in the serum of melanoma patient AU precipitate an antigen from 125I-labelled extracts of cultured autologous melanoma cells. The antigen, which is probably not a cell surface component, is present in other pigmented melanomas but not in non-pigmented melanomas or other tumor cell types, and the amount of antigen is correlated with the degree of pigmentation. These conclusions are based on absorption experiments with 11 pigmented melanomas, 8 non-pigmented melanomas, 3 astrocytomas, 12 carcinomas of various histological types, I leukemia, 2 EB-virus-transformed B lymphocyte lines, and human erythrocytes. The antigen was also detected in cultured human melanocytes. It has a molecular weight of 70,000, an isoelectric point of pH 5.3, and it binds to concanavalin A-Sepharose. Ninety-six sera from other melanoma patients were examined and none of them precipitated this antigen. As described previously, the serum from patient AU also has antibodies to a unique (Class I) tumor antigen found only on AU melanoma cells. The pigmentation-associated, differentiation antigen and the unique antigen are clearly different in their distribution, but some relationship between these unusual antibody responses is possible.

Amplification of the murine leukemia virus Mr 70,000 glycoprotein gene product by human xenografts in athymic mice

Passage of human tumors in athymic mice is accompanied by an increase in serum levels of the Mr 70,000 murine leukemia virus envelope protein, gp70. Elevated levels of gp70 can be detected in tissues of the hematopoietic systems of mice bearing human xenografts, but there is no evidence of synthesis of gp70 in these tissues. By far, the highest concentration of gp70 is in the human xenografts themselves. When assayed for gp70, 8 human xenografts and 12 cell lines established from human xenografts were all positive. In the plasma membrane of the human astrocytoma xenograft, T24, the gp70 was found to be approximately 10% of the total membrane protein. In contrast, the concentration of the Mr 30,000 viral core protein, p30, was 17-fold less. Only trace amounts of complete infectious virus could be detected. A human prostate carcinoma line that had not been grown in the athymic mice was found to have no gp70, but was shown to be able to synthesize gp70 after a single passage in the athymic mice.

Monoclonal antibodies reactive with epitopes restricted to glial fibrillary acidic proteins of several species

The highly reproducible histochemical localization of glial fibrillary acidic protein (GFAP)+ qualifies it as an important marker of astrocytes in both research and clinical applications. The primary objective of this study was to produce monoclonal antibodies having the advantage of invariant specificity, affinity, and titer to GFAP-specific epitopes of wide species distribution. We report here the characterization of four monoclonal antibodies that recognize the same or spatially close epitopes specific to GFAP. The epitope(s) detected has been phylogenetically conserved; human, bovine, ovine, canine, porcine, rabbit, guinea pig, rat, murine, and chicken brain homogenates all specifically absorb monoclonal antibody activity. Of importance to the routine application of these new anti-GFAP monoclonal antibodies is the demonstration here of the stability of the antigen-antibody interaction in normal, reactive, and neoplastic astrocytes of both rat and human origin following various methods of fixation.

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.

Depressed T lymphocyte function in brain tumor patients: monocytes as suppressor cells

Depressed cellular immune function has been demonstrated in patients with a variety of lymphoreticular and nonlymphoreticular neoplasms, including patients harboring brain tumors. In the present study, peripheral T lymphocytes from more than fifty percent of patients with central nervous system tumors, both primary and metastatic, exhibited depressed incorporation of 3H-thymidine in response to phytohemagglutinin (PHA) when tests were performed in the absence of autologous serum. Increased numbers of monocytes were present within mononuclear cell suspensions from brain tumor patients, and most of the cell populations containing elevated monocytes also exhibited depressed responses to PHA. A role for monocytes as suppressor cells was suggested by the finding that partial reconstitution of T cell function could frequently be effected by adherent cell depletion. However, total reversal of the defect was rare and there was no relationship between monocytes and T cell dysfunction in some patients. The results suggest that while monocytes may be involved in the immune depression seen in some patients with a brain tumor, the complete explanation is as yet unknown.

Detection of circulating immune complexes associated with brain tumors. Correlation with histological differentiation and length of clinical history

Sera from 30 patients with primary brain tumors were studied for the presence of circulating immune complexes by means of two different assays: the solid-phase conglutinin-binding test and the 125I-labeled Clq-binding test. Control sera were obtained from 16 healthy donors, and intra-assay control sera from 5 patients with intracerebral metastases from adenocarcinoma. The data yielded by both methods show the highest incidence of positivity in the metastases (80%), followed by poorly differentiated tumors (50%) and well-differentiated tumors (10%). The results obtained suggest that high levels of circulating immune complexes depend on the degree of histological differentiation of the tumor and on the length of the clinical history, since they were found not only in anaplastic tumors but also in tumors classified as benign but with a long clinical history.

In vitro studies on the cell-mediated immune response to human brain tumors. I. Requirement for third-party stimulator lymphocytes in the induction of cell-mediated cytotoxic responses to allogeneic cultured gliomas

For study of those properties of human gliomas that might contribute to their ability to escape cell-mediated immune attack, cultured human glioma cells were examined for their ability to elicit allogeneic cytolytic lymphocyte responses in vitro. Of 9 glioma lines, 5 were unable to elicit allogeneic cytolytic lymphocyte responses in mixed lymphocyte--tumor cultures although the concentration of stimulating glioma cells was varied over a fortyfold range. However, lymphocytes specifically cytolytic for 4 of the nonstimulatory lines could be generated if irradiated, third-party stimulator lymphocytes were added to cultures containing responder lymphocytes and glioma cells. The specific cytolytic lymphocytes produced in these cultures were inactivated by treatment with the monoclonal anti-T-cell antibody OKT3 plus complement and were thus identified as T-cells. However, nonspecific, non-T-lytic effectors were also generated. The results of these experiments demonstrated that certain cultured gliomas possessed a defect in immunogenicity that can be overcome by "help" from an allogeneic mixed lymphocyte reaction. The possible nature of this help and the potential implications of these results for the immunotherapy of human gliomas are discussed.

[Detection and clinical significance of immune complexes in the sera of brain tumor patients]

Levels of circulating immune complexes (IC) in the sera of 87 patients with brain tumor were measured by Raji cell radioimmunoassay and Clq binding assay. The control samples were obtained from 40 healthy blood donors and 40 cerebrovascular patients. The patients with glial tumor had a high incidence of elevated level of IC than patients with non-glial benign tumor, elevated level of IC than patients with non-glial benign tumor, cerebrovascular disease and normal controls. There was a significant association between these Clq binding activity and Raji cell binding activity in the sera of glial tumor patients. As regards the sensitivity, high IC levels are more frequent among Raji cell assay than Clq binding assay. The level of IC was found to be higher in patients with recurrent glial tumor than in those with primary tumors. However, the level of IC in the sera from patients with glial tumor did not always decrease during remission after successful treatment. Our data indicate that the measurement of IC may prove useful in the management of patients with brain tumor, in particular, to detect recurrence or progression of tumor growth.

Cell surface antigens of human astrocytoma defined by mouse monoclonal antibodies: identification of astrocytoma subsets

The surface antigens of cultured human malignant astrocytomas were analyzed by using mouse monoclonal antibodies. BALB/c mice were immunized repeatedly with either SK-MG-1 [a glial fibrillary acidic protein (GFA)-negative astrocytoma line] or SK-AO2 (a GFA-positive astrocytoma line). After fusion with NS/1 mouse myeloma cells, 12 antibody-producing clones were selected for detailed study. Serological analysis permitted the identification of nine distinct antigenic systems. Four monoclonal antibodies (Ab AJ225, Ab AO10, Ab AJ8, and Ab AO122) identified cell surface antigens preferentially expressed on tumors of neuroectodermal origin, and these antibodies subdivided the astrocytoma panel into distinguishable subsets. The determinant detected by Ab AO10 and Ab AJ8 showed mutually exclusive expression on the astrocytoma lines. The AO10 and AJ8 phenotypes appeared to reflect the differentiation state of the cultured cells; 4/7 AO10-positive astrocytomas expressed GFA, an intracellular astrocyte differentiation antigen, whereas all AJ8-positive astrocytoma (9/9) were GFA-negative. Five antibodies (Ab AJ10, Ab AJ9, Ab AJ17, Ab AJ425, and Ab AJ2) recognized determinants widely distributed on normal and malignant cells. Four antibodies defined in this study precipitated proteins from reduced preparations of radioisotope-labeled SK-MG-1 and SK-AO2 cells: Ab AJ225 (Mr 145,000); Ab AO122 (Mr265,000); Ab AJ10 (Mrs 195,000 and 165,000); and Ab AJ2 (Mrs 170,000, 140,000, 140,000, and 28,000).

Mechanisms by which human gliomas may escape cellular immune attack

Whereas substantial evidence indicates that the majority of glioma patients make humoral immune responses to their own tumours, the evidence that glioma patients make significant cellular immune responses is more tenuous and controversial. In order to study those properties of human gliomas that might contribute to their ability to escape cell-mediated immune attack, we have examined the ability of cultured human glioma cells to elicit allogeneic cytolytic lymphocyte responses in vitro. Five of ten glioma lines were unable to elicit allogeneic cytolytic lymphocyte responses in mixed lymphocyte-tumour cultures, despite the presence of serologically detectable alloantigens on the surface of the glioma cells. Analysis of the reasons why certain glioma lines failed to stimulate cytolytic lymphocyte responses revealed three distinct mechanisms by which human gliomas may escape cellular immune attack: 1. a defect in immunogenicity which can be overcome by "help" from an allogeneic mixed lymphocyte reaction, 2. the secretion of a protective mucopolysaccharide coat, and 3. the production of macromolecular immunosuppressive substance(s). The implications of these findings for the immunotherapy of human gliomas are discussed.

Human intracranial tumors: effect of autologous serum addition on leucocyte migration inhibition

42 human intracranial tumours were investigated by the leucocyte migration inhibition technique at various antigen concentration with and without autologous serum addition. A correlation was found between migration rate and antigen concentration. Autologous serum addition resulted in a non-specific stimulation of migration, however, stimulation by immune complexes was also present. Migration stimulation, as an in-vitro-equivalent of immunologic tumor enhancement, is discussed.

Detection of cell-surface antigens of bovine ocular squamous cell carcinoma

A serologic study was conducted to identify surface antigens on cultured cells of bovine ocular squamous cell carcinoma. Sera from cattle with various stages of disease were tested for reactivity with surface antigens of cultured autologous and allogeneic cells. Radioiodine-labeled protein A assays were conducted to determine the presence of antibodies for tumor cells. It was found that all sera tested had antibodies at a high level to autologous cells, whereas the reactivity of allogeneic serum to cultured cells varied. Furthermore surface reactivity was not observed in these sera in tests for reactivity with normal epithelial cells. Reactive sera were analyzed by absorption tests with autologous and allogeneic cells. Absorbed sera showed no reactivity to surface antigens on autologous or allogeneic cells. Also, results of quantitative absorption studies indicated that absorption with precarcinoma cells eliminated the reactivity of sera from carcinoma- (cancer-) bearing animals toward cultured tumor cells. This indicates that there might be a shared antigen among the cells from precarcinoma and carcinoma lesions.

Natural antibodies to cell-surface antigens of human astrocytoma

Sera of 200 non-transfused healthy male blood donors were tested for antibody reactivity to cell-surface antigens of cultured astrocytoma cells. Positive reactions were observed only rarely by protein-A assay (PA), in about half the cases by immune adherence assay (IA) and in nearly all cases by anti-C3 mixed hemadsorption assay (C3-MHA). In general, titers were low and only seven sera showed reactivity at 1:1,000. Serum 537 showed the strongest reaction. The anti-astrocytoma reactivity in this serum was due to an IgG antibody. Extensive absorption analysis with a panel of cell lines and fresh cells of both benign and malignant origin, as well al fetal cells, revealed that this serum detected an antigen that was present on most neural-crest-derived tumors (astrocytomas, melanomas and neuroblastomas), on very few other malignant tumors and on fetal brain. The antigen detected by serum 537 shows close relationship to the astrocytoma antigen AJ which had been defined by the serum of a patient with astrocytoma. Both antigens appear to be differentiation antigens present predominantly on non-epithelial neoplasms. The antigen detected by serum 537 is heat-stable and pronase-resistant. The sera of two other healthy donors apparently had a similar specificity, whereas the four other high-titered sera and all other sera detected class-III antigens which were non-specific and not tumor-restricted.

Human Thy-1: expression on the cell surface of neuronal and glial cells

The Thy-1 antigen is a cell surface glycoprotein found in neural tissue of all mammalian species so far studied. The distribution and amount of this antigen has been measured on 4 human neuronal and 2 neuroglial cell lines and on fresh tumour cells of neuronal origin. In 3 out of 4 neuronal lines (LAN-1, TR14, CHP 212) more than 90% of cells were Thy-1+, however, LAN-1 cells showed only weak immunofluorescence and bore on average 2.4 times fewer molecules of Thy-1 per cell than those of either TR14 or CHP 212. The mean number of Thy-1 molecules per TR14 cell was shown to be approximately 2.25 x 10(5). In contrast, only 66% of cells in the fourth neuronal line (CHP 100) were Thy-1+, although these showed strong immunofluorescence. Both glial cell lines, UCH-203 and H314/123, showed strong Thy-1 immunofluorescence on more than 90% of cells. Similarly, with fresh neuronal tumour cells, although approximately 80% of tumours were Thy-1+ (essentially 100% of cells in these being positive) there were considerable differences in the intensity of labelling by immunofluorescence between different tumours. Such heterogeneity in cell lines and malignancy may reflect normal in vivo variation. Different phenotypes might therefore represent separate neural cell lineages, or simply differences in maturational status within a lineage. The very low frequency of Thy-1+ cells in normal bone marrow (less than 0.1% of nucleated cells) indicates that anti-Thy-1 antibodies may be valuable in both the diagnosis and subsequent treatment of neuroblastoma.

Histocompatibility antigens on astrocytoma cells

Biopsies tumour cells from astrocytoma-bearing patients were grown in primary culture for 3-5 days. Both low and high grade tumours were represented in the study. The cultured cells could be shown to express the HLA-A and -B antigens using a multispecific allo-antiserum and a rabbit anti-beta-2 microglobulin antibody. The tumour cells were negative for the HLA-DR determinants when tested with either rabbit anti-Ia-like antisera or specific anti-HLA-DR allo-antisera. They also failed to stimulate allogeneic lymphocytes in primary mixed lymphocyte-tumour cell cultures but stimulated lymphocytes primed to tumour cells in vitro. The tumour cells were also capable of stimulating autologous lymphocytes from the tumour-bearing patient in most of the combinations tested.