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

Establishment and partial characterization of a continuous human malignant glioma cell line: NG97

1. A human glioma cell line, NG97, was established from tissue obtained from a patient diagnosed with a grade III astrocytoma. 2. The NG97 cell line has been subcultured for more than 100 passages in standard culture media without feeder layer or collagen coatings. 3. NG97 cells grow in vitro as two subpopulations with distinct morphological appearance: stellate cells with pleomorphic nuclei, and small round cells with few processes. The cells have a doubling time of about 72 h and a plating efficiency of 1%. The injection of NG97 cells into congenitally athymic mice induced the formation of solid tumor masses that could be retransplanted every 4 weeks. The cells obtained from tumor mass when cultivated in vitro had a morphology comparable to those of the initial culture. 4. This cell line may prove useful for cellular and molecular studies as well as in studies of gliomas treatment.

Neurosurgery at the University of Lausanne

The University of Lausanne was founded in 1537. The faculty of medicine was created in 1890, and the service of surgery was directed by César Roux. Roux, a well-known surgeon, was visited by Harvey Cushing during 1900-1901. In the early 1930s, Jean Rossier from Lausanne trained with Cushing, but Rossier passed away in 1942. Eric Zander created the division of neurosurgery in 1959; it became an independent service in 1967. Nicolas de Tribolet served as chairman from 1984 until 1994, when he was asked to take charge of the merger of the university services of Geneva and Lausanne. In October 1997, Jean-Guy Villemure joined him in the newly merged department, becoming chairman in Lausanne, while de Tribolet is chairman in Geneva and head of the department comprising both services.

Generation of cytotoxic immune responses against a rat glioma by in vivo priming and secondary in vitro stimulation with tumor cells

Cytotoxic T lymphocyte (CTL) responses to most antigens are generated by in vivo priming and secondary stimulation with antigen in vitro. The present studies were designed to determine whether that strategy could be used to stimulate development of CTL against brain tumors. Rats were primed with one of two tumors, RT2, an astrocytoma, or 9L, a gliosarcoma, and Corynebacterium parvum. Spleen cells from primed rats were stimulated with tumor cells and interleukin-2 in vitro to generate CTL. CTL generated against RT2 killed RT2 and 9L, but not allogeneic or histopathologically unrelated tumor cells, suggesting that the killing was brain tumor-specific and major histocompatibility complex gene product-restricted. Similar results were obtained with rats primed and secondarily stimulated with 9L. Specific cytotoxic cells only developed when syngeneic brain tumor cells were used for both priming and secondary stimulation. The cytotoxic cell populations were composed of OX-19+ T cells with a mixed CD4/CD8 phenotype. Controls consisting of spleen cells from unprimed or primed rats tested before culture exhibited low levels of cytotoxicity against brain tumor targets. Culturing unprimed or primed cells with interleukin-2 alone stimulated cell proliferation, but the cells that grew out exhibited only low levels of cytotoxicity for brain tumor cells. Cell populations exhibited consistent cytotoxicity against natural killer cell targets. None of the cell populations killed lymphokine-activated killer cell targets. The results demonstrated that brain tumor-specific CTL could be produced by priming in vivo followed by secondary stimulation with brain tumor cells in vitro. The results further demonstrated that RT2 and 9L share antigens that both induce and serve as target structures for specific cytotoxic cells.

Immunobiology of brain tumors

In summary, many actual interactions between tumors in the CNS and the immune system have been demonstrated. The normal brain does not possess a lymphatic system and is partially hidden from the systemic immune system by the BBB, furthermore brain cells do not express MHC antigens which are necessary for the initiation of an immune response. In pathological conditions however, immunocompetent cells may find their way through transformed endothelial cells. Microglia and astrocytes may function as antigen presenting cells. Glioma cells when stimulated by cytokines such as IFN gamma can be induced to express MHC class I and class II antigens, thus making them more susceptible to an immune attack. In addition glioma cells are capable of secreting several cytokines including IL 1, IL 3 and IL 6 also involved in the generation of an immune response. Indeed, a functional analysis of lymphocytes infiltrating gliomas has revealed the accumulation at the tumor site of cytotoxic T lymphocytes as well as NK cells. However host-immune responses against gliomas seem to be weak in comparison to other cancers. Glioma cells are known to secrete TGF beta 2 and PGE 2 which may in part be responsible for this lack of immune response, thus shielding themselves from immune attack. In order to be recognized by the immune system the tumor cells must express TAA in addition to MHC antigens, and such TAA have been identified by MAbs. These MAbs can be used for "targeted" therapy when coupled to toxic agents or radionuclides. Preclinical studies have shown that, after intravenous or intracarotid injection, there is specific accumulation of the MAb in the tumor but in insufficient amounts for therapeutic use. The relatively small amount of MAb binding to the tumor in vivo can be due to several factors: not all the cells in a single tumor express a given tumor-associated antigens, the MAb may have a low affinity for the antigen, the BBB may hinder the passage of the MAb. Attempts have been made to overcome these drawbacks by opening the BBB for example. In addition MAbs can readily be used for the treatment of carcinomatous meningitis. There has been little success in the development of immunotherapy with IFN beta 1 and even less with adoptive immunotherapy using LAK cells plus IL 2. TIL as well as LAK cells can be expanded in vitro with IL2 and it is feasible to reinject these cells into the tumor site.(ABSTRACT TRUNCATED AT 400 WORDS)

Immunology of central nervous system tumors

With progress in cellular immunology and the development of hybridoma technology, the idea of manipulating host-tumor immune interactions to improve the prognosis of brain tumors has aroused renewed interest. Although no brain tumor-specific antigens have been found, and in spite of the wide antigenic heterogeneity of brain tumor cells, some monoclonal antibodies possessing restricted specificity have been isolated and their potential clinical applications investigated. One of the most pronounced changes in the cellular immune responses of brain tumor patients is a profound depression of the T4-helper lymphocytes. Clinical and laboratory trials are under way to assess the ability of lymphokines, such as gamma-interferon or interleukin-2, to restore immunologic competence in these patients and potentiate a specific anti-tumor immunologic response. Recent work suggests that the endothelium-astrocyte complex may have a pivotal role in assisting the escape of brain tumors from the host's immunologic responses, since it is responsible for the intracerebral sequestration of antigens and local anti-tumor responses. In this review, the data on the antigenic properties of central nervous system tumors and the host's humoral and cellular immune responses to them are analyzed and potential immunologic therapies are discussed.

Immunology of gliomas

The treatment of cerebral gliomas continues to challenge neurosurgeons and research scientists. The lack of major success with chemotherapy and radiation therapy has given rise to further investigation into the biology of these tumors and host reactions to them. Much of this research has centered upon the evaluation of tumor cell antigenicity and on both the humoral and cellular immune responses to gliomas. Contrary to previous considerations, evidence suggests that astrocytes, glioma cells, and tumor endothelial cells may all have pivotal roles in the initiation and prolongation of both local and systemic immune responses to the tumor. In this review we will discuss the immunobiology of the glioma with specific reference to the interactions between the tumor and the host immune system. In addition, ideas for potential therapeutic manipulation of the host-glioma immune interactions will be reviewed, stressing potential pitfalls and risks.

Establishment and characterization of a malignant glioma cell line, GBM8401/TSGH,NDMC

A permanent human brain malignant glioma cell line, GBM8401/TSGH,NDMC, has been successfully established from a 31-year-old Chinese female with brain glioblastoma multiforme (GBM) in monolayer culture and has been subcultured for more than 100 passages during 24 months in vitro. The tumor cell doubling time in vitro was approximately 38 hr. The tumorigenicity in athymic nude mice was observed; the tumor volume doubling time was approximately 4 days. Glial fibrillary acidic protein (GFAP) and 10-nm-diameter intermediate filaments were identified by immunohistochemical peroxidase-antiperoxidase (PAP), immunofluorescence assay, and transmission electron microscopic methods. The scanning electron microscope revealed numerous surface microvilli and various-sized blebs. Karyotypic analysis showed this malignant glioma cell line to be of human origin, near-diploid with a modal chromosome number of 48,XX.

Immunological and biochemical strategies for the identification of brain tumor-associated antigens

Various strategies have been used to identify and characterize the antigens associated with human brain tumors. These approaches have included the raising of polyclonal and monoclonal antibodies against tumor antigens and, more recently, efforts toward the direct biochemical identification of such proteins. This review summarizes the progress made in this area, suggests reasons for the broad antigenic cross-reactivity and heterogeneity revealed by these studies, and proposes additional methods for deciphering the complex antigenic composition of human brain tumors.

Binding specificity of two monoclonal antiglioma antibodies: immunocytochemical studies using a new tissue embedding technique

The binding specificities of two monoclonal antiglioma antibodies (MAB) derived from hybrids GE2 and BF7 (Schnegg et al. 1981) were tested by indirect immunofluorescence (IF) and two immunoperoxidase (IP) methods. Studies were done on biopsies from 33 human CNS tumors, human derived glioma cells, and N-ethylnitrosourea-induced neurogenic rat cells in culture. The immunohistochemical reactions of MAB were investigated in snap-frozen tumor material, conventionally paraffin-embedded material, and tumors embedded in formol sucrose/gum sucrose/paraffin (FSGSP) by the new tissue processing technique of Bolton and Mesnard (1982), which preserves and enhances the antigenicity of tissues. The FSGSP processing offered a better immunocytochemical staining with MAB as compared to cryostat material, while the conventionally embedded paraffin sections of tumors did not stain at all. The binding of MAB revealed an affinity to both glial tumor cells and normal astrocytes. The techniques described are suitable for the identification of an astrocytic subpopulation within gliomas, and may improve the understaining of antigen expression in various stages of astrocytic dedifferentiation.

Immunobiology of brain tumors

The treatment of the cerebral glioma continues to challenge neurosurgeons and basic scientists. The lack of major success with chemotherapy and radiation therapy has spurred further investigation into the biology of this tumor and host reactions to it. Much of this research has centred upon evaluation of tumor cell antigenicity and the cellular immune responses to the glioma. Contrary to previous considerations evidence suggests that astrocytes, glioma cells and tumor endothelial cells may all have pivotal roles in the initiation and prolongation of both local and systemic immune responses to the tumor. In this review we will discuss the immunobiology of the glioma with specific reference to the interactions between the tumor and the host immune system. In addition, ideas for potential therapeutic manipulation of the host-glioma immune interactions will be reviewed stressing potential pitfalls and risks.

Immunohistochemical demonstration of IgG in meningioma

Twenty human meningiomas were examined for IgG and IgM by the direct immunofluorescence of immunoperoxidase methods, or both. IgG was conspicuously found in and around the blood vessels, whorls, and psammoma bodies. It was also clearly present on the cytoplasmic membranes of the tumour cells. On the other hand, IgM was seen only within the blood vessels. Significance of these findings is briefly discussed including possible humoral immune reactions in regard to whorl and psammoma body formation in meningioma.

Characterization of an established human malignant glioma cell line: LN-18

A human malignant glioma cell line, LN-18, has been established in monolayer culture and subcultured for more than 115 passages. LN-18 cells grow in vitro as bipolar or stellate cells with pleomorphic nuclei, have a doubling time of about 72 h and a plating efficiency of 3%. The glial nature of these cells has been assessed by ultrastructural examination. The synthesis of glial fibrillary acidic and S-100 proteins could not be demonstrated, although the initial biopsy tissue and the early cultures were positive for the former. The presence of Ia-like antigens on the surface of these cells was demonstrated using allo and xeno antisera. LN-18 cells were also shown to synthesize large quantities of fibronectin. The injection of LN-18 cells into nude mice induced the formation of solid tumor masses that could be retransplanted every 3 weeks and showed a morphology comparable to that of the initial biopsy. Karyotype analysis revealed the presence of three marker chromosomes, constantly present before and after hetero-transplantation.