The induction of intercellular adhesion molecule 1 (ICAM-1) expression on human fetal astrocytes by interferon-gamma, tumor necrosis factor alpha, lymphotoxin, and interleukin-1: relevance to intracerebral antigen presentation.

Antigen presentation reactions are dependent upon the expression of the class II major histocompatibility antigens (MHC), the T-cell receptor, and the presented antigen. Recent studies demonstrate that such processes also require the presence of adhesion molecules such as lymphocyte functional antigen 1 (LFA-1) and its cell surface ligand, intercellular adhesion molecule 1 (ICAM-1). It has been suggested that the brain astrocyte can function as a facultative antigen presenting cell (APC). This hypothesis is based upon the ability to induce the expression of the class II MHC antigens on astrocytes, and on their ability to present myelin basic protein to encephalitogenic T-cells in vitro. The best in vivo data showing that astrocytes serve as intracerebral APCs is the finding that astrocytes in multiple sclerosis plaques are DR+ (class II MHC in human). However, it still remains to be resolved whether the in vivo expression of the MHC antigens in disease states is instrumental to antigen presentation mechanisms or whether these cell surface glycoproteins are expressed secondary to brain immune responses. If astrocytes function as immunocompetent APCs within the brain, it would seem that they would also be able to express molecules important for intercellular adhesion. Here, we present the first data that indicates that human astrocytes are capable of expressing ICAM-1 in response to cytokines that either induce or upregulate the expression of DR. In essence, cytokines derived from different cell types seem to exert similar pleiotropic effects on the modulation of MHC and ICAM-1 expression on astrocytes.(ABSTRACT TRUNCATED AT 250 WORDS

Rat mitogen-stimulated lymphokine-activated T killer cells: production and effects on C6 glioma cells in vitro and in vivo in the brain of Wistar rats.

An in vitro technique was developed to generate activated rat T cells, with antitumor activity. Splenic mononuclear cells (SMC) from outbred Wistar and inbred Wistar-Munich rats were stimulated with Concanavalin A and recombinant human interleukin-2 (rIL-2) in vitro for 48 h. After 2 days, the nonadherent cells began proliferating and were maintained in rIL-2 for up to 18 days in vitro. FACScan analysis revealed that SMC was a mixture of cell types; however, CD5+ T cells rapidly increased and became the predominant cell type after 5 days in culture. SMC induced cytolysis of YAC-1, but not C6 glioma cells in 4 h 51Cr release assays. In contrast, 5- and 9-day T cells lysed C6 glioma and YAC-1 cells. The C6 cells were admixed with cultured effector cells at various effector-to-target (E:T) ratios and were injected into the right cerebral hemisphere of Wistar and Wistar-Munich rats for a Winn assay. Histopathologic evaluations revealed that a) SMC had no effect; b) 2- and 5-day T cells, injected at E:T ratios greater than 5:1, caused significant reduction in tumor size; and c) 2- or 5-day T cells, at a 40:1 E:T ratio, resulted in little or no histologic evidence of tumor. Eighty-three percent of animals receiving C6 and 5-day mitogen-stimulated lymphokine activated killer cells at an E:T ratio of 40:1 were alive 120 days postinjection (p less than 0.05)

Rat mitogen-stimulated lymphokine-activated T killer cells: production and effects on C6 glioma cells in vitro and in vivo in the brain of Wistar rats.

An in vitro technique was developed to generate activated rat T cells, with antitumor activity. Splenic mononuclear cells (SMC) from outbred Wistar and inbred Wistar-Munich rats were stimulated with Concanavalin A and recombinant human interleukin-2 (rIL-2) in vitro for 48 h. After 2 days, the nonadherent cells began proliferating and were maintained in rIL-2 for up to 18 days in vitro. FACScan analysis revealed that SMC was a mixture of cell types; however, CD5+ T cells rapidly increased and became the predominant cell type after 5 days in culture. SMC induced cytolysis of YAC-1, but not C6 glioma cells in 4 h 51Cr release assays. In contrast, 5- and 9-day T cells lysed C6 glioma and YAC-1 cells. The C6 cells were admixed with cultured effector cells at various effector-to-target (E:T) ratios and were injected into the right cerebral hemisphere of Wistar and Wistar-Munich rats for a Winn assay. Histopathologic evaluations revealed that a) SMC had no effect; b) 2- and 5-day T cells, injected at E:T ratios greater than 5:1, caused significant reduction in tumor size; and c) 2- or 5-day T cells, at a 40:1 E:T ratio, resulted in little or no histologic evidence of tumor. Eighty-three percent of animals receiving C6 and 5-day mitogen-stimulated lymphokine activated killer cells at an E:T ratio of 40:1 were alive 120 days postinjection (p less than 0.05)

Generation of stimulated, lymphokine activated T killer (T-LAK) cells from the peripheral blood of normal donors and adult patients with recurrent glioblastoma.

Peripheral blood mononuclear cells (PBM) from normal donors and patients with recurrent glioma were activated initially for 48-72 h with phytohemagglutinin-P (PHA) and recombinant human interleukin-2 (IL-2), and then proliferated in vitro for up to 5 months with IL-2. These cells are termed mitogen-stimulated lymphokine-activated T killer (T-LAK) cells. We measured patterns of T-LAK cell growth, in vitro cytolytic activity on a panel of continuous and primary tumor cells, and the phenotypes of the cells in these cultures. Lymphocyte viability declined dramatically over the first 3-5 days; and then the remaining cells in these cultures began to divide and maintained a constant 30-36 h doubling time for long periods in vitro. Phenotyping revealed that cells in the initial few days of culture were heterogeneous, but became almost totally CD3 T cells after 7-10 days in culture. The T-LAK cells from individual normal donors and cancer patients demonstrated a non-genetically restricted cytolytic ability against a panel of both continuous cell lines and primary autologous and allogeneic glioblastoma cells in vitro. This technique provides a method of generating large numbers of autologous cytolytic T cells with non-restricted anti-tumor activity that can be derived from peripheral blood mononuclear cells