Biosynthesis and expression of the disialoganglioside GD2, a relevant target antigen on small cell lung carcinoma for monoclonal antibody-mediated cytolysis.

Monoclonal antibodies (MAbs) 126 (immunoglobulin M) and 14.18 (immunoglobulin G3) react strongly with the cell surface of small cell carcinoma of the lungs (SCCL) and are unreactive with most normal tissues and other neoplasms with the notable exception of tumors derived from cells of neural crest origin. These MAbs react specifically with the oligosaccharide portion of the disialoganglioside GD2.

Disialoganglioside GD2 distributes preferentially into substrate-associated microprocesses on human melanoma cells during their attachment to fibronectin.

Human melanoma cells (M21) actively attach and spread on a fibronectin substrate. Indirect immunofluorescence assays with specific monoclonal antibodies directed to the disialoganglioside GD2, the major ganglioside expressed on M21 melanoma cells, indicate that during the cell attachment process this molecule redistributes into microprocesses that make direct contact with the fibronectin substrate. Scanning and transmission immunoelectron microscopic studies with anti-GD2 monoclonal antibodies and immuno-gold staining demonstrate that GD2 preferentially localizes into substrate-associated microprocesses that emanate from the plasma membrane of the M21 cells.

Disialogangliosides GD2 and GD3 are involved in the attachment of human melanoma and neuroblastoma cells to extracellular matrix proteins.

Human melanoma cells express relatively large amounts of the disialogangliosides GD3 and GD2 on their surface whereas neuroblastoma cells express GD2 as a major ganglioside. Monoclonal antibodies (Mabs) directed specifically to the carbohydrate moiety of GD3 and GD2 inhibit melanoma and neuroblastoma cell attachment to various substrate adhesive proteins, e.g.

Disialoganglioside GD3 on human melanoma serves as a relevant target antigen for monoclonal antibody-mediated tumor cytolysis.

Monoclonal antibody MB3.6 (IgG3) recognizes disialoganglioside GD3, which represents a major surface marker on most human melanoma cells. We demonstrate that this antibody effectively lyses four human melanoma cell lines expressing significant levels of GD3 on their surface by either of two mechanisms: antibody-dependent cellular cytotoxicity (ADCC) or complement-mediated cytotoxicity.

Characterization of a membrane surface glycoprotein associated with T-cell activation.

A cell surface antigen (gp140) was previously shown to exist on T cell subsets as well as on monocytes and macrophages in normal peripheral blood. Elevated expression of this antigen was associated with immune system disorders, acute lymphocytic leukemias, and in vitro activation of T cells. The antigen could be identified with monoclonal antibody (MAb) T305.

Detection of ganglioside GD2 in tumor tissues and sera of neuroblastoma patients.

A murine monoclonal antibody (monoclonal antibody 126) produced against cultured human neuroblastoma cells (LAN-1) was found to be specifically directed to a disialoganglioside (GD2) antigen preferentially expressed on both cell lines and tissues derived from melanoma and neuroblastoma. In enzyme-linked immunosorbent assays, monoclonal antibody 126 failed to react with leukemic and lymphoblastoid cells as well as with a variety of carcinoma and sarcoma cell lines. Immunohistological analysis by the immunoperoxidase technique revealed strong reactivity of monoclonal antibody 126 with frozen and formaldehyde-fixed neuroblastoma and melanoma tissues.

Localization of the gangliosides GD2 and GD3 in adhesion plaques and on the surface of human melanoma cells.

The predominant gangliosides produced by two cultured human melanoma cell lines are GD3 and/or GD2. These gangliosides were found to be cell associated and present in substratum-attached material after cell removal by EDTA. Monoclonal antibodies directed to GD2 and GD3 specified the cell-surface distribution of these gangliosides and localized them in focal adhesion plaques at the interface of cells and their substratum.

O-acetylation of disialoganglioside GD3 by human melanoma cells creates a unique antigenic determinant.

Monoclonal antibody Mab D1.1 recognizes on human melanoma cells a ganglioside antigen characterized by an alkali-labile O-acetylated sialic acid residue. Immunochemical analysis showed that this molecule is an O-acetylated product of the neuroectoderm-associated disialoganglioside GD3.

A monoclonal antibody recognizes an O-acylated sialic acid in a human melanoma-associated ganglioside.

Monoclonal antibody D1.1 originally prepared against the B49 cell line derived from a rat brain tumor was shown to react with a ganglioside present in fetal rat brain. We have found that this antigen is also present in human malignant melanoma tumors as well as many melanoma cell lines.

Interaction of an acute phase reactant, alpha 1-acid glycoprotein (orosomucoid), with the lymphoid cell surface: a model for non-specific immune suppression.

alpha 1-Acid glycoprotein (AG), a serum component elevated during acute inflammation, has been implicated in the suppression of various immunological responses. Pretreatment of lymphoid cells with AG at a concentration commonly found in patients with acute inflammation results in the inhibition of mitogen induced lymphoproliferation as well as capping of concanavalin A (Con A) receptors and surface immunoglobulin (sIg) on the lymphoid cell surface. In order to determine a potential interaction of AG with the lipid bilayer we examined the effects of purified AG on synthetic phosphatidyl choline vesicles.

Blocked herpes simplex virus type 2-specific DNA synthesis in simian virus 40-transformed hamster cells permissive for herpes simplex virus type 1.

Simian virus 40-transformed hamster cells (LL-1) permissive to herpes simplex virus type 1 (HSV-1) were shown to be relatively nonpermissive to HSV-2. When LL-1 cells were infected with HSV-2, there was a 3- to 4-log reduction in infectious viral progeny at 24 h postinfection as compared with HSV-1 under identical cultured conditions. HSV-2 could be carried in the LL-1 cell line for up to 12 passages without any appreciable cytopathology.

Mitogen-induced blastogenesis and receptor mobility inhibition by breast cancer serum with elevated orosomucoid (alpha 1-acid glycoprotein) levels.

Sera from cancer patients have been shown to suppress normal lymphoid cell responsiveness in vitro. In the present study, sera from breast cancer patients were demonstrated to be inhibitory to the concanavalin A (Con A)-, Proteus vulgaris-derived phytohemagglutinin-, and pokeweed mitogen-induced blastogenic responses of normal lymphoid cells. Orosomucoid (OR) (alpha 1-acid glycoprotein), an acute-phase reactant, was elevated in these sera, and a positive correlation existed between the OR level in the sera and its immunosuppressive capacity.

Maximizing differences in the concanavalin A-induced blastogenic responses of lymphocytes from breast cancer patients and controls by the use of alpha-methyl-D-mannoside.

In an attempt to magnify differences in the immune responses of potentially immunosuppressed cancer patients and normal controls, an assessment was made on the effects of the competitive inhibitor alpha-methyl-D-mannoside on the concanavalin A (Con A)-induced blastogenic responses of lymphocytes from each of these populations. Lymphocytes from breast cancer patients with metastatic disease were significantly deficient in their capability to undergo blast transformation regardless of whether the monosaccharide inhibitor was added to the assay cultures. In contrast, lymphocytes from breast cancer patients who did not display metastatic disease were capable of normal blastogenic responses to Con A.