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Biomedical subjects

B S Wilson

Publications and source records attributed to B S Wilson.

At least 109 records · Page 6Linked to original sources

A 94,000-dalton glycoprotein expressed by human melanoma and carcinoma cells.

The IgG2a monoclonal antibody (MoAb) 376.96S, secreted by a hybridoma derived from a mouse immunized with cultured human melanoma cells COLO 38, reacts with a single 94,000-dalton glycoprotein that is peripherally associated with the plasma cell membrane of cultured melanoma cells. Indirect immunofluorescence analysis with cryostat thin sections of human tissues showed that this antigen is absent from a large variety of normal tissues but is readily detectable on melanomas, nevi, and several different carcinomas. The MoAb 376.96S binds with cultured melanoma and carcinoma cell lines to a similar extent and can mediate both complement-dependent and cell-dependent lysis of these cells. The 94,000-dalton glycoprotein detected by MoAb 376.96S is distinct in its tissue distribution, antigenicity, and molecular profile from several structures previously identified with monoclonal antibodies that have similar molecular weights.

Antibodies, Monoclonal↗

Distribution and molecular characterization of a cell-surface and a cytoplasmic antigen detectable in human melanoma cells with monoclonal antibodies.

The monoclonal antibodies 225.28S and 465.12 to human melanoma-associated antigens have been tested with a large variety of surgically removed skin lesions and malignant tumors as well as with a panel of cultured cell lines in serological and immunochemical assays. The antibody 225.28S reacts with a plasma membrane antigen while the antibody 465.12 detects a cytoplasmic antigen. Both antibodies fail to react with melanocytes from normal skin as well as benign skin lesions but react with nevi, melanoma cells and some skin carcinomas. Analysis with surgically removed tumors and cultured human cell lines indicated that the plasma membrane antigen is restricted to skin lesions whereas the cytoplasmic antigen is synthesized by tumor cells of various histological origins. The plasma membrane antigen is composed of two glyco-polypeptides of 280,000 and greater than 440,000 daltons, while the cytoplasmic antigen consists of 4 glycopolypeptides of 94,000, 75,000, 70,000 and 25,000 daltons. None of these components are bridged by disulfide bonds. The cytoplasmic antigen was readily detected in the spent culture medium of melanoma cell lines in the form of a major 94,000 dalton and a minor 72,000 dalton structure, while the plasma membrane antigen was detectable only after vastly increasing the sensitivity of the assay system.

Antibodies, Monoclonal↗

Effect of tunicamycin on the assembly and antigenicity of HLA antigens: analysis with monoclonal antibodies.

The effect of glycosylation on the assembly and antigenicity of HLA antigens was investigated by examining HLA antigens synthesized in the presence of the antibiotic tunicamycin, an inhibitor of asparagine-linked oligosaccharide addition, with monoclonal antibodies specific for a variety of antigenic determinants. The monoclonal antibody Q5/13 reactive with a determinant expressed on the beta chain of human Ia-like antigens immunoprecipitated alpha and beta subunits with reduced apparent molecular weights from tunicamycin-treated cells, indicating that glycosylation is not required for association of the Ia-like antigen alpha and beta subunits. Immunoprecipitation of HLA-A,B,C antigens from tunicamycin-treated cells with four monoclonal antibodies specific for the heavy chain and one specific for beta 2-microglobulin showed that the heavy-chain determinant detected by the antibody Q6/64 is absent from the non-glycosylated molecule. This is the first demonstration that carbohydrate addition during biosynthesis affects the protein conformation of the HLA-A,B,C heavy chain.

Antibodies, Monoclonal↗

Structural properties and tissue distribution of the antigen recognized by the monoclonal antibody 653.40S to human melanoma cells.

The hybridoma 653.40S, constructed with splenocytes from an inbred BALB/c mouse immunized with cultured human melanoma cells, secreted an antibody that had been shown to recognize an antigenic determinant restricted to human melanoma cell lines. The monoclonal antibody (MoAb) 653.40S showed immunoprecipitation of two glycopolypeptides synthesized by melanoma cells, one with the apparent molecular weight of 280,000 and the other one with a molecular weight larger than 500.000. These two glycopolypeptides were not bridged by disulfide bonds and were peripheral rather than integral to the plasma cell membrane. Comparison of the reactivity of cells of the melanocyte lineage with the MoAb 653.40S and with the MoAb Q5/13 to human Ia-like antigens showed that the former reacted with proliferating melanocytes and melanoma cells, whereas the latter reacted only with melanoma cells. The MoAb 653.40S did not react with a large variety of surgically removed normal and tumor tissues except for some instances of basal cell and squamous cell carcinomas. These results suggested that double staining of pigmented skin lesions with the MoAb 653.40S and with an MoAb to Ia-like antigens may help to solve controversial diagnosis of melanoma. Furthermore, the MoAb 653.40S may be useful for radioimaging and immunotherapy of melanoma.

Animals↗

Alterations in activity at auditory nuclei of the rat induced by exposure to microwave radiation: autoradiographic evidence using [14C]2-deoxy-D-glucose.

Autoradiographic maps of brain activity in rats exposed to pulsed or continuous-wave (CW) microwave radiation were made using [14C]2-deoxy-D-glucose ([14C]2-DG). Special emphasis was given to measurements of activity in the auditory system because previous work had shown that pulsed microwave radiation can elicit auditory responses in man and other animals. In particular, one middle ear was ablated in nine rats to attenuate the transmission of air-borne sound to one cochlea. The resulting imbalance in auditory input for four animals not exposed to microwave radiation was reflected as a bilateral asymmetry of [14C]2-DG uptake at the inferior colliculus and medial geniculate body. In contrast, a symmetrical pattern of uptake at these structures in an animal exposed to pulsed microwave radiation showed that this stimulus bypasses the middle ear in eliciting auditory responses. This result established the utility of the [14C]2-DG method for demonstrating a known effect of microwave radiation on brain activity. The results also revealed responses at auditory nuclei in 4 animals exposed to CW microwave radiation. These responses, which have not been observed with other methods, were evident at the power densities of 2.5 and 10 mW/sq. cm. To exclude the possibility that CW microwave radiation produced this result by direct action on brain tissue, additional data were obtained from two rats with one cochlea destroyed. In both animals, the uptake of [14C]2-DG at the inferior colliculus and medial geniculate body was virtually identical to the uptake in animals not exposed to microwave radiation, i.e. greatest on the side of the brain contralateral to the intact cochlea. This finding, coupled with the finding of a bilateral symmetry of [14C]2-DG uptake in the auditory pathways of animals with one middle ear ablated, confirmed the hypothesis that auditory responses to CW microwave radiation originate within the cochlea. Effects on brain activity outside of the auditory system were not found in qualitative analyses of autoradiographs for the conditions of exposure to CW microwave radiation noted above or for exposure to pulsed microwave radiation at the average power density of 2.5 mW/sq. cm.

Animals↗

Human melanoma associated antigens: a solid-phase assay for detection of specific antibody.

A solid-phase radioimmunometric binding assay is described utilizing 125I-labeled protein A for the detection of antibody to human melanoma associated antigens. The novel aspect of this assay is the use of chemically defined spent culture medium of melanoma cells at target antigens previously depleted of fibronectin by affinity chromatography. This makes it possible to screen for antibody in unabsorbed antiserum. Sensitivity, reproducibility and ease of performance of the assay are optimized by conjugating target antigens to a background of bovine serum albumin dried onto polyvinyl 96-well microtiter plates and cross-linked with glutaraldehyde. The use of an immobilized soluble antigen target derived from a large pool of spent culture medium facilitates direct interassay comparisons and permits extensive absorption analysis of antisera. The assay has considerable potential in screening for alloantibody and both poly- and monoclonal xeonoantibody to human melanoma associated antigens.

Animals↗

DR (Ia-like) antigens on human melanoma cells. Serological detection and immunochemical characterization.

11 cultured human melanoma cell lines were tested for the expression of DR antigens by using specific allo- and xenoantisera in an indirect rosette microassay. Four of these melanoma cell lines expressed DR antigens, but in lower amounts than expressed on cultured human B-lymphoid cells. Rabbits injected with the DR-positive melanoma cells produced antibodies that were serologically and immunochemically reactive with B-cell-derived DR antigens. Immunochemical studies indicate that melanoma cell-derived DR antigens have a two-chain structure with 34,000 and 27,000 mol wt components. The melanoma cell-derived DR beta-chain at 27,000 mol wt is slightly smaller than that of the Victor cell DR beta-chain whose mol wt is 29,000.

Antigens, Neoplasm↗

Detection of human histocompatibility (HLA) antigens with an indirect rosette microassay.

An indirect rosette assay which utilizes erythrocytes coupled with purified antiimmunoglobulin (Ig) antibodies was modified into a microassay for detecting HLA allo-and xenoantibodies. The test, which is performed in microtiter plates, is specific, reproducible and can handle large numbers of samples. As an inhibition assay the test can detect HLA antibodies even if mixed with antibodies to other cell surface structures. The rosette microassay is at least 10 times more sensitive than the complement-dependent microcytotoxic test and can use target cells which exhibit low viability or abnormal susceptibility to lysis.

Animals↗

Production and characterization of DR xenoantisera: use for detection of serum DR antigens.

Immunoadsorbents consisting of rabbit anti-DR antibodies bound to Staphylococcus aureus were used to bind DR antigens from NP40 cellular extracts of cultured B lymphoid cells. When injected into rabbits, these DR antibody absorbents elicited the production of antibodies that were shown by both serologic and immunochemical techniques to react specifically with the DR antigen molecule. A rosette inhibition assay with B lymphoid cells and anti-DR xenoantisera was used to detect DR antigens in human serum. DR serum antigens could be found in an enriched preparation of serum lipoproteins obtained by centrifugation in KBr. In addition, sera from some patients with neoplastic diseases contained higher levels of DR serum antigens than those found in normal individuals.

Animals↗