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J A Drebin

Publications and source records attributed to J A Drebin.

At least 37 records · Page 2Linked to original sources
PubMed1988

Monoclonal antibodies specific for the neu oncogene product directly mediate anti-tumor effects in vivo.

We have produced a panel of monoclonal antibodies which bind cell surface domains of the 185 Kd tumor antigen (p185) encoded by the neu oncogene. All of these antibodies stain neu-transformed cells in immunofluorescence assays and immunoprecipitate p185 from metabolically labeled cell lysates. All of the anti-p185 monoclonal antibodies, regardless of isotype, exert a selective cytostatic effect on the growth of neu-transformed cells suspended in soft agar, demonstrating their ability to directly inhibit the transformed phenotype. Anti-p185 antibodies of the IgM, IgG2a, and IgG2b isotypes exert a cytolytic effect on neu-transformed cells in the presence of complement. Only one IgG2a monoclonal antibody is also able to mediate minimal levels of antibody-dependent cellular cytotoxicity (ADCC) (Roussel et al., 1984) in the presence of non-immune spleen cells. In vivo administration of anti-p185 antibodies of the IgG1, IgG2a, and IgG2b isotypes exerts a profound inhibitory effect on the tumorigenic growth of neu-transformed cells. This tumor inhibitory effect is unaffected by depleting tumor bearing animals of complement, and is only minimally affected by depleting tumor bearing animals of macrophages. This suggests that neither complement-mediated killing nor ADCC are necessary for the anti-tumor effects of p185-specific monoclonal antibodies. The results presented here demonstrate that monoclonal antibodies reactive with cell surface domains of an oncogene-encoded protein can directly inhibit tumor growth in vitro and in vivo. Such antibodies may prove useful in the therapy of certain malignancies.

Animals↗
PubMed1987

Stage- and tissue-specific expression of the neu oncogene in rat development.

The neu oncogene (also referred to as c-erbB-2 and HER2) encodes a 185-kDa transmembrane glycoprotein with tyrosine kinase activity termed p185. The p185 glycoprotein is structurally related to the epidermal growth factor receptor. It is thought that p185 is the receptor for an as yet unidentified growth factor. In the present study, RNA blot analyses and immunohistochemical studies were performed on rat tissues obtained from a variety of prenatal and postnatal stages to examine the expression of the neu oncogene and its product, p185, during normal development. Expression of the neu gene was detected in mid-gestation embryos in a variety of tissues including nervous system, connective tissue, and secretory epithelium, but not in lymphoid tissue. In adult animals, secretory epithelial tissues and basal cells of the skin expressed neu. These studies demonstrate that the neu gene is expressed in a tissue- and developmental stage-specific manner. We suggest that the p185 molecule plays an important role in the growth and development of a variety of tissues, and, in particular, in epithelial tissue.

Animals↗
PubMed1986

Inhibition of tumor growth by a monoclonal antibody reactive with an oncogene-encoded tumor antigen.

The neu oncogene encodes a 185-kDa transmembrane glycoprotein tumor antigen, termed p185. We have recently described a monoclonal antibody reactive with a cell surface domain of the p185 molecule. In vivo treatment with this anti-p185 monoclonal antibody was able to significantly inhibit the tumorigenic growth of neu-transformed NIH 3T3 cells implanted into nude mice. Such treatment had no effect on the tumorigenic growth of Ha-ras-transformed NIH 3T3 cells. Furthermore, anti-p185 antibody treatment was able to inhibit the growth of the rat neuroblastoma cells from which the neu oncogene was initially isolated. These results demonstrate that a monoclonal antibody reactive with the extracellular domain of an oncogene-encoded protein can exert a significant antitumor effect; such antibodies may prove useful in the therapy of certain malignancies.

Animals↗
PubMed1985

Down-modulation of an oncogene protein product and reversion of the transformed phenotype by monoclonal antibodies.

Exposure of neu-oncogene-transformed NIH 3T3 cells to monoclonal antibodies reactive with the neu gene product, p185, results in the rapid and reversible loss of both cell-surface and total cellular p185. Although not directly cytotoxic, monoclonal anti-p185 antibody treatment causes neu-transformed NIH 3T3 cells to revert to a nontransformed phenotype, as determined by anchorage-independent growth. Isotype matched control antibodies of an unrelated specificity do not affect p185 levels or colony formation in soft agar by neu-transformed NIH 3T3 cells. Soft agar colony formation by NIH 3T3 cells transformed by ras oncogenes is not affected by anti-p185 antibody treatment. Anchorage-independent growth of cells from the ethylnitrosourea-induced rat neuroblastoma line in which neu was originally detected by DNA transfection is also inhibited in the presence of anti-p185 monoclonal antibodies. Collectively, these results suggest that p185 is required to maintain transformation induced by the neu oncogene.

Animals↗
PubMed1984

Analysis of hapten-specific T suppressor factors: genetic restriction of TsF1 activity analyzed with synthetic hybrid suppressor molecules.

We have analyzed the first-order suppressor factor secreted by an azobenzenearsonate (ABA)-specific T suppressor cell (Ts) hybridoma. Treatment of the factor with 5 mM dithiothreitol (DTT) yields two fragments with distinct phenotypes and functional capabilities. One fragment is bound by a monoclonal anti-I-J antibody, the other is not. Further, although neither molecular fragment by itself is sufficient to suppress an ABA response, a mixture of the two reconstitutes the suppressive activity. The I-J- portion of the first-order suppressor factor (TsF1) presumably guides the antigen specificity; activity of the ABA-specific Ts I-J- TsF1 factor can be reconstituted with an I-J+ subunit of a TsF molecule of either sheep red blood cell (SRBC) or ABA specificity. The genetic restriction for Igh-linked determinants of the ABA/SRBC hybrid TsF molecules is influenced by the I-J+ portion, regardless of the original antigen specificity of that molecule. The data support a two-subunit TsF model. Polyclonal ABA-specific TsF1 molecules appear to resemble the monoclonal factor in structure.

Animals↗
PubMed1984

Suppressor T cells and the immune response to tumors.

In this paper we have attempted to define the role of suppressor T cells in many well-defined murine tumor systems. We have knowingly omitted a blocking antibodies, suppressor B cells as mediators of tumor immunosuppression in various murine tumor systems; these have been well reviewed elsewhere. Also, we have focused on the importance of two different types of antigen-presenting cells in the induction and suppression of cell-mediated immunity and on some of the different modalities employed to inhibit Ts function. Finally, we have discussed the acquired immunodeficiency syndrome and the possible role of a defective helper pathway and enhanced suppressor pathway in its pathogenesis. We and others believe that the suppressor pathway is preferentially activated by tumor antigen(s) in the cases of many immunogenic murine tumors--possibly due to the release of tumor antigen(s) from tumor cells, their subsequent trafficking to specific areas of the spleen and other organs, and, ultimately, their presentation by certain APC to Ts. Ts may then act directly upon helper Lyt 1+2- T cells as these cells interact with tumor antigen(s) on I-A+ APC. Alternatively, if the effector pathway were somehow impaired--e.g., by ultraviolet radiation or a virus--then the suppressor pathway may be activated in an unregulated manner, often to the detriment of the host. Biochemical characterization of the tumor antigens that stimulate Ts generation and, presumably, tumor growth and definitive documentation of a role of APC in the processing and presentation of these tumor antigens to Ts need to be done. Then selective stimulation of the effector immune response, along with inhibition of the suppressor response, to tumor antigens with drugs, monoclonal antibodies, and soluble mediators or their analogues may be possible in the near future.

Acquired Immunodeficiency Syndrome↗
PubMed1984

Regulation of the immune response to tumor antigens. X. Activation of third-order suppressor T cells that abrogate anti-tumor immune responses.

The experiments described further define the suppressor T cell pathway in the S1509a tumor system. We demonstrated previously that S1509a-induced Ts1, TsF1, and Ts2 specifically suppress in vivo Ly1+2- T cell-dependent responses to S1509a and that Ts1 suppress in vivo Ly-1+2- T cell-mediated proliferative responses to S1509a. We have now shown that in vivo administration of either S1509a-induced TsF1 or TsF2 suppresses both in vivo and in vitro Ly-1+2- T cell-mediated responses to S1509a. Furthermore, we revealed the existence of Ts3, which are activated by S1509a tumor antigen and TsF2, in this murine tumor system. Finally, we demonstrated that cyclophosphamide abrogates the suppressive effect of TsF2 but not that of Ts3. These results are discussed with respect to T cell-mediated suppression in other murine tumor systems and the possible pivotal role for a tumor antigen-presenting cell in activating Ts3 in the S1509a tumor system.

Animals↗
PubMed1984

Differential antigen presentation in tumor immunity.

The tumor S1509a elicits a cell-mediated immune response in immune A/J mice but leads to the generation of suppressor T cells (Ts) in nonimmune mice. Previous studies have shown that I-A+ antigen-presenting cells (APC) present S1509a tumor antigen and thereby activate immune T cells. Recent studies with polyoma-induced tumors reveal similar findings. Administration of anti-I-A antibodies not only prevents effective T cell activation by I-A+ APC bearing S1509a tumor antigen but also induces Ts after a tumor challenge. Ts, which inhibit S1509a tumor immunity, may be activated by tumor antigen presented on I-J+ APC. Examination of the immunologic effects of cyclophosphamide and UV radiation supports this hypothesis.

Animals↗
PubMed1983

Identification of an I-J+ antigen-presenting cell required for third order suppressor cell activation.

We have found that an I-J+ I-A- antigen-presenting cell (APC) is required for Ts3 activation in vivo. Together with the I-J restriction previously reported for Ts3 induction (Takaoki, M., M.-S. Sy, A. Tominaga, A. Lowy, M. Tsurifiji, B. Benacerraf, R. Finberg, and M. I. Greene, 1982, J. Exp. Med., 156:1325), it appears that this I-J+ APC is responsible for I-J restriction in the triggering of Ts3. This restriction may be exerted via a pre-Ts3 associative recognition of antigen and I-J encoded determinants, analogous to the T helper recognition of antigen in the context of I-A and I-E determinants.

Animals↗
PubMed1983

Regulation of the immune response to tumor antigens. IX. In vitro Lyt-1+2- cell proliferative responses to cellbound or subcellular tumor antigen.

We investigated the cellular basis of immune reactivity to the S1509a fibrosarcoma in tumor-immune A/J mice. In a Winn assay, immune Lyt-1+2- T cells are capable of retarding S1509a tumor growth in naive A/J mice. In vitro proliferation to S1509a is also mediated by tumor-immune Lyt-1+2- T cells. This response is specific to the immunizing tumor and appears 5 to 7 days after reexposure to the tumor in vivo. Proliferation also requires the presence of a population of adherent cells. In fact, adherent peritoneal exudate cells pulsed with tumor membrane fragments derived from S1509a cells can stimulate proliferation. Proliferation is blocked by the addition of anti-I-Ak monoclonal antibody to the culture medium without complement or by treatment of the responder population with anti-I-Ak and complement. In vitro responsiveness is also inhibited by the presence of tumor-specific suppressor T cells in vivo. These observations suggest in vitro proliferation may provide a potential means of defining tumor antigens and cell-surface structures involved in tumor immunity.

Animals↗
PubMed1983

Inhibition of tumor growth by monoclonal anti-I-J antibodies.

In this paper we have examined the effects of i.v. administered monoclonal anti-I-J antibodies on tumor growth in syngeneic and semi-syngeneic hosts. These antibodies inhibit tumor growth in mice bearing the appropriate I-J-encoded gene product on their lymphoid cells at nanogram dosages. The spleens of monoclonal anti-I-J-treated primary tumor-bearing mice do not contain transferable tumor-specific cells. These findings suggest that inhibition of suppressor cell function may be the mechanism by which anti-I-J antibodies inhibit tumor growth. We have also demonstrated that tumors growing in F1 hybrid mice are inhibited by monoclonal anti-I-J antibodies reactive with either parental haplotype and that there is no evidence of synergy when both antibodies are administered simultaneously. This may indicate that I-J molecules are codominantly expressed on a critical component of the F1 suppressor pathway.

Animals↗
PubMedDate not supplied

Results of a new strategy for reconstruction of biliary injuries having an isolated right-sided component.

Poor results after repair of biliary injuries are most common when injuries are above the bifurcation of the left and right hepatic ducts or involve aberrant ducts. We have developed a novel approach to the right-sided component of such injuries. Preoperatively all isolated sections of the biliary tree are intubated percutaneously. At surgery the left duct is found by the Hepp-Couinaud approach. Dissection is continued to the right, staying within the coronal plane of the left hepatic duct, and continuing across the gallbladder plate into segment 5 between the hepatic parenchyma and the Wallerian sheath of the right portal pedicle. Hepatic parenchyma, anterior to the sheath, is resected. After a length of portal pedicle is exposed, right-sided bile ducts are opened on their anterior surface, using the percutaneous transhepatic stents as a guide, and hepaticojejunostomy is performed. Twenty-three patients were treated from May 1993 to February 1999. Injury types and (number of patients) were as follows: B (n = 2), C (n = 5), E4 (n = 10), and E5 (n = 6). There were no perioperative deaths. Follow-up ranged from 8 months to 7 years (median 3 years). There have been no cases of restricture, reoperation, or jaundice, and no interventional procedures. Serum bilirubin is normal in all patients. Alkaline phosphatase is normal or less than two times the normal value in 21 of 22 living patients. This novel approach brings the benefits of the Hepp-Couinaud approach to the right hepatic ducts. Very satisfactory results were obtained in the most severe types of biliary injury.

Adolescent↗
PubMedDate not supplied

Genetically restricted antigen presentation for immunological tolerance and suppression.

The activation of some subsets of T cells requires the recognition of antigen in association with self Ia determinants. It is not clear, however, whether this is also necessary for the induction of unresponsiveness and the active suppression of hapten-specific T cells. We have studied the regulation of the delayed-type hypersensitivity (DTH) response in mice. Subcutaneous (s.c.) injection of haptenated syngeneic cells primarily activates T helper cells, while intravenous (i.v.) injection results in unresponsiveness and the activation of T suppressor cells. Presentation of antigen by an I-A-positive antigen-presenting cell (APC) seems to be critical for T helper cell activation. We now show that the activation of first-order T suppressor cells requires the presentation of hapten on an I-J-positive APC. However, i.v. injection of I-J-depleted haptenated cells also results in hepten-specific unresponsiveness. This non-transferable T-cell tolerance requires the presence of an I-A-positive APC and is genetically restricted. These results suggest that distinct modes of antigen presentation and administration are required for immunity, suppression and non-transferable tolerance.

Animals↗
PubMedDate not supplied

The neu oncogene: an erb-B-related gene encoding a 185,000-Mr tumour antigen.

A series of rat neuro/glioblastomas all contain the same transforming gene (neu) which induces synthesis of a tumour antigen of relative molecular mass (Mr) 185,000 (p185). The neu oncogene bears homology to erb-B and the tumour antigen, p185, is serologically related to the epidermal growth factor (EGF) receptor. The two proteins, EGF receptor and p185 appear to be distinct, as they coexist in nontransformed Rat-1 cells.

Animals↗