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Biomedical subjects

R H Neubauer

Publications and source records attributed to R H Neubauer.

At least 37 records · Page 2Linked to original sources
PubMed1981

Reactivity of monoclonal antibodies against human leucocyte antigens with lymphocytes of non-human primate origin.

The phylogenetic distribution of antigens present on human lymphocytes was investigated by incubating human or simian cells with murine anti-human monoclonal antibodies and then determining the level of reactivity with a radiolabelled anti-murine IgG reagent. The monoclonal antibodies used were specific for a T-cell antigen, lymphoid and lymphoid:myeloid antigens, Ia antigens, and beta 2 microglobulin. The cells examined included B- and T-lymphoblastoid cell lines and fresh peripheral blood lymphocytes separated by sheep erythrocyte rosetting into T-cell and non T-cell fractions. Results of these studies showed that the antibodies gave complete cross-reactivity with gorilla and chimpanzee cells while B-cell lines of orangutan origin had lost lymphoid and beta 2 microglobulin markers. Gibbon cells and cells of Old World and New World monkeys reacted strongly only with monoclonal antibodies against Ia antigenic determinants. These Ia antigens were found on the non T-cell fraction of fresh peripheral lymphocytes, on B-cell lines and on some virus induced T-cell tumour lines. Immunoprecipitation analysis using the anti-Ia antibodies showed a degree of molecular diversity on owl monkey and marmoset cells compared to the Ia antigens associated with human cells.

Animals↗
PubMed1981

Infection of multiple T-cell subsets and changes in lymphocyte functions associated with Herpesvirus saimiri infection of owl monkeys.

We examined the association of Herpesvirus saimiri with lymphocyte subsets and the functional integrity and distribution of these populations in owl monkeys with chronic, disease-free infections, in uninoculated, control animals, and in one monkey with H. saimiri-induced lymphoma. The lymphocyte subpopulations examined included total T cells, T cells with receptors for the Fc portion of immunoglobulin G (the Tgamma cells), T cells lacking this receptor (the Tgamma(-) population), and non-T cells. These studies showed that in chronically infected monkeys, H. saimiri was found in both Tgamma and Tgamma(-) populations and that the relative distribution of lymphocyte subsets was not different than the relative distribution in normal animals. The peripheral blood of the one leukemic animal studied showed an increase in total T cells, and both Tgamma and Tgamma(-) cells were increased in number and contained recoverable H. saimiri. In animals with chronic infections, which previously were thought to be immunologically normal, we showed that the Tgamma cells had lost the ability to respond to phytohemagglutinin. When the level of nonspecific cytotoxic activity was examined, we found that the lymphocytes from infected animals were as active as those from uninfected monkeys and that this activity was maintained at normal levels during disease. In the leukemic blood there was a relative increase in the cytotoxic activity of the Tgamma(-) cells. The Tgamma(-) cells obtained from leukemic blood lacked the ability to respond to phytohemagglutinin and could suppress the phytohemagglutinin response of normal cells. This suppressor cell activity was resistant to 3,000 rads of X irradiation. We also found that cells reactive to H. saimiri antigens could be demonstrated in the lymph nodes but not in the peripheral circulation of the lymphomatous monkey.

Animals↗
PubMed1981

Identification of an Epstein-Barr virus nuclear antigen by fluoroimmunoelectrophoresis and radioimmunoelectrophoresis.

A 65,000-dalton (65K) antigen found in Raji cells by fluoroimmunoelectrophoresis and radioimmunoelectrophoresis has been identified as an Epstein-Barr virus nuclear antigen (EBNA). This identification is based on the following evidence. The 65K antigen is detected in Raji cells but not in three Epstein-Barr virus (-) human B cell lines. It is not detected with EBNA (-) sera. The 65K antigen is found predominantly in the nucleus and co-elutes with EBNA during partial purification by DNA-Sepharose and Blue Dextran-Sepharose chromatography. Finally, the partially purified 65K antigen is an effective absorbant of EBNA antibody as measured in an anticomplement immunofluorescence assay. Antigens with molecular weights of 72, 70, and 73K have been detected in B95-8, P3HR-1, and Namalwa cells, respectively. These antigens are the likely homologues of the 65K Raji EBNA. In addition, an Epstein-Barr virus-associated, 81K DNA-binding antigen has been detected in both B95-8 and Raji cells.

Antigens, Viral↗
PubMed1981

Spontaneous release of a factor with properties of T cell growth factor from a continuous line of primate tumor T cells.

A continuous lymphoid cell line had been previously established from a gibbon with spontaneous lymphosarcoma. This cell line, designated as MLA144, when tested after several years in culture was shown to release spontaneously a factor biologically and biochemically similar to human T cell growth factor (TCGF). Conditioned media (CM) from MLA144 cells support growth and DNA synthesis of T cells from humans, several other species of primates, and also from mice and rabbits. The activity in the MLA144 CM is resistant to 60 degrees C and to low and high pH, has a m.w., as determined by gel filtration, of 21,500, elutes from DEAE-cellulose at 0.04 to 0.06 M sodium phosphate buffer, pH 7.6, and has an isoelectric point of about 6.45. Surface-marker analysis of MLA144 cells by rosetting techniques indicates that they are T cells lacking in the receptor for the Fc portion of IgG. The release of TCGF by MLA144 cells should have practical value in terms of ease of TCGF production and should be of great help in the facilitation of studies on the cell biology and molecular biology of TCGF production.

Animals↗
PubMed1980

Comparisons of nuclear antigens of Epstein-Barr virus (EBV) and EBV-like simian viruses.

Nuclear antigens (NA) of EBV (EBNA), Herpesvirus gorilla, H. papio, H. pongo and H. pan were tested with sera of human, gorilla, chimpanzee, orangutan, gibbon and baboon origins. Both conventional anticomplement immunofluorescence (ACIF) and acid-fixed nuclear binding of antigen followed by ACIF (AFNB) procedures were used. Comparisons of antibody titres by ACIF and AFNB suggested that human sera detected the same antigenic determinants on EBNA by the two procedures but gorilla sera measured different determinants on H. gorilla NA. Asymmetric cross-reactions were found with gorilla, chimpanzee and baboon sera but individual human and orangutan sera were found which had extensive cross-reactivities. Absorption experiments with these broadly reactive sera with H. gorilla NA and comparisons of antibody titres of human sera with EBNA, H. gorilla and H. papio NA suggested the presence of an EBV-specific determinant as well as a broadly reactive determinant on EBNA.

Animals↗
PubMed1980

Antiviral cell-mediated immune responses and effect of chromosome polymorphism in Herpesvirus saimiri-infected monkeys.

Herpesvirus saimiri is a horizontally transmitted virus of squirrel monkeys (Saimiri sciureus) which, when inoculated into owl monkeys (Aotus trivirgatus), induces fatal malignant lymphoma in 75 to 80% of the animals. Previous immunological and virological studies have not indicated why 20 to 25% of inoculated owl monkeys develop a chronic, disease-free H. saimiri infection. In the present study, we examined two parameters to explain why certain owl monkeys are resistant to H. saimiri-induced disease. The first possibility was that the animals in which H. saimiri established a chronic infection were all of the same karyotypic class. In studying four such animals, we found that three of the seven known karyotyes were represented, indicating that chromosome polymorphism does not explain disease resistance. The second possibility examined was that animals which develop disease do so as a result of a failure in specific anti-H. saimiri cell-mediated immunity. Naturally infected squirrel monkeys exhibited long-lasting, virus-specific cell-mediated immunity in a lymphocyte proliferation assay, whereas such reactivity could not be demonstrated either in chronically infected owl monkeys or in an owl monkey with a primary H. saimiri infection. The failure of owl monkeys to respond to viral antigens was not due to a basic immunological defect, since these animals gave normal responses to heterologous cells and were capable of being sensitized with the protein antigen keyhole limpet hemocyanin.

Animals↗
PubMed1979

Biochemical identification of primate lymphoid cell-surface glycoproteins.

We have employed the galactose oxidase-tritiated sodium borohydride labelling method to examine the surface glycoproteins of cotton-topped marmoset and other primate cell lines either established from tumors or transformed in vitro by different lymphotropic herpesviruses. The labelled surface glycoproteins were separated on acrylamide gels in the presence of sodium dodecyl sulfate (SDS) and analyzed by fluorography. Our results indicate that (1) lymphocytes of the same class from different primate species are similar but can be distinguished; (2) T and B lymphocytes of the same species can be differentiated; (3) cotton-topped marmoset lymphocytes of the same class show marked similarities regardless of tumor or in vitro origin or virus used for transformation; (4) three cell lines established from different EBV-induced tumors of the same marmoset show essentially the same labelling pattern, supporting the hypothesis that they originated from a single clone.

Animals↗
PubMed1979

Antibody responses to Herpesvirus papio antigens in baboons with lymphoma.

An Epstein-Barr virus-related herpesvirus, termed Herpesvirus papio (HVP), was isolated from baboons (Papio hamadryas) at the Institute of Experimental Pathology and Therapy, Sukhumi, USSR, where there is a continuing outbreak of lymphoma. In the present study sera from diseased baboons and from age- and sex-matched control animals were examined for antibodies to HVP antigens. Results showed that animals with lymphoid disease had antibodies to HVP virus capsid, early, soluble, and nuclear antigens at higher frequencies and at higher titers than did control animals. Antibody titers were not age- or sex-related. No concordancy was detected for antibodies to soluble and nuclear antigens. The sera were also examined for antibodies to two other widely distributed viruses of hamadryas baboons, cytomegalovirus and foamy virus. The results of these studies did not indicate a disease-related role for either of these viruses.

Animals↗
PubMed1979

Establishment of a lymphoblastoid cell line and isolation of an Epstein-Barr-related virus of gorilla origin.

A B-lymphoid cell line was established from a normal gorilla. The cells contained Epstein-Barr virus-related antigens, and herpesvirus particles were demonstrated by electron microscopy. DNA-DNA reassociation kinétics revealed 30 to 40% hybridization to Epstein-Barr virus with 50 genomes per cell. Examination of the viral nuclear antigen with gorilla sera showed this to be a unique isolate termed Herpesvirus gorilla. H. gorilla transformed gibbon B-lymphocytes in vitro.

Animals↗
PubMed1979

Production of monoclonal antibodies against nucleocapsid proteins of herpes simplex virus types 1 and 2.

We prepared mouse hybrid cell lines which produced antibodies against herpes simplex virus type 1 and 2 nucleocapsids. Cell lines 1D4 and 3E1, respectively, secreted immunoglobulin G1 herpes simplex virus type 1 and immunoglobulin G1 herpes simplex virus type 2 antibodies which immunoprecipitated proteins designated p40 and p45 from homologous nucleocapsid preparations but precipitated no proteins from heterologous preparations. In contrast, guinea pig antisera prepared against either herpes simplex virus type 1 or 2 p40 precipitated p40 and p45 from both homologous and heterologous preparations. These findings suggest that p40 and p45 possess similar antigenic determinants and that the monoclonal antibodies that were tested reacted preferentially with the homologous determinants.

Antibodies, Viral↗
PubMed1979

Correlation between Epstein-Barr virus membrane antigen and three large cell surface glycoproteins.

A correlation between Epstein-Barr virus membrane antigen (MA) and three surface glycoproteins has been established on the basis of radio-immunoprecipitation and immunoabsorption experiments. For radio-immunoprecipitation, Epstein-Barr virus-infected cells were radiolabeled either with neuraminidase-galactose oxidase tritiated borohydride, a procedure highly specific for surface glycoproteins, or with a general tritiated amino acid mixture. Intact cells were incubated with MA(-) or MA(+) human sera, washed free of unbound immunoglobulins, and then lysed with Nonidet P-40. The antigen-antibody complexes were bound to protein A-Sepharose and after elution with sodium dodecyl sulfate were analyzed by acrylamide gel electrophoresis in sodium dodecyl sulfate. MA(+) sera specifically precipitated three glycoproteins with molecular weights of 236,000, 212,000, and 141,000 from B95-8 cells induced with 12-O-tetradecanoylphorbal-13-acetate (TPA) and from Raji cells superinfected with P3HR-1 virus. These glycoproteins were not detected on Epstein-Barr virus-negative Ramos cells treated with TPA or on B95-8 cells treated simultaneously with TPA and phosphonoacetic acid. Soybean lectin-Sepharose bound all three glycoproteins, and lectin-Sepharose-bound glycoproteins from TPA-induced P95-8 cells absorbed MA-specific antibody from MA(+) human sera. The data strongly suggest that either all three glycoproteins have MA determinants or they are part of a complex in which one or more of the components constitute the reactive antigen.

Animals↗
PubMed1978

Further characterization of a herpesvirus-positive orang-utan cell line and comparative aspects of in vitro transformation with lymphotropic old world primate herpesviruses.

An orang-utan (Pongo pygmaeus) suspension line, CP81, was shown to lack myeloid markers of lysozyme activity an d phagocytosis but to be positive for lymphocytic N-alkaline phosphatase activity, and to release a B-cell-tropic herpesvirus. This herpesvirus, termed Herpesvirus pongo, had 30--40% DNA homology with EBV and was present at 2-3 genome copies per CP-81 cell. Gibbon lymphocytes transformed by H. pongo, Epstein-Barr virus (EBV), and H. papio (of baboon, Papio hamadryas, origin) were found to be virus antigen-positive B cells. Gibbon lymphocytes transformed by H. pongo and EBV and transplanted to nude mice by the intracranial (IC) route (had a 75% and a 45% success rate, respectively), while transplants of similar cells transformed by H. papio were only 10% successful. None of these lines transplanted subcutaneously (SC) nor manifested a high degree of colony formation in 0.33% agarose (less than or equal to 0.5%), Gibbon lymphocytes transformed by H. pongo were hypodiploid while those transformed by EBV or H. papio were diploid. CP-81 cells themselves could be transplanted both IC (100%) and SC (70%) and showed a relatively high degree of colony formation in agarose (6.4-7.6%). B95-8 cells (marmoset, Saguinus oedipus-EBV) could be transplanted IC (66%) but not SC and had a low but significant ability to grow in agarose (1.6%). 594S (baboon, P. hamadryas-H. papio) cells could be transplanted IC (25%) but not SC, and grew to very low levels in agarose (0.1%).

Alkaline Phosphatase↗
PubMed1978

Selective stimulation and differentiation of early antigens in lymphoblastoid cell lines producing Epstein-Barr-like viruses.

Comparisons of early antigens (EA) of EBV-related lymphotropic herpes virus of Old World primates have proved difficult to accomplish because antigen levels are low in infected cells and the ratio of virus capsid antigen to EA is generally high. To overcome these difficulties, we have developed a procedure which combines antigen stimulation with inhibition of late virus functions and results in the selective stimulation of EA. Using this procedure, we have examined the EA of EBV, herpesvirus papio, h. pongo, and h. pan. The results show that the EA of these viruses are composed of both R (restricted) and D (diffuse) components and that the EA, while related, are distinguishable.

Animals↗
PubMed1978

Characteristics of cell lines established from Epstein-Barr virus induced marmoset tumors.

The inoculation of a cotton-topped marmoset with B95-8 strain of EBV resulted in the induction of a multifocal lymphoma and lymphoblastoid cell lines were established from liver, spleen and mesenteric lymph node tumors. The cell lines were remarkably similar to each other with respect to the presence of EBV and its expression, the surface properties of the cells and their stability, and the functional products of the cells. Karyotypic examination of the cell lines revealed the common loss of a single chromosome. The slight differences noted in karyotypes suggest some divergence from a tumor stem cell and imply a clonal origin. Thus, EBV-induced lymphomas in cotton-topped marmosets resemble Burkitt's lymphoma in man.

Animals↗
PubMed1978

Spontaneous esophageal carcinoma and epithelial cell line of an adult rhesus monkey.

A continuous epithelial cell line, 816A, was established from a lymph node of an adult rhesus monkey with metastatic esophageal carcinoma. These cells are characterized by the presence of desmosomes and a markedly heteroploid karyotype. At a relatively early culture age, electron microscopy showed both budding and extracellular type C virus. Antigen reactive with antisera to Mason-Pfizer monkey virus was observed by complement-fixation. The level of this antigen decreased with increased culture age. To our knowledge, the 816A cells represent the only established simian or human cell line of esophageal carcinoma origin.

Animals↗
PubMed1978

Augmentation of the in vitro mitogenic response of owl monkey peripheral blood lymphocytes by levamisole and loss of this effect with the development of herpesvirus saimiri-induced lymphoma.

Levamisole (LMS) has been shown to be capable of enhancing the proliferative response of normal owl monkey peripheral blood lymphocytes (PBL) to PHA, and, to a lesser degree, of increasing the level of spontaneous DNA synthesis. With the development of herpesvirus saimiri-induced lymphoma, these stimulatory responses were lost. LMS was not capable of stimulating tumour cells to normal functions, or of reversing the disease-induced suppressed functions on normal cells.

Animals↗
PubMed1978

In vitro lymphocyte transformation by Epstein-Barr virus (EBV)-like viruses isolated from Old-World non-human primates.

EBV-like viruses and lymphoid cell lines have been isolated from baboons and an orangutan. The cell lines have properties of B- or undifferentiated lymphocytes and have antigens and DNA related to those of EBV. The baboon virus has a broad in vitro transformation host range among lymphocytes of Old-World simian species whereas the orangutan isolate has a narrower host range. Baboon and orangutan viruses as well as EBV have shown transforming activity for gibbon lymphocytes. Baboon virus is infectious for rhesus monkeys and baboons but has not induced neoplastic disease in these species.

Animals↗