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Characterization of an established mouse-human heterohybridoma and its application for production of (mouse-human)-human triple hybridoma secreting human immunoglobulin.

We report the construction of a mouse-human (M-H) heterohybridoma by fusion of the murine myeloma cell line NS-1 and human spleen cells from a 17 week old fetus. The nonsecreting, cloned hybridoma cell line II was resistant to 8-azaguanine (8-AG) and sensitive to hypoxanthine, aminopterin and thymidine (HAT) medium. It grew rapidly in 8-AG containing medium (doubling time 20 hrs.), but did not grow in HAT medium or in non-serum medium. It had a high fusion frequency with human lymphocytes from regional lymph nodes. Five human chromosomes were retained stably for over 6 months by this cell line II. Nine (mouse-human)-human ((M-H)-H) triple hybridomas secreting human IgG 1 or IgM were established by the fusion of this parental cell line II and human lymphocytes from regional lymph nodes. Immunoglobulin secretion was stable and has been maintained for over 8-10 months without recloning in these hybridomas. Secretion of immunoglobulin varies from 2.1-3.0 micrograms/10(6) cells/day, and these hybridomas contain from 3 to 16 human chromosomes, including No. 14. So, this M-H heterohybridoma II is an excellent useful parental cell line for the production of hybridomas secreting human immunoglobulin.

Animals

Autoantibodies to crude human leucocyte interferon (IFN), native human IFN, recombinant human IFN-alpha 2b and human IFN-gamma in healthy blood donors.

Recently, naturally occurring antibodies to IFN-alpha were discovered in a few systemic lupus erythematosus (SLE) and cancer patients; however, in most patients monitored for anti-IFN antibodies before treatment, no antibodies were found. In an attempt to explain the 'IFN-blocking effect' that we observed in all serum samples we investigated 200 sera from healthy blood donors. We isolated the globulin fraction, and used rabbit anti-human IgG and IgM columns, protein A columns and T-gel affinity chromatography to isolate human IgG and IgM. All sample fractions were tested in a biological IFN neutralization assay by means of a sensitive MTT-assay. We found that normal human serum contained autoantibodies to crude human leucocyte IFN, native human fibroblast IFN, recombinant human leucocyte IFN-alpha 2b and recombinant human IFN-gamma, and that these naturally occurring antibodies were biologically active immunoglobulins of IgG and IgM type. These anti-IFN antibodies were also present in purified human normal immunoglobulin pools. We conclude that all humans have naturally occurring anti-interferon antibodies in their serum, and it is a tempting theory that human cytokines and lymphokines are, at least partly, regulated by immunoglobulins.

Adolescent

Synthesis and incorporation of human ribosomal protein S14 into functional ribosomes in human-Chinese hamster cell hybrids containing human chromosome 5: human RPS14 gene is the structural gene for ribosomal protein S14.

In Chinese hamster ovary cells, mutations in the RPS14 gene (which was previously designated emtB) render cells resistant to normally cytotoxic concentrations of the protein synthesis inhibitor, emetine. Several lines of evidence indicate the RPS14 gene in Chinese hamster is the structural gene for ribosomal protein S14, including the finding that mutants with alterations in this gene produce an electrophoretically altered form of this protein. A human gene which complements the defect in CHO RPS14 mutants and renders them sensitive to emetine has previously been assigned to the long arm of chromosome 5. The analysis of ribosomal proteins extracted from CHO Emtr X human cell hybrids, which contain human chromosome 5 and are emetine sensitive, demonstrated the presence of both the normal human and altered hamster forms of ribosomal protein S14. Human chromosome 5, the emetine-sensitive phenotype, and the human form of ribosomal protein S14 segregate concordantly from hybrids, confirming that the human gene in question is the structural gene for this protein. In addition, the results indicate that in interspecific cell hybrids, the human form of S14 is either incorporated into functional ribosomes more efficiently than the altered hamster protein or the human gene is overexpressed relative to the corresponding hamster gene.

Animals

Characterization of mouse-human hybridoma as a useful fusion partner for the establishment of mouse-human-human hybridoma secreting anti-tetanus toxoid human monoclonal antibody of IgM or IgG class.

We succeeded in establishing a mouse-human (M-H) heterohybridoma clone which provides parental cells useful for human monoclonal antibody (hMoAb) production. Electron micrographs show that the M-H hybridoma cells retain characteristics of murine origin with regard to chromatin patterns, small granules, granular endoplasmic reticulum and Golgi apparatus. The human DNA incorporated into the M-H hybridoma is estimated to be about 1% of the total human chromosomal DNA. Mouse-human-human (M-H-H) hybridomas obtained by hybridization of the M-H hybridoma cells with Epstein-Barr virus(EBV)-transfected human B cells secrete immunoglobulin (Ig) in amounts comparable to those of murine hybridomas. Also the M-H-H hybridomas grow in nude mice and are capable of producing ascites containing large quantities of Ig. The Ig class switching takes place in the M-H-H hybridomas at a much higher frequency than in the original EBV transformant and the M-H hybridoma. Cells secreting specific monoclonal antibody of different Ig classes could be separated and concentrated by the use of fluorescence activated cell sorter (FACS).

Animals

Pokeweed mitogen-stimulated human lymphocytes fused to LICR-2 (HMY2) generate human-human hybridomas producing monoclonal IgG antibodies reactive to human breast carcinoma and malignant melanoma.

Human-human hybridomas were generated using pokeweed mitogen-stimulated lymphocytes from the regional lymph nodes of cancer patients by fusion to the LICR-2 human myeloma cell line. A total of 35 fusions, using the regional lymph node lymphocytes of cancer patients, resulted in hybrid growth in 23% of wells plated with 21 IgG ELISA positive clones, 6 of which have maintained stable human monoclonal antibody production. Mononuclear cells were separated on Ficoll-Paque and grown for 3-4 days in 1% pokeweed mitogen and fused to the LICR-2 human myeloma cell line. Human-human hybridoma producing membrane reactive IgG antibodies have been isolated and react to the following cancers: breast; melanoma. Twenty-seven fusions from 8 breast carcinoma patients resulted in 13 ELISA positive IgGs, 3 of which were stable after cloning. A total of 5,071 wells were plated after polyethylene glycol fusion with resultant hybrid growth in 1210 wells (24% hybrid growth) after hypoxanthine-aminopterin-thymidine selection. In 8 fusions using regional lymph node lymphocytes of other types of cancer, including 6 fusions using lymphocytes from malignant melanoma patients, there were 1,580 wells plated with positive growth in 20% of the wells (311 wells). Of these, 8 clones were ELISA positive and 3 stable clones all producing IgG anti-melanoma antibody were isolated. The overall hybrid frequency was 43 x 10(-7) fused lymphocytes (39 x 10(-7) non-breast and 45 x 10(-7) breast). A total of 21 IgG-producing clones were identified to crude membranes of allogeneic tumor cell lines and stable antibody production was achieved for 6 (29% stable clones).(ABSTRACT TRUNCATED AT 250 WORDS)

Antibodies, Monoclonal

Effects of recombinant human tumor necrosis factor alpha, recombinant human gamma-interferon, and prostaglandin E on colony formation of human hematopoietic progenitor cells stimulated by natural human pluripotent colony-stimulating factor, pluripoietin alpha, and recombinant erythropoietin in serum-free cultures.

The influences of pure human pluripotent colony-stimulating factor, highly purified pluripoietin alpha, pure recombinant human tumor necrosis factor alpha, pure recombinant human gamma-interferon, and natural prostaglandin E1 (PGE1) were evaluated on colony formation of multipotential and erythroid progenitor cells in the presence of recombinant erythropoietin and hemin and on colony formation of granulocyte-macrophage progenitors in normal human marrow cultured in the presence or absence of serum. Serum was replaced by bovine serum albumin, iron-saturated transferrin, cholesterol, and calcium chloride. Increasing concentrations of pluripotent colony-stimulating factor and pluripoietin alpha stimulated increasing numbers of colonies from nonadherent low-density T-lymphocyte-depleted cells in the absence and presence of serum. Growth was usually greater in the presence of serum and on a unit basis pluripoietin alpha was more active than pluripotent colony-stimulating factor. Recombinant human tumor necrosis factor alpha and recombinant human gamma-interferon suppressed colony formation colony forming unit-granulocyte-macrophage, burst forming unit-erythroid, and colony forming unit-granulocyte-erythroid-macrophage-megakaryocyte; PGE1 suppressed colony formation by colony-forming unit-granulocyte-macrophage, stimulated colony formation by burst forming unit-erythroid, and had no effects on colony formation by colony forming unit-granulocyte-erythroid-macrophage-megakaryocyte in both serum-containing and serum-free medium. The PGE1 enhancing effects on erythroid colony formation required T-lymphocytes. Thus, results are similar using serum-containing and serum-free cultures of human bone marrow cells and serum-free defined culture medium can be used to study the mechanism of action of purified natural and recombinant growth and suppressor molecules in vitro.

Bone Marrow Cells

Human monoclonal antibody against human lymphocytic cells. A human monoclonal antibody that reacts preferentially with human lymphocytic cells.

Human monoclonal antibodies may replace human or xenogeneic antisera and mouse monoclonal antibodies for therapeutic applications. The human IgM monoclonal antibody Ha6D3 was produced after in vitro immunization and fusion with a mouse myeloma. Its reactivity against human normal and leukemic cells was investigated in cytotoxicity assays, and the antigen distribution in normal tissues was investigated with biotinylated Ha6D3 and avidin-peroxidase complexes. It was shown that Ha6D3 reacts preferentially with human lymphocytic cells. Only moderate reactions with epithelial cells in some organs were observed in cryostat sections, but because of poor accessibility in vivo these reactions were considered to be negligible.

Antibodies, Monoclonal

Existence of PAF receptors in human platelets and human lung tissue but not in the human myocardium.

The aim of this study was to investigate whether platelet-activating factor (PAF), PAF receptors, and PAF receptor-mediated effects in the human myocardium play a role in cardiac depression during anaphylaxis or septic shock. The effects of PAF, the biologically inactive derivative lyso-PAF, and the specific PAF antagonist WEB 2086 were studied in human myocardial tissue, in human coronary arteries, in human platelets, and in human lung tissue. PAF (C16-PAF, C18-PAF; 0.000001 to 1 mumol/L) had no effect on isometric force of contraction of electrically driven right atrial trabeculae (patients undergoing aortocoronary bypass surgery) and left ventricular papillary muscle strips (mitral valve replacement). PAF (0.2 mumol/L) did not influence the concentration-response curve of either the beta-adrenoceptor agonist isoprenaline (ISO, 0.0001 to 1 mumol/L) or the m-cholinoceptor agonist carbachol (CARB, 0.0001 to 10 mumol/L). The effectiveness (ISO +4.7 +/- 0.7 mN, PAF + ISO + 4.3 +/- 0.44 mN, CARB -2.7 +/- 1.06 mN; PAF + CARB -2.6 +/- 0.52 mN) and the potency--as indicated by the EC50 values--of both isoprenaline and carbachol were identical with and without pretreatment with PAF (0.2 mumol/L). PAF at concentrations of 0.000001 to 10 mumol/L exerted no effect on force of contraction either precontracted (prostaglandin F2 alpha, 0.3 mumol/L) or unprecontracted in human coronary artery rings. Histamine (0.01 to 100 mumol/L) and noradrenaline (0.001 to 30 mumol/L) initiated concentration-dependent contraction in human coronary artery rings (EC50: histamine, 1.86 mumol/L; noradrenaline, 0.69 mumol/L). At lower concentrations (PAF, 0.01 mumol/L) PAF produced complete aggregation of human platelets. In human platelet membranes and lung membranes, 3H-WEB 2086 exhibited saturable high-affinity binding (KD 14.4 nmol/L and 14.3 nmol/L). The maximal binding capacity was 292 fmol/mg protein and 268 fmol/mg protein, respectively. In displacement experiments PAF (0.01 to 10000 nmol/L) and WEB 2086 (0.01 to 10000 nmol/L), but not lyso-PAF, completely displaced 3H-WEB 2086 from its binding sites on human and lung membranes. In contrast, neither in left ventricular membranes nor in right atrial membranes was specific binding of 3H-WEB 2086 observed. These results suggest that there are neither specific PAF receptors nor direct PAF-mediated actions in human myocardial tissue or human coronary artery rings. The effects of PAF on myocardial function may be due to the activation of mediators (e.g., histamine).

Azepines

Defective repair of UV-damaged DNA in human tumor and SV40-transformed human cells but not in adenovirus-transformed human cells.

The DNA repair capacities of five human tumor cell lines, one SV40-transformed human cell line and one adenovirus-transformed human cell line were compared with that of normal human fibroblasts using a sensitive host cell reactivation (HCR) technique. Unirradiated and UV-irradiated suspensions of adenovirus type 2 (Ad 2) were assayed for their ability to form viral structural antigens (Vag) in the various cell types using immunofluorescent staining. The survival of Vag formation for UV-irradiated Ad 2 was significantly reduced in all the human tumor cell lines and the SV40-transformed human line compared to the normal human fibroblasts, but was apparently normal in the adenovirus-transformed human cells. D0 values for the UV survival of Ad 2 Vag synthesis in the tumor and virally transformed lines expressed as a percentage of that obtained on normal fibroblast strains were used as a measure of DNA repair capacity. Percent HCR values ranged from 26 to 53% in the tumor cells. These results indicate a deficiency in the repair of UV-induced DNA damage associated with human tumorigenesis and the transformation of human cells by SV40 but not the transformation of human cells by adenovirus.

Adenoviruses, Human

[Study of anticancer human monoclonal antibody--establishment of human monoclonal antibody to gastric cancer by human-mouse hybridoma].

A human immunoglobulin M (IgM) antibody secreting hybridoma, HMG1, has been established and studied for its reactivity against human gastric cancer cells. Lymphocytes isolated from a regional lymph node of patient with gastric adenocarcinoma were fused with mouse myeloma cells NS-1. Supernatants from the generated human-mouse hybrids were first screened for immunoglobulin production by ELISA. The identified human IgM-secreting hybridomas were expanded and subcloned for further analysis or cryopreservation. The screening for binding of antibodies to a panel of human cancer cell lines and normal fibroblast was carried out with PAP or indirect immunofluorescence stain. The selected hybridoma, HMG1 after being cloned three times, was stable in secreting IgM (about 4 micrograms/1 x 10(6) cells) for more than 9 months. Large amount of ascites was obtained by injecting this hybrid to BALB/C nude mice pretreated with anti-lymphocyte serum and pristane. The ascitic fluid contained 5-19 mg human Ig/ml. Subsequently this IgM was extracted from ascitic fluid by saturated ammonium sulphate solution. This crude extract was further purified with immuno-affinity chromatography. Both this purified ascite-IgM as well as IgM from HMG1 supernatant would react with gastric cancer cell line BGC-823 but not with human normal fibroblasts 350Q by PAP or immunofluorescence analysis. The human HMG1-IgM reacted with gastric cancer cells on paraffin embedded tissue section but did not react with normal gastric mucosa cells. HMG1-IgM had some complement dependent cytotoxicity against BGC-823. These results suggest that the establishment of anticancer human monoclonal antibodies with human-mouse hybridoma technique be feasible. There is a possibility for clinical applications of this human monoclonal antibody in the future.(ABSTRACT TRUNCATED AT 250 WORDS)

Adenocarcinoma

Human interleukin-9: genomic sequence, chromosomal location, and sequences essential for its expression in human T-cell leukemia virus (HTLV)-I-transformed human T cells.

We have isolated the genomic sequence of human interleukin-9 (IL-9) based on its sequence homology with a human IL-9 cDNA isolated from human T-cell leukemia virus (HTLV)-I-transformed T cells by expression cloning. The entire genomic sequence has been determined and the gene consists of five exons and four introns. The human IL-9 gene is mapped to the long arm of human chromosome 5 at band 5q31-32, a region found to be deleted in a number of patients with acquired 5q- abnormalities and hematologic disorders. Several blocks of transcriptional control sequences have been identified at the 5'-flanking region of the human IL-9 gene that may play an important role in the control of IL-9 gene expression. The 5'-regulatory region of the human IL-9 gene also contains sequences identified in the 5'-flanking regions of other cytokine genes mapped to the long arm of human chromosome 5, including IL-3, IL-4, IL-5, and granulocyte-macrophage colony-stimulating factor and other T-cell growth factor genes including IL-2 and IL-6. The IL-9 gene is constitutively expressed in the HTLV-I-transformed human T cells and the expression of IL-9 in these cells can be further induced by 12-O-tetradecanoyl phorbol 13-acetate. Transient transfection analysis using the plasmid containing the 5'-flanking region of IL-9 gene upstream from the firefly luciferase ciferase report gene indicated that the 0.9-kb Smal-Sacl fragment of the IL-9 gene contains sequences required for the constitutive and activated expression of IL-9 gene in HTLV-I-transformed cells. These results will now allow us to study the regulatory mechanism of IL-9 gene expression in normal and leukemic human T cells.

Amino Acid Sequence

Characterization of the human liver vasopressin receptor. Profound differences between human and rat vasopressin-receptor-mediated responses suggest only a minor role for vasopressin in regulating human hepatic function.

The [Arg8]vasopressin (AVP) receptor expressed by human hepatocytes was characterized, and compared with the rat hepatic V1a vasopressin receptor subtype. In addition to determining the pharmacological profile of the human receptor, the cellular responses to AVP were measured in human and rat hepatocytes by assaying glycogen phosphorylase alpha activity and DNA synthesis. Marked differences were observed between human and rat hepatocytes regarding vasopressin receptors and the intracellular consequences of stimulation by AVP. Data presented in this paper demonstrate the following, (i) Vasopressin V1a receptors are present in low abundance on human hepatocytes. (ii) Species differences exist between human and rat V1a receptors with respect to the affinity of some selective antagonists. (iii) AVP-stimulated glycogen phosphorylase a activation in human hepatocytes was approx. 5% of that observed in rat cells. (iv) In contrast with rat hepatocytes, DNA synthesis in human cells in culture was not stimulated by AVP. It is concluded that vasopressin plays only a minor role in the regulation of human hepatic function. Furthermore, conclusions drawn from observations made with AVP and its analogues on rat hepatic function cannot be directly extrapolated to the human situation.

Animals

Human pituitary and placental hormones control human insulin-like growth factor II secretion in human granulosa cells.

Human granulosa cells cultured with calf serum actively proliferated for 18-20 generation and secreted progesterone into the medium; progesterone levels appeared to decline with increase in generation number. Cells cultured under serum-free conditions secreted significant amounts of progesterone and insulin-like growth factor II (IGF-II). The progesterone secretion was enhanced by the addition of human follitropin, lutropin, and chorionic gonadotropin but not by growth hormone. These cells, when challenged to varying concentrations of human growth hormone, human chorionic somatomammotropin, human prolactin, chorionic gonadotropin, follitropin, and lutropin, secreted IGF-II into the medium as measured by specific IGF-II RIA. Among these human hormones, chorionic gonadotropin, follitropin, and lutropin were most effective in inducing IGF-II secretion from these cells. When synthetic lutropin-releasing hormone and alpha-inhibin-92 were tested, only lutropin-releasing hormone was effective in releasing IGF-II. The results described suggest that cultured human granulosa cells can proliferate and actively secrete progesterone and IGF-II into the medium. IGF-II production in human granulosa cells was influenced by a multi-hormonal complex including human growth hormone, human chorionic somatomammotropin, and prolactin.

Cells, Cultured

Antibody-producing human-human hybridomas. III. Derivation and characterization of two antibodies with specificity for human myeloid cells.

Peripheral blood mononuclear cells from a patient with acute myeloid leukemia (AML) and spleen cells from a patient with chronic myeloid leukemia (CML) were fused with HAT-sensitive human B lymphoma cells (RH-L4) in attempts to generate human monoclonal antibodies (Mab) against antigens with high specificity for myeloid leukemia cells. Forty-seven of 246 hybridomas secreted Ig that bound to AML cell surface constituents, as determined by FACS analysis of viable cells that were FITC-stained with the human Mab as the first-step reagent and FITC-conjugated rabbit anti-human Ig as second-step. Two of the 47 human Mab (one from each patient and designated AML-19 and CML-20, respectively) bound to both autologous and allogeneic myeloid leukemia cells. No significant binding was observed to cell surface constituents on human bone marrow cells, granulocytes, lymphocytes, erythrocytes, thymocytes, monocytes, lymphoblastic leukemia cells, fibroblasts, malignant B and T lymphocytic cell lines, and murine bone marrow cells. Both human Mab were IgG and were cytotoxic to myeloid leukemia cells in the presence of complement. About 70% of peripheral blood cell samples from 46 AML patients contained AML-19- and CML-20-positive cells, but the reactivity pattern had no correlation to the morphologic FAB classification of the samples. The promyelocytic HL60 cell line and the K562 cell line reacted with the two antibodies. Dot blot analysis of binding of AML-19 and CML-20 to cellular extracts immobilized on nitrocellulose paper showed that both human Mab in this assay also reacted with normal bone marrow cells. This was supported by microscopic immunofluorescence because both human Mab stained intracytoplasmatic structures in normal bone marrow cells, but both intracytoplasmatic and cell surface components stained in myeloid leukemia cells. Moreover, immunoblotting demonstrated that both human Mab in leukemia cells reacted with two cellular proteins with Mr approximately 14,500 and 18,000, and in normal bone marrow cells with a molecule with Mr approximately 20,000. Immunoprecipitation of cell membrane molecules with both the AML-19 and CML-20 antibody precipitated from leukemic cells only the molecule with Mr approximately 18,000 and no components from normal bone marrow cells. It is concluded that myeloid leukemogenesis may result in generation of cell surface expression of either new or abnormally processed molecules that are immunogenic in the autochthonous host. These molecules may also be useful as markers in diagnosis of myeloid leukemia.

Antibodies, Monoclonal

Recombinant human growth hormone promotes human lymphocyte engraftment in immunodeficient mice and results in an increased incidence of human Epstein Barr virus-induced B-cell lymphoma.

Recombinant human growth hormone (rhGH) previously has been demonstrated to promote human or mouse T-cell engraftment in immunodeficient mice. We then wanted to examine long-term effects of rhGH on human cell engraftment in these mice. Mice with severe combined immune deficiency (SCID) were given human peripheral blood lymphocytes or human bone marrow cells and daily injections of rhGH (20 micrograms ip every other day). Upon later assessment for engraftment by flow cytometric analysis, it was determined that rhGH strongly promoted human T-cell engraftment in the thymus and spleens of these mice. However, there was considerable variability in both the incidence and extent of engraftment which appears to be due to donor-to-donor variation. Additionally, rhGH promoted B lymphomagenesis in these mice since long-term treatment of these xenogeneic chimeras with rhGH resulted in the increased incidence of human Epstein-Barr virus (EBV)-infected B-cell lymphoma. Thus, while rhGH can be used to optimize human T-cell engraftment in SCID mice, it also increases the likelihood of B-cell lymphoma generation when the donor is EBV infected. The results suggest that the activation of human T cells by rhGH results in an increased ability of these cells to traffic to the peripheral lymphoid organs of the SCID mice and results in a lymphoid microenvironment conducive to the outgrowth of EBV-transformed B lymphocytes.

Animals

The recombinant human interferon-gamma receptor is fully functional in a human x murine hybrid containing human chromosome 21.

It has previously been shown that stimulation of class I MHC antigen expression by human interferon gamma (Hu-IFN gamma) depends on the presence of both human chromosomes 6 and 21. Even although the presence of human chromosome 6 results in normal expression of the IFN gamma receptor on the cell surface, chromosome 21 is required for this biological response. Here, we transfected the cDNA encoding the Hu-IFN gamma receptor into a mouse cell line, L(tk-), and into a mouse x human hybrid, GM08, containing the human chromosome 21 as the only human genetic material. Two clones, L-gamma R.8 and GM08-gamma R.9, were tested for different biological responses to Hu-IFN gamma. Only the hybrid containing the human chromosome 21 (GM08-gamma R.9) exhibited a biological response when assayed for the stimulation of murine class I MHC antigen expression by Hu-IFN gamma. Moreover, transcriptional induction of 2'-5'-oligoadenylate synthetase and 1-8 genes, as well as antiviral protection, were observed only in the GM08-gamma R.9 transfectants. These results show that human chromosome 21 encodes a factor which mediates different biological activities of Hu-IFN gamma.

Blotting, Northern

Do highly oncogenic group A human adenoviruses cause human cancer? Analysis of human tumors for adenovirus 12 transforming DNA sequences.

Adenovirus 12 (Ad12) (Huie) (highly oncogenic group A) readily induces tumors in newborn rodents. Since Ad12 is isolated from human fecal samples, we investigated whether it plays a role in the etiology of human gastrointestinal cancer. If Ad12 is a causal agent of human cancer, then human tumors should contain Ad12 transforming genes, as indicated by studies of cells transformed in vitro and in vivo by oncogenic viruses. Ad12 DNA and the Ad12 transforming restriction fragment (EcoRI-C fragment, left 16% of the viral genome) were labeled in vitro to 10(7) to 4 X 10(8) cpm/mug by the nick translation reaction of DNA polymerase of Escherichia coli. The fidelity and sensitivity of these probes were established by (i) analysis of DNA from Ad12-transformed cells and from hamsters with tumors induced by Ad12, (ii) reconstruction experiments with added Ad12 DNA and EcoRI restriction fragments, and (iii) comparison of annealing characteristics with Ad12 probes labeled in vivo. With Ad12 [3H]DNA as probe, no viral DNA sequences were detected in 18 normal gastrointestinal tissues and 34 gastrointestinal tumors, including cancers of the colon, rectum, small intestine, and stomach, under conditions that would detect 0.1 copy of the Ad12 genome per tumor cell. Similar analyses of Ad12-transformed hamster cells and Ad12 primary hamster tumors indicated 6-18 copies per cell of over 90% of the viral genome. With the Ad12 EcoRI-C transforming fragment as probe, no hybridization was detected with 32 human gastrointestinal tumors and five normal tissues; this result excludes 1-2% of the Ad12 genome per tumor cell. Our date are strong evidence that Ad12 is not a major cause of human gastrointestinal cancer. The Ad12 transforming EcoRI-C fragment hybridized (50-68% efficiency) with other Ad12 isolates and with Ad18 and 31 (members of oncogenic group A), but not at all with 28 other human Ad serotypes (manuscript in preparation). Thus other group A members probably are also not involved in human gastrointestinal cancer. No viral DNA sequences were detected in 12 normal lungs and 22 lung tumors, suggesting that respiratory cancer does not involve an Ad12 etiology.

Adenoviruses, Human

Production and characterization of human-human and human-mouse hybridomas secreting Rh(D)-specific monoclonal antibodies.

Human monoclonal antibodies specific for the Rh(D) antigen were produced by cell lines generated by the fusion of pooled Epstein-Barr virus (EBV)-transformed B-cell lines secreting Rh(D) antibodies with the murine myeloma cell line NS.1 or with the human lymphoblastoid cell line HOA.1. The selection of hybrids was achieved in RPMI 1640 medium containing HAT and ouabain. Higher fusion efficiency was obtained with the NS.1 cell line; however, the hybrids with HOA.1 exhibited a greater clonal stability. The products of four clones (three human-human and one human-mouse) that consistently secreted antibodies for over 11 months were tested for specificity with a panel of red cells of various Rh phenotypes. The supernatants of all four clones showed anti-Rh(D) specificity but failed to react with the red cell Du phenotypes categorized as DV(Dw+) and DVI. Two of the three human-human clones secreted IgM(lambda) and the third IgG(kappa). The human-mouse clone produced IgG(kappa) antibody.

Animals