Differentiation antigens of mouse teratocarcinoma stem cells defined by monoclonal antibodies

Three differentiation antigens of mouse teratocarcinoma stem cells are defined using a panel of ten IgM-class monoclonal antibodies raised against teratocarcinoma F9 cells. TEC-01 and four other antibodies define an antigen that corresponds to SSEA-1. TEC-02 antibody defines an antigen that is expressed on teratocarcinoma stem cells, parietal yolk sac cells PYS-2, unfertilized eggs including the zona pellucida and blastocysts. It is absent from all mouse adult tissues tested. Three other antibodies exhibit binding properties similar to TEC-02. TEC-03 antibody defines an antigen that is expressed on teratocarcinoma stem cells, PYS-2 cells and mouse blastocysts. It is absent from all mouse adult tissues except for lungs.     

Protein patterns of developmentally totipotent mouse teratocarcinoma cells and normal early embryo cells

Protein patterns of mouse teratocarcinoma stem cells were compared, by two-dimensional gel electrophoresis, with those of early embryo cells. These malignant cells were known from previous experiments (B. Mintz and K. Illmensee, 1975, Proc. Nat. Acad. Sci. USA72, 3585–3589) to be capable of conversion to normalcy and of contributing to embryogenesis when introduced into a blastocyst. The protein comparisons were intended to reveal whether totipotent teratocarcinoma cells most nearly resemble normal totipotent cells of a specific stage, as a possible clue to their developmental origins. A simple method was devised for the purpose of generally facilitating comparisons of two-dimensional gels, among which technical variations commonly alter the absolute positions of individual proteins. This variation was normalized by the use of a reference constellation, or a network of lines connecting shared landmark proteins identified in all the gels. Whereas the network may undergo topological change from one gel to another, it continues to provide a readily recognized standard of reference. Protein patterns displayed many similarities and some differences, hence nonidentity, between teratocarcinoma cells and all normal preimplantation embryo stages tested, as well as between the various embryo stages themselves. The results also unexpectedly disclosed, however, that changed physiological states or posttranslational alterations may contribute significantly to some of the protein differences irrespective of the developmental status or potentialities of the cells. For example, in the OTT 6050 teratocarcinoma transplant line, pure teratocarcinoma cell groups (“cores”) found in the ascites fluid synthesized several proteins not expressed when the cores were enveloped (in embryoid bodies) by a yolk saclike epithelium; yet the core cells from both sources form comparable tumors if injected subcutaneously and are able to undergo differentiation if injected into blastocysts. In another comparison, some proteins that were present in inner cell masses isolated from blastocysts were absent in intact blastocysts, possibly because of their modification by the surrounding trophoblast in the latter case. These observations imply that protein differences between embryo regions or stages, however real, are not necessarily relevant for an evaluation of their developmental prospects.     

Phylogenetic cross-reactivities of monoclonal antibodies produced against rat neurophysin

Previously described mouse monoclonal antibodies against rat neurophysins [Ben-Barak, Y., et al. (1985); Whitnall, M. H., et al. (1985)] were studied here for their cross-reactivities to neurophysins (NPs) from other vertebrate species. Posterior pituitary extracts from various mammals (rat, mouse, cow, human) and lower vertebrates (frog, ratfish) were studied. The monoclonal antibodies displayed several distinct patterns of cross-reactivity to the various species, indicating that the epitopes which they recognized were different. PS 67 bound strongly to rat pituitary extract in solid-phase radioimmunoassay (RIA) but showed no cross-reactivity with extracts from any of the other species tested, including the mouse. PS 36 cross-reacted with mouse and frog extracts but showed almost no cross-reactivity with cow and none to ratfish extracts. PS 41 cross-reacted with mouse, cow, and frog extracts. PS 45 was the most cross-reactive antibody and recognized an antigen in extracts from mouse, cow, frog, and ratfish pituitaries. Electrophoresis of proteins extracted from posterior pituitaries, followed by immunoblot staining with either PS 36 or PS 45, demonstrated that the NP-like molecules within each species are heterogeneous, i.e., more than two bands stained in each species. The frog NP stained by PS 45 was about twice the molecular weight of the mammalian NPs. The possible valve of the PS 45 antibody for future molecular cloning experiments on the arginine vasotocin precursor in lower vertebrates is discussed.     

Characterization of three mouse monoclonal antibodies that react with high-molecular-mass glycopeptides isolated from F9 mouse teratocarcinoma cells

Three IgM mouse monoclonal antibodies, NL-9, Thy-22, and HL-5, which were produced primarily against human hematopoietic cells, were tested for their reactivity with various mouse cell lines and were found to react predominantly with mouse embryonal carcinoma cells. Thy-22 reacted with 2-cell-stage mouse embryos, whereas the other two antibodies were not reactive at this stage. All three antibodies, however, reacted with 8-cell-stage embryos. At the blastocyst stage, Thy-22 reacted with the entire surface of the trophectoderm cells, whereas the reactivity of NL-9 and HL-5 was weaker and was polarized on the mural trophectoderm. Immunohistological examination of 6th-day mouse embryos using anti-complement immunofluorescence demonstrated that the embryonic ectoderm was positive for all three antibodies: the reaction of NL-9 and Thy-22 was uniformly distributed over these cells, whereas HL-5 predominantly stained the luminal aspects of the cells lining the proamniotic cavity. Visceral-endoderm cells and trophoblastic cells were positive with all three monoclonal antibodies, whereas the parietal endoderm, extraembryonic ectoderm, and ectoplacental cone were negative. In 19th-day fetuses and adult tissues, certain epithelial cells were stained by these three antibodies. The biochemical nature of the antigens detected was also investigated. Farr's assay showed that both NL-9 and Thy-22 precipitated approximately 10% of the high-molecular-mass glycopeptides isolated from F9 cells, while HL-5 reacted with about 5% of these glycopeptides. The reactivity of the three antibodies against the glycopeptides was completely inhibited by the presence of X-hapten-conjugated silica.(ABSTRACT TRUNCATED AT 250 WORDS)     

Basement membrane components produced by a mouse ascites teratocarcinoma TB 24 : Analysis with monoclonal and polyclonal antibodies

Monoclonal antibodies were produced against two basement membrane glycoproteins, laminin and entactin. The specificity of the antibodies and the absence of cross-reactivity were established by radio-immunoprecipitation of mouse ascites teratocarcinoma cell lysates. This teratocarcinoma, TB24, formed large embryoid bodies filled with extracellular matrix. The major component of the matrix was laminin. Abundant entactin, substantial amounts of fibronectin and rather little collagen type IV were also found in the matrix by biochemical and immunofluorescence analyses. TB24 teratocarcinoma appears to be a good model to test anti-basement membrane antibodies and to isolate certain extracellular matrix components in preparative quantities.     

Production of monoclonal antibodies against mouse molar papilla cells

To develop markers for the analysis of the molecular mechanisms of dental papilla cells differentiation, 10 monoclonal antibodies were produced against trypsin-isolated mouse molar dental papilla cells. These antibodies identify matrix components, cell membrane associated antigens and intracellular-constituents. Changes of the staining patterns were correlated with a typological hierarchy of dental papilla cells and with terminal differentiation of odontoblasts.     

Serological analysis of serogroup icterohaemorrhagiae using monoclonal antibodies

Eighteen serovars (19 strains) of serogroup Icterohaemorrhagiae were serologically analyzed using 18 monoclonal antibodies against serovar copenhageni Shiromizu, M20 and serovar icterohaemorrhagiae RGA strains. The reaction patterns of the serovars against these monoclonal antibodies were different. According to these results, we divided the serovars, except for serovar tonkini, into the following three subgroups: Subgroup 1 reacted to many monoclonal antibodies including serovars icterohaemorrhagiae, copenhageni, hualien, monymusk, mankarso, and budapest. Subgroup 2 fell between subgroups 1 and 3 including serovars dakota, naam, bogvere, birkini, smithi, ndambari, gem, ndahambukuje and mwogolo. Subgroup 3 reacted to only a few monoclonal antibodies: serovars weaveri and sarmin. Serovar tonkini did not react to any of the monoclonal antibodies used. There is a possibility that serovar tonkini does not belong to serogroup Icterohaemorrhagiae. Further studies on the serological reactions of each strain revealed that it was impossible to distinguish the RGA strain from the serovar hualien LT11-31 strain, indicating that they may be identical. It was also observed that serovar copenhageni and monymusk seemed to be closely related. Serovars birkini and smithi, and serovars ndambari and gem were alike in their serological reactivities. Among the 18 monoclonal antibodies, RGAMA-1 was a unique antibody which reacted only to serovar icterohaemorrhagiae and serovar hualien, indicating that it must be the serovar icterohaemorrhagiae specific antibody. On the other hand, SHIRMA-2, 5, 6 reacted to all the serovars except for serovars weaveri, sarmin, and tonkini. These antibodies exhibited a broad reaction spectrum.     

Serological analysis of H-2 and Ia molecules with monoclonal antibodies

Five H-2 and seven Ia monoclonal antibodies were tested against a panel of 43 independentH-2 haplotypes (11 of laboratory-mouse and 32 of wild-mouse origin), 33 recombinantH-2 haplotypes, and up to 74 wild mice. All the antibodies gave negative reactions in the PVP hemagglutination tests; all, however, gave positive reaction with some members of the panel in the dye-exclusion cytotoxic test. Four of the antibodies (H-2.m2,Ia.m2, Ia.m5 and Ia.m7) reacted identically to conventional antibodies detecting determinants H-2.2., and Ia-1.2, Ia-1.15, and Ia-5.7, respectively (this statement does not apply to wild mice in which minor differences in reactivity patterns of the corresponding antibodies were found: the reproducibility of these differences, however, could not be checked by absorption). Five other antibodies (H-2.m5, H-2.m3, H-2.m4, Ia.ml, and Ia.m6) had very similar though not identical reactivity patterns to conventional antibodies detecting determinants H-2.5, H-2.11, H-2.25, Ia-1.2, and Ia-1.19, respectively. The last three monoclonal antibodies (H-2.ml, Ia.m3, and Ia.m4) had a reactivity pattern that did not match those of any known conventional antibodies. The near identity or great similarity of many monoclonal and conventional antibodies indicates that the cleanest of the conventional antisera are truly monospecific, and gives credence to the H-2 serology as defined by conventional antibodies. The serological analysis of monoclonal antibodies supports the true existence of private and public determinants, and reveals that the H-2 and Ia determinants are complex, even when the antibody is simple.     

Specific monoclonal antibodies against the surface of rat islet beta cells

Type 1 diabetes arises from the autoimmune destruction of islet beta cells, with the participation of both arms of the immune system. To better characterize the beta cell membrane, we have raised monoclonal antibodies to the surface of the INS-1 insulinoma cell line. Twenty-two such antibodies were produced, 21 of the IgG class, all reactive to different cell membrane proteins from INS-1 and neonatal islet cells, yielding identical electrophoresis patterns, with molecular weights mainly between 45 and 60 kD. We have focused on three such antibodies that recognize different protein targets, and are specific for islet beta cells. The target protein of antibody AA4, also found on monkey islets, is expressed at significantly higher levels on beta cells (55.8 vs 30.6% of cells, plus 3-4 fold increase in average fluorescence intensity per cell) when neonatal rat islet cells are incubated with high (16 mM vs 3mM) glucose concentrations. Further identification of the target antigens is in progress and is expected to shed more light on the properties of beta cell membrane proteins, and their probable participation in various disease processes.     

Surface antigenic analysis of rosette-forming cells in rat thymus--using monoclonal antibodies against T cell surface markers.

We have assumed that rat thymocytes capable of rosette-formation with guinea pig erythrocytes were double positive (CD4+8+) cells. Therefore surface-binding erythrocytes on rosette-forming lymphocytes (RFLs), separated in highly pure state, were eliminated by a hypotonic shock. The surface markers of RFLs, without surface erythrocytes, were analyzed by flow cytometry using two kinds of monoclonal antibodies (anti-CD4, anti-CD8) labelled with different fluorescence materials. About 96.2% of cells in the RFL population were sorted in two areas, into which double positive cells were separated. This result substantiates the assumption mentioned above. It was, furthermore, discussed that the RFLs without surface erythrocytes would be one of the valuable materials for disclosing the mechanisms of differentiation and maturation from double positive thymocytes to single positive ones.     

Mouse monoclonal antibodies against rat estramustine binding protein

Hybridomas producing antibodies against rat prostatic estramustine binding protein (rEMBP) have been obtained by fusion of spleen lymphocytes from Balb/c mice, immunized with rEMBP, and SP2/0 Ag 14 mouse myeloma cells. Anti-rEMBP IgG producing cultures were identified in a solid phase ELISA using alkaline phosphatase conjugated sheep antimouse IgG. Cultures producing specific antibodies were subcloned and expanded. The produced immunoglobulins were characterized according to interaction with subunits of rEMBP. No interaction was found with [3H]estramustine-human estramustine binding protein. Following development of a radioimmunoassay, tissue distribution of rEMBP in the rat was studied. Despite high specificity, shown by selective interaction with rEMBP (F and S subunits), macromolecules interacting with anti-rEMBP were found in high concentrations in the prostrate and also in low concentrations, in other tissues of the male genital tract, and further in the adrenals, pancreas and submaxillary gland. The high specificity also makes it possible to study the F and S subunit selectively. These results show that macromolecules very similar to rEMBP are present in hormone-sensitive tissues in the rat.     

Inhibitory monoclonal antibodies against rat liver alcohol dehydrogenase

Eleven hybridoma clones which secrete monoclonal antibodies against purified rat liver alcohol dehydrogenase (EC 1.1.1.1) were isolated. Antibodies (R-1-R-11) were identified by their ability to bind to immobilized pure alcohol dehydrogenase in an enzyme-linked immunoadsorbent assay, in which antibody R-9 showed the highest binding capacity. Except for R-1 and R-7, all antibodies inhibited catalytic activity of the enzyme isolated from inbred (Fischer-344) or outbred (Sprague-Dawley) strains (R-11 greater than R-9 greater than R-4 greater than R-6 greater than R-10 greater than R-8 greater than R-2 = R-3 = R-5). The inhibition of enzyme activity by antibodies was noncompetitive for ethanol and NAD+, and was dependent on antibody concentration and incubation time. Antibodies R-4, R-9, and R-11 were most effective when enzyme activity was assayed below pH 7.7-7.8, a condition thought to protonate the enzyme's active center. These three antibodies did not inhibit horse liver alcohol dehydrogenase activity, indicating their species specificity. Such antibodies will be useful to delineate structural and functional roles of rat liver alcohol dehydrogenase.     

Antigenic analysis of flaviviruses with monoclonal antibodies against Negishi virus

Twelve monoclonal antibodies against Negishi virus were obtained and characterized by hemagglutination inhibition (HI) and neutralization (NT) tests using five flaviviruses isolated in the pan-Pacific region. The reaction pattern of the antibodies showed that Negishi virus was most closely related to Langat virus, followed by 3-Arch, JE and Apoi viruses in that order. Hemagglutinating (HA) antigen of the virus had distinct HI relating sites which were Negishi virus specific, tick borne encephalitis (TBE) virus complex specific and flavivirus cross-reactive. Monoclonal anti-Negishi antibodies cross-reactive to Japanese encephalitis (JE) virus in the HI test had neutralizing activity to JE virus but no activity to homologous Negishi virus.     

Splenic microenvironment of the CBA/N mouse: immunohistochemical analysis using monoclonal antibodies against lymphocytes and nonlymphoid cells

CBA/N mice carry an X-linked immune-deficiency gene, leading to a defect in the ability to form antibodies against T-independent type 2 antigens. By using immunohistochemistry, the organization of the spleen of the immune-deficient male (xid) CBA/N F1 and the normal female F1 were compared. Staining with antilymphocyte markers showed that the total number of cells in the various T- and B-cell areas was smaller in the xid mouse, resulting in very small white pulp compartments. Fewer B cells were seen in the marginal zone. When the spleens of the F1 mice were examined for macrophage markers, the rings of marginal-zone macrophages and the ring of marginal metallophilic macrophages were much thinner in the xid mouse. In particular, the marginal-zone macrophages are thought to play a role in the response against thymus-independent type 2 antigens, and their small numbers in the xid mouse are suggestive of a role for the microenvironment in the defects in these mice.     

Human monoclonal antibodies to Pseudomonas aeruginosa produced by EBV-transformed cells

Numerous lymphoblastoid cell lines (LCLs) which secreted antibodies against Pseudomonas aeruginosa (all Fisher's immunotypes and Homma's immunotype 1) were established by Epstein-Barr virus (EBV)-transformation of lymphocytes. Five LCLs were established as long-term culture lines and their properties were determined. These LCLs produced monoclonal antibodies to Fisher's immunotype 1 and 4 and Homma's immunotype 1, and their immunoglobulin classes were IgM, IgG, and IgA. We found that three monoclonal antibodies (G3-1, H7-2, and E10-1) among them successfully protected mice from the corresponding immunotype of P. aeruginosa infection. Their protective dose (PD50) values were 0.5, 2.6, and 3.1 micrograms immunoglobulin/mouse. These human monoclonal antibodies against P. aeruginosa prepared by EBV-transformation method will be a valuable aid for the treatment for severe P. aeruginosa infections.     

Homophilic binding of mouse monoclonal antibodies against GD3 ganglioside.

R24, a mouse IgG3 mAb against GD3 ganglioside, was shown to bind to itself in a homophilic manner. This was demonstrated by augmented binding of 125I-labeled R24 to the cell surface of GD3+ cells by unlabeled R24 and by direct binding of biotinylated R24 to R24 adsorbed on solid phase. Although homophilic binding was evident when R24 was bound to solid phase, R24-R24 aggregates could not be detected in solution under otherwise identical conditions. R24 bound to four other mAb (two IgG3, one IgG2a, one IgM) directed against GD3 but did not bind to a panel of 21 other mAb including other IgG3 mAb and mAb directed against non-GD3 ganglioside. Evidence implicating the GD3-binding site of R24 in homophilic binding included the following observations: 1) F(ab')2 fragments of R24 could bind to R24, 2) an antiidiotypic mAb against the GD3-binding site of R24 inhibited R24 homophilic binding, 3) an IgM anti-GD3 mAb also demonstrated homophilic binding to R24, and 4) homophilic binding was a function of immunoreactivity and avidity for GD3. R24 variants with 40-fold lower avidity for GD3 demonstrated a similar decrease in homophilic binding. Inasmuch as R24 bound to R24 F(ab')2 fragments and specifically to anti-GD3 mAb, it appeared that the target for homophilic binding was an epitope within the V region of anti-GD3 mAb. It is likely that homophilic interactions result in increased affinity of R24 for GD3 through increased effective valency of antibody-Ag complexes.     

Somatic cell hybrids between totipotent mouse teratocarcinoma and rat hepatoma cells.

We have produced somatic cell hybrids between totipotent mouse teratocarcinoma cells and rat hepatoma cells. These hybrids were tested for the expression of liver specific functions expressed in the hepatoma cell parent and for their ability to differentiate when injected into nude mice. The results of this study indicate that hybrid cell clones do not resemble either of the parental cells, since they do not produce albumin and tyrosine aminotransferase that are expressed in the rat hepatoma parent, and are incapable of forming either teratocarcinomas or hepatomas when injected in experimental animals.     

Isolation and analysis of monoclonal antibodies against various gangliosides

Female BALB/c mice were immunized with human melanoma (Mewo) cells containing ganglioside GD3 as a surface antigen. Immune splenocytes were fused with syngeneic P3-X63.Ag 8 myeloma cells. Antibodies produced by hybrid clones were analyzed by solid phase immunoassay. B, C, D and Q clones producing antibodies against Raja clavata brain gangliosides were obtained. Monoclonal B and C antibodies bound monosialogangliosides. Monoclonal D antibody bound a number of gangliosides but reacted predominantly with GD1a. Monoclonal Q antibody reacted selectively with GQ1c. It is assumed that ganglioside GQ1c is expressed on the melanoma cell surface and may be found only in the early stage of ontogenesis of high vertebrates.