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C M Croce

Publications and source records attributed to C M Croce.

At least 415 records · Page 23Linked to original sources
PubMed1982

Translocation of immunoglobulin VH genes in Burkitt lymphoma.

We have produced cell hybrids between mouse myeloma cells, which do not produce immunoglobulin chains, and Burkitt lymphoma cells (Daudi), which express surface IgM. Daudi Cells carry a reciprocal chromosome translocation between chromosomes 8 and 14, described as (8;14)(q24;q32). The hybrids were studied for the expression of human immunoglobulin chains and human isozyme markers, for the presence of human chromosomes, and for the presence of the human genes for heavy chain variable regions (VH) and mu and gamma chain constant (C) regions. The results indicate that the expressed mu chain gene is on normal chromosome 14 in Daudi cells. We have also determined that the chromosome 14 involved in the translocation (14q+) carries the gene for C mu and C gamma 1-4 and probably several genes for the variable region (V). Certain hybrids had lost both the chromosomes 14 but had retained the abnormal chromosome 8 (8q-) that carries the terminal end of the long arm of chromosome 14. These hybrids were studied for the presence of human VH, C mu,, and C gamma DNA sequences, and the results indicated that the hybrid cells with the 8q- chromosome contained VH genes that not C genes. Therefore, we conclude that, in the Daudi Burkitt lymphoma, the break in chromosome 14 occurred within the chromosome segment containing V region genes. As a result of the translocation some of these VH genes became associated with chromosome 8. It is possible that the expression of malignancy in Burkitt lymphoma is caused by immunoglobulin V region gene translocation resulting in activation of a gene on the long arm of human chromosome 8.

Binding Sites, Antibody↗
PubMed1982

Antigen-specific human T-cell hybridomas with helper activity.

Human T cell hybridomas were produced by fusing the hypoxanthine phosphoribosyltransferase-deficient line of the human T cell lymphoma Jurkat with a continuous line of normal human T cells specific for tetanus toxoid (TeT). The hybridomas were selected for their ability to produce interleukin 2 after exposure to TeT on semiautologous monocytes and for their ability to bind to TeT-pulsed semiautologous monocytes. These antigen-specific T hybridomas demonstrated potent helper activity for semiautologous B cells as determined by the production of high levels of anti-TeT antibody in vitro.

Antibody Formation↗
PubMed1982

Human c-myc onc gene is located on the region of chromosome 8 that is translocated in Burkitt lymphoma cells.

Human sequences related to the transforming gene (v-myc) of avian myelocytomatosis virus (MC29) are represented by at least one gene and several related sequences that may represent pseudogenes. By using a DNA probe that is specific for the complete gene (c-myc), different somatic cell hybrids possessing varying numbers of human chromosomes were analyzed by the Southern blotting technique. The results indicate that the human c-myc gene is located on chromosome 8. The analysis of hybrids between rodent cells and human Burkitt lymphoma cells, which carry a reciprocal translocation between chromosomes 8 and 14, allowed the mapping of the human c-myc gene on region (q24 leads to qter) of chromosome 8. This chromosomal region is translocated to either human chromosome 2, 14, or 22 in Burkitt lymphoma cells.

Burkitt Lymphoma↗
PubMed1981

Transcription of the simian virus 40 genome in DNA-transformed murine teratocarcinoma stem cells.

To study the molecular basis for lack of expression of the simian virus 40 (SV40) early region genes in murine teratocarcinoma-derived stem cells, we introduced a recombinant plasmid consisting of pBR322 linked to the herpes simplex virus type 1 thymidine kinase gene and SV40 genome into thymidine kinase-deficient F9 stem cells. The resulting stem cell clone, 12-1, and a retinoic acid-induced differentiated daughter cell clone, 12-1a, each contain one copy per cell of the entire recombinant plasmid integrated into the cellular genome through a site on the pBR322 genome. Restriction endonuclease analyses indicate that there is no difference in integration site or organization of the three component parts of the plasmid genome within cellular DNA of stem and differentiated cells; yet the differentiated cells, 12-1a, express SV40 large tumor antigen whereas the stem cells, 12-1, do not. Both stem and differentiated cells produce two size classes of polyadenylylated RNA, 2900 and 2600 bases in length, homologous to the early region of the SV40 genome, detectable by RNA blotting analysis. S1 nuclease analysis of the SV40 transcripts present in stem and differentiated cells indicate that the SV40 mRNAs were identically spliced in the two cell types, in a manner consistent with that observed for spliced large and small tumor antigen mRNAs in SV40-infected monkey kidney cells. Thus, the failure of 12-1 teratocarcinoma stem cells, containing an integrated SV40 genome, to express SV40 tumor antigen is not due to a lack of transcription of the SV40 early region or to an inability to splice primary transcripts.

Animals↗
PubMed1981

Deoxyribonuclease I sensitivity of plasmid genomes in teratocarcinoma-derived stem and differentiated cells.

The DNase I (EC 3.1.21.1) sensitivities of the simian virus 40 (SV40) genome, the pBR322 genome, and the herpes simplex virus type 1 thymidine kinase (HSV-1 tk) gene have been compared in teratocarcinoma-derived stem (12-1) and differentiated (12-1a) cell lines established by transfection of thymidine kinase (ATP:thymidine 5'-phosphotransferase, EC 2.7.1.21)-deficient F9 cells with DNA from a tripartite plasmid genome consisting of the pBR322 genome, the SV40 genome, and the HSV-1 tk gene. HSV-1 tk is present in both stem and differentiated cells; SV40 early proteins are present in differentiated cells but not in stem cells; the pBR322 genome is not expressed in either cell type. The SV40 and pBR322 genomes are more sensitive to DNase I digestion in stem cells than in differentiated cells, reflecting the DNase I-hypersensitivity of total stem-cell chromatin. The HSV-1 tk gene is the least sensitive to DNase I digestion in both cell types.

Animals↗
PubMed1981

Control of expression of histocompatibility antigens (H-2) and beta 2-microglobulin in F9 teratocarcinoma stem cells.

Murine teratocarcinoma stem cells, unlike most other cell types, do not express major histocompatibility antigens. The steady-state levels of beta 2-microglobulin and H-2 mRNA from F9-derived teratocarcinoma stem and differentiated cells were examined by blot hybridization using cloned DNA probes specific for these mRNAs. No H-2- or beta 2-microglobulin-specific RNA was detected in F9 teratocarcinoma stem cells (clone 12-1); thus, F9 teratocarcinoma stem cells (clone 12-1) contain no more than 1/10 the H-2 and beta 2-microglobulin mRNAs of the differentiated daughter cells (clone 12-1a). We suggest that this regulation of major histocompatibility antigen expression is due to transcriptional control of the major histocompatibility antigen genes, H-2 and beta 2-microglobulin. The transcriptional regulation of these genes is accompanied by a change in their DNase I sensitivity. Normally, transcriptionally inactive genes are DNase I resistant, while active genes are DNase I sensitive. In contrast, the silent major histocompatibility antigen genes of teratocarcinoma stem cells are more DNase I sensitive than the active genes of the differentiated cells.

Beta-Globulins↗
PubMed1980

Production of human hybridomas secreting antibodies to measles virus.

Monoclonal antibodies against a variety of antigens can be produced using techniques of somatic cell hybridization between cells of rodent myeloma lines and B cells derived from animals immunized against a given antigen. However, because of the monoclonal antibodies secreted by these hybridomas are of rodent origin, their use in human immunotherapy is limited. Thus the production of B-cell hybrids that secrete human monoclonal antibodies may be of considerable value. We have hybridized a hypoxanthine phosphoribosyl transferase (HPRT)-deficient human B-cell line derived from a patient suffering from multiple myeloma with peripheral lymphocytes obtained from a patient with subacute sclerosing panencephalitis (SSPE). These hybridomas were found to secrete human IgM specific for measles virus nucleocapsids.

Antibodies, Viral↗
PubMed1980

Expression of the teratocarcinoma phenotype in hybrids between totipotent mouse teratocarcinoma and myeloma cells.

We have produced somatic cell hybrids between totipotent mouse teratocarcinoma and myeloma cells. These hybrids behave like the teratocarcinoma cell parent and express teratocarcinoma embryonal antigens. However, they also express the myeloma H-2 antigens. THe availability of these hybrids should make it possible to study the expression of already rearranged immunoglobulin genes during mouse development.

Animals↗
PubMed1980

Cloning and partial nucleotide sequence of human immunoglobulin mu chain cDNA from B cells and mouse-human hybridomas.

Purified mRNAs coding for mu and kappa human immunoglobulin polypeptides were translated in vitro and their products were characterized. The mu-specific mRNAs, derived from both human lymphoblastoid cells (GM607) and from a mouse-human somatic cell hybrid secreting human mu chains (alpha D5-H11-BC11), were copied into cDNAs and inserted into the plasmid pBR322. Several recombinant cDNAs that were obtained were identified by a combination of colony hybridization with labeled probes, in vitro translation of plasmid-selected mu mRNAs, and DNA nucleotide sequence determination. One recombinant DNA, for which the sequence has been partially determined, contains the codons for part of the C3 constant region domain through the carboxy-terminal piece (155 amino acids total) as well as the entire 3' noncoding sequence up to the poly(A) site of the human mu mRNA. The sequence A-A-U-A-A occurs 12 nucleotides prior to the poly(A) addition site in the human mu mRNA. Considerable sequence homology is observed in the mouse and human mu mRNA 3' coding and noncoding sequences.

Animals↗
PubMed1980

Uniparental propagation of mitochondrial DNA in mouse-human cell hybrids.

The retention of the two parental mitochondrial DNAs has been investigated in a large number of mouse-human cell hybrids segregating either mouse or human chromosomes, by using a highly sensitive and specific method for detection of the DNA; the results have been correlated with the karyotype and isozyme marker pattern in the same hybrid lines. In all the hybrids examined, a consistent pattern was observed for the type of mitochondrial DNA retained: the mitochondrial DNA of the parent whose chromosomes were segregated from the nucleus was undetectable or present in marginal amounts. This was true also of hybrids containing a complete set of the segregating chromosomes in the total or a large fraction of the cell population.

Animals↗
PubMed1980

DNA-transformed murine teratocarcinoma cells: regulation of expression of simian virus 40 tumor antigen in stem versus differentiated cells.

Thymidine kinase-deficient (TK-; ATP:thymidine 5'-phosphotransferase, EC 2.7.1.21)F9 teratocarcinoma stem cells have been transformed with a recombinant plasmid genome consisting of the pBR322 genome linked to a herpes simplex virus type 1 thymidine kinase gene (HSV-1 tk) and a simian virus 40 (SV40) genome. A clonal line of stem cells was obtained that contains only one copy of plasmid DNA, which is integrated into murine chromosomal DNA through a site on the pBRR322 genome. The HSV-1 tk gene, which is adjacent to the SV40 genome, is expressed in stem cells, whereas SV40 gene expression is not detectable. If differentiation of these stem cells is induced, the differentiated cells express SV40 early gene products. Thus, we have constructed a stem cell which contains a set of genes (SV40), the expression of which is regulated differently in stem and differentiated cells. This cell line could be used to determine the mechanism of suppression of expression of these genes in stem cells.

Animals↗
PubMed1979

A murine teratocarcinoma stem cell line carries suppressed oncogenic virus genomes.

Murine teratocarcinoma stem cells are nonpermissive for productive infection by a variety of DNA (polyoma and SV40 virus) and RNA (murine leukemia and sarcoma virus) tumor viruses whereas differentiated murine cells derived from the stem cells are permissive for productive (or abortive in the case of SV40) infection by these same viruses. The block to productive infection by these oncogenic viruses is at a postpenetration step in the replication cycle of these viruses but the precise level of the block has not been established for any of these viruses. In this report we describe teratocarcinoma-derived stem and differentiated cell lines which should be especially useful in determining the level of the block to replication of ecotropic murine leukemia virus in murine teratocarcinoma stem cells. The stem cell line, OTT6050AF1 BrdU, which is completely nonpermissive to productive infection by Moloney murine leukemia virus and consists of 97% pluripotent stem cells, contains DNA copies of an RNA tumor virus which is indistinguishable from the N-tropic murine leukemia virus of AKR mice. The stem cells are negative for expression of viral reverse transcriptase, p30 and gp69/71 and no virus is found by XC plaque assay or other biological tests. Differentiated cells established from the same teratocarcinoma tumor are 100% positive for viral gp69/71, p30, and produce large amounts of reverse transcriptase activity and N-tropic virus as detected by biological assay. The virus isolated from the differentiated cells is closely related, if not identical to AKR N-tropic virus by nucleic acid hybridization studies and is thus not an endogenous virus of the 129 strain of mice. The teratocarcinoma tumor from which the cell lines were established had been carried in 129 mice and perhaps at some time in the mouse passage history the tumors were infected (nonproductively) with the N-tropic virus. Regardless of the origin of this viral DNA, the OTT6050A derived stem and differentiated cell lines should be extremely useful in defining in stem cells the step at which ecotropic murine leukemia virus replication is blocked.

Animals↗