scholarly journals Multiple immunoglobulin heavy-chain gene transcripts in Abelson murine leukemia virus-transformed lymphoid cell lines.

1982 ◽  
Vol 2 (4) ◽  
pp. 386-400 ◽  
Author(s):  
F W Alt ◽  
N Rosenberg ◽  
V Enea ◽  
E Siden ◽  
D Baltimore
Keyword(s):  
Heavy Chain ◽  
Lymphoid Cell ◽  
Murine Leukemia Virus ◽  
Leukemia Virus ◽  
Lymphoid Cells ◽  
Chain Gene ◽  
Rna Sequences ◽  
Abelson Murine Leukemia Virus ◽  
Polypeptide Chains ◽  
Murine Leukemia

Lymphoid cells transformed by Abelson murine leukemia virus (A-MuLV) contain three classes of RNA transcripts from immunoglobulin mu genes. P mu-mRNAs (productive) correspond to the normal 2.7-kilobase (kb) membrane (mu m) and 2.4-kb secreted (mu s) mu mRNA species both in size and coding capacity and occur at approximately equal abundance in most mu-positive (pre-B-like) A-MuLV transformants. A mu-mRNAs (aberrant) generally fall into one of two categories--aberrantly small 2.3-kb mu m and 2.0-kb mu s mRNAs which encode aberrantly small mu polypeptide chains, or normal-sized, V H-containing mu RNAs which do not encode immunologically identifiable mu polypeptide chains. In one case, the latter type of A mu-mRNA was demonstrated to result from an in-phase termination codon in the D segment of the mu mRNA. Also, most, if not all, A-MuLV transformants express members of a 3.0 to 1.9-kb set of C mu-containing, but V H-negative S mu-RNAs (for sterile), the expression of which may occur simultaneously with but independently of P mu-mRNAs or A mu-mRNAs. The S mu-RNA sequences do not encode immunologically identifiable mu chains and can be produced by cells with unrearranged heavy-chain alleles, such as T-lymphocytes, although the structure of the S mu-RNAs from T-lymphoid cells appears to be different from that of B-lymphoid cell S mu-RNAs. Certain A-MuLV transformants also express gamma-RNA sequences that are probably analogous to the three different forms of mu RNA. These data support the concept that heavy-chain allelic exclusion, like that of light chains, is not mediated by control at the DNA or RNA levels but is probably a consequence of feedback control from cytoplasmic mu chains.

scholarly journals Multiple immunoglobulin heavy-chain gene transcripts in Abelson murine leukemia virus-transformed lymphoid cell lines

1982 ◽  
Vol 2 (4) ◽  
pp. 386-400
Author(s):  
F W Alt ◽  
N Rosenberg ◽  
V Enea ◽  
E Siden ◽  
D Baltimore
Keyword(s):  
Heavy Chain ◽  
Lymphoid Cell ◽  
Murine Leukemia Virus ◽  
Leukemia Virus ◽  
Lymphoid Cells ◽  
Chain Gene ◽  
Rna Sequences ◽  
Abelson Murine Leukemia Virus ◽  
Polypeptide Chains ◽  
Murine Leukemia

Lymphoid cells transformed by Abelson murine leukemia virus (A-MuLV) contain three classes of RNA transcripts from immunoglobulin mu genes. P mu-mRNAs (productive) correspond to the normal 2.7-kilobase (kb) membrane (mu m) and 2.4-kb secreted (mu s) mu mRNA species both in size and coding capacity and occur at approximately equal abundance in most mu-positive (pre-B-like) A-MuLV transformants. A mu-mRNAs (aberrant) generally fall into one of two categories--aberrantly small 2.3-kb mu m and 2.0-kb mu s mRNAs which encode aberrantly small mu polypeptide chains, or normal-sized, V H-containing mu RNAs which do not encode immunologically identifiable mu polypeptide chains. In one case, the latter type of A mu-mRNA was demonstrated to result from an in-phase termination codon in the D segment of the mu mRNA. Also, most, if not all, A-MuLV transformants express members of a 3.0 to 1.9-kb set of C mu-containing, but V H-negative S mu-RNAs (for sterile), the expression of which may occur simultaneously with but independently of P mu-mRNAs or A mu-mRNAs. The S mu-RNA sequences do not encode immunologically identifiable mu chains and can be produced by cells with unrearranged heavy-chain alleles, such as T-lymphocytes, although the structure of the S mu-RNAs from T-lymphoid cells appears to be different from that of B-lymphoid cell S mu-RNAs. Certain A-MuLV transformants also express gamma-RNA sequences that are probably analogous to the three different forms of mu RNA. These data support the concept that heavy-chain allelic exclusion, like that of light chains, is not mediated by control at the DNA or RNA levels but is probably a consequence of feedback control from cytoplasmic mu chains.

scholarly journals Nonrandom cytogenetic changes accompany malignant progression in clonal lines abelson virus-infected lymphocytes

Blood ◽  
1994 ◽  
Vol 84 (12) ◽  
pp. 4301-4309 ◽  
Author(s):  
SS Clark ◽  
Y Liang ◽  
CK Reedstrom ◽  
SQ Wu
Keyword(s):  
Tumor Progression ◽  
Murine Leukemia Virus ◽  
Leukemia Virus ◽  
Lymphoid Cells ◽  
Full Transformation ◽  
Cytogenetic Abnormalities ◽  
Cytogenetic Changes ◽  
Abelson Murine Leukemia Virus ◽  
Murine Leukemia ◽  
Over Time

Initially, lymphoid cells transformed by v-abl or BCR/ABL oncogenes are poorly oncogenic but progress to full transformation over time. Although expression of the oncogene is necessary to initiate and maintain transformation, other molecular mechanisms are thought to be required for full transformation. To determine whether tumor progression in ABL oncogene-transformed lymphoid cells has a genetic basis, we examined whether progression of the malignant phenotype of transformed clones correlates with particular cytogenetic abnormalities. A modified in vitro bone marrow transformation model was used to obtain clonal Abelson murine leukemia virus-transformed B lymphoid cells that were poorly oncogenic. Multiple subclones were then derived from each clone and maintained over a marrow-derived stromal cell line for several weeks. Over time, clonally related Abelson murine leukemia virus-transformed subclones progressed asynchronously to full transformation. The data show that tumor progression can occur in the absence of detectable cytogenetic changes but, more importantly, that certain cytogenetic abnormalities appear reproducibly in highly malignant subclones. Therefore, three independent subclones showed deletion in a common region of chromosome 13. Other highly malignant cells carried a common breakpoint in the X chromosome, and, finally, two subclones carried an additional chromosome 5. These results are consistent with the hypothesis that ABL oncogenes are sufficient for the initial transformation of cells but that additional genetic events can drive oncogenic progression. These observations further suggest that diverse genetic mechanisms may be able to drive tumor progression in cells transformed with ABL oncogenes.

Lymphoid and other tissue-specific phenotypes of polyomavirus enhancer recombinants: positive and negative combinational effects on enhancer specificity and activity

1986 ◽  
Vol 6 (6) ◽  
pp. 2068-2079
Author(s):  
B A Campbell ◽  
L P Villarreal
Keyword(s):  
Cell Lines ◽  
Heavy Chain ◽  
Murine Leukemia Virus ◽  
Tissue Specificity ◽  
Leukemia Virus ◽  
Simian Virus 40 ◽  
Simian Virus ◽  
Lymphoid Cells ◽  
B Lymphoid ◽  
Murine Leukemia

Heterologous enhancer recombinants and deletions of the polyomavirus (Py) noncoding region were constructed and analyzed for tissue specificity of DNA replication and transcription in a number of lymphoid and other cell lines. The simian virus 40 72-base-pair repeat, mouse immunoglobulin heavy-chain enhancer, and Moloney murine leukemia virus enhancer were inserted into the PvuII-D locus (nucleotides 5128 through 5265) of Py. The ability of these recombinants and the parental PvuII-D deletion mutant to replicate in permissive 3T6 cells and MOP-6 cells as well as in nonpermissive mouse B lymphoid, T lymphoid, mastocyte, and embryonal carcinoma cells was determined. Wild-type Py DNA was not permissive for replication in most lymphoid cell lines, except one hybridoma line. Simply deleting the Py PvuII-D region, however, gave Py an expanded host range, allowing high-level replication in some T lymphoid and mastocytoma cell lines, indicating that this element can be a tissue-specific negative as well as positive element. Substitution of the murine leukemia virus enhancer for Py PvuII-D yielded a Py genome which retained the ability to replicate in 3T6 cells but also replicated well in B lymphoid cells. Substitution with the immunoglobulin heavy-chain enhancer allowed replication in B lymphoid cells but interfered with replication in 3T6 cells and mastocytomas. Surprisingly, substitution with the simian virus 40 72-base-pair enhancer repeat gave a recombinant which would not replicate in any cell line tried, including MOP-6 cells, even though other recombinants with this enhancer would replicate. Thus, we observed both cooperation and interference in these combinations between enhancer components and the Py genome and that these combined activities were cell specific. These results are presented as evidence that there may be a positional dependence, or syntax, for the recognition of genetic elements controlling Py tissue specificity.

scholarly journals Selective transformation of primitive lymphoid cells by the BCR/ABL oncogene expressed in long-term lymphoid or myeloid cultures.

1988 ◽  
Vol 8 (10) ◽  
pp. 4079-4087 ◽  
Author(s):  
J C Young ◽  
O N Witte
Keyword(s):  
Lymphoid Cell ◽  
Murine Leukemia Virus ◽  
Leukemia Virus ◽  
Lymphoid Cells ◽  
Myelogenous Leukemia ◽  
Moloney Murine Leukemia Virus ◽  
B Lymphoid ◽  
Enriched Cultures ◽  
Murine Leukemia

The BCR/ABL gene, formed by the Philadelphia chromosome translocation (Ph1) of human chronic myelogenous leukemia, encodes an altered ABL gene product, P210. P210 is strongly implicated in the malignant process of chronic myelogenous leukemia, but it precise role is unknown. Infection of long-term bone marrow cultures enriched for B-lymphoid cell types with a Moloney murine leukemia virus retroviral vector containing the BCR/ABL cDNA resulted in clonal outgrowths of immature B-lymphoid cells which expressed abundant P210 kinase activity. Surprisingly, infection of long-term myeloid lineage-enriched cultures also resulted in clonal outgrowths of immature B-lymphoid cells. The P210-expressing lymphoid cell lines resulting from either type of culture were resistant to the lethal effects of corticosteroids. These findings indicate that high levels of P210 expressed from a Moloney murine leukemia virus long terminal repeat preferentially stimulate the growth of immature B-lineage cells, and this effect is apparent even in myeloid lineage-enriched cultures, in which few if any lymphoid cells can be detected prior to infection.

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