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J Even

Publications and source records attributed to J Even.

60 records · Page 4Linked to original sources
PubMed1981

onc sequences (v-fes) of Snyder-Theilen feline sarcoma virus are derived from noncontiguous regions of a cat cellular gene (c-fes).

Type C sarcoma viruses are genetic recombinants containing portions of replication-competent helper viruses linked to sarcoma virus-specific sequences (generically designated onc genes) which are thought to be required for acute fibroblast transformation. The onc elements of different avian and mammalian sarcoma viral isolates are each homologous to subsets of cellular DNA sequences which have no well-defined role in normal cells. Because of the lack of significant homology between helper viral genes and cellular onc sequences, the recombinational mechanisms which facilitate the formation of sarcoma viral genomes remain unclear. In Moloney murine sarcoma virus, viral onc (or v-mos) and cellular onc (or c-mos) sequences exhibit complete and uninterrupted homology as determined by heteroduplex and restriction enzyme analyses of molecularly cloned DNA. By contrast, the cellular counterparts of the onc elements of Rous sarcoma virus (G. Cooper and R. Parker, personal communication), avian erythroblastosis virus (B. Vennstrom, personal communication), Abelson leukaemia virus (D. Baltimore, personal communication), Harvey sarcoma virus (E. Scolnick, personal communication) and simian sarcoma virus (R. Gallo, personal communication) are now known to contain intervening sequences which do not appear in the respective viral genomes. Here we report the use of the Southern blot technique to examine cat cellular DNA sequences (c-fes) homologous to the onc gene (v-fes) of Snyder-Theilen feline sarcoma virus (ST-FeSV). We used cloned DNA 'probes' containing defined portions of the ST-FeSV genome to show that v-fes sequences originate from at least four noncontiguous sequences in cat cellular DNA, separated from each other by intervening sequences.

Animals↗
PubMed1981

Recombinant bacteriophages containing the integrated transforming provirus of Gardner--Arnstein feline sarcoma virus.

The integrated DNA provirus of the Gardner-Arnstein (GA) strain of feline sarcoma virus (FeSV) was molecularly cloned in a bacteriophage lambda vector. The cloned DNA fragment is 14.4 kilobase pairs long and contains a 6.7-kilobase provirus flanked by cellular sequences derived from nonproductively transformed mink cells. Transfection of mouse NIH/3T3 cells with the cloned DNA fragment induced foci of transformation at efficiencies of 10(4) focus-forming units/pmol of sarcoma virus DNA. Restriction endonuclease mapping and heteroduplex analyses were used to compare the GA-FeSV provirus with that of Snyder-Theilen (ST)-FeSV, a second strain that contains homologous transformation-specific sequences (v-fes). Both viruses have the general structure 5'-gag-fes-env-c region-3', each having retained portions of the feline leukemia virus (FeLV) gag and env genes. In addition to segments shared by the two sarcoma viruses, GA-FeSV contains 1.7 kilobases of extra sequences not found in ST-FeSV. Of these, at least 400-500 base pairs located near the 5' end of v-fes encode a portion of the GA-FeSV polyprotein; the remaining 1.2 kilobases are derived from the FeLV env gene but do not appear to encode any detectable product related to the FeLV envelope glycoprotein. The close homology of the v-fes sequences shows that GA- and ST-FeSV were formed by recombination of FeLV with similar portions of a cat cellular gene (c-fes).

Bacteriophage lambda↗
PubMedDate not supplied

Spread of clonal T-cell expansions in rheumatoid arthritis patients.

Despite a large number of studies identifying expanded T-cell clones among infiltrating lymphocytes, little is known about their distribution in patients suffering from rheumatoid arthritis. To evaluate the clonality of alpha/beta T-cell populations in arthritic locations and PBL, we determined the CDR3 size lengths of TCR beta-chain transcripts using BV (Vbeta), BC (Cbeta), BJ (Jbeta), and clonotype-specific primers. Transcripts from PBL of healthy donors show gaussian profiles of approximately eight CDR3 size peaks in most BV subfamilies. Dominant peaks standing out above the normal background identify expansions of one or several T-cell clones within a given BV subfamily. The analysis of six patients suffering from rheumatoid arthritis showed clonal expansions in all samples including PBL. Synovial tissue infiltrates revealed less complex repertoires with a greater number of expanded clones than PBL. Expanded clones varied from one patient to another; no recurrences were observed. Most interestingly, identical clones were identified bilaterally in arthritic knee joints and PBL from the same patient. Our data show that given T-cell clones are not only locally expanded but can also be found in the periphery, and strongly suggest that many similar clones spread throughout the bodies of patients.

Adult↗