Rauscher-leukemia-virus-related sequences in human DNA: presence in some tissues of some patients with hemotopoietic neoplasias and absence in DNA from other tissues

Nucleic acid probes in clinical microbiology

The infectious disease applications of nucleic acid probe have been described. In addition, the basic procedures of nucleic acid probe technology have been discussed, as have the factors affecting implementation of probe technology in diagnostic laboratories. Despite the questions raised, nucleic acid probes will become part of the diagnostic laboratory in the near future. Commercial interests are developing and marketing new probes, reagents, and kits which will expedite the employment of this technology. High-volume reference laboratories will first use probes as part of a battery of tests which will include ELISA and monoclonal antibody methods. In all probability, probes will replace methods: that have proven to be ineffective, difficult, or costly such as culturing for some enteric pathogens and Legionella, that require long incubation periods, such as mycobacteria, or that have high costs and low yields, such as virology.

Herpesvirus saimiri-induced lymphoblastoid rabbit cell line: growth characteristics, virus persistence, and oncogenic properties

A nonproducer lymphoblastoid cell line (7710) containing the herpesvirus saimiri (HVS) genome was established from the HVS-positive spleen of a male, inbred New Zealand White rabbit (III/J strain) which had developed a well-differentiated lymphoma after inoculation of HVS and 12-O-tetradecanoylphorbol-13-acetate (TPA). Antibodies to HVS early and late antigens were detected in the serum of rabbit 7710 by indirect immunofluorescence and immunoprecipitation. The cell line was of T-cell origin, did not produce HVS, and could not be superinfected with HVS. However, HVS early antigens could be induced in the cells with n-butyric acid and TPA or TPA alone. On the other hand, late antigens were never observed, and infectious virus could not be rescued by cocultivation of 7710 cell with OMK cells. The 7710 cells were T-cell growth factor dependent, even after many in vitro passages. The 7710 cell line contained multiple copies of a nonintegrated, covalently closed circular HVS genome. As is characteristic of some other HVS-transformed nonproducer lymphoid cell lines, a large segment of unique light (L) DNA was missing in the persistent circular viral DNA present in 7710 cells. This deletion spanned at least 42.5 kilobases, corresponding to the segment between 12.3 and 50.7 map units of full-length, infectious virion L-DNA. The 7710 cells failed to induce tumors in athymic nude mice, but inbred rabbits inoculated with as few as 100 of these cells developed fatal lymphomas. Chromosomal analysis showed that tumors were due to the growth of donor cells. Cells recovered from one of the rabbits inoculated with 7710 cells also contained HVS DNA and, after in vitro culture, induced the same type of lymphoma when inoculated into two other III/J-strain rabbits. None of the previously described HVS-transformed cell lines have been able to induce tumors in either their host species or nude mice. Thus, our demonstration that the 7710 cell line is readily transplantable in syngeneic rabbits represents the first available model which allows analysis of many biological and molecular aspects of the in vivo oncogenicity of HVS.

Genetic studies in multiple myeloma. II. Immunoglobulin allotype associations

A weakly positive but statistically significant association between HLA-Cw5 and myeloma has been reported in black patients. The authors attempted to determine whether immunoglobulin allotypes of the Gm series demonstrate any such association. They were identified in the sera of 29 black patients and 160 healthy black control subjects by a standard hemagglutination-inhibition technique. The results indicate that the G3m(g5) allotype is significantly associated with myeloma. Furthermore, addition of that immunoglobulin allotype to a Gm phenotype that is negatively associated with myeloma gives a phenotype that is positively associated with the disease, both associations being statistically significant. It was concluded that G3m(g5) is a marker of inherited susceptibility to myeloma in black Americans. Furthermore, as G3m(g5) is present in almost 50% of normal control subjects, it was proposed that its expression in a much greater proportion of patients may be related to an underlying genetic rearrangement that is also associated with neoplastic transformation.

Nucleic acid relationships among Acholeplasma species

3H-labeled Acholeplasma DNA probes were generated in vitro by the nick-translation method and used to determine the nucleotide sequence homology among the type strains of the eight currently recognized species of Acholeplasma. Very little nucleotide sequence homology (less than or equal to 18%) was found among the eight species, with heteroduplexes showing at least 12% or more mismatching as determined by thermal elution midpoints. The small amount of nucleotide sequence homology among the eight species indicates that these species are quite distinct and are not closely related to each other genomically.

Genomic and phenotypic analyses of Mycoplasma pneumoniae strains

Mycoplasma pneumoniae strains PI-1428, M129, B176, FH, and MAC were analyzed for homology by DNA-DNA hybridization, thermal elution midpoints of the DNA-DNA heteroduplexes, DNA cleavage patterns with restriction endonucleases, and protein gel electrophoretic profiles. These properties were compared with biological assays, such as antigenic reactivity with reference antisera in the growth inhibition and metabolic inhibition tests, as well as the ability to attach to human WiDr cell cultures. The avirulent, nonhemadsorbing strain B176 could be differentiated from the others by diminished attachment capacity to WiDr cells and by slightly reduced DNA homology. The other strains appeared to be identical when examined by these procedures. No significant differences were detected among any of the strains by the metabolic inhibition or growth inhibition tests. The DNA cleavage patterns of the five strains were also similar, although strains FH and MAC differed from the other three strains in a few bands. These results demonstrate that these five strains are similar and that the species M. pneumoniae is remarkably homogeneous.

Isolation and identification of lymphocytic and myelogenous leukemia-specific sequences in genomes of gibbon oncornaviruses

Five gibbon ape leukemia virus substrains (two from gibbons with lymphocytic leukemia and three from gibbons with myelogenous leukemia) were examined for unique genomic sequences specific for each form of leukemia. By using sequential adsorption procedures, the genome from each gibbon ape leukemia virus was fractionated into four sets of distinct nucleotide sequences. Based on their hybridization specificities toward DNAs of leukemic tissues, these sequences were designated as follows: (i) "COM," (ii) "LYM" or "MYE," (iii) "UNI," and (iv) "UND." The COM fraction represented sequences common to all of the viral genomes. The LYM fraction, which was isolated only from gibbon ape leukemia viruses associated with lymphocytic leukemia, represented genomic sequences associated with lymphocytic leukemia since the RNA hybridized at a 4- to 15-fold-higher rate to infected tissue DNA from lymphocytic leukemic gibbons than to infected tissue DNA from myelogenous leukemic gibbons. The MYE fraction, which was isolated only from gibbon ape leukemia viruses associated with myelogenous leukemia, represented genomic sequences associated with myelogenous leukemia since the RNA hybridized at a 5- to 15-fold-higher rate to infected tissue DNA from myelogenous leukemic gibbons than to infected tissue DNA from lymphocytic leukemic gibbons. The UNI fraction contained sequences unique to one virus substrain. The UND fraction contained sequences which varied depending upon the substrains involved in the adsorption procedures. These findings suggest that each gibbon ape leukemia virus examined in this study contains subgenomic sequences that are specifically identifiable only with the form of leukemia from which the virus was isolated.

Characterization of tumor-specific DNA sequences: molecular grading of the astrocytomas

Tumor-specific DNA sequences or unique sequences have been found in a number of human cancer cells including gliomas but not in equivalent normal cells. In a continuing effort to further elucidate the nature of these sequences, thermal analysis using the hydroxyapatite technique was carried out on the various grades of astrocytomas. A recycled DNA molecular probe from Grade IV astrocytomas was annealed to the various grades of astrocytoma DNAs and to normal brain DNA which served as control. There was an increasing percentage of hybridization in direct proportion to the degree of malignancy. The same results were obtained using a recycled DNA probe from medulloblastomas. Thermal melt analysis of these same tumors revealed a Tm (melting temperature or temperature of reassociation) of about 83 degrees C, irrespective of degree or grade of malignancy. These results would indicate that the type of genetic DNA sequences or tumor-specific DNA sequences involved in this type of tumor is the same, whether the tumor is benign or malignant. The demonstration of the increasing percentage of hybridization based on the increasing degree or grade of malignancy and the further demonstration that the involved tumor-specific DNA sequences are the same irrespective of the degree of malignancy, justify the conclusion that the number of copies of these sequences determines the degree or grade of malignancy. Pending further laboratory confirmation, this fact may be assumed to be true with respect to cancers from other organ sites.

Tumor-specific DNA sequences in human gliomas

Utilizing the technique of hydroxyapatite chromatography, normal cellular DNAs were used to recycle off the repeat or normal sequences found in [3H]DNA copied off 70S RNA from malignant astrocytomas. The recycled [3H]DNA were then used to hybridize against DNAs from normal human brain tissues and DNAs from malignant astrocytomas or Grade IV astrocytomas. The results indicated the presence of tumor-specific DNA sequences in malignant astrocytomas, absent in normal brain tissues. The percentages were 88% and 7%, respectively. When recycled medulloblastoma 70S[3H]DNA probes were utilized against DNA'S FROM Grade IV astrocytomas and from normal brain, similar results were obtained. The respective percentages of hybridization were 67% and 7%. Thus it would appear that malignant gliomas contain tumor-specific DNA sequences which are not found in normal brain tissues.

Search for Epstein-Barr and type C oncornaviruses in systemic lupus erythematosus

Lymphoblastoid cell lines were derived from patients with active systemic lupus erythematosus by allowing spontaneous transformation of peripheral B lymphocytes (B cells) harboring endogenous Epstein-Barr virus or by superinfecting peripheral lymphocytes with exogeneous Epstein-Barr virus. Results of extensive studies aimed at identifying type C oncornaviruses in these lymphoblastoid cells were entirely negative by electron microscopy, DNA-DNA hybridization, reverse transcriptase assays, and cocultivation experiments. These results do not support the postulated association of oncornavirus infection in human systemic erythematosus.

Retrovirus sequences in a leukemic gibbon and its contact: evidence for partial provirus in the nonleukemic gibbon

Integrated viral DNA sequences were detected in tissues from two gibbon apes, a leukemic gibbon (6G-1) from whose leukocytes a distinct strain of gibbon ape leukemia virus (GaLVH) was isolated, and gibbon 6G-4, a contact of 6G-1 from the same colony that had uremia and cachexia of unknown origin. Although 6G-4 had no detectable neoplasia or viral proteins, its serum contained persistent antibody against GaLV antigens. Whereas DNA from most of the tissues of 6G-1 contained GaLV provirus, DNA from only three tissues (kidney, spleen, and liver) from 6G-4 showed detectable viral sequences, and the extent of hybridization in each case was lower than with 6G-1. After cleavage with BamHI, two virus-specific DNA fragments were detected in tissues of 6G-1. Only one of these fragments was detected in the positive tissues of 6G-4. The results indicate that: (i) 6G-4 was exposed to and infected by GaLV; (ii) early target sites for infection of gibbon by GaLV may be limited to a few tissues; and (iii) infection can be contained by integration of only partial provirus in a few tissues.

Surface antibodies of human myelogenous leukaemia leukocytes reactive with specific type-C viral reverse transcriptases

Purified immunoglobin G (IgG) from patients with chronic myelogenous leukaemia specifically neutralised RT from feline leukaemia virus while purified IgG from other types of leukaemias and from normal blood cells were less reactive and in some cases preferentially reacted with RT from horizontally transmitted primate type-C viruses (simian sarcoma virus-gibbon ape leukaemia virus group). This indicates the presence of a heterogeneous immune response to RT or to an RT-like molecule in humans.

Search for type-C oncornavirus-related genetic information in tissues from patients with systemic lupus erythematosus

Single-stranded 3H-DNA probes complementary to the RNA of Rauscher murine leukemia virus and of simian sarcoma virus were prepared using techniques that permitted complete transcription of the viral genome of each virus. These probes were used in DNA-DNA hybridization studies with the cellular DNA from uncultured specimens of spleens and placentas of patients with systemic lupus erythematosus (SLE). No proviral DNA sequences related to these viruses were detected in these tissues. The results presented here do not support previously reported antigenic data implicating type-C oncornavirus infection of these organs in SLE.