Human RNA Viruses Research Articles

Characterization, sequence, and expression of the cloned human neuropeptide Y gene.

The human neuropeptide Y (NPY) gene was isolated from a human genomic DNA library. The transcription unit spans approximately 8 kilobase pairs and is interrupted by three intervening sequences. The first exon contains only nontranslated DNA. The site where transcription initiates was determined by primer extension analysis using a primer derived from a human cDNA, pheochromocytoma RNA and avian myeloblastosis virus reverse transcriptase. A TATA-like sequence and a CAAT-like sequence occur 25 and 70 base pairs 5' to the transcription start site, respectively. The second exon begins with the initiator Met for preproNPY and extends to the Arg (residue 63) which precedes the Tyr-amide of mature NPY. The third exon contains the coding region for 27 amino acids, and the fourth exon codes for the terminal heptapeptide and the 3' nontranslated DNA. Transcriptional control elements were investigated by fusing 581 base pairs of the 5' sequences of the NPY gene to the promoterless structural gene for chloramphenicol acetyltransferase. NPY promoter activity was assayed by transfection of these hybrid constructions into CA-77 and PC12 cells followed by the determination of chloramphenicol acetyltransferase activity in cellular extracts. DNA sequences located within 530 bases of the start of transcription are sufficient for transient expression in the two neuronally derived cell lines examined.

Unique cell lines harbouring both Epstein-Barr virus and adult T-cell leukaemia virus, established from leukaemia patients.

Members of three distinct classes of animal virus have been associated with naturally occurring neoplasias in man: Epstein--Barr virus (EBV), a DNA virus belonging to herpesvirus group, papillomavirus, and a novel human RNA (retro) virus, human T-cell leukemia virus or adult T-cell leukaemia (ATL) virus. We have established seven continuous cell lines from ATL patients and 0.1-7% of these cells consistently express ATL-specific antigens (ATLA). EBV-associated nuclear antigen (EBNA) is also found in more than 90% of these cells. We have cloned cells from two of these lines and show here that both ATLA and EBNA were present in the same B-cell clone carrying surface immunoglobulin (sIg).

IN VITRO EFFECTS OF MONOLAURIN COMPOUNDS ON ENVELOPED RNA AND DNA VIRUSES.

Monolaurin alone and monolaurin with tert‐butylhydroxyanisole (BHA), methylparaben, or sorbic acid were tested for in vitro virucidal activity against 14 human RNA and DNA enveloped viruses in cell culture. At concentrations of 1% additive in the reaction mixture for 1 h at 23°C, all viruses were reduced in infectivity by >99.9%. Monolaurin with BHA was the most effective virucidal agent in that it removed all measurable infectivity from all of the viruses tested. The compounds acted similarly on all the viruses and reduced infectivity by disintegrating the virus envelope.

Relationships between membrane antigens of human leukemic cells and oncogenic RNA virus structural components.

Leukemic cells from all human chronic granulocytic leukemia (CGL) and some acute myelomonocytic leukemia (AMML) donors are lysed by rabbit antisera to a purified glycoprotein of Friend murine leukemia virus (FLV gp71) in a microcytotoxicity assay. These antisera are not cytotoxic to cells from patients with acute myelocytic leukemia (AML), acute lymphocytic leukemia (ALL), chronic lymphocytic leukemia (CLL), or to peripheral blood lymphocytes from normal donors. A goat antiserum to gradient purified FLV in addition to reacting with cells from CGL and AMML donors also reacted with cells from AML patients and some ALL donors. However, this antiserum failed to react with cells from CLL patients. Peripheral blood and bone marrow leukocytes prepared from leukemic patients in clinical remission failed to react with antisera to FLV and FLV gp71. Absorption experiments demonstrated that the antigen on CGL cells which is reacting with the antiserum to FLV gp71 is also present on normal human platelets and neutrophils. Similar absorption studies showed that the antigen on AML cells detected by the FLV antiserum is not present on normal leukocytes and platelets and appears to be related to the major internal p30 antigens of mammalian RNA tumor viruses. Another antigenic relationship between oncornaviruses and membrane antigens of human leukemia cells was shown by the ability of FLV antigens to absorb the cytotoxic reactivity of nonhuman primate antisera detecting human leukemia-associated antigens. FLV and FLV gp71 antigens were able to absorb all cytotoxic activity of monkey and chimpanzee antisera to human myeloid leukemia antigens when these antisera were tested with CGL cells. These two approaches to an analysis of cross-reactivity indicate that the antigenic determinant(s) detected by the cytotoxic reactions of the FLV gp71 antiserum with human CGL cells is different from the determinant on FLV gp71 which is responsible for the inhibition of the reactivity of simian antisera with CGL cells. Since the goat and rabbit antisera to FLV and FLV gp71 are able to distinguish AML from CGL cells by direct cytotoxicity testing and absorption, they may be valuable reagents for the serological diagnosis of myeloid leukemia. In addition, since peripheral blood cells from AML and CGL patients in clinical remission were seronegative, the antisera may be valuable as management aids. The data in this report indicates that whatever the mechanism of leukemogenesis is in man, cells from CGL and AML patients possess certain membrane antigens which cross-react with FLV structural components such as p30 and gp71.

Oncogenic properties of human viruses

Cancer biology today encompasses a variety of specialties ranging from epidemiology to molecular biology and chemotherapy. One of the very active areas of research is that which supports the concept of a virus etiology for at least some forms of cancer. For several years it has been generally accepted that a variety of both DNA and RNA viruses can transform animal cells in vitro and that they are transplantable and induce tumors in vivo. The virus-transformed cells exhibit changes in growth characteristics typical of cancer cells, and commonly contain virus-specific nucleic acids and antigens. Characterization of tumor viruses and virus-cell associations are being explored by virologists, biochemists, epidemiologists, geneticists, molecular biologists, and immunologists. The nature of the complex problems involved requires the participation of experts in a variety of specialties. In this communication, we present an overview of the status of DNA tumor viruses as they relate to human cancer and to transformation in general. No human C-type RNA virus has yet been identified, although there are reports of primate C-type viruses. The potentially important human papovaviruses, human adenoviruses and the Herpesvirus group, including herpes simplex virus, cytomegalovirus, and the EpsteinBarr virus are discussed. The importance of the Herpesvirus group today as it relates to human neoplasia prompted us to emphasize this area.

Homology between human breast tumour RNA and mouse mammary tumour virus genome.

SEVERAL studies have provided indirect evidence linking particles related to mouse mammary tumour virus (MuMTV) with human breast cancer1–3. In addition to morphological and biochemical similarities between human milk particles and known oncornaviruses shown in several laboratories4, Axel et al.5 demonstrated partial homology between MuMTV genome and polysomal RNA isolated from human breast tumour by molecular hybridisation experiments. Using Cs2SO4 density gradient analysis they showed that 67% out of 29 tumours tested had detectable amounts of MuMTV-related RNA. But because of intrinsic problems involved in Cs2SO4 gradient analysis it is not possible to determine hybridisation quantitatively. In this paper we describe hybridisation experiments using MuMTV-specific DNA probes and human tumour RNA under stringent conditions.

Isolation of RNA virus from papillary tumors of the human renal pelvis.

Virus particles were detected by electron microscopy in three papillary cancers of the human renal pelvis. Similar particles were seen in cells from all three tumors in primary culture. An RNA virus was isolated from these tumors. The serum of tumor patients contains neutralizing antibodies against virus isolated from two of the tumors. Initial studies suggest that this agent is not a known human RNA virus.

Symposium on Mammary Neoplasia

An international conference on mammary neoplasia sponsored by the Institute for Medical Research and the National Institutes of Health was held in Cherry Hill New Jersey on November 11-13 1971. 2 reports given focused on the genetic aspects of breast cancer. Bulbrook reported on the urinary steroid excretion patterns in women while Brennan and Wolfe studied the usefulness of xeroradiography in detecting ductal hyperplasia. Paymaster reviewed the epidemiology of breast cancer in India while Ozzello suggested that human breast cancer cells may perform a variety of synthetic and secretory activities. Sarkar suggested that there may be a connection between human breast cancer and RNA viruses and Dalton presented the ultrastructural detail of the mouse feline and human RNA virus. Nandi discussed his recent studies which attempt to locate the mammary tumor virus activity in blood. Concerning tissue and organ culture Lasfargues outlined a new method of growing human breast cancer cells in suspension cultures. Concerning immunology and interferon Blair attempted to elucidate the observation that immunodepression depressed MTV-induced mammary tumor development. Studies have shown striking regression of spontaneous breast cancers in animals following the administration of interferon inducers. Although the role of specific RNA viruses in the oncogenesis of many animal tumors is widely accepted the exact genetic mechanisms by which the viral RNA is expressed causes malignant transformation in the intact animals are not clear. The recent discovery of the enzyme reverse transcriptase and the subsequent demonstration that it is an integral part of all RNA tumor virions has opened a new field of investigation. Spiegelman Schlom Gallo and Temin all reported on it. Muhlbock reported on the influence of prolactin and estrogen on breast cancer as did Meites and Pearson. Thus the relation of an oncogenic virus to breast cancer and the role of reverse transcriptase in tumor viruses were thoroughly discussed at the conference.