Interaction of Herpesvirus ateles and Hepesvirus saimiri with primate lymphocytes. I. Selective adsorption of virus by lymphoid cells

A semiquantitative infectious bioassay, described by Sairenji and Hinuma for the measurement of Epstein-Barr virus (EBV) receptors, was adapted to study the adsorption of the lymphotropic New World herpesvirus ateles (HVA) to established lymphoid lines and lymphocytes of human versus marmoset origin. All marmoset T-cell lines [HVA- or HVS (herpesvirus saimiri)-carrying] had a high adsorbing capacity. EBV-carrying marmoset or human B-cell lines, one EBV-negative human B-lymphoma line, and one human myeloid leukemia-derived line failed to adsorb detectable virus. Two human T-cell derived cell lines of acute lymphatic leukemia origin showed moderate but significant adsorption, and the same was true for unfractionated marmoset lymphocytes. Human peripheral blood did not adsorb, before or after fractionation, whereas normal human thymocytes showed moderate but significant adsorption. It is concluded that HVA receptors are present on human T cells, probably belonging to certain subclasses.

Herpesvirus papio: state and properties of intracellular viral DNA in baboon lymphoblastoid cell lines

Herpesvirus papio (HVP) is an indigenous B-lymphotropic virus of baboons (Papio sp.) present in latent form in baboon lymphoblastoid cell lines. It shares cross-reacting viral capsid and early antigens with the Epstein-Barr virus (EBV), and HVP DNA and EBV DNA show partial sequence homology. EBV-specific complementary RNA was employed here as a probe to investigate the physical state of the HVP DNA component in baboon lymphoblastoid cells after fractionation of cellular DNA by density gradient centrifugation. Five virus-producing cultures contained both free and integrated HVP DNA sequences while one non-producing cell line had two or three viral genome equivalents per cell in an apparently integrated form. Further analysis of one virus-producing line showed that the free HVP DNA fraction was composed of both linear and circular viral DNA. Contour length measurements of HVP circular DNA molecules by electron microscopy revealed that they were similar in length to the EBV circular DNA present in human lymphoblastoid cells.

More acidic metabolites of delta1-tetrahydrocannabinol isolated from rabbit urine

The in vivo metabolism of delta1-tetrahydrocannabinol (delta1-THC) was further investigated in the rabbit after i.v. administration. Nine acidic metabolites were isolated from a previously not investigated fraction of the urine and identified by gas chromatography-mass spectrometry and by proton magnetic resonance spectroscopy. The major metabolites were side-chain hydroxylated monocarboxylic acids. Three side-chains monocarboxylic acids hydroxylated in allylic positions in the isoprene moiety were also characterized. The metabolites 4''-hydroxy-delta1-THC-7-oic acid and 7-hydroxy-4'',5''-bisnor-delta1-THC-3''-oic acid were hitherto not identified. An earlier described dicarboxylic metabolite was present in high concentration. Further, the identity of an O-glucuronide as an in vivo urinary metabolite of delta1-THC was here for the first time unambiguously established by m.s. and p.m.r.

Size of the intracellular circular Epstein-Barr virus DNA molecules in infectious mononucleosis-derived human lymphoid cell lines

The size of non-integrated circular Epstein-Barr virus (EBV) DNA molecules isolated from seven different human lymphoblastoid cell lines of infectious mononucleosis origin has been determined by sedimentation analysis and by direct contour length measurements on electron micrographs. Six lines had intracellular circular EBV genomes of the same size as linear virion DNA molecules. The seventh line, established with the B95-8 strain of EBV, was the only one found to have circular EBV DNA molecules significantly smaller than virion DNA. The data show that intracellular EBV DNA circles of reduced size do not generally occur in infectious mononucleosis-derived cell lines.

Transformation of marmoset lymphocytes in vitro with Herpesvirus ateles

Circulating lymphocytes from three species of marmoset monkeys were transformed in vitro with Herpesvirus ateles (HVA) either by co-cultivation with lethally X-irradiated HVA-producing lymphoblastoid cells or by infection with cell-free virus: 42 transformed lymphocyte cultures were obtained from 72 transformation attempts. Attempts to transform squirrel monkey lymphocytes were unsuccessful in 29 attempts. Association of HVA with each transformed culture was demonstrated by staining of antigen-positive cells in indirect fluorescent antibody (FA) tests and recovery of HVA after co-cultivation of the transformed cells with permissive monolayer cells. Cells of most transformed cultures possessed T lymphocyte properties: i.e. formation of E rosettes, reactivity with a specific anti-marmoset T lymphocyte serum and lack of surface Ig.

Antigen-inducing ability of herpesvirus papio in human and baboon lymphoma lines, compared to Epstein-Barr virus

Herpesvirus papio(HVP)-carrying baboon lymphoblastoid lines do not express a nuclear antigen like the Epstein-Barr virus(EBV)-determined nuclear antigen (EBNA), as judged by in situ anticomplement fluorescence staining, although the carry multiple viral genomes and, in the case of producerlines, early antigen (EA) and viral capsid antigen (VCA) that cross-react with the corresponding human EBV-determined antigens. To test whether the lack of in situ nuclear antigen expression is a property innate to the baboon virus or the baboon cell, nonproducer HVP-carrying baboon lymphoid cells of the 26 CB-1 line were superinfected with two human EBV strains. B95-8-derived EBV induced brilliant EBNA staining, proving that the baboon lymphoid cell was competent to synthesize EBNA. In the mirror experiment, HVP derived from the 9B or the 18C baboon line was added to the EBV-carrying Raji line, the EBV-negative Ramos and BJAB lines and the HVP-carrying nonproducer 26 CB-1 line, respectively. HVP induced EA and VCA in Raji, and EA in BJAB and 26 CB-1. EBNA was not induced in any of the three EBNA-negative lines, BJAB, Ramos and 26 CB-1. It is concluded that the lack of in situ nuclear staining in HVP-carrying baboon lines is a HVP-associated property and is not due to any innate inability of the baboon lymphoid cell to synthesize an antigen of the EBNA type.

Detection of a nuclear, EBNA-type antigen in apparently EBNA-negative Herpesvirus papio (HVP)-transformed lymphoid lines by the acid-fixed nuclear binding technique

In agreement with the findings of previous authors, we could not detect a virally determined nuclear antigen in Herpesvirus papio (HVP)-transformed baboon lymphoid lines by anticomplementary staining in situ, as for EBNA. However, by means of our recently developed acid-fixed nuclear binding technique an EBNA-like antigen could be readily demonstrated, after extraction from both producer and non-producer lines. We propose to designate the antigen as HUPNA. It can be detected by a human anti-EBNA antibody, suggesting cross-reactivity, if not identity, between EBNA and HUPNA. HVP-DNA carrying non-producer lines, negative for in situ ACIF stainability but capable of yielding HUPNA by the nuclear binding technique, can be superinfected with EBV, with brilliant EBNA expression as the result, suggesting that the defective in situ staining is a property associated with the baboon HVP, rather than the baboon lymphoid cell per se.

Human lymphoblastoid cell lines derived from individuals without lymphoproliferative disease contain the same latent forms of Epstein-Barr virus DNA as those found in tumor cells

The physical state of the intracellular Epstein-Barr virus DNA was characterized in four human lymphoblastoid cell lines, F-265, NC-37, U-303 L, and PG-1, derived from individuals without lymphoproliferative disease. For comparison, a previously investigated Burkitt lymphoma line, Raji, and a more recently established cell line of that origin, Rael, were also studied. The techniques employed were CsCl density gradient centrifugation, glycerol gradient centrifugation, and ethidium bromide-CsCl density gradient centrifugation in combination with nucleic acid hybridization, as well as electron microscopy contour length measurements of purified circular EBV DNA. All six cell lines contained multiple copies of covalently closed circular EBV DNA-molecules of the same size, as well as viral DNA with the properties of integrated DNA. No differences could be detected between the forms of EBV DNA present in cell lines derived from non-malignant sources and those present in lymphoma lines.

Properties of a baboon lymphotropic herpesvirus related to Epstein-Barr virus

Three lymphoblastoid cell lines were established from splenic lymphocytes of a lymphomatous baboon (Papio hamadryas) by co-cultivation of the lymphocytes with X-irradiated cells of marmoset or baboon lymphoblastoid cell cultures; the baboon splenic lymphocytes failed to grow when cultured alone. A herpesvirus, associated with each cell line, was identified by immunofluorescence, molecular hybridization and electron microscopy. Antigenic comparison with Epstein-Barr virus (EBV) showed that the baboon herpesvirus and EBV shared cross-reacting viral capsid antigens (VCA): 20 of 20 (100%) anti-VCA (EBV)-positive human sera and 55 of 62 (89%) baboon sera reacted with the baboon lymphoblastoid cells and baboon sera stained EBV VCA in P3HR-1 and EB-3 cells. No nuclear antigen, as assayed by anti-complement immunofluorescence tests, was detected in baboon lymphoblastoid cells when human or baboon anti-VCA positive sera were used. Baboon anti-VCA-positive sera also failed to stain EBV nuclear antigens (EBNA) in Raji or P3HR-1 cells. Preliminary molecular hybridization studies showed only approximately 40% homology between viral DNA of baboon cell lines and DNA of EBV derived from P3HR-1 cells.

Epstein-Barr virus: experimental infection of Callithrix jacchus marmosets

Eight common marmoset monkeys (Callithrix jacchus) were inoculated with about 10(4) transforming units of B95-8 virus; seven of the marmosets died 50-111 days post inoculation and all seven showed microscopic and/or macroscopic lesions compatible with a diagnosis of lymphoproliferative disease. Low levels of anti-VCA antibodies were detected in plasma from six marmosets. Attempts failed to establish continuous EBV-carrying lymphoblastoid cell cultures by cultivation in vitro of circulating lymphocytes or minced lymphoid tissues obtained at necropsy.

Experimental infection of squirrel and marmoset monkeys with attenuated Herpesvirus saimiri

Herpesvirus saimiri (HVS) was propagated in vero cells for 3 passages at 39 degrees and cloned 3 times at 34 degrees. This virus was inoculated into cotton-topped marmoset and squirrel monkeys; all inoculated monkeys became infected as HVS was reisolated after their circulating lymphocytes were cultured with vero cells and measurable levels of antiviral antibodies developed that were measured by immunofluorescence and/or neutralization tests. None of the inoculated monkeys developed any signs of overt disease and all inoculated monkeys have survived 9 to 14 months postinoculation. The attenuated virus appears to be genetically stable as virus isolated from an infected marmoset was passed 3 times in vitro and then inoculated into other marmosets, which became infected and remained clinically well. Marmosets latently infected with attenuated HVS were not protected when challenged with a large dose (770 plaque-forming units) of oncogenic HVS, although these marmosets survived about 3 times longer than did inoculated control marmosets.

Effect of bacillus Calmette-Guérin immunization in marmosets infected experimentally with Herpesvirus saimiri

Eight white-lipped marmosets immunized with BCG and 3 sham-immunized marmosets were studied after inoculation with Herpesvirus saimiri (HVS). BCG immunization had no significant influence on the incidence of infection by HVS, incidence of fatal malignant lymphoma, time of leukemia onset, development or titer of HVS antibodies, or average survival time. One BCG-immunized, HVS-infected marmoset failed to develop malignant lymphoma, whereas the remaining 10 HVS-infected marmosets died of malignant lymphoma. Prolonged survival occurred also in 1 marmoset immunized with BCG 100 days after HVS inoculation. The development and disappearance of lymphocyte reactivity to tuberculin were followed in 4 BCG-immunized marmosets.