Detection of a polyoma virus-induced tumor-associated membrane antigen in mouse cells by the macrophage migration inhibition test

Soluble membrane fractions derived from polyoma tumor cells trigger lymphocytes, derived from polyoma-immunized animals, but not from nonimmunized controls, to release the lymphokine, macrophage migration-inhibitory factor. The reaction can be blocked by sera from polyoma-bearing animals. Absorption of these sera with polyoma cells, but not with nonpolyoma cell lines, abrogates this activity. These findings suggest that there is a polyoma virus-induced membrane component that can induce polyoma-specific macrophage migration inhibition.

An EBV genome carrying pre-B cell leukemia in a homosexual man with characteristic karyotype and impaired EBV-specific immunity

A Burkitt-like lymphoma/leukemia confined to bone marrow was detected in a human T cell leukemia virus (HTLV)-III/LAV- and Epstein-Barr virus (EBV)-seropositive homosexual man. The tumor cells were EBNA-positive and contained at least 22 EBV genomes per cell. They were totally immunoglobin negative, but showed other markers for B cells detected with monoclonal antibodies. The patient had an impaired cellular immunity to EBV antigens and EBV-infected cells at diagnosis, but these reactions normalized during treatment. Cell clones derived from the bone marrow tumor in vitro also carried EBV and had six different marker chromosomes, including the typical 14q+ chromosome and a t(8 - ;8), which resulted in trisomy for the largest part of 8q. Partial trisomy for 12q was also observed. The patient completed six courses of combination chemotherapy and remains in excellent health after 34 months of follow-up.

Multiple chromosomal rearrangements in a spontaneously arising t(6;7) rat immunocytoma juxtapose c-myc and immunoglobulin heavy chain sequences

Spontaneously arising immunocytomas in Lou/Wsl rats contain a consistent translocation between chromosomes 6 and 7. The c-myc gene has been localized to chromosome 7 and has been shown to be rearranged in the majority of the rat immunocytomas. We now report the cloning of the rearranged 11-kilobase EcoRI c-myc fragment from the IgE-secreting IR75 tumor. Sequence analysis revealed that the cytogenetically visible t(6;7) translocation must have involved several events in this tumor. One event has led to the juxtaposition of c-myc and the switch mu region, in a head-to-head orientation. The breakpoint is approximately 850 base pairs upstream from the proximal c-myc promoter on chromosome 7. This area is distinct from the more common mouse plasmacytoma- and Burkitt lymphoma-associated translocation breakpoints and also differs from the known murine retroviral insertion sites. A second rearrangement has led to the transposition of sequences upstream from the switch gamma 1 region to the c-myc-distant end of the switch mu region, tail-to-tail. This requires at least two events, including one inversion. In addition to showing that identical loci (c-myc, immunoglobulin) are juxtaposed via chromosomal translocations in three different tumors (Burkitt lymphoma, mouse plasmacytoma, and rat immunocytoma) in different species (human, mouse, and rat), the multiple rearrangements in IR75 and some other tumors emphasize the selective value of c-myc activation by an immunoglobulin locus in the tumorigenic process.

An Epstein-Barr virus (EBV)-determined nuclear antigen (EBNA5) partly encoded by the transformation-associated Bam WYH region of EBV DNA: preferential expression in lymphoblastoid cell lines

Four peptides were synthesized on the basis of amino acid sequences deduced from a highly spliced transcript encoded by the Bam W, Y, and H fragments of the Epstein-Barr virus (EBV) genome [Bodescot, M., Chambraud, J. B., Farrell, P. J. & Perricaudet, M. (1984) EMBO J. 3, 1913-1917]. Rabbit antisera against three of the four peptides identified a nuclear polypeptide that varied between 22 and 70 kDa in molecular size. Four of 20 EBV-positive human sera contained antibodies against this polypeptide. Since this is the fifth EBV-determined nuclear antigen (EBNA) discovered in growth-transformed cells, it is designated EBNA5. The antigen was detected in virus nonproducer lines (less than 0.01% EBV early antigen expression) and is thus not dependent on the viral cycle. It was differentially expressed depending on the origin of the lines. All 10 lymphoblastoid cell lines tested expressed EBNA5, but it could not be detected in 10 of 11 EBV-carrying Burkitt lymphoma lines. Infection of tonsillar lymphocytes with the B95-8 strain of EBV induced six EBNA5-specific polypeptides that varied between 41 and 70 kDa in molecular size with regular increments of 6 kDa. This may be due to the fact that the EBNA5 coding sequence includes the Bam W internal repeat. Parallel infection of the EBV-negative Burkitt lymphoma line Ramos with the same viral substrain did not induce detectable levels of EBNA5, nor was this antigen present in permanently EBV-converted Ramos sublines. These findings imply that the expression of the viral genome varies among B cells having different phenotypes.

Kinetics of fluid-phase pinocytosis in Dictyostelium discoideum amoebae

Kinetics of pinocytosis in Dictyostelium discoideum were investigated over an extended period of time (up to 6 hours) using fluorescein isothiocyanate (FITC)-dextran as a fluid-phase marker. FITC-dextran added to the medium accumulated rapidly inside the cells with a rate of influx equivalent to 9 microns3 of fluid/cell x min. After a period of about 90 min of uptake, the intracellular FITC-dextran level reached a plateau which corresponded to a strict balance between pinocytosis and exocytosis as shown both by efflux measurements and pulse experiments with (3H) dextran. At equilibrium, the amount of internalized marker reached a value equivalent to 790 microns3 of fluid taken up per amoeba, i.e. a volume paradoxically higher than the total aqueous space of the cell (520 microns3 ). FITC-dextran was thus markedly concentrated intracellularly. The endocytic compartment in which the intracellular FITC-dextran was concentrated could be completely washed out when FITC-dextran was removed from the external medium.

[Occupational factors in rheumatic diseases as a principle of rehabilitation--analysis of patients of the pension insurance administration for workers in Austria]

The study evaluates unselected "blue-collar" patients (n = 642) included under the social insurance law guidelines of rehabilitation. Rehabilitation measures had become necessary in these patients because of existing or impending invalidity in diseases of rheumatic origin. In 421 patients (= 66%), a connection with the place of work appeared possible. This entailed adaptation or change of the place of work in 297 patients (= 71%), the result of these measures after a period of two to three years being described. General aspects of occupational rehabilitation measures are discussed.

Differentiation-dependent sensitivity of human B-cell-derived lines to major histocompatibility complex-restricted T-cell cytotoxicity

Sets of Burkitt lymphoma lines and Epstein-Barr virus (EBV)-transformed lymphoblastoid cell lines (LCLs) derived from the same individuals were compared for sensitivity to cytotoxic T-lymphocyte (CTL) clones. Major histocompatibility complex class I antigen-restricted CTL clones were generated by stimulating the lymphocytes of an EBV-seropositive individual with the autologous LCL. One clone (BK-20) lysed the autologous and allogeneic HLA-A11-expressing LCLs but not mitogen-induced B lymphoblasts. Thus the clone was selectively cytotoxic for LCLs. Allospecific CTL clones directed against the HLA-A11 antigen were generated from an EBV-seronegative individual. One clone (WP-36) was selectively cytotoxic for the appropriate allospecific LCL, whereas another clone (WP-21) lysed also T and B lymphoblasts. None of the four Burkitt lymphoma lines established in parallel with the CTL-sensitive LCLs were lysed. Two of the Burkitt lymphoma lines were EBV-negative, and EBV-positive sublines were derived from these by in vitro infection. One but not the other of the two convertants became sensitive to all three types of CTL clones. The CTL-sensitive converted line had also acquired some LCL characteristics: increased cell size, aggregation, and a shift in several of the B-cell-specific surface markers. The CTL-resistant convertant expressed EBV antigens but showed no phenotypic change. These findings suggest that the cellular phenotype plays a decisive role in the sensitivity of B-cell-derived lines to the lytic effect of LCL-selective autologous and allogeneic CTLs.

Human T-cell leukemia virus-associated nuclear antigen (HTLV-NA)

Replication-competent retroviruses are not known to encode or induce nuclear antigens that are immunogenic in their natural hosts. We describe here the detection of a human T-lymphotropic virus (type I and type II) associated nuclear antigen (HTLV-NA) by an anticomplement immunofluorescence assay. Antibody to HTLV-NA is detected in 18 of 68 (26%) HTLV-I seropositives.

Conditioned tumorigenicity of activated oncogenes

Virally transduced oncogenes (v-onc) have a restricted target cell spectrum. They transform only a small part of the cell types in which they are expressed. Temperature-sensitive (ts) mutant studies have shown that some of them may act by blocking specific steps of maturation. If the cell can bypass the block, e.g., by a temporary switch off of the temperature-sensitive transforming protein, reexpression of the oncogene product at the permissive temperature may be unable to restore the transformed phenotype. Consideration of these facts, together with evidence concerning the reversion of the transformed phenotype and the suppression of tumorigenicity in hybrids derived from the fusion of normal and malignant cells, leads to the concept of "conditioned tumorigenicity." It states that the transforming and/or tumorigenic effect of a given oncogene, activated by structural or by regulatory changes, is restricted to specific and often quite narrow differentiation or maturation windows within each susceptible lineage. A similar restriction seems to apply to oncogenes activated by chromosomal translocation. The regular juxtaposition of the c-myc gene to one of the three immunoglobulin loci in Burkitt's lymphoma, mouse plasmacytoma, and rat immunocytoma is a case in point. The myc-carrying chromosome can break at many different places, within, upstream, or downstream of the gene, but not within its coding exons. This suggests that the break occurs at random and the myc protein plays an essential role in the selective, i.e., tumorigenic process. If so, other oncogenes should be equally transposable to the "Ig hot spots" during the long series of cell divisions in the preneoplastic target cell population that characterizes the prehistory of both BL and MPC. In other human B-cell leukemias and lymphomas, other (e.g., 11;14 and 14;18) translocations have been found, confirming that this can actually occur, but only in histologically different neoplasms. The exclusive involvement of myc in BL and MPC must be relatable to the specific functional features of the precursor cells and to the normal role of the myc protein. Recent evidence indicates that the myc gene is regularly turned off before or at the time when the cell enters a pathway that is programmed to lead it towards a resting Go state. Clonally expanded B-cells are believed to turn into resting memory cells upon waning of the antigenic stimulus. The normal, nontranslocated myc allele is regularly switched off in both BL and MPC, indicating that the cell has already obeyed a program involving the down-regulation of myc.(ABSTRACT TRUNCATED AT 400 WORDS)

B cell activation by the nontransforming P3HR-1 substrain of the Epstein-Barr virus (EBV)

The P3HR-1 substrain of Epstein-Barr virus does not transform B cells. This defect is known to be determined by the loss of the coding sequence for the nuclear antigen EBNA-2. The virus can attach to and enter resting B cells. The initial events after EBV infection are reminiscent of those induced by polyclonal B cell activators. Similar to the effect of these, P3HR-1 virus lowers membrane IgD expression on B cells and abrogates the transient elevation of activation markers BB-1 and LB-1 induced by the culture conditions. An important event of B cell activation is the acquisition of competence to respond to specific growth factors produced by T cells. This was induced by the P3HR-1 virus. The infected B cells had elevated [3H]thymidine incorporation when exposed to the supernatant of PHA-treated T cells. The EBV receptor is identical with the complement receptor CR2. Ligand binding to CR2 has been shown both with mouse and human B cells to deliver certain activation signals. Therefore, it is possible that the early step of activation by EBV is initiated through the binding to the receptor and is thus a cell surface event.

Immunoprecipitation of Epstein-Barr virus EBNA1 protein using human polyclonal serum

We have developed a method that permits the use of human polyclonal serum to immunoprecipitate BamH1-K EBNA(EBNA1) from EBV transformed cell lines and from cells transfected with an expression vector containing the Bam K region of EBV. Serum from healthy seropositive donors is preabsorbed once with lysate of EBV-negative Burkitt lymphoma cells, then fractionated by gel filtration. The main IgG fraction is then used for the immunoprecipitations. Immunoprecipitated material is visualized by immunoblotting using the same serum. Two proteins with apparent molecular weights of 74 and 62 kD are specifically precipitated from extracts of B95-8 cells. Several proteins are immunoprecipitated from cells transfected with the Bam K containing vector, the apparent molecular weights of the 4 major bands are 74, 68, 62 and 57 kD. Labelling of transfected cells with [3H]glycine and [32P]orthophosphate shows that the 74 and 62 kD proteins can be labelled with both isotopes.

Suprofen sustained release kinetics in healthy male volunteers. 1st communication: a single dose open crossover bioavailability study of suprofen sustained release tablets versus capsules

An open crossover study was performed in 12 healthy male volunteers to compare the bioavailability of alpha-methyl-4-(2-thienyl-carbonyl)phenylacetic acid (suprofen, Suprol) 600 mg sustained release tablets versus the suprofen capsule (2 X 200 mg). The pharmacokinetic profiles in plasma and urine were determined by a HPLC assay. In the dose range studied, the two suprofen formulations were not associated with any clinically significant effects on the blood pressure, heart rate or ECG. The results of the physical and neurological examinations showed no abnormal results. The results of haematology, clinical chemistry and urinalysis also showed no significant modifications. However, increased serum creatinine values were observed in some volunteers following suprofen administration. A drug relationship to this finding cannot be excluded with certainty. Two volunteers complained of nausea and vomiting following administration of two suprofen capsules. For this reason, volunteer no. 9 was withdrawn by the investigator from the study and replaced by an eligible substitute. In general, single doses of the two suprofen formulations investigated, were subjectively and objectively well tolerated. From the suprofen plasma-concentration time profiles, it was apparent that, whilst the elimination of suprofen was similar for both formulations, there was a marked delay in absorption of the tablet formulation. This formulation resulted in statistically significantly later maximum plasma levels and longer mean residence time (p less than 0.001). In comparison to the reference capsule formulation, the tablet had statistically significantly lower (75%) bioavailability. Measurement of suprofen concentrations in the urine indicated that less than 1% of the administered dose was excreted by this route.

Plasma concentrations of high-density lipoprotein (HDL)-2 and HDL-3 in myocardial infarction survivors and in control subjects

The serum concentration of several lipids, including high-density lipoprotein-cholesterol (HDL-C) and the HDL subfractions, HDL-2-C and HDL-3-C, were measured in 44 male and 26 female survivors of myocardial infarction and compared with those of a control group matched for age, sex, and body weight. Serum concentrations of total cholesterol (TC) and low-density lipoprotein (LDL-C) were significantly increased in patients as compared to control individuals. The total HDL-C concentration was lower in patients than in controls. By differential quantitation of HDL subfractions with a new precipitation method using polyethylene glycol, it was found that HDL-3-C was not significantly different between female patients and controls. The reduction of HDL-3-C in male patients was only of borderline significance. HDL-2-C in contrast was highly significantly reduced in both male and female patients. The greatest difference between patients and controls was found in the HDL-2/HDL-3-C ratio. It is therefore concluded that HDL-2-C quantitation is a valuable risk indicator for myocardial infarction yielding a better discrimination of patients from controls than total HDL-C quantitation.

Localization of the rat immunoglobulin heavy chain locus to chromosome 6

We have previously used rat/mouse somatic cell hybrids to localize the rat c-myc gene to chromosome 7 (Sümegi et al. 1983) and the rat immunoglobulin kappa locus to chromosome 4 (Perlmann et al. 1985). We now report that by utilizing rat/mouse somatic cell hybrids, we have localized the rat immunoglobulin heavy chain locus to chromosome 6.

Investigations of the influence of nonsteroidal antirheumatic drugs on the rates of sister-chromatid exchange

For detection of possible damage to genetic material due to nonsteroidal antirheumatic drugs, a technique was used to determine sister-chromatid exchange rates. The SCE rates before and after therapeutic application of several nonsteroidal antirheumatic drugs (diclofenac, flurbiprofen, ibuprofen, indomethacin, isoxicam, ketoprofen, piroxicam, pirprofen, tiaprofenic acid) were determined in human lymphocytes in vivo. The cytogenetic investigations of these nonsteroidal antirheumatic agents did not reveal any genetic effects during a treatment period of two weeks.

Suprofen sustained release kinetics in healthy male volunteers. 2nd communication: a multiple dose steady-state kinetics of suprofen sustained release tablets during 6 days in healthy male volunteers

To 12 healthy male volunteers, who had given their consent, 11 administrations of alpha-methyl-4-(2-thienyl-carbonyl)phenylacetic acid (suprofen, Suprol) sustained release tablets 600 mg were given twice a day with a dosage interval of 12 h. It could be demonstrated that suprofen given as multiple dose application of sustained release tablets was well tolerated. Effective mean plasma levels were reached after the second dosage. There was no indication of accumulation nor accelerated elimination during the 6-day period. There was no statistically significant difference between the mean plasma curve after the last administration of the 6-day period and the mean plasma curve after the 3rd application. Also the AUC's in the respective intervals turned out not to be statistically significantly different from each other. Clinical and laboratory tests showed no clinically relevant deviations from the normal range. No adverse reactions whatsoever were observed.

Quantitation of Epstein-Barr virus (EBV)-determined nuclear antigen (EBNA) by a two-site enzyme immunoassay, in parallel with EBV-DNA

A two-site enzyme (TSE) immunoassay was developed for the quantitation of the Epstein-Barr virus (EBV)-determined nuclear antigen (EBNA) using a rabbit serum raised against a synthetic peptide derived from the BamHI K region of the viral genome. Comparison of 12 EBNA-positive and 3 negative cell lines proved that the test was EBV-specific. A dot-blot assay utilizing cloned and nick translated EBV-DNA BamHI M fragment confirmed the EBV-carrier status of the EBNA-positive lines. The results obtained with both the TSE immunoassay and dot-blot assay were in agreement with published values. In contrast to earlier reports, we could not demonstrate any correlation between the content of EBNA and the number of viral genome copies.

Interaction between aurovertin and adenine nucleotide binding sites on mitochondrial F1-ATPase and the isolated beta subunit

The effect of aurovertin on the binding parameters of ADP and ATP to native F1 from beef heart mitochondria in the presence of EDTA has been explored. Three exchangeable sites per F1 were titrated by ADP and ATP in the absence or presence of aurovertin. Curvilinear Scatchard plots for the binding of both ADP and ATP were obtained in the absence of aurovertin, indicating one high affinity site (Kd for ADP = 0.6-0.8 microM; Kd for ATP = 0.3-0.5 microM) and two lower affinity sites (Kd for ADP = 8-10 microM; Kd for ATP = 7-10 microM). With a saturating concentration of aurovertin capable of filling the three beta subunits of F1, the curvilinearity of the Scatchard plots was decreased for ATP binding and abolished for ADP binding, indicating homogeneity of ADP binding sites in the F1-aurovertin complex (Kd for ADP = 2 microM). When only the high affinity aurovertin site was occupied, maximal enhancement of the fluorescence of the F1-aurovertin complex was attained with 1 mol of ADP bound per mol of F1 and maximal quenching for 1 mol of ATP bound per mol of F1. When the F1-aurovertin complex was incubated with [3H]ADP followed by [14C]ATP, full fluorescence quenching was attained when ATP had displaced the previously bound ADP. In the case of the isolated beta subunit, both ADP and ATP enhanced the fluorescence of the beta subunit-aurovertin complex. The Kd values for ADP and ATP in the presence of EDTA were 0.6 mM and 3.7 mM, respectively; MgCl2 decreased the Kd values to 0.1 mM for both ADP and ATP. It is postulated that native F1 possesses three equivalent interacting nucleotide binding sites and exists in two conformations which are in equilibrium and recognize either ATP (T conformation) or ADP (D conformation). The negative interactions between the nucleotide binding sites of F1 are strongest in the D conformation. Upon addition of aurovertin, the site-site cooperativity between the beta subunits of F1 is decreased or even abolished.

Differential recognition of tumor-derived and in vitro Epstein-Barr virus-transformed B-cell lines by fetal calf serum-specific T4-positive cytotoxic T-lymphocyte clones

Two interleukin-2 (IL-2)-dependent cytotoxic T-cell clones were obtained by limiting dilution from a lymphocyte culture stimulated in vitro with the autologous Epstein-Barr virus-transformed lymphoblastoid cell line (LCL) in the presence of fetal calf serum (FCS). Both clones uniformly had a T3+, T4+, Dr+ phenotype and lysed autologous B blasts, the autologous LCL, and allogeneic B cell lines sharing major histocompatibility complex (MHC) class II antigens. The cytotoxic function was triggered by FCS-derived components. There was no killing if the sensitive targets were cultured in serum-free medium or in medium supplemented with human serum. Sensitivity to lysis could be restored by exposing the targets to FCS for at least 6 hr at 37 degrees C. Monoclonal antibodies directed to T-cell-specific surface antigens and MHC class II antigens inhibited lysis with different efficiencies depending on the target cell origin. Killing of Burkitt's lymphoma (BL)-derived cell lines was blocked more easily than killing of LCLs. LCLs but not BL lines induced proliferation of the T-cell clones in the absence of exogenous IL-2. The differences were not related to quantitative variations in the expression of MHC class II antigens, indicating that BL lines differ from LCLs in other cell membrane properties that may influence antigen presentation. The results suggest that the affinity of effector/target binding, which is probably influenced by the concentration of antigenic determinants expressed on the target cell membrane, determines whether proliferative responses or cytotoxicity are induced in the antigen-recognizing T cells.

Leukocyte migration inhibition demonstrates a human T-cell response to a membrane protein expressed in latent Epstein-Barr virus infection

Leukocyte migration inhibition tests show that lymphocytes of Epstein-Barr virus-seropositive individuals recognize a Raji cell membrane antigen and a membrane protein encoded by Epstein-Barr virus in latently infected cells. Antiserum against the latter blocks the leukocyte migration inhibition triggered by both preparations, suggesting that the two antigens are associated with the same protein complex.