[The LMP1 oncogene sequence variations in patients with oral tumours associated or not associated with the Epstein Barr].

The role of the Epstein-Barr virus (EBV), a ubiquitous lymphotropic human herpesvirus type 4, in the etiology of nasopharyngeal carcinoma (NPC) is not fully understood. The mechanism of NPC carcinogenesis, associated with the virus, is also not clear. The objective of present investigation was to carry out comparative analysis of the structure of an LMP1 oncogene of EBV in viral isolates obtained from patients with two types of tumors of the oral cavity: (a) associated (i.e., NPC) and (b) not associated (other tumors of the same anatomical region, OTOC) with EBV. Comparative analysis of C-terminal regions of LMP1 variants that was based on a sequence analysis of LMP1 from tumor, blood and throat washing samples of NPC and OTOC patients showed that all structural characteristics of LMP1 in both groups of patients were genetically similar, and differences found between compared parameters were statistically insignificant. Thus, for the first time it has been revealed that in NPC and OTOC patients in Russia genetically related EBV strains with structurally similar LMP1 variants are persisting that are likely to reflect a polymorphism of the virus circulating in population. The findings allow us to suggest that in non-NPC-endemic regions of the world, which include Russia, the risk of NPC development does not depend on the EBVstrain and its variant of LMP1 so much, but mostly from the genetic predisposition of infected persons to the disease and the exposure to other, as yet unknown agents.

[LMP1 gene polymorphism in patients with Epstein-Barr virus-negative gastric carcinomas in Russia].

The investigation was undertaken to study the molecular characteristics of Epstein-Barr virus (EBV) LMP1 gene samples amplified from the tumor and intact tissues of patients with EBV-negative forms of gastric carcinoma (GC). The genetic structure of these samples determined by their sequencing was compared with that of the gene samples isolated from the cells of oropharyngeal washing specimens from the same patients with GC, as well as peripheral blood lymphocytes of patients with infectious mononucleosis (IM) and blood donors. The findings suggest that the samples of tumor tissue LMP1 from patients with GC have higher divergence than those from patients with IM and blood donors although no specific variants of the gene for GC were found. Comparison of LMP1 sequences from tumor tissue and cells of oropharyngeal washing specimens from the same patients with EBV-negative GC revealed the common LMP1 variant in 2 cases while they differed in 3 cases. The findings are an initial step in studying the role of EBV in the carcinogenesis of EBV-negative GC that is likely to be established by investigations on representative clinical material, by applying the up-to-date technologies.

[Mutations of the Epstein-Barr virus LMP1 gene mutations in Russian patients with lymphoid pathology and healthy individuals].

Epstein-Barr virus (EBV) is an etiological agent of a number of benign and malignant human diseases, such as infectious mononucleosis (IM), Hodgkin's lymphoma (HL), and non-Hodgkin's lymphoma (NHL). EBV latent membrane protein 1 (LMP1) gene (recognized as a viral oncoprotein) of various clinical and geographical origin was found to have different types of amino acid mutations affecting its biological activity. Since there was no information on the strain differences in LMP1 of EBV persisting in Russia, the authors made a sequence analysis of LMP1 samples amplified from the biological materials of Russian patients with IM, HL, and NHL and healthy individuals. The studies have shown that LMP1 variants of Russian origin are a mixed heterogeneous group containing both the earlier characterized and presumably new genetic variants. Among the point amino avid substitutions, the mutations S366T, F106Y, 185L, and E328Q associated with the enhanced transforming activity of a LMP1 molecule and its reduced cytotoxicity. There was no specific association between the certain Russian variants of LMP1 and the specific forms of the disease (IM, HL, and NHL).

[The distribution of HLA genes in Russian patients with germ cell tumors].

The correlation between DRB1, DQA1, and DQB1 genes of HLA class II, and the development of germ cell tumors (GCTs), as well as serological response to HERV-K proteins were investigated. Genomic DNA prepared from 99 GST patients was subjected to HLA typing by polymerase chain reaction (PCR) using the set of sequence specific primers (PCR-SSP). This set of primers made it possible to detect 14 specificities of DRB 1 locus, 12 alleles and groups of alleles of DQB 1 locus, and 8 alleles of DQA1 locus. Alongside with the definition of the occurrence of HLA markers in the total group of patients, the frequency of the occurrence of HLA-DR-DQ alleles was calculated in: 1) patients with different morphological forms of GSTs (seminomas and non-seminomas); 2) GCT patients producing or non-producing antibodies to Gag and/or Env HERV-K proteins. The comparison group consisted of 300 Moscow blood donors. The study did not reveal statistically significant differences in the frequency of the occurrence of DRB1, DQA1, and DQB1 alleles between the total group of GCT patients, its subgroup, and the control group. Thus, the data obtained demonstrated the absence of a strict correlation between the distribution of HLA class II alleles and GCT occurrence in the Russian population, as well as the ability of GCT patients to develop an antibody to HERV-K proteins, though more numerous observations are required to confirm this conclusion.

[LMP1 gene variants of Epstein-Barr virus in patients with some lymphoproliferative malignancies].

The samples of tumor biopsy, blood, and saliva from 10 patients with Hodgkin's disease, 10 patients with non-Hodgkin's lymphoma, and the blood samples of 20 donors were tested by polymerase chain reaction (PCR) for standard (wild) B95-8 and Cao-like (deleted) variants of the LMP1 gene. The paraffin sections of most PCR-tested tumors were also investigated by immunohistochemistry using the monoclonal antibodies S12 or 7D7 to detect the expression of the standard or Cao-like variants of LMP1 protein, respectively. It is suggested that Eptein-Barr virus (EBV) that contains the above deletion is not crucial for the development of the study lymphoproliferative malignancies. The fact that in some cases there is the Cao-like variant of LMP1 in the tumor biopsy specimen and its standard variant LMP1-B95-8 in the biological fluids of the same patient is very likely to suggest that the patient is infected with both types of the virus or there is genetic mutation(s) of EBV during viral carcinogenesis preceding or accompanying the development of a tumor.

[Antibodies to the human T-cell leukemia virus in the blood serum of the inhabitants of Sakhalin and Iuzhno-Kuril'sk]. / Antitela k virusu T-kletochnogo leikoza cheloveka v syvorotke krovi u zhitelei Sakhalina i Iuzhno-Kuril'ska.

Two immunological tests were used in testing of 808 blood serum samples from inhabitants of Sakhalin and of the city of Yuzhno-Kurilsk for antibodies against HTLV-1 etiologically associated with human T-cell leukemia. Antibodies to HTLV-1 were detected in 4.2% of Nivkhs, 1.2% of Oroks and 1.5% of Russians. The highest level of virus-carriers reaching 6.0% was detected in Nivkhs from the middle part of Sakhalin. The antibodies were detected more often in persons of old age and in women.

[Serological examination of the population of the Far East for the presence of antibodies to human T cell leukemia virus HTLV-1]. / Serologicheskoe obsledovanie zhitelei Dal'nego Vostoka na nalichie antitel k virusu T-kletochnogo leikoza cheloveka HTLV-1.

Antibodies to HTLV-1 were detected in sera from 1298 healthy adult persons living in the Far East. It is shown that virus infectivity of the Nigidalts was 8%, Nivkhs--2%, Udegeits--2.9%, Oroches--2.4%, Russians--0.9%. However, the incidence of acute leukemia in these regions is low. It is suggested that these regions are not endemic areas for HTLV-1-associated haemoblastoses.

[Effect of vaccination of mice with endogenous retrovirus on the development of tumors induced by gamma-irradiation or 7,12-dimethylbenz[a]anthracene]. / Vliianie vaktsinatsii myshei éndogennym retrovirusom na razvitie opukholei, indutsirovannykh gamma-oblucheniem ili 7,12-dimetilbenz[a]antratsenom.

Mouse vaccination with alive endogenous N-tropic virus OA-3 inhibited and decreased the development of the Rauscher leukemia in C57B1/6 mice (B-type) and SWR mice (N-type) as well as the development 7,12-dimethyl benzanthracene (DMBA)-induced tumours in mouse hybrids (neither N-, nor B-types). The effect of vaccination was DMBA- or MLV-P-dose-dependent. Vaccination with the same virus did not affect the incidence of gamma-irradiation-induced leukemia in CBA mice (N-type) and C57B1/6 mice while it increased twice the incidence of radiation leukemia in DBA mice (N-type). However, the incidence of thymomas lowered in radiation leukemia-bearing vaccinated mice of all the 3 strains, which may result from inhibition of murine thymotropic endogenous virus reproduction. The data obtained indicate the participation of murine own endogenous viruses in DMBA- or gamma-irradiation induced carcinogenesis.

[Detection and characterization of gastric carcinoma associated with epstein-barr herpes virus]. / Obnaruzhenie i kharakteristika opukholei zheludka, assotsiirovannykh s virusom gerpesa épstein-barr.

The present investigation was carried out to estimate the incidence of Epstein-Barr virus (EBV)-associated cases among gastric carcinoma (GC) patients in Russia. Carcinoma specimens from 184 patients with GC treated at the Cancer Research Center were investigated by EBV encoded RNA-1 (EBER-1) in situ hybridization. Seventeen (9.24%) cases showed uniform EBER-1 expression restricted to the carcinoma cells. Hybridized signals were not detected in the non-neoplastic gastric epithelium. EBV involvement was significantly more frequent among males, especially in the tumors belonging to less differentiated types (moderately differentiated tubular adenocarcinomas and poorly differentiated solid adenocarcinomas) and located in the upper stomach (cardia and middle part). Most EBV-positive GCs were characterized by great lymphoid compartment involvement. The findings of the distribution of EBV-positive. GCs by sex, site, and histology are similar to those in Japan; however, the detection rate of EBV-positive cases in Russia is higher than that in Japan (6.7%) and lower than that in the USA (16%).

[Molecular biological and clinical-morphological studies of gastric tumors associated with Epstein-Barr virus]. / Molekuliarno-biologicheskoe i kliniko-morfologicheskoe issledovaniia opukholei zheludka, assotsiirovannykh s virusom Epshteina-Barr.

The paper presents the results of the studies of gastric cancer (GC) associated with Epstein-Barr virus (EBV) among the patients residing in 4 geographical regions. In situ hybridization (ISH) techniques revealed that 49(11.4%) of the 430 examinees were EBV positive (EBV+), the virus-specific marker mRNA-1 of EBV, EBER-1) was found to be present in 80-100) of tumor cells. The proportion of EBV(+)-associated GC cases in different geographic regions ranged from 7.3 to 15%. These tumors were predominant in males (15%) as opposite to females (5.5%). Histological types most common among EBV+ tumors and their location in the stomach are also described. Serological findings indicated that the increased anti-EDV antibody response in 70% of GC cases coincided with the presence of the viral genetic information detected by ISH. In contrast to a humoral response to EBV, a humoral response to Helicobacter pylori was equal both in patients with EBV(+)- and EBV(-)-associated gastric tumors. Further molecular biological analysis of EBV isolates from virus positive and virus negative GC may answer the question whether there are really the so-called tumor and non-tumor variants of EBV.

[A mixed infection of lymphoid cell lines by the human T-lymphotropic retrovirus type I (HTLV-I) and the measles vaccine virus]. / Smeshannaia infektsiia limfoidnykh kletochnykh linii T-limfotropnym retrovirusom cheloveka I tipa (HTLV-I) i vaktsinnym virusom kori.

Interaction of HTLV-1 and vaccine strain of measles virus (VM-L16) in different T and B cell lines was studied. VM-L16 replicated in T and B cells with a cytopathic effect. At a multiplicity of infection of 1 TCD50 per 10 cells, all the cells in cultures died within 4-13 days. No effect of HTLV-1 on cell sensitivity to VM-L16 was demonstrated. HTLV-1 produced in various T-cell lines had different syncytium-forming activity in XC cell cultures. Cocultivation of C91/pL cells with XC cells led to the formation of multiple syncytia. HUT-102 cells had no such activity. Infection of these cell lines with VM-L16 did not change their properties. Another HTLV-1-infected cell line, MT-2, caused insignificant aggregation of XC cells. Infection of the latter with VM-L16 increased the number of racemations 8-fold, and they consisted of numerous adhesive cells. The cell adhesion, however, which is the first stage of syncytium formation did nor terminate in cytoplasm confluence. MT-2 nad XC cell lines may be used as model systems for the study of various factors influencing HTLV-1 activation.

[Vaccinating properties of the Kekava 55 strain of attenuated Marek's disease virus]. / Vaktsiniruiushchie svoistva attenuirovannogo virusa bolezni Mareka, shtamm Kekava 55.

Two attenuated strains of oncogenic herpes virus, Marek's disease virus, were obtained: one by cultivation in chick fibroblast cultures at 37 degrees C, the other at 41 degrees C, i. e. at chicken body temperature. Both attenuated strains throughout a large number of passages retain high vaccination efficacy, on the average 76% and 77.3%, respectively. The virus attenuated at 41 degrees C is superior to that attenuated at 37 degrees C in higher reproduction rate in vitro and, possibly, in a greater range of passages during which good vaccinating properties are retained. Unlike turkey herpes virus, both attenuated strains reduce the spread of the infection markedly.

[Mechanism of postvaccinal immunity in Marek's disease]. / K mekhanizmu postvaktsinal'nogo immuniteta pri bolezni Mareka.

The apathogenic variant No. 38 of Marek's disease virus, Kekava strain (MDV-Kekava), at the level of the 16th and 45th passages in vitro made chickens resistant to Marek's disease when inoculated 14 days before the infection of the chickens with the pathogenic variant No. 55 of MDV-Kekava. A simultaneous administration of both variants did not protect the animals against the disease. The occurrence in variants of MDV-Kekava of genetic markets manifest upon virus passages in chick embryo fibroblast (CEF) cultures provided an opportunity to study the interactions between them in chickens, using the CEF culture for virus isolation. The results of virus isolation from the blood cells of vaccinated chickens showed interference to occur in chickens between the virus variants as the rate of isolation of the pathogenic variant was 3 times as low as that of apathogenic MDV-Kekava, and both virus variants persisted in different cells. When chickens were inoculated simultaneously with both virus variants, the recovery rate of both pathogenic and apathogenic variants from the blood cells was similar. In such cases, persistence of two virus variants in one cell is also possible. The experimental results suggest that in the mechanism of resistance of vaccinated chickens to Marek's disease a significant role may be played by interference between the viruses in which the "occupation" of target cells by vaccine virus protects them from pathogenic MDV.

[Possible connection of the vaccinia virus and carcinogenesis]. / O vozmozhnoi sviazi virusa ospovaktsiny s kantserogenezom.

The data are presented indicating a possible carcinogenic danger of vaccinia virus. Vaccinia virus with reduced lytic properties was shown to be capable of inducing morphological and malignant transformation of cells of primary mammal tissue cultures (mouse, rat, man).

[Effect of a mixed viral infection on the development of neoplasms induced by oncogenic viruses]. / Vliianie smeshannoi virusnoi infektsii na razvitie neoplazii, indutsirovannykh onkogennymi virusami.

Data are presented concerning the stimulating effect of vaccinia and herpes simplex type 2 viruses on the development of leukemia in BALB/C, C57BL/6, and AKR mice. Mixed infection with PAB-49 and Marek disease virus of brown leghorn chickens was shown to increase the frequency of lymphomas development.

[Detection of HTLV-I viral antibodies in donor blood samples]. / Obnaruzhenie antitel k virusu HTLV-I v obraztsakh donorskoi krovi.

Sera from 867 donors were tested for antibodies to the virus of T-lymphocyte leukemia of adults (HTLV-I) in parallel by indirect immunofluorescence on acetone-fixed cells of HUT-102 culture producing HTLV-I and by agglutination test using a commercial set ("Serodia-ATLA", Japan). Twelve (1.38%) out of 867 sera were positive in the agglutination test and only 7 of them in immunofluorescence test. The specificity of the results was verified by absorption experiments. The activity of the sera in the agglutination test disappeared completely after their absorption with HUT-102 culture cells but did not change after absorption with LLU cells producing no HTLV-I despite a low percent of virus infection, donor blood control for HTLV-I infection becomes mandatory.

[Variants of the interaction of the human T-cell leukemia virus (HTLV-I) with the B-cells of lymphoblastoid lines]. / Varianty vzaimodeistviia virusa T-kletochnogo leikoza cheloveka (HTLV-I) s B-kletkami limfoblastoidnykh linii.

B-cell lymphoblastoid lines which are known to be derived by in vitro inoculation of B-lymphocytes with Epstein-Barr herpes virus (EBV) were shown to be infected with HTLV-1. Three possible variants of HTLV-1 interaction with cells were demonstrated by immunoblot, polymerase chain reaction, and virus isolation: (1) prolonged productive infection; (2) infection of the cells manifested only by the presence of "silent" virus sequences; (3) temporary production of HTLV-1 (3.5 months) after the end of which genetic material persisted in the cells. The long-term productive HTLV-1 infection in EBV-infected B-cells was found to influence the functioning of EBV genome which was manifested by expression of two additional proteins of EBNA-5 group and by changes in the intensity and pattern of LMP and EBNA-2 proteins the functioning of which is associated with immortalizing and transforming properties of EBV.

[Comparative antigenic characteristics of 2 Marek's disease virus variants and of herpesvirus of turkeys isolated in the USSR]. / Sravnitel'naia antigennaia kharakteristika dvukh variantov virusa bolezni Mareka i virusa gerpesa indeek, vydelennykh v SSSR

The antigens induced by pathogenic (55) and nonpathogenic (83) variants of Marek's disease virus, the Kekava strain (MDV-Kekava) and herpesvirus of turkeys, the M-24-72 strain (HVT-M24-72) were tested in the agar gel precipitation test. The antigens were prepared from feather follicles (FF) of the infected chickens, from the infected cultures of chick embryo fibroblasts (CEF) and from the culture fluid (CF) of these culttures. In the FF and CEF cultures infected with MDV-Kekava-83, the synthesis of the antigens was 6-10 times as low as in the FF and CEF cultures infected with MDV-Kekava-55. Both variants of MDV-Kekava retained their capacity for antigen synthesis in the CF up to 84 passages. Three antigens or three groups of antigens were found in the preparations examined: (1) strong common antigens in the CF and FF preparations; (2) weak common antigens in cell preparations and CF; (3) strong antigen(s) in cell preparations not identical to the CF and FF antigens. In CEF culture preparations infected with MDV-M-24-72, using sera from chickens with Marek's disease an antigen was detected partially identical to the weak antigen of cell preparations and cross-reacting with strong antigens of the FF, CF and cell antigens of MDV. No antigen was found in concentrates of CF from the CEF cultures infected with MDV-M-24-72 with the sera used. It is suggested that the CF and FF MDV antigens are virus antigens, while antigens of the cell preparations of this strain are autoantigens or embryonal antigens. Data are presented on relationship between the MDV-Kekava antigens with the MDV-HPRS-16 antigen.

[Properties of pigeon sera containing complement-fixing antibodies to the gs-antigen of the avian leukosis-sarcoma complex]. / O nekotorykh svoistvakh syvorotok golubei, soderzhashchikh komplementsviazyvaiushchie antitela k gs-antigenu leikozo-sarkomatoznogo kompleksa ptits.

Pigeons bearing tumors caused by the Schmidt-Ruppin strain of Rous sarcoma virus were used for withdrawing sera containing complement-fixing (CF) antibody to the gs-antigen of avian leukosis-sarcoma complex. In the course of this study it was found that some of these sera, while having a high titer of CF antibody to the gs-antigen of the tumor tissue, did not detect this antigen in chicken embryonal tissue and feather follicles. It is suggested that these sera distinguish different components of gs-antigen in the tumor tissue on the one hand and in the embryonal tissue and feather follicles on the other. There was a correlation in the detection or lack of gs-antigen in preparations of feather follicles and embryonal tissue with all the sera examined. Feather follicles may serve as a convenient source of gs-antigen in practical work.

[Study of the synthesis of Rous virus-specific RNA in chick embryo cells]. / Issledovanie sinteza RNK, spetsifichnoi dlia virusa Rausa, v kletkakh kurinykh émbionov.

The presence of virus-specific RNA in commercial chick embryos and its lack in chick embryos of leukemia-free chicken farm of the USSR AMS Oncological Research Center as well as in cell cultures from RIF-free chicken infected with Marek's disease virus was demonstrated by hybridizationof 3H-DNA-product of Rous sarcoma virus synthesized in vitro in the presence of actinomycin D with the total preparation of cellular RNA.