[Antibodies to the structural proteins of the measles virus studied in some chronic diseases]. / Issledovanie antitel k strukturnym belkam virusa kori pri nekotorykh khronicheskikh zabolevaniiakh.

The qualitative and quantitative analysis of antibodies to measles virus (MV) structural proteins (SP) in sera from patients with chronic glomerulonephritis (CGN), chronic active hepatitis (CAH), and liver cirrhosis (LC) was done. The patients were shown to have neutralizing antibody titres (NAT) higher than those in healthy subjects. An analysis of antibodies to SP was carried out by the radioimmunoprecipitation assay. Antibodies were detected to hemagglutinin, nucleoprotein (NP), fusion protein and to matrix protein (M) both in sera from the patients with these chronic diseases, healthy subjects, and patients with active measles. (The two latter groups were selected for comparison). However, some patients with CAH and LC had no antibodies to M protein in spite of very high NAT. The quantitative analysis of MV antibodies to SP was done only for NP because this antibody had the least individual variations. The quantity of anti-NP antibodies was higher in most sera from patients with chronic diseases than in those from healthy subjects, and reached the level of that in patients with active measles. The presence of MV genome in the peripheral blood lymphocytes from patients CAH, CGN, and LC had been shown earlier. So it is assumed that MV persists in lymphoid tissue where the expression of all SP genes is realized.

[The persistence of the distemper virus in continuous human cells]. / Persistentsiia virusa chumy plotoiadnykh v perevivaemykh kletkakh cheloveka.

Two cultures chronically infected with distemper virus (HEP-2 and L-41) were obtained. The cultures produced a small-plaque cell-associated virus and a virus-specific antigen which was demonstrated by the fluorescence antibody technique in 40%-60% of the cells. The chronically infected cells produced interferon as judged by their resistance to superinfections with heterologous viruses. The virus-carrier state was characterized by temperature sensitivity.

[Persistence of the measles virus genome in peripheral blood lymphocytes in patients with glomerulonephritis and systemic lupus erythematosus]. / Persistentsiia genoma virusa kori v limfotsitakh perifericheskoi krovi u bol'nykh glomerulonefritom i sistemnoi krasnoi volchankoi.

Punctate hybridization was used to examine measles virus genome in peripheral blood lymphocytes from patients with glomerulonephritis (GN) and systemic lupus erythematosus (SLE). Measles virus genome was revealed in 47 (54%) out of 87 GN patients, in 27 (74%) out of 36 SLE patients and in none of the control group patients. GN patients manifested a tendency towards increase of the rate of measles virus demonstration with the rise of the titres of measles antibodies. All SLE patients with a high antibody titre (1:512 and higher) demonstrated measles virus genome. The rate of measles virus genome demonstration in GN and SLE patients did not depend on the sex, age, duration and clinical disease pattern or the content of IgA, IgM, IgG in blood serum. During disease exacerbation, the rate of measles virus demonstration was higher in 41 (59.4%) out of 69 patients than during remission--in 6 (33.3%) out of 18 patients (p less than 0.05).

[Detection of the measles virus genome in the peripheral blood lymphocytes of patients with chronic and acute glomerulonephritis]. / Vyiavlenie genoma virusa kori v limfotsitakh perifericheskoi krovi bol'nykh khronicheskim i ostrym glomerulonefritom.

The presence of the measles (rubeola) virus genome was searched for in the lymphocytes from the peripheral blood of patients suffering from the acute (16 persons) or chronic (164 persons) glomerulonephritis. Dot hybridization technique with the plasmid borne probes to the measles viral genes NP, P and H have been used for the search. The measles viral genome has been detected in 58% of lymphocytes from the patients with the chronic glomerulonephritis and in 50% of lymphocytes from the patients suffering from the acute form of the disease. The genome was not found in the material from the control group including donors and traumatology ward patients. 25 samples of lymphocytes from the patients with the chronic glomerulonephritis contained the RNA that was not hybridizable with the viral genes probes by dot hybridization technique, thus containing no genes homologous to parotitis viral genes. The average titer of anti-measles antibodies in the serum from patients with chronic glomerulonephritis the lymphocytes of which contained the measles viral genome was 1:304, while it was 1:154 for patients with the negative probes. The average anti-measles antibodies titers are the same (1:166 and 1:142) for analogical groups of patients with acute form of disease.

[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.

[Mechanisms of disrupting DNA repair in human cells. IV. Interferon protects DNA of noninfected and chronically infected human cells from damage caused by cadmium chloride]. / Mekhanizmy narushenii reparatsii DNK v kletkakh chelovka. Soobshchenie IV. Interferon zashchishchaet DNK neinfitsirovannykh i khronicheski infitsirovannykh kletok cheloveka ot povrezhdenii, vyzyvaemykh khloristym kadmiem.

The protective activity of interferon on the cadmium chloride-treated human cells (Hep-2), infected chronically with meals virus and uninfected, was studied. It was found that cadmium chloride induced the formation of partially non-repairable DNA lesions. Decrease in cell repair activity was observed in the cells chronically infected with virus. Pretreatment of cells with interferon protected cell DNA from formation of DNA breaks and caused more effective resynthesis of DNA breaks.

[Experimental measles infection in rodents]. / Eksperimental'naia korevaia infektsiia u gryzunov.

The sensitivity of newborn hamsters to inoculation with the vaccine L-16 strain of measles virus and the Lec strain isolated from a patient with subacute sclerosing panencephalitis as well as the possibility of persistence of these viruses in the animals were studied. Intracerebral inoculation of the L-15 strain was shown to produce in hamsters acute meningoencephalitis leading to death in 85%-100% of cases. Over 30 days after inoculation, the infectious virus, the virus-specific antigen and virus genome were found in the brain. In the brains of the sick animals, all the structural proteins of measles virus with the exception of hemagglutinin were expressed. After inoculation with the Lec strain, the clinical signs of the disease were less manifest, and mortality was 40%. The infectious virus could be detected in the brain up to 20 days postinoculation, the genome, up to 31 days. All the structural proteins of measles virus were expressed in the brains of the inoculated animals. No persistence of L-16 and Lec strains of measles virus could be demonstrated at langer intervals after inoculation (90-180 days) in the brains of hamsters.

Detection of measles virus genome in blood leucocytes of patients with certain autoimmune diseases.

RNA isolated from lymphocytes of peripheral blood was dot-hybridized to a hybrid plasmid containing specific sequences for measles virus nucleocapsid protein. Viral RNA was detected in the lymphocytes of 28 of 34 (82%) patients with systemic lupus erythematosus (SLE) and of 40 of 68 (59%) patients with chronic glomerulonephritis (CGN), and was not detected in 29 control patients.

[Avian CELO adenovirus as a possible contaminant in cell cultures of Japanese quail embryos]. / Adenovirus ptits CELO kak vozmozhnyi kontaminant kul'tur kletok émbrionov iaponskikh perepelov.

Avian adenovirus CELO was found to replicate poorly in Japanese quail embryos (JQE) and cell cultures of them. The infectious process in these systems was latent. The antigen of adenovirus CELO in JQE cell culture was detectable by the fluorescent antibody method (FAM) within the first 24-72 hours after inoculation as fluorescent cytoplasmic granules. Subsequently, fluorescence of nuclei and macrophage cytoplasm was observed. The results indicate that JQE and their cell cultures are not contaminated with avian adenovirus CELO despite regular circulation of this agent among avian populations. The advantages of FAM (rapidity and clearness) for identification of adenovirus as substrates contaminant as compared with other biological methods have been demonstrated.

[Epitope analysis of mumps virus proteins in a persistent cell culture infection: changes in the hemagglutinin-neuraminidase polypeptide]. / Epitopnyi analiz belkov virusa parotita pri persistentnoi infektsii kletochnykh kul'tur: izmeneniia v polipeptide gemaggliutinin-neiraminidaza.

Monoclonal antibodies (MABs) against major structural mumps virus proteins were used for epitope analysis in primarily and persistently infected HEp-2 cells by means of immunofluorescence and radioimmunoprecipitation techniques. Qualitatively, no differences were found in MAB binding between corresponding proteins of the original and persistent viruses, whereas quantitative differences observed might be explained in terms of weakened viral protein synthesis in persistent infection. Limited proteolysis of MAB-bound antigen has revealed alterations in certain epitopes on persistent virus HN polypeptide. Despite the inability of HEp-2 infected cells for hemadsorption, HN protein was expressed on the surface of these cells to the same extent as in the hemadsorbing system of mumps virus-infected Vero cells.

[Analysis of the possible mechanisms for the persistence of the vaccinal strain of the measles virus in a human cell culture]. / Analiz vozmozhnykh mekhanizmov persistentsii vaktsinnogo shtamma virusa kori v kul'ture kletok cheloveka.

The mechanisms (factors) of the measles virus vaccine L-16 strain persistence in HEp-2 cell culture were analysed. Among the known mechanisms, most likely is the reduction of the cell-destroying properties of the persisting virus due to mutations in nucleoprotein gene manifested by changes of the isoelectric point of NP protein and temperature sensitivity of its synthesis.

[Electron microscopy study of the nucleocapsid structure of the measles virus isolated from cell cultures with primary and chronic infections]. / Elektronno-mikroskopicheskoe izuchenie struktury nukleokapsidov virusa kori, vydelennykh iz kul'tur kletok pri pervichnoi i khronicheskoi infektsii.

Electron microscopic examination of isolated intracellular measles virus nucleocapsids (NC) revealed a relationship between their structure, cell system, and the type of infection. Acute virus infection of Vero or Japanese quail embryo cells gave rise to the formation of linear NC strands with regularly and tightly stacked turns. Acutely infected L-41 or HEp-2 cells contained heteromorphous viral NC populations which included both typical and loosely packed NC. Persistently infected L-41 and Hep-2 cells predominantly contained NC of the latter type with the appearance of a "strings of beads".

Pathomorphologic characterization of CNS damage in monkeys infected with persistent variant of measles virus vaccine strain L-16.

The lesions of CNS were examined in monkeys infected intracerebrally (i.c.) with a variant of measles virus vaccine strain L-16 isolated after prolonged persistence in human cell culture NEr-2. The persisting virus variant appeared pathogenic for monkeys. The changes which had developed in their CNS within 30 to 60 days post-infection (p.i.) were alike to acute measles encephalitis which was evidenced by giant cell formation at the injection site. Twenty-two months p.i. the chronic character of lesions was evident from the appearance of foci of neuron destruction. Based on morphologic findings it was suggested that strain L-16-H has acquired some properties characteristic of nonattenuated virus.

Non-infectious morphologically altered nucleocapsids of measles virus from persistently infected cells.

Persistent measles virus infection of human HEp-2 or L-41 cells was accompanied by pronounced structural and functional changes of isolated intracellular viral nucleocapsids (NCs). The bulk of persistent NCs possessed altered conformation and a "string-of-beads" appearance, contained substantial amounts of subgenomic size RNAs, exhibited reduced transcriptase activity in vitro and lacked infectivity on transfection of susceptible cells. Immunogold staining revealed negligible binding of anti-P protein monoclonal antibodies to the "string-of-beads" type NCs, thus suggesting their non-functional state.

[Repair of DNA damage induced by gamma radiation and UV and gamma mimetics in virus-infected human cells]. / Reparatsiia povrezhdenii DNK, indutsirovannykh gamma-izlucheniem, UF- i gamma-mimetikami v infitsirovannykh virusami kletkakh cheloveka.

The method of chromatography of cell lysates on the columns with hydroxyapatite (HAP) and the method of ultracentrifugation of cell lysates in neutral sucrose gradient were used to study the mutagen-induced repair activity of human cells HEp-2 noninfected and chronically infected with measles and rubella viruses in order to determine the sedimentation properties of complexes containing DNA. Gamma-radiation, bleomycin, 4-nitroquinoline-1-oxide, and mitomycin C were used as DNA damaging agents. It was shown that the chronic infectious process inhibited repair of DNA damages induced by 4-nitroquinoline-1-oxide and mitomycin C and did not influence repair of DNA lesions caused by gamma-radiation and bleomycin.

[Characteristics of the ribonucleoprotein of the measles virus persisting in a human cell culture]. / Kharakteristika ribonukleoproteida virusa kori, persistiruiushchego v kul'ture kletok cheloveka.

The properties of virus-specific RNPs recovered from human HEp-2 and L-41 cells chronically infected with measles virus were studied in comparison with those of RNPs formed in acute infection of L-41 cells. The persisting RNP was shown to contain nucleoprotein not differing in the electrophoretic mobility from the same protein of measles virus virions, and RNA in the persisting RNP was found to be insensitive to the action of RN-ase. RNP from chronically infected cells had a changed ultrastructure and conformation as compared with RNP of the original virus and, unlike the latter had no infectivity upon transfection of the sensitive cells by calcium-phosphate precipitation. No differences in relationships of RNP with the cytoskeleton of the infected cells in the acute and chronic infection were observed.