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Zusammenfassung Der Vaccinia-Virusstamm MVA besitzt neben zahlreichen anderen Markern der Unschadlichkeit fur Mensch und Tier auch die Eigenschaft einer stark reduzierten Virulenz fur menschliche Zellkulturen. Primarkulturen aus menschlichen, embryonalen Nieren und menschlichen Amnionzellen und U-Zellkulturen waren gegenuber dem MVA-Virus um den Faktor > 104 weniger sensibel als gegen die Vergleichsstamme CVA und Elstree (WHO-Referenzstamm). Des weiteren fehlte dem MVA-Virus die Fahigkeit, in Zellkulturen aus menschlichen, embryonalen Nieren und U-Zellen Plaques zu bilden. Der Elstree-Stamm bildete dagegen in beiden Systemen Plaques. Die fehlende Plaque-Bildung des MVA-Virus in menschlichen Zellen differierte gegenuber dem Elstree-Stamm ebenfalls urn den Faktor > 104. Der TC-Marker des MVA-Virus wird damit durch die Marker der abortiven Vermehrung und fehlenden Plaquebildung in menschlichen Zellkulturen, Faktor > 104, erweitert. Der avirulente MVA-Stamm bietet sich wegen seiner Unschadlichkeit fur Mensch und Tier und seiner protektiven Eigenschaften generell fur die Schutzimpfung gegen Tierpocken, die durch Orthopoxviren hervorgerufen werden, an. Als Methode der Wahl wird die subkutane Applikation vorgeschlagen. Meiner langjahrigen Med. Tech. Assistentin Fraulein Ruth Bottcher danke ich fur ihre hervorragende und zuverlassige Mitarbeit und ihre Eigeninitiative. Summary TC marker of the attenuated vaccinia vaccine strain “MVA” in human cell cultures and a discussion of protective immunization against orthopox diseases in animals The vaccinia virus strain MVA possesses, in addition to numerous other markers of inocuity for man and animal, the additional property of a markedly reduced virulence for human cell cultures. Primary cultures from human foetal kidneys and amnion cells and U-cell cultures were less sensitive to the MVA virus by a factor of 104 compared with the control strains CVA and Elstree (WHO reference strain). MVA virus also lacked the ability to form plaques in cell cultures from human embryonic kidney and U-cells. The Elstree strain, in contrast, produced plaques in both systems. Failure to produce plaques by the MVA strain in human cells also differs from the Elstree strain by a factor of 104. The TC marker of the MVA virus is thus by its characters of abortive multiplication and failure to form plaques in human cell cultures widened by a factor of more than 104. The avirulent MVA strain, because of its harmlessness for man and animal and its protective properties, is universally suited for protection against poxes caused by orthopox viruses. The best method of administration is subcutaneous. Resume TC-Marker en cultures de cellules humaines de la souche vaccinale attenuŕe vaccinia „MVA” Une contribution a l'immunization contre les varioles animales due a des orthopoxvirus La souche virale Vaccinia MVA possede en dehors de nombreux autres signes de son innocuite pour l'homme et l'animal, une virulence fortement reduite pour des cultures cellulaires humaines. Des cultures primaires a partir de cellules humaines renales embryonnaires, amniotiques et de cellules U furent moins sensibles pour le facteur > 104 au virus MVA qu'aux souches comparables CVA et Elstree (souche de reference OMS). Le virus MVA n'a pas ete en mesure de former des plaques dans les cultures de cellules embryonnaires humaines et de cellules U. La souche Elstree forma par contre des plaques dans les deux systemes. La formation de plaques manquante pour le virus MVA dans des cellules humaines fut egalement differente de la souche Elstree pour le facteur > 104. Le TC-Marker de la souche MVA est ainsi complete avec une multiplication avortee et un manque de formation de plaques dans les cultures de cellules humaines, facteur > 104. La souche avirulente MVA convient pour la vaccination contre une variole animale due a des Orthopoxvirus a cause de son innocuite pour l'homme et l'animal et pour ses proprietes generales de protection. On propose l'application sous-cutanee comme methode de choix. Resumen La estirpe vacunal Vaccinia „MVA” atenuada con marca TC en cultivos celulares humanos La estirpe viral Vaccinia MVA posee tambien, al lado de otras numerosas marcas de innocuidad para personas y animales, la propiedad de una virulencia harto reducida para los cultivos celulares de personas. Los cultivos primarios de rinones embrionarios humanos y de celulas amnioticas humanis y cultivos celulares U eran menos sensible; frente al virus MVA en el factor > 104 que frente a las cepas comparables CVA y Elstree (cepa de referencia de la OMS). Al virus MVA le faltaba ademas la capacidad de formar plaques en cultivos celulares de rinones embrionarios humanos y en celulas U. Sin embargo, la cepa Elstree formaba plaques en ambos sistemas. El defecto de formacion de plaques por parte del virus MVA en celulas humanas diferia tambien frente a la cepa Elstree en el factor > 104. Con ello, se ve ampliada la marca TC del virus MVA por las marcas de multiplicacion abortiva y formacion ausente de plaques en cultivos celulares humanos en el factor > 104. La cepa MVA avirulenta se brinda en general para la vacunacion contra las viruelas animales ocasionadas por ortopoxvirus, debido a la innocuidad para personas y animales y a sus propiedades protectoras. Como metodo de eleccion, se recomienda la aplicacion subcutanea.

Zusammenfassung Vergleichende Untersuchungen mit Hilfe des CA-Testes an Frenkel- und BHK-allergischen Rindern bestatigen, das fur die nach einer mehrmaligen MKS-Schutzimpfung auftretende Allergie vom Spattyp sowohl das MKS-Virus allein als auch in Kombination mit allergenen BHK-Zellbestandteilen verantwortlich sein kann. Das MKS-Virus allein wirkt nur schwach allergen. Enthalten MKS-Vakzinen allergene BHK-Zellanteile, so bringen sie das Virus-Allergen im Sinne eines Adjuvans-Effektes starker in Reaktion. Durch Aufspaltung des Virus gewonnene Virus-RNS war nicht allergen. Das isolierte Virus-Protein dagegen besas eine stark allergene Wirkung. Modellversuche an sensibilisierten Meerschweinchen bestatigten diese Beobachtung. Meerschweinchen konnten sowohl mit komplettem, gereinigtem MKS-Virus, mit abgespaltenem MKS-Virus-Protein als auch mit BHK-Zellsubstanzen sensibilisiert werden. Die Allergie lies sich durch Makrophagen ubertragen. Die MKS-Allergie war in der Regel schwacher ausgebildet als die BHK-Allergie. Eine Ausnahme bildeten die Meerschweinchen, welche mit hochgereinigtem und konzentriertem Ultrazentrifugen-Virus-Pellet sensibilisiert worden waren. Hier traten im CA-Test praktisch nur noch virusspezifische Reaktionen auf. Mit reiner Virus-RNS konnten die Meerschweinchen nicht sensibilisiert werden. Das aus hochgereinigtem MKS-Virus abgespaltene Protein sensibilisierte die Meerschweinchen in starkerem Mase als das komplette Virus. Im Kreuz-CA-Versuch an Meerschweinchen, die gegen die Virustypen O1, A5 oder C1 sensibilisiert worden waren, reagierten A5 und C1 starker miteinander als mit O1. Dieser Typ besas dagegen die starkste sensibilisierende Wirkung. Aluminiumhydroxyd und DEAE-Dextran zeigten an nichtsensibilisierten Meerschweinchen eine stark toxische, komplettes Freund'sches Adjuvans dagegen eine schwach toxische Wirkung. In sensibilisierten Meerschweinchen fuhrte komplettes Freund'sches Adjuvans zur Immunzellbildung, die sich mit Makrophagen passiv ubertragen liesen. Summary Further Investigations on FMD-Allergy of the Delayed Type Comparative investigations on Frenkel- and BHK-allergic cattle by means of the CA-Test verified that an allergy of the delayed type as appears after repeated vaccinations is due to the FMD-virus alone as well as to FMD-virus in combination with allergenic BHK-cell components. The FMD-virus alone gives only a weak reaction. FMD-vaccines, containing allergenic BHK-cell components, cause the virus allergen to react more strongly in a sort of adjuvant effect. The virus RNA, obtained by splitting the virus, appeared not to be allergenic. The isolated virus-protein however had a strong allergenic action. Tests with sensitized guinea pigs supported this observation. Guinea pigs could be sensitized with the complete, purified FMD-virus as well as with split FMD-virus-protein or with BHK-cell substances. This allergy can be transmitted by macrophages. Generally the FMD-allergy was weaker than the BHK-allergy. An exception was in guinea pigs which were sensitized by a highly purified and concentrated virus pellet. In these animals in the CA-Test the reaction was almost entirely virus specific. It was not possible to sensitize the guinea pigs with pure virus-RNA. On the other hand the protein obtained from intensively purified FMD-virus caused a much higher degree of sensitization in guinea pigs than the complete virus. In the cross-CA-Test with guinea pigs sensitized against the virus types O1, A5, or C1, types A5 and C1 had a stronger reaction with one another than with O1. This type, however, had the strongest sensitizing effect. Aluminium hydroxide and DEAE dextran appeared to be highly toxic for non-sensitized guinea pigs, whereas Freund adjuvant, in contrast, was only slightly toxic. It appeared that in sensitized guinea pigs complete Freund adjuvant caused the production of immune cells which were transmissible passively by macrophages. Resume Suite des recherches sur la fievre aphteuse-allergie cellulaire Des analyses comparees a l'aide du test CA sur les boeufs allergiques au Frenkel et BHK confirment que, pour une allergie cellulaire (delayed type) apres une vaccination repetee, le virus-FA seul ainsi que combine avec des elements cellulaires-allergeniques-BHK provoque l'allergie. Le virus-FA seul n'a qu'un faible effet allergenique. Si les vaccines-FA contiennent des elements cellulaires-allergeniques-BHK ils amenent le virus-allergen a une reaction plus forte dans le sens d'un effet-adjuvant. La ribonucleine acide, gagnee par la division du virus n'a pas agie d'une facon allergenique. Par contre la proteine isolee avait un fort effet allergenique. Experiences servant d'exemple sur des cobayes sensibilises constaterent cette observation. Des cobayes purent ětre sensibilises non seulment par le virus-FA complet et depure ainsi que par la proteine divise du virus-FA, mais encore avec des elements cellulaires-BHK. Cet allergie se transmit grace aux macrophages. En regle l'allergie-FA avait une constitution plus faible que l'allergie-BHK. A l'exception des cobayes qui avaient ete sensibilises par le virus-pellet intensivement depure et concentre. Dans le cas present n'apparurent pratiquement que des reactions de virus specifique. Les cobayes ne purent ětre senibilises par l'acide Ribonucleine pure du virus. La proteine, separee du virus-FA fortement depuree avait sensibilise les cobayes avec plus d'intensite que le virus complet. Au test CA de croisement avec de cobayes qui etaient sensibilises contre les virus de type O1, A5, ou C1, les types A5 et C1 reagirent ensemble plus forte au test-CA qu'avec le type O1. Ce type, par contre, avait le plus fort de sensibilisation. Aluminiumhydroxyd et DEAE-dextrane avaint montre un fort effet toxique sur des cobayes non sensibilises, par contre, le Freund adjuvant avaient montre un faible effet toxique. Il apparait donc des cobayes sensibilises que le Freund adjuvant mene a la formation de cellules immunisees (immun-cells) qui etaient passivement transmissibles par les macrophages. Resumen Nuevas investigaciones sobre la alergia aftosa del tipo diferido Los estudios comparativos con ayuda de la prueba de anafilaxia cutanea (AC) en reses bovinas alergicas frente a la vacuna segun Frenkel o la elaborada en celulas renales de hamsters lactantes (BHK) confirman que la alergia del tipo diferido, registrada a continuacion de vacunaciones repetidas contra la glosopeda, se puede deber tanto al virus aftoso solo como en combinacion con los componentes celulares BHK alergenos. El virus aftoso solo no tiene mas que una accion alergena muy debil. Cuando las vacunas antiaftosas contienen fracciones celulares BHK alergenas, llevan al alergeno del virus a una reaccion mas intensa en el sentido de un efecto coadyuvante. El acido ribonucleico obtenido por desdoblamiento del virus no era alergeno, mientras que la proteina aislada del virus poseia una accion alergena muy marcada. Las observaciones experimentales en cobayas sensibilizados confirman este lance. Los cobayas se pudieron sensibilizar con el virus aftoso completo y purificado, con proteina disociada del mismo virus y tambien con substancias celulares BHK. La alergia pudo transmitirse a traves de macrofagos. Por regla general, la reaccion alergica aftosa se manifestaba de forma mas debil que la alergia BHK. Una excepcion la constituyeron los cobayas que previamente se sensibilizaron con concentrados de virus altamente purificados en la ultracentrifuga. En la prueba de AC no se obtuvieron practicamente mas que reacciones especificas de virus. Con acido ribonucleico puro del virus no resulto posible sensibilizar cobayas. La proteina disociada a partir de un virus aftoso harto purificado sensibilizaba los cobayas de manera mas efectiva que el virus completo. En la prueba cruzada de AC en cobayas, los cuales habian sido sensibilizados frente a los tipos de virus O1, A5 o C1, el A5 y C1 reaccionaban entre si con intensidad mayor que con O1. Pero este ultimo tipo poseia el efecto sensibilizante mas intenso. El hidroxido de aluminio y el DEAE-dextrano manifestaban en cobayas no sensibilizados una accion toxica fuerte, a la vez que el coadyuvante completo de Freund una accion toxica debil. En cobayas sensibilizados, el coadyuvante completo de Freund ocasionaba la formacion de celulas inmunes, las cuales se podian transmitir pasivamente por medio de los macrofagos.

The reptilian paramyxoviruses FDLV and GOV initiated the production and release of cytokines like IL-1alpha, IL-1beta, IL-2, TNF-alpha and IFN-alpha in human peripheral blood mononuclear cells (PBMC) at 37 degrees C. The target cells produced the cytokines without replication of virus.

The poxvirus preparation CONPIND initiated the production of the two major inflammatory mediators interleukin-1 alpha (IL-1 alpha) and tumour necrosis factor-alpha (TNF-alpha) in whole blood and in blood mononuclear cell cultures of man at 37 degrees C within 12-48 h. The release of the cytokines followed a dose-efficacy curve. High levels of IL1-alpha (up to 810 pg/ml) and TNF-alpha (up to 533 pg/ml) were determined by sandwich enzyme-linked immunosorbent assay.

In order to detect contamination in foodstuffs originating from animals, three different diagnostic methods were tested in comparison: cultivation in permissive cell cultures, microparticle antigen capture system per FACS (MAS) and polymerase chain reaction (PCR). Assessment implied relevance for health, sensitivity and specificity. Aujeszky infection in swine served as a model. The blood and organs of healthy, but persistently infected as well as specifically diseased animals were examined. In addition, artificially Aujeszky-contaminated milk, black pudding and minced meat were included in the comparison of methods. Basically, all three methods of detecting contamination in raw foodstuffs originating from animals were useful. The virus detection in cell cultures as well as the efficacy of MAS were inhibited by meat products according to their preparation (e.g., virus protein denaturation). PCR turned out to be the only reliable method to confirm the contamination in foodstuffs. Using PCR, viral contamination in foodstuffs originating from healthy but persistently infected animals could be detected. Each of the three virus detection systems has various advantages and disadvantages. They are listed and discussed in detail. With regard to the relevance of health, virus detection in raw meat via cell culture remains the preferred method. Besides the detection of an individual virus, routine examinations of foodstuffs for unknown zoonotic virus contamination, sets based on permissive cell cultures, primer sets for the PCR as well as sets based on various monoclonal antibodies for MAS have to be developed and made available at the diagnostic laboratories.

The interferon (IFN)-inducing capacities of intact NDV virions, β-propiolactone-inactivated particles and several structural components were compared, using human PBML as the IFN producing cells. Intact and inactivated virions as well as the nucleocapsid fraction did not differ significantly in their IFN-inducing capacity. In contrast, genomic RNA as well as M protein fraction and envelopes induced IFN titres to a level of about 10% of those achieved with virions. NDV-induced IFN production could be blocked specifically by incubation with polychonal anti-NDV-monoclonal antibodies (mAbs) and with two of three anti-HN-mAbs, but not with anti-NDV-mAbs directed against the F, M or NP protein. In addition, IFN induction by fixed MDBK cells, expressing NDV surface proteins after infection with NDV Ulster, was inhibited by one of two anti-F-mAbs. The results suggest that the induction of IFN synthesis in human PBML is a complex process involving not only the HN protein but also the uncleaved F protein precursor, a component of the M protein fraction and — once having entered the cell — the genomic RNA.

Summary The reptilian paramyxovirus GOV was successfully adapted to Vero cells in 80 passages at 30°C. The virus replicated with HA titres of 1 : 64 and 107.5 TCID50/ml in the heterologous host cells forming syncytia, giant cells and cytoplasmic inclusion bodies. After 80 passages GOV was identified by immuno-fluorescence, by immune electron microscopy and by PCR. Sequencing of RT-PCR products of GOV after 80 passages did not reveal changes in the nucleotide sequence of the partial l-gene of GOV.

A double sandwich blocking-ELISA using a genus-specific neutralizing monoclonal antibody (MAb) against the vaccinia virus 32 kD adsorption protein (D8L open reading frame; ORF) was developed to detect orthopoxvirus (OPV) antibodies in sera. A collection of 2173 feline serum samples was examined in an epidemiological study. The blocking-ELISA revealed 44 (2%) sera with positive titres of 1:2-1:256. ELISA results were confirmed by the plaque-reduction test. A close correlation between titres of both assays could be observed ( r = 0.986). In general, the sensitivity of the blocking ELISA was two to four times higher. Neutralizing OPV-antibodies were found in nine sera with ELISA-titres > 1:4. Antibody specificity of OPV was also demonstrated by Western blotting analysis with selected feline sera. The epidemiographical distribution of the ELISA-positive sera and case histories of 37 seropositive cats available from the referring veterinarians are demonstrated. The blocking-ELISA enables a rapid serological diagnosis and can be used in veterinary and human medicine. It allows OPV-antibody screening in human and other animal species.

Despite many attempts to find reliable in vitro criteria for the efficacy of Biological Response Modifiers--BRMs (immunomodulators, paramunity inducers) animal challenge models are still the only way to demonstrate the totality of interlocking defense mechanisms. Challenge models with mouse pathogenic viruses provide an excellent possibility to study protective effects of BRMs against acute or chronic forms of viral diseases. For comparative studies two completely different virus challenge models--Pseudorabies PR and Stomatitis Vesicularis VSV--were developed with adult and baby NMRI mice respectively. The potency of BRMs in preventing lethal disease reveals significant differences depending upon the sort of BRM, the route of application and the time of pretreatment. Defense mechanisms important for the control of Pseudorabies virus infection in adult NMRI mice were tested in vitro (ex vivo) and correlated well with the degree of protection in vivo. Comparison of BRM efficacy in selective viral challenge models combined with screening of a variety of antiviral defense functions in infected animals in vitro provide reliable methods in demonstrating the potency of BRMs against viral infections.

Successful cultivation and titration of Borna disease virus in cell cultures enabled detailed studies of the virus properties. Borna virus is labile towards treatment with heat, pH 3.0 and lipid solvents. It is relatively stable at low temperatures and in frozen state. It is easily inactivated by ultraviolet light as e.g. vesicular stomatitis virus. After ultrafiltration studies, the size of the infectious virus unit is between 80 and 100 nm. Its buoyant density in cesium chloride is 1.165 g per ml. The one step multiplication curve shows that Borna virus has a replication cycle of about 2 days in BSC 1 cells. In growth experiments using antimetabilites it behaves like certain RNA containing viruses. As its multiplication is not inhibited by bromo- and iododeoxyuridine and actinomycin D, no DNA step seems to be involved in virus synthesis. Regarding these properties and the intracellular antigen distribution as shown by fluorescent antibodies, it is not possible to attribute Borna virus to any of the established virus groups.

Summary Evidence for and identification of poxvirus in domestic cats Two cases in Southern Germany of pox in cats could be diagnosed virologically. A cowpox-like virus was isolated, its biological and serological characteristics defined. The source of infection could not be traced. The contraindication of treatment with corticosteroids and the pathogenicity of the orthopoxvirus demonstrated here for humans is pointed out. Zusammenfassung Bei zwei Fallen von Katzenpocken in Suddeutschland konnte die Diagnose virologisch gesichert, als Erreger ein Kuhpocken-ahnliches Virus isoliert werden. Die biologischen und serologischen Merkmale des Virus wurden bestimmt. Nicht ermittelt werden konnte die Ansteckungsquelle. Auf die Kontraindikation einer Behandlung mit Corticosteroiden und auf die Humanpathogenitat der bei Katzenpocken nachgewiesenen Orthopockenviren wird hingewiesen.

Mandatory vaccination against smallpox was abolished on the account of smallpox-eradication proclaimed by the WHO and the postvaccinal complications detected after smallpox vaccination. At the same time vaccine banks with the vaccinia virus strain "Elstree" were organized. Should mass vaccinations with this vaccinia virus strain be carried out in a case of emergency, severe postvaccinal diseases and complications can arise in overaged and immunosuppressed vaccinees after primovaccination. Therefore attenuated vaccinia virus strains should be used for vaccine banks, which cannot be activated, or increase in virulence in impaired vaccinees after primovaccination. For these individuals the vaccinia virus strain "MVA", among other attenuated vaccinia strains, is recommended. The MVA virus strain can be applied parenterally without complications. From the scientific and field-relevant point of view it was tried to combine the vaccinia virus strain "MVA" with tetanus toxoid and to develop a combination vaccine "tetanus-smallpox". In immunization experiments using mice, piglets and monkeys, safety and efficacy of the vaccine were investigated. Efficacy was demonstrated by means of postvaccinal antibody determination and by the mouse protection test. Tetanus antitoxin was measured by ELISA and indirect hemagglutination test, antibody levels to vaccinia virus were investigated employing the neutralization test and hemagglutination inhibition test. No significant differences in potency could be demonstrated between the combination vaccine and the corresponding monovalent vaccines in mice, piglets and monkeys. The combination vaccine consisted of 12 Lf tetanus toxoid and 10 TCID50 vaccinia virus "MVA" preserved with gelatine and glucosamine. The double intramuscular immunization of monkeys stimulated average tetanus antitoxin titers of 1:310 and average vaccinia virus titers of 1:195 2 weeks p. revacc. Similar results were obtained in mice and piglets. Side reactions were not observed in mice and piglets. Except for occasional local reactions of short duration at the injection site of the monkeys, similarly no adverse reactions were observed after intramuscular vaccination with the combination vaccine.

Isolation of a viral agent (107) directly from brain explants of a 15-month-old heifer with symptoms of a sporadic encephalomyelitis is described. The virus shares properties with the paramyxovirus family. It grows in a variety of cell cultures from different species, and induces nuclear and cytoplasmic inclusion bodies in infected cells. Nucleocapsids measuring 17 nm in diameter were found in the nucleus and cytoplasm of these cells when studied electron microscopically, thus indicating a close relationship of the agent to the measles-distemper-rinderpest group. No infectious virus was released from infected cells, although alignment of nucleocapsids was observed beneath the cell membrane, and no hemagglutinating activity could be detected with the methods employed. The 107 agent was compared serologically with parainfluenza viruses type 1, 2 and 3, simian virus 5, mumps and Newcastle disease virus (NDV), two bovine respiratory syncytial viruses and measles/subacute sclerosing panencephalitis, distemper and rinderpest viruses, always using 107 virus infected CV1 cells and antiserum of the different viruses in indirect FA tests. Positive FA reactions were observed only with two sera obtained from SSPE patients with high antibody titer to SSPE virus, and with one rabbit-anti-rinderpest serum. The titers of these sera to 107 virus, however, were significantly lower than those against homologous viruses. Five out of 9 sera from randomly selected healthy cattle showed antibody titers between 1:10 and 1:80 to 107 virus in FA tests. The significance of these results is discussed with respect to the epidemiology of SSPE in children and its possible implication with rinderpest in Europe.

Summary Experimental proof of paraspecific effects of purified and inactivated pox virus The paraspecific effect of pox viruses i.e. stimulation of the nonspecific part of the complex immune system, was demonstrated in vitro and in vivo for 3 different types of virus (vaccinia virus, avipox virus, parapox virus). By means of purification, concentration and inactivation, it was possible to prove that the paraspecific effect is brought about by the pox virus particle per se. The effect is induced by certain epitopes in the complex structure of the virus and is independent of virus multiplication. Both purified pox viruses and inactivated, purified pox viruses stimulate NK cell activity, the CSA and the formation of interferon, and reach higher efficacy indices in a challenge test with baby mice using stomatitis vesicularis virus than non-purified and non-inactivated cell culture material. The degree of purity of the pox virus preparations was established using the electron microscope and monoclonal antibodies. The purified and concentrated pox virus preparations proved to be pyrogen-free; they were not toxic to baby mice in vivo. An endotoxin-induced effect could be ruled out. The broad paraspecific effect of pox viruses and their structural components lends itself to use as paramunity inducers in prophylaxis and therapy. Zusammenfassung Die paraspezifische Wirkung von Pockenviren, d. h. die Stimulierung speziell des unspezifischen Teiles des komplexen Immunsystems, lies sich bei 3 verschiedenen Virusgenera (Vacciniavirus, Avipoxvirus, Parapoxvirus) in vitro und in vivo nachweisen. Mittels Reinigung, Konzentrierung und Inaktivierung wurde bewiesen, das die paraspezifische Wirkung durch das Pockenviruspartikelchen per se bedingt ist. Sie wird durch bestimmte Epitope in der komplexen Struktur des Virus induziert und ist unabhangig von der Vermehrung des Virus. Sowohl gereinigte als auch gereinigte und inaktivierte Pockenviren stimulieren die NK-Zell-Aktivitat, die CSA, die Interferonbildung und erreichen im Challenge-Test bei Babymausen mit dem Virus der Stomatitis Vesikularis hohere Wirkungsindices als nicht gereinigtes und nicht inaktiviertes Zellkulturmaterial. Der Reinheitsgrad der Pockenpraparate wurde im Elektronenmikroskop und mit Hilfe monoklonaler Antikorper uberpruft. Die gereinigten und konzentrierten Pockenviruspraparate erwiesen sich pyrogenfrei, sie waren in vivo fur Babymause nicht toxisch. Eine Endotoxin-induzierte Wirkung konnte ausgeschlossen werden. Die Nutzung der breiten Wirkung von Pockenviren bzw. ihrer Strukturkomponenten als Paramunitatsinducer bietet sich prophylaktisch wie therapeutisch an.

The genome of stomatitis papulosa virus (a parapoxvirus) was cleaved with the restriction endonucleases HindIII and EcoRI, each giving rise to 6 fragments respectively. Double digestion with both enzymes resulted in 8 bands, two of which contained DNA fragments in double molar concentrations as revealed by reciprocal digests of isolated DNA fragments. The genome size, estimated by summation of the molecular weights of the fragments, is approximately 86 X 10(6) daltons, some 30 X 10(6) daltons smaller than vaccinia virus (an orthopoxvirus) DNA. The cleavage sites of HindIII and EcoRI endonucleases were mapped on the genome by analysis of reciprocal digests of isolated DNA fragments and by cross-hybridization experiments. This yielded two mapped segments which were then oriented relative to one another by cleavage of isolated partial digestion products. The terminal restriction fragments show rapid renaturation after alkali denaturation and subsequent neutralization, indicating that stomatitis papulosa virus DNA contains terminal cross-links analogous to those found in vaccinia virus DNA.

Tissue cultures of chick embryo fibroblasts are suitable for culturing fowl-, pigeon-, and canary pox viruses. Virus multiplication is accompanied by cytopathogenic effects which allow the titration of these viruses and the differentiation between different virus strains, especially in the fowl pox group.

A virus isolated from horses after abortion was propagated in cultures of swine kidney cells. Shape and structure of the virus particles as seen in negatively stained preparations and changes observed in ultrathin sections of infected cells suggest that the virus belongs to the herpes group. However, most of the virus particles in the nucleus and in the cytoplasm have a structure different from that of herpes virus. Instead of the nucleoid, vesicle-like formations are arranged in the particle, so as to produce a cross-shaped light area in the center of the particle.

Durch zahlreiche Passagen in Schweinenierenkulturen veranderten sich, parallel zur Abnahme der Virulenz fur das Schwein, auch die chemischphysikalischen Eigenschaften des Teschenvirus.

SummaryThis is the first report on the cultivation of Borna virus in tissue culture. In subcultures of lamb kidneys, the virus reproduces with a latent period of several weeks. At 48–72 hr postinfection, the infectivity of the subcultures for rabbits disappears but recurs after 5–10 weeks. The infectivity is not lost by subcultivation of the cells, and the infected cultures show an enhanced growth rate. After several weeks, plaque-like areas with enlarged cells and nuclei can be observed in the infected cultures. Nuclear inclusion bodies are found, but very rarely, and show no correlation to the infectivity of the cells for rabbits. The behavior of Borna virus in cell cultures is typical of a slow virus infection, and thus, the Borna infection of tissue cultures offers itself as a new model for the study of slow viruses.

Summary Through in vitro stimulation of different cell types with various stimulating substances, production of mediators with antiviral activity in vivo was studied. In two lethal virus mouse challenge models — adult NMRI-mice challenged with pseudorabies virus (PRV) and baby mice challenged with stomatitis vesicularis virus (VSV) — antiviral efficacy of cell culture supernatants (CCSs) was demonstrated. In a plaque reduction assay, interferon activity in CCSs and in serum of CCS-treated mice was investigated. Prophylactic treatment with CCSs from murine hybridomas and human lymphomas — stimulated by inactivated parapoxvirus ovis — reduced the mortality rate of challenged mice significantly. None of the cell cultures secreted interferon into the medium, whereas intraperitoneal application of some CCSs induced interferon activity in serum of mice. A possibility for production of non-antigen-specific mediators was shown by appropriate stimulation of certain cell types in vitro. Prophylactic treatment with these mediators triggered non-specific defence mechanisms in mice against two lethal virus infections. Zusammenfassung Steigerung der unspezifischen Virusabwehr bei NMRI-Mausen durch Mediatoren aus Zellkulturen Mit verschiedenen Stimulationssubstanzen wurde versucht, in vitro unterschiedliche Zellarten zur Sekretion von Mediatoren mit antiviraler Wirksamkeit in vivo anzuregen. Die Prufung der antiviralen Wirksamkeit der Zellkulturuberstande (ZKU) erfolgte in zwei Virusbelastungsmodellen, wobei adulte NMRI-Mause mit Aujeszky-Virus und juvenile Mause mit Vesicularis Stomatitis-Virus belastet wurden. Mit einem Plaque-Reduktions-Test wurde die Interferon (IFN)-Aktivitat in einigen ZKU und im Serum ZKU-behandelter Tiere bestimmt. Vorbeugende Behandlung mit ZKU aus murinen Hybridomas bzw. humanen Lymphomas, die mit inaktiviertem Parapoxvirus ovis stimuliert waren, verringerte die Mortalitatsrate von virusbelasteten Mausen erheblich. Keine der Zellkulturen sezernierte IFN in den Uberstand, wahrend die intraperitoneale Verabreichung einiger ZKU IFN-Aktivitat im Serum der Mause induzierte. Die Versuche zeigen die Moglichkeit auf, bestimmte Zellarten mit geeigneten Stimulationssubstanzen zur Sekretion von Mediatoren anzuregen, mit denen sich bei Mausen in vivo die unspezifische Infektabwehr gegen bestimmte Virusinfektionen erhohen last.

Virus particles with a buoyant density between 1.14 and 1.20 g/ml, with a peak density of 1.15 to 1.16 g/ml were shown to cause hog cholera disease in pigs. In electron microscopic studies particles of two distinct sizes were demonstrated in these fractions. A lipid enveloped particle with an outer diameter of 39–40 mμ and an inner (core) diameter of 28–29 mμ was proposed to be hog cholera virus.

Characteristics of a small DNA virus isolated from kidney cell cultures of healthy 3 week-old pigs are described. The virus isolate multiplies in kidney cell cultures of pig origin, produces intranuclear inclusion bodies, and hemagglutinates guinea pig, human group 0, chicken, cat, rat and mouse red blood cells. It multiplies in pigs resulting in antibody production, but is not pathogenic for newborn hamsters and mice. The virus particle is 20–22 mμ in size, hexagonal in shape and without a lipid containing envelope. Buoyant density is between 1.37 and 1.38g/ml. This virus is stable within a wide range of pH, resistant to heat (56°C), against treatment with trypsin, and lipid solvents. The porcine virus was proposed as a member of the picodna virus group, and named “Porcine Picodna Virus (PPV)”.

Variola- and alastrim field strains obtained from recent epidemics in India and Africa were inoculated and submitted to passages through heterologous host system in an attempt to obtain transformation into vaccinia virus. We studied in a similar manner variola virus strains cultivated in the embryonated egg, the mouse, and in tissue culture cells. Ruminants, pigs, monkeys, rabbits, eggs and various tissue cultures were used for this purpose. By none of these methods did we obtain a successful transformation of the variola- or alastrim virus into vaccinia virus. The observation of the behaviour of the variola and alastrim virus in the various host systems showed two distinct groups. The first group comprises the embryonated egg, the infant mouse, a number of tissue cultures and the monkey. The variola and alastrim viruses showed good adaptation to these hosts, as well as readiness to undergo an unlimited number of passages without modification of their original properties. We placed the rabbit, the pig and the ruminants into a second group. Although the inoculation of variola and alastrim virus to these hosts was occasionally followed by pathological reaction at the site of inoculation,. the attempts to carry on further virus passages and to obtain transformation was unsuccessful. Our efforts to transmit variola virus from the different hosts of group I to the animals of group II were unsuccessful. The successful experiments reported previously in the literature regarding the transformation of variola and alastrim virus into vaccinia virus are discussed. A new hypothesis is devised concerning the origin of the vaccinia virus.

Ten calves and 15 lambs were intracerebrally inoculated with cell-free and cell-associated SSPE virus, measles virus, and distemper virus. Only animals inoculated with SSPE cell-associated virus showed neurological symptoms of myoclonic jerks, ataxia, decreased irritability, and blindness of the eyes. SSPE virus antigen could be located in the brains of two calves, and infectious SSPE virus was isolated from one calf after fusion of its brain cells maintained in tissue culture with indicator cells. None of the animals that received SSPE virus developed homologous antibodies. In contrast, animals inoculated with measles and distemper viruses, but who had no clinical symptoms, developed antibodies against the homologous virus. The occurrence of sporadic bovine meningoencephalomyelitis, histologically similar to experimental SSPE disease in cattle, is discussed as a possible link in nature in the causes of human SSPE.