Volker Moennig

Properties of mouse leukemia viruses: VIII. The major viral glycoprotein of Friend leukemia virus. Seroimmunological, interfering and hemagglutinating capacities

Abstract The purified major glycoprotein (GP 71 ) of Friend leukemia virus revealed type-specific as well as species-specific and interspecies antigenicities in various types of seroimmunological tests. It was also able to induce the production of neutralizing antibodies, to interfere with murine leukemia viruses from two different serotypes, and to hemagglutinate. Demonstration of hemagglutination became possible after reconstitution of GP 71 to multivalent complexes by suitable species-specific antibody (indirect hemagglutination).

C-type particles produced by a permanent cell line from a leukemic pig: I. Origin and properties of the host cells and some evidence for the occurrence of C-type-like particles

Abstract A permanent tissue culture line was established from a lymph node of a leukemic pig. The cells produced C-type-like particles after treatment with bromode-oxyuridine and dimethyl sulfoxide. The newly isolated particle was found to be infectious for normal pig kidney cells.

Properties of mouse leukemia viruses: X. Occrrence of viral structural antigens on the cell surface as revealed by a cytotoxicity test

Abstract Rabbit antisera directed against the major structural antigens of Friend leukemia virus (FLV) were used to test a variety of mammalian cell lines in a complement-dependent cytotoxic assay. A strong reaction was obtained with proteins GP71 and P12 antisera on murine C-virus-producing cells. P12 antiserum revealed type-specific reactivity; GP71 antiserum, type- and group-specific reactivity. In addition, the latter showed a weak but reproducible interspecies reactivity, detectable with cat cells producing classical feline virus but not with two simian cell lines producing gibbon and woolly monkey C-type viruses. P10, P15, and P31 antigens acted as cytotoxic targets only on a single murine cell line producing large quantities of Friend leukemia virus, and here only to a lower degree as compared to P12 and GP71 antigens. All of the three lines of murine sarcoma virus-transformed nonproducer cells examined (K Balb, MSV85, and HT-1) were negative when reacted with the P10, P12, P15, P31, and GP71 antisera.

C-type particles produced by a permanent cell line from a leukemic pig. II. Physical, chemical, and serological characterization of the particles.

Abstract The particle (PLCP) produced by a porcine lymphoma cell line is electron microscopically indistinguishable from C-type particles of other mammalian species possessing surface knobs, hexagonally arranged subunits in the core shell and a filamentous nucleoid. Furthermore, as in other C-type viruses, 60–70 S RNA as well as reverse transcriptase was found. Serologically PLCP could be clearly differentiated from murine as well as classical feline C viruses by the Ouchterlony test. Its mammalian C-type particle character was, however, documented by the presence of at least one interspecies antigenic determinant which is shared by most of the mammalian C viruses studied so far. According to its special interspecies reactivity, PLCP seems to be more closely related to woolly monkey (SSV-1), Gibbon ape, and RD 114 viruses than to classical feline and small rodents C viruses.

Polypeptides of mammalian oncornaviruses: II. Characterization of a murine leukemia virus polypeptide (p15) bearing interspecies reactivity☆

Polypeptide p15 from Friend leukemia virus was isolated by multiple gel filtration steps in guanidine hydrochloride. Because of its marked tendency to aggregate, renaturation of the protein was performed in the presence of 0.2% sodium deoxycholate. Serological analyses revealed cross reactivity with other mammalian C-type oncornaviruses.

Characterization of the immune response to the major glycoprotein (gp71) of Friend leukemia virus. II. Response in C57BL/6 mice.

Abstract C57BL/6 mice responded to immunization with purified gp71 of Friend murine leukemia virus by mounting both humoral and cell-mediated responses. As measured by a number of tests, the responses were generally stronger than those obtained in BALB/c mice. However, in contrast to the BALB/c mice, immunization of C57BL/6 mice with gp71 did not result in the development of cytotoxic lymphocytes, although spleen lymphocytes were capable of undergoing blastogenesis when incubated with purified gp71. As in the BALB/c mice, the humoral response was type-specific. A unique feature of the response in gp71-immunized C57BL/6 mice was the accelerated activation of the endogenous virus as measured by the development of an immune response to its distinct envelope antigens. This resulted in the production of three distinguishable antibody populations: (1) type-specific antibodies to FLV gp71; (2) type-specific antibodies reacting with AKR gp71 (AKR virus being related to the endogenous virus of C57BL/6 mice); and (3) antibodies directed against p15 (E) which reacted both with AKR and Friend-Moloney-Rauscher viruses and are therefore considered group-specific in the murine system. The possible significance of the activation of the endogenous virus subsequent to gp71 immunization of C57BL/6 mice is discussed.

Morphological, Chemical, and Antigenic Organization of Mammalian C-Type Viruses

New features in the architecture of mammalian type C viruses, in particular knoblike surface projections and hexagonally arranged subunits on the core shell could be demonstrated by electron microscopy, taking advantage of newly developed preparation techniques. As examples, murine leukemia viruses (MuLVs) and newly isolated porcine and bovine C viruses are presented. The major proteins of a MuLV were isolated and partially characterized in chemical terms and with respect to their serological and other biological activities, such as interfering and hemagglutinating (HA) capacity. Most of the characterized proteins could be localized in particular substructures of the virion either by selective removal or isolation of electron microscopically identifiable constituents. The information obtained allowed the design of a more detailed model of mammalian C viruses. Special attention was devoted to the further characterization of interspecies antigens of mammalian C viruses. Different antigenic determinants were revealed. Their distribution allows further subgrouping of mammalian C viruses.

Partielle Reinigung und biologisch-serologische Charakterisierung Kohlenhydrat-haltiger K om ponenten aus Präparaten von Friend- Leukämie-Virus / Partial Purification and Biological-serological Characterization of Carbohydrate Containing Com­ ponents from Preparations of Friend-leukemia-virus

Abstract Glycoproteins, mouse leukemia virus

Nachweis verschiedener antigener Determinanten vom interspecies Typ in RNS-Tumorviren (C-Typ) der Säuger / Evidence for the Existence of Different Antigenic Determinants of the Interspecies Type in Mammalian RNA-C -Type Tumor Viruses

In C-type particles of mammalian origin, two different antigenic determinants of the interspecies type have been revealed by a comparative study of murine-, feline-, suidian-, simian (woolly monkey) (SSV-1)-and RD114-viruses. With respect to the distribution of interspecies determinants, these viruses can be arranged into two distinct groups; one comprises the rodent- and cat-, the other the pig- and monkey-viruses. RD114-virus appears to share a certain non-interspecies antigenic component with cat viruses (strains Rickard and Gardner) but behaves, as far as its interspecies antigenic determinant is concerned, more similar to pig- and woolly monkey-viruses. In showing the serological differences mentioned, IgG antibody could replace whole serum.