Comparative study of different methods for extraction of Rubella haemagglutinin from infected cells BHK-21.

The results from a comparative study of some methods for extraction of Rubella haemagglutinin from infected BHK-21 cells are presented. The best haemagglutinin extraction was achieved after the cells were treated with Tween 80-ether. The combined application of alkaline extraction and Tween 80-ether treatment also gave good results.

Preparation and efficacy of antiherpes type 1 and 2 subunit vaccines.

DNA free antiherpes subunit vaccines were prepared from diploid human embryonic lung cells infected either with type 1 or type 2 herpes simplex viruses (HSV). Virion and membrane-bound virus-specific glycoproteins were solubilized with Nonidet P-40 and separated by ultracentrifugation. The antigenic properties of the vaccine were tested in guinea pigs. Antibody response was followed by virus neutralization and complement fixation. The vaccine itself was low-immunogenic, however its immunogenicity has considerably increased by usage of suitable adjuvants. In virus neutralization test higher antibody titre was found against homologous virus. The antibody response was related to protein content and to the frequency of vaccination.

Enzyme-linked immunosorbent assay for quantification of rabies antibodies in human sera.

A double antibody enzyme linked immunosorbent assay (ELISA) was elaborated for detection of rabies antibodies in human sera. The procedure consisted of coating polyvinylchloride plates with rabbit antirabies serum followed by attachment of partially purified fixed virus and human rabies antibodies. The rabies-specific antibodies in human antisera were quantified by means of antihuman peroxidase conjugate. Titration of antisera from human volunteers immunized with the "Fermi" vaccine revealed excellent correlation of the virus neutralization test and ELISA.

Induction capacity and influence of dThdMP on thymidine kinase activity of type 1 and 2 strains of herpes simplex virus.

The thymidine kinase inducing ability of 104 strains of herpes simplex virus was studied comparatively. A pronounced relationship was established between induction of the enzyme and the serotype of the strains. As a rule, the strains of serotype 2 are weaker inducer of dThd- and dCyd-kinase activity than serotype 1 strains. A certain parallelism exists between induction of both enzymes, however the activity of the thymidine kinase increases after infection with herpes simplex virus 4--5 times more than that of the dCyd-kinase. Adaptation of the strains to cell cultures only slightly modifies the inducing ability of the herpes simplex virus strains. The thymidine kinase activity induced by HSV-1 and HSV-2 differ from each other and are different from the cell enzyme with respect to their thermal stability at 40 degrees C. These differences are expressed more clearly in the presence of 480 muM dThdMP during inactivation. dThdMP stabilizes the type 1 but not the type 2 enzyme.

The effect of exogenous histone on the synthesis of DNA, RNA and proteins in Coxsackie B4 virus infected cells.

The incorporation of labelled precursors of DNA, RNA and proteins in F. cells infected with Coxsackie B4 virus has been traced both in the presence and absence of total histone from nucleated erythrocytes during the infectious process. In comparison with the virus infection alone, the exogenous histone supressed the incorporation of 3H-thymidine in early hours and the incorporation of 3H-uridine and 14C-leucine in the 9th hour after virus infection. The established repression of the incorporation of the labelled precurssors for RNA and proteins correlates with a drop in the order of 90 to 99% in the yield of infectious virus.