Vol 57, No 3 (2012)

The fact that the spread of new pandemic influenza A strains poses a constant threat to public health attracts the particular attention of scientists to heterosubtypic immunity (HIS) against different subtypes of this pathogen. This review summarizes data from the world scientific literature on studies of HIS. It presents HIS-related data on the epidemiology of influenza, immunity factors, and groundwork for the design of a universal influenza vaccine

A new target has been revealed for therapy for herpes simplex type 2. The target is RS1 mRNA whose activation is a key stage in regulating the expression of the early genes of herpes simplex virus type 2 (HSV-2). The targeted knockdown of the function of this gene by small interfering RNAs (siRNAs) has been found to result in the complete suppression of HSV-2 infection. The designed interfering RNAs are able to interact with both HSV-1 and HSV-2. The findings suggest that siRNAs have protective properties against the cytopathic effect of HSV-2 and cause no toxicity to infected Vero cells.

The purpose of the study was to evaluate the modulating effect of glutamyl-tryptophan (EW), glycyrrhizic acid (GA), and their combination on the course of experimental infection caused by influenza A (H3N2) virus in mice. The animals were infected with influenza A/Aichi/2/68 (H3N2) virus in a dose of 1 or 10 LD50. GA (10 mg/kg body weight) and EW (0.1, 10, and 1000 Mg/kg) alone or in combination were intraperitoneally injected for 5 days, starting on day 1 of virus infection. Rimantadine 50 mg/kg/day was used as a comparison drug. The combination of EW (1000 Mg/kg) and GA (10 mg/kg) was ascertained to exert the maximum protective effect manifesting itself in reducing the death of infected animals (by 75-79% compared to the control depending on the viral dose) and the titers of viruses accumulated in the lung (5-6 log EID50) and in preventing lung tissue edema and inflammation. The noted effect was comparable with that seen in the use of rimantadine. The agents used alone had a lower efficacy than rimantadine. The findings permit the combination of GA and EW to be considered to be a promising agent for the treatment of influenza.

Eighteen polytypic tick-borne encephalitis virus (TBEV) strains containing the fragments of E and NS1 protein genes of Siberian and Far Eastern, occasionally Siberian and European subtypes were isolated in the European and Asian parts of the tick-borne encephalitis (TBE) area. They were identified using real-time polymerase chain reaction, hybridization-fluorescence detection with genotype-specific probes, restriction fragment length polymorphism analysis, and E protein sequencing. The polytypic strains were isolated from individual Ixodes persulcatus ticks, their pools, from the blood of patients and the brain of dead patients. The isolation rates of the polytypic strains in the sympathry area of different TBEV subtypes ranged from 4.4% (the Irkutsk Region) to 15.1% (the Yaroslavl Region). In addition to 2 polytypic strains, a strain similar to the TBEV 886-84 strain was isolated. The TBEV subtypes entering into the composition of the polytypic strains show nongenetic interactions, such as neutral replication or competition. The polytypic strains are stable during passages in the cultured pig embryo kidney epithelial cells and on cloning. Mouse brain passage promotes dissociation of polytypic strains. The conditions for the formation of polytypic strains and their role in the etiology of TBE are discussed.

The nucleotide sequences of the envelope (E) protein gene of three tick-borne encephalitis virus (TBEV) strains 80, 85, and 290 isolated from Ixodes ricinus ticks in the Crimea in 1989-1990 were determined. A comparative analysis of the genetic structure of the strains showed their identity. A phylogenetic analysis of these strains with 34 other TBEV strains could assign them to the European genotype and showed their maximum (97.24%) identity to the Pan strain that occupies a separate position among the sequenced TBEV strains. The findings indicate that the TBEV European genotype strains circulated together with the TBEV Far Eastern genotype ones in the Crimea in 1980-1990