Attenuated Strain of Mycobacterium tuberculosis BN: Characteristics.

We evaluated the vaccine properties of a novel attenuated strain of M. tuberculosis BN (Mtb BN) and its impact on the gut microbiota in inbred female mice in comparison with a virulent strain Mtb H37Rv and a vaccine strain BCG. The Mtb BN strain demonstrated the highest anti-tuberculosis vaccine effect in I/St mice highly susceptible to tuberculosis infection and the same effect as BCG in mice of the recombinant strain B6.I-100 and in ß2 microglobulin gene knockout mice. No adverse effects of the new Mtb BN strain on the gut microbiota of BALB/c mice were revealed. The virulent strain Mtb H37Rv and the vaccine strain BCG decreased the main indicators of normocenosis (Bifidobacterium spp., Bifidobacterium animalis subsp. lactis, Akkermansia, and Erysipelotrichaceae) and led to disappearance of Clostridium perfingens, E. coli, Pseudomonas spp., which contributed to reduction of species diversity and the development of dysbiosis.

Efficacy of BCG Vaccination Depends on Host Genetics.

We studied the effectiveness of anti-tuberculosis vaccination with BCG in mice of inbred strains and F1 hybrids (highly resistant to tuberculosis infection) that represent a wide range of genetically determined differences in susceptibility to infection with virulent Mycobacterium tuberculosis. The greatest relative effect was found in susceptible mice, with the exception of highly susceptible I/St mice that were practically not protected by vaccination. Despite significant effect of vaccination in inbred mice, their resistance to M. tuberculosis infection did not exceed that of non-vaccinated highly resistant F1 hybrids.

Host genetics in susceptibility to and severity of mycobacterial diseases.

The genetic analysis of susceptibility to infections has proven to be extremely useful for identification of key cells, molecules, pathways, and genes involved in the battle between two genomes - the essence of the infectious process. This is particularly true for tuberculosis and other mycobacterial infections which traditionally attracted much attention from both immunologists and geneticists. In this short review, we observe results of genetic studies performed in human populations and in animal models and compare relative input of forward and reverse genetic approaches in our knowledge about genetic control of and immune responses to mycobacterial infections.

[Expression of Mycobacterium tuberculosis small RNAs in mice models of tuberculosis].

Identification of mechanisms that contribute to bacterial pathogens survival in the infected organism is a powerful approach to influence the pathogenic bacteria. Recently it was established that bacteria use small RNAs to regulate their metabolism. We studied the expression level of the three most highly expressed M. tuberculosis small RNAs MTS0997, MTS 1338 and MTS2823 at different stages of infection in. mice with different genetic resistance to tuberculosis. The maximum expression level of these small RNAs was observed at the early stages of infection.

[A locus involved in tuberculosis infection control in mice locates in the proximal part of the H2 complex].

One of genetic loci involved in tuberculosis (TB) infection control in mice is located within the segment of Chr. 17 occupied by the H2 complex, the mouse MHC. As far as this region includes approximately 40 Mb and contains hundreds of genes affecting immune responses and host-parasite interactions, narrowing the interval by genetic recombination is pre-requisite for identification of particular gene(s). We have developed a panel of recombinant congenic strains bearing different parts of the H2 complex from TB-susceptible I/St mice on the genetic background of TB-resistant C57BL/6 mice. By superposing the phenotype "severe vs. mild infectious course" against the chart of alleles inherited by these new strains from the two parental strains, we have mapped a locus involved in TB control within the segment 33.305-34.479 Mb (-1.1 Mb) of the Chr. 17. Such a location indicates that allelic variants of the prominent pro-inflammatory factor TNF do not affect TB course in our experimental system. This result was confirmed by the assessment of the TNF level in the lung tissue of infected mice of different strains. The QTL (quantitative trait locus) mapped in our study influences several important parameters of TB infection: multiplication of mycobacteria in the lungs, severity of lung pathology and regulation of the early inflammatory response.

[Recognition of emotions based on facial expressions in subjects with different personality traits]. / Opoznanie émotsii po litsevoi ékspressii ispytuemymi s raznym lichnostnym profilem.

A reaction time and accuracy of visual recognition of emotions of joy, anger and fear in their relation to personality traits was studied in 68 healthy subjects. According to scores of Kettell Questionnaire all the participants were divided into two groups: emotionally unstable and emotionally stable, which differed in their emotional and communication traits. It was shown that in the stable group recognition of fear was significantly worse and more slowly than in the unstable group. Besides, the emotionally stable subjects recognized the frightened facial expression less accurate and slowly than they did the joyous and threatening ones. The reaction time and recognition level was found to be closely correlated with some personality traits. These traits were different in two groups and differed from data in the control session of gender recognition. The conjunction between recognition of fearful facial expression and the personality traites and its adaptive significance were discussed. The data seems to be essential for understanding of individual strategy of communication.

[Hemispheric asymmetry of visual evoked potentials during human recognition of facial emotional expressions]. / Mezhpolusharnaia asimmetriia korkovoi vyzvannoi aktivnosti u cheloveka pri opoznanii émotsii po litsevoi ékspressii.

Visual evoked potentials (VEP) in standard 16 EEG derivations were recorded in 26 young men and 20 women during recognition of facial emotional expressions and geometric figures. The stimuli were presented on a computer screen in the center of the visual field or randomly in the right or left vision hemifields. Peak VEP latency and mean amplitude in 50-ms epochs were measured; spatiotemporal VEP dynamics was analyzed in a series of topographic maps. The right hemisphere was shown to be more important in processing emotional faces. The character of the asymmetry was dynamic: at earlier stages of emotion processing the electrical activity was higher in the right inferior temporal region compared to the left symmetrical site. Later on the activity was higher in the right frontal and central areas. The dynamic mapping of "face-selective" component N180 of VEPs revealed the onset of activation over the right frontal areas that was followed by the fast activation of symmetrical left zones. Notably, this dynamics didn't correlate with the hemifield of stimuli exposition. The degree of asymmetry was lower during presentation of figures, especially in the inferior temporal and frontal regions. The prominent asymmetry of information processes in the inferior temporal and frontal areas was suggested to be specific for recognition of facial expression.

[Design of the human tumor-associated VNTR(Muc1) antigen gene, fused with streptavidin, its expression in Escherichia coli. Study of properties of the hybrid protein]. / Konstruirovanie gena opukholeassotsiirovannogo antigena VNTR(Muc1) cheloveka, slitogo so streptavidinom, ego ékspressiia v Escherichia coli. Izuchenie svoistv gibridnogo belka.

A gene of human tumor-associated antigen VNTR(MUC1) bound to streptavidin, an expression plasmid, and a highly effective hybrid protein-producing strain were constructed. It was shown that the streptavidin leader peptide ensures an effective secretion of the hybrid protein into the periplasmic space of Escherichia coli cells. The hybrid protein was isolated in a homogeneous state and its immunogenic properties were studied.

[Protein synthesizing structures and protein synthesis in mouse lymphocytes]. / Beloksinteziruiushchie struktury i sintez belka v limfotsitakh myshi.

The properties of cytoplasmic mRNP particles from spleen lymphocytes (sedimentation coefficients and buoyant density) and the kinetics of incorporation of impulse amino acid label at definite labelling periods (5, 15, 30, 60 sec) were studied. After 5 or 15 sec labelling periods the labelled amino acid was detected in the polysomes (sedimentation coefficient 130-240S, buoyant density 1.55 g/cm3) and in small-sized particles (sedimentation coefficient 80S and less, buoyant density 1.34, 1.50 and 1.60 g/cm3). After 30 sec of labelling the label is incorporated into the medium-sized particles (sedimentation coefficient 80-120 S, buoyant density 1.47 g/cm3); no increase of the label incorporation into the small-sized particles is observed. After 60 sec the label content in all the three sucrose gradient zones is increased. The observed succession of the amino acid label incorporation first into the small-sized particles and then into the large-sized ones having a different buoyant density and the data from impulse uridyl labelling suggest that in the lymphocytes the translation occurs already in the complexes of informosomes with single ribosomes and continues in the course of their conversion to polysomes. The short-time labelling of the cells with an impulse amino acid label allows to determine the time of the polypeptide chain translation from the time of polysome saturation with the label.