Olga Masalova

Dr. Olga Masalova

Ivanovsky Institute of Virology, Gamaleya National Research Center for Epidemiology and Microbiology of the Russian Ministry of Health, Moscow, Moskva, Russia
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Academic Career Length

31Years (1996-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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13 September 2011 in PLOS ONE
Verified
Journal Article
Open access
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Alexander V. IvanovAlexander V. Ivanov
Alexander V. Ivanov
OSOlga A. Smirnova
Olga A. Smirnova
OMOlga Masalova
Olga Masalova
SKSergey Kochetkov
Sergey Kochetkov
MIMaria Isaguliants
Maria Isaguliants
OIOlga Ivanova
Olga Ivanova
Hepatitis C virus (HCV) is a highly pathogenic human virus associated with liver fibrosis, steatosis, and cancer. In infected cells HCV induces oxidative stress. Here, we show that HCV proteins core, E1, E2, NS4B, and NS5A activate antioxidant defense Nrf2/ARE pathway via several independent mechanisms. This was demonstrated by the analysis of transient co-expression in Huh7 cells of HCV proteins and luciferase reporters. Expression, controlled by the promoters of stress-response genes or their minimal Nrf2-responsive elements, was studied using luminescence assay, RT-qPCR and/or Western-blot analysis. All five proteins induced Nrf2 activation by protein kinase C in response to accumulation of reactive oxygen species (ROS). In addition, expression of core, E1, E2, NS4B, and NS5A proteins resulted in the activation of Nrf2 in a ROS-independent manner. The effect of core and NS5A was mediated through casein kinase 2 and phosphoinositide-3 kinase, whereas those of NS4B, E1, and E2, were not mediated by either PKC, CK2, PI3K, p38, or ERK. Altogether, on the earliest stage of expression HCV proteins induced a strong up-regulation of the antioxidant defense system. These events may underlie the harmful effects of HCV-induced oxidative stress during acute stage of hepatitis C.
1 June 2012 in Virus Research
Verified
Journal Article
Closed access
IRIrina Rudneva
Irina Rudneva
AIAnna Ignatieva
Anna Ignatieva
TTTatiana Timofeeva
Tatiana Timofeeva
ASAleksandr Shilov
Aleksandr Shilov
AKAlla Kushch
Alla Kushch
NKNikolai Kaverin
Nikolai Kaverin
1 April 2010 in Viral Immunology
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Journal Article
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IRIrina A. Rudneva
Irina A. Rudneva
AKAlla Kushch
Alla Kushch
OMOlga Masalova
Olga Masalova
TTTatiana A. Timofeeva
Tatiana A. Timofeeva
RKRegina Klimova
Regina Klimova
NKNikolai V. Kaverin
Nikolai V. Kaverin
The highly pathogenic avian influenza H5N1 viruses have become widespread and evolved into several clades. In our previous studies, the antigenic sites of the H5 hemagglutinin (HA) were characterized by selection and sequencing of escape mutants. In the present studies we analyzed the antigenic epitopes recognized by monoclonal antibodies against avian influenza A/Duck/Novosibirsk/56/05 (H5N1) virus isolated in western Siberia and belonging to subclade 2.2 of the H5N1 viruses. The analysis revealed several antigenically relevant positions of amino acid residues in the globular head of the HA not encountered earlier in the escape mutants of the H5 subtype. The newly recognized positions (113, 117, 118, 120, and 123, mature H5 numbering) are concentrated in an area adjacent to the region described in earlier studies as corresponding to site B in H3 HA, but extending far beyond this area. The amino acid positions recognized by the monoclonal antibodies against A/Duck/Novosibirsk/56/05 (H5N1) virus differ from the positions recognized by the monoclonal antibodies against H5N2 influenza viruses. The data suggest that the evolution of the HA of H5 avian influenza viruses is associated not only with the changes of antigenic epitopes recognized by antibodies, but also with a change in the dominance of the immunogenicity of different sites in the HA.
1 May 1998 in Journal of Medical Virology
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Journal Article
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OMOlga Masalova
Olga Masalova
SAS. N. Atanadze
S. N. Atanadze
ESE. I. Samokhvalov
E. I. Samokhvalov
NPN. V. Petrakova
N. V. Petrakova
TKT. I. Kalinina
T. I. Kalinina
AKA. A. Kushch
A. A. Kushch
1 March 2006 in Molecular Biology
Verified
Journal Article
Closed access
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ERE. A. Rechkina
E. A. Rechkina
GDG. F. Denisova
G. F. Denisova
OMOlga Masalova
Olga Masalova
LLL. F. Lideman
L. F. Lideman
DDD. A. Denisov
D. A. Denisov
AKAlla Kushch
Alla Kushch
Analysis of the properties for individual hepatitis C virus (HCV) proteins makes it possible to establish their molecular structure and conformation, to localize antigenic and immunogenic determinants, to identify protective epitopes, and to solve applied problems (e.g., design of diagnostic tests, vaccines, and drugs). Linear and conformational epitopes of HCV proteins were localized using the phage display technique, and the peptides exposed on the phages selected with monoclonal antibodies against HCV proteins were tested for immunogenicity. Of the 11 epitopes revealed, three were strongly linear; two depended on the secondary; and one on the tertiary structure of the corresponding protein (conformational epitopes). Amino acid sequences involved in the other epitopes were established. The results can be used to improve the diagnosis of hepatitis C, to study the effect of amino acid substitutions on the antigenic properties of HCV proteins, and to analyze the immune response in patients infected with genotypically different HCV. It was shown with the example of the NS5A epitope that phage particles with epitope-mimicking peptides (mimotopes) induce production of antibodies against the corresponding HCV proteins.
2 February 2020 in Vaccines
Verified
Journal Article
Open access
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OMOlga Masalova
Olga Masalova
ELEkaterina Lesnova
Ekaterina Lesnova
RKRegina Klimova
Regina Klimova
EMEkaterina D. Momotyuk
Ekaterina D. Momotyuk
VKVyacheslav V. Kozlov
Vyacheslav V. Kozlov
AKAlla Kushch
Alla Kushch
Hepatitis C virus (HCV) is one of the major causes of chronic liver disease and leads to cirrhosis and hepatocarcinoma. Despite extensive research, there is still no vaccine against HCV. In order to induce an immune response in DBA/2J mice against HCV, we obtained modified mouse mesenchymal stem cells (mMSCs) simultaneously expressing five nonstructural HCV proteins (NS3-NS5B). The innate immune response to mMSCs was higher than to DNA immunization, with plasmid encoding the same proteins, and to naïve unmodified MSCs. mMSCs triggered strong phagocytic activity, enhanced lymphocyte proliferation, and production of type I and II interferons. The adaptive immune response to mMSCs was also more pronounced than in the case of DNA immunization, as exemplified by a fourfold stronger stimulation of lymphocyte proliferation in response to HCV, a 2.6-fold higher rate of biosynthesis, and a 30-fold higher rate of secretion of IFN-γ, as well as by a 40-fold stronger production of IgG2a antibodies to viral proteins. The immunostimulatory effect of mMSCs was associated with pronounced IL-6 secretion and reduction in the population of myeloid derived suppressor cells (MDSCs). Thus, this is the first example that suggests the feasibility of using mMSCs for the development of an effective anti-HCV vaccine.