scholarly journals DEVELOPMENT AND PROPERTIES OF NEUTRALIZING MONOCLONAL ANTIBODIES FOR FUSION PROTEIN OF RESPIRATORY SYNCYTIAL VIRUS

2019 ◽  
Vol 64 (2) ◽  
pp. 90-96
Author(s):  
A. A. Kushch ◽  
R. R. Klimova ◽  
N. E. Fedorova ◽  
O. V. Masalova ◽  
A. A. Niconova ◽  
...  

Introduction. Respiratory syncytial virus (RSV) is the most common cause of lower respiratory tract infections in infants and the elderly. The absence of a wide range of therapeutic drugs and vaccines indicates to the high relevance of the development of new effective drugs for the prevention and treatment of RSV infections. Purpose: to obtain highly active and specific monoclonal antibodies (MAbs) capable of detecting RSV in infected cells and neutralizing the infectious activity of the virus in vitro. Material and methods. RSV reference strains of group A 2 subgroups (A2 and Long) were propagated in HEp-2 and MA-104 cell lines, respectively. Mice were immunized with purified RSV A2 virus. MAbs were obtained using hybridoma technology. Results. A panel of 6 MAbs reacting with RSV strains А2 and Long has been obtained. Four MAbs were IgG (IgG2a or IgG2b subtype), two MAbs were IgM. All MAbs reacted with RSV F-protein in immunochemical tests. The MAbs actively reacted with RSV in ELISA, in immufluorescence and peroxidase staining of infected cells, and in immunodot test. Five out of 6 MAbs neutralized of RSV in cell culture. Different properties of MAbs suggest that they target different antigenic sites of F-protein. Discussion. Comparative analysis suggests that the obtained MAbs can be used for the development of diagnostic preparations, for RSV detection in clinical materials and confirmation of infection etiology by rapid culture method. Conclusion. High activity and specificity of MAbs indicate that they can serve as a basis for development vaccines and preventive medicines.

Author(s):  
N. A. Demidova ◽  
R. R. Klimova ◽  
A. A. Kushch ◽  
E. I. Lesnova ◽  
O. V. Masalova ◽  
...  

The aim of this study was to obtain hybridomas producing monoclonal antibodies (Mabs) to the G-protein of the respiratory syncytial virus (RSV), and to evaluate their immunological characteristics and virus-neutralizing activity.Material and methods. Mouse Mabs were obtained using hybridoma technology. The properties of Mabs were studied by enzyme-linked immunosorbent assay (ELISA), immunofluorescence staining (IF) of infected cells, as well as by biological neutralization test in vitro (NT). To identify epitopes recognized by the Mabs on G protein ELISA additivity test was used.Results. Hybridization of splenocytes with Sp2/0 myeloma cells and primary screening showed that 75 hybridomas produce antibodies interacting with purified virus, 17 of them also react with the recombinant G-protein in ELISA. In NT 4, hybridomas suppressed in vitro RSV infection by more than 50%. Cloning of these hybridomas revealed 4 monoclones producing the most active Mabs. Mab 1C11 was IgG2a, 3 others (5D4, 5G11 and 6H4) were IgM. Three IgM Mabs actively reacted with both RSV A2 and Long, and with G-protein; Mab 1C11 was less reactive with all antigens tested. All Mabs suppressed RSV infection, while Mab 5D4 supressed it almost completely (98%). IF analysis showed that all Mabs detected RSV G-protein in the cell cytoplasm, the largest number of infected cells was detected using Mab 5D4 (80%). It was shown that the isolated Mabs were directed to two non-overlapping epitopes on the RSV G-protein.Conclusion. The isolated Mabs can be used to detect RSV in clinical samples by ELISA and IF. The isolated Mabs can be used for humanized recombinant antibodies construction and for the treatment of RSV infection in future.


2015 ◽  
Vol 60 (1) ◽  
pp. 6-13 ◽  
Author(s):  
Laurent Detalle ◽  
Thomas Stohr ◽  
Concepción Palomo ◽  
Pedro A. Piedra ◽  
Brian E. Gilbert ◽  
...  

ABSTRACTRespiratory syncytial virus (RSV) is an important causative agent of lower respiratory tract infections in infants and elderly individuals. Its fusion (F) protein is critical for virus infection. It is targeted by several investigational antivirals and by palivizumab, a humanized monoclonal antibody used prophylactically in infants considered at high risk of severe RSV disease. ALX-0171 is a trimeric Nanobody that binds the antigenic site II of RSV F protein with subnanomolar affinity. ALX-0171 demonstratedin vitroneutralization superior to that of palivizumab against prototypic RSV subtype A and B strains. Moreover, ALX-0171 completely blocked replication to below the limit of detection for 87% of the viruses tested, whereas palivizumab did so for 18% of the viruses tested at a fixed concentration. Importantly, ALX-0171 was highly effective in reducing both nasal and lung RSV titers when delivered prophylactically or therapeutically directly to the lungs of cotton rats. ALX-0171 represents a potent novel antiviral compound with significant potential to treat RSV-mediated disease.


2020 ◽  
Vol 97 (1) ◽  
pp. 7-14
Author(s):  
N. A. Demidova ◽  
R. R. Klimova ◽  
A. A. Kushch ◽  
E. I. Lesnova ◽  
O. V. Masalova ◽  
...  

The aim of this study was to obtain hybridomas producing monoclonal antibodies (Mabs) to the G-protein of the respiratory syncytial virus (RSV), and to evaluate their immunological characteristics and virus-neutralizing activity.Material and methods. Mouse Mabs were obtained using hybridoma technology. The properties of Mabs were studied by enzyme-linked immunosorbent assay (ELISA), immunofluorescence staining (IF) of infected cells, as well as by biological neutralization test in vitro (NT). To identify epitopes recognized by the Mabs on G protein ELISA additivity test was used.Results. Hybridization of splenocytes with Sp2/0 myeloma cells and primary screening showed that 75 hybridomas produce antibodies interacting with purified virus, 17 of them also react with the recombinant G-protein in ELISA. In NT 4, hybridomas suppressed in vitro RSV infection by more than 50%. Cloning of these hybridomas revealed 4 monoclones producing the most active Mabs. Mab 1C11 was IgG2a, 3 others (5D4, 5G11 and 6H4) were IgM. Three IgM Mabs actively reacted with both RSV A2 and Long, and with G-protein; Mab 1C11 was less reactive with all antigens tested. All Mabs suppressed RSV infection, while Mab 5D4 supressed it almost completely (98%). IF analysis showed that all Mabs detected RSV G-protein in the cell cytoplasm, the largest number of infected cells was detected using Mab 5D4 (80%). It was shown that the isolated Mabs were directed to two non-overlapping epitopes on the RSV G-protein.Conclusion. The isolated Mabs can be used to detect RSV in clinical samples by ELISA and IF. The isolated Mabs can be used for humanized recombinant antibodies construction and for the treatment of RSV infection in future.


2003 ◽  
Vol 77 (9) ◽  
pp. 5054-5064 ◽  
Author(s):  
Janet L. Douglas ◽  
Marites L. Panis ◽  
Edmund Ho ◽  
Kuei-Ying Lin ◽  
Steve H. Krawczyk ◽  
...  

ABSTRACT Human respiratory syncytial virus (RSV) is a major cause of respiratory tract infections worldwide. Several novel small-molecule inhibitors of RSV have been identified, but they are still in preclinical or early clinical evaluation. One such inhibitor is a recently discovered triphenol-based molecule, VP-14637 (ViroPharma). Initial experiments suggested that VP-14637 acted early and might be an RSV fusion inhibitor. Here we present studies demonstrating that VP-14637 does not block RSV adsorption but inhibits RSV-induced cell-cell fusion and binds specifically to RSV-infected cells with an affinity corresponding to its inhibitory potency. VP-14637 is capable of specifically interacting with the RSV fusion protein expressed by a T7 vaccinia virus system. RSV variants resistant to VP-14637 were selected; they had mutations localized to two distinct regions of the RSV F protein, heptad repeat 2 (HR2) and the intervening domain between heptad repeat 1 (HR1) and HR2. No mutations arose in HR1, suggesting a mechanism other than direct disruption of the heptad repeat interaction. The F proteins containing the resistance mutations exhibited greatly reduced binding of VP-14637. Despite segregating with the membrane fraction following incubation with intact RSV-infected cells, the compound did not bind to membranes isolated from RSV-infected cells. In addition, binding of VP-14637 was substantially compromised at temperatures of ≤22°C. Therefore, we propose that VP-14637 inhibits RSV through a novel mechanism involving an interaction between the compound and a transient conformation of the RSV F protein.


2020 ◽  
Vol 5 (2) ◽  

Respiratory Syncytial Virus (RSV) is the major cause of the lower respiratory tract illness (RTI) in the elderly and in immunocompromised patients and children under 5 years of age. The disease causes deaths of approximately 500 infants each year. Conventional vaccine against the disease demonstrated immunological pitfalls to enhance T-helper responses and developed non-neutralising antibodies. This study aimed to predict epitopes from the fusion F protein of SRV that elicit the immune system and acted as safer efficacious vaccine. A total of 199 strains of RSV were retrieved from the NCBI database. The immune epitope database analysis resources (IEDB) were used for epitopes prediction against B and T cells. The population coverage was also calculated for the proposed epitopes against the whole world. Only two epitopes (441-YVSNK-445 and 440-DYVS-443) successfully passed all B cell prediction tools and demonstrated higher score in Emini and Kolaskar and tongaonker software. Thus were proposed as B cells epitopes. For T cells, a total of 177 epitopes were found to interact with MHC-I alleles. Among them four epitopes (53-YTSVITIEL-61; 250-YMLTNSELL-258, 198-YIDKQLLPI-206, and 450-VSVGNTLYY-458) were proposed since they interacted with the highest number of alleles and the best binding affinity to MHC-1 alleles. Moreover, a total of 397 core epitopes were found to interact with MHC-П alleles. However, the best four core proposed epitopes that interacted with higher number of MHC-II alleles were 217-IETVIEFQQ-226; 250-YMLTNSELL-258; 477-FYDPLVFPS-485 and 505-FIRKSDELL-513. Strikingly the epitope 250-YMLTNSELL-258 successfully interacted with both MHC-1and MHC-П alleles. The population coverage was 48.61% and 99.64% for MHC-I and MHC-II epitopes, respectively, and 100% for all T cells epitopes. Taken together ten epitopes successfully proposed as vaccine candidate against RSV. In vivo and in vitro clinical trials studies are required to elucidate the effectiveness of these epitopes as vaccine.


Vaccines ◽  
2021 ◽  
Vol 9 (6) ◽  
pp. 624
Author(s):  
Laura M. Stephens ◽  
Steven M. Varga

Respiratory syncytial virus (RSV) is most commonly associated with acute lower respiratory tract infections in infants and children. However, RSV also causes a high disease burden in the elderly that is often under recognized. Adults >65 years of age account for an estimated 80,000 RSV-associated hospitalizations and 14,000 deaths in the United States annually. RSV infection in aged individuals can result in more severe disease symptoms including pneumonia and bronchiolitis. Given the large disease burden caused by RSV in the aged, this population remains an important target for vaccine development. Aging results in lowered immune responsiveness characterized by impairments in both innate and adaptive immunity. This immune senescence poses a challenge when developing a vaccine targeting elderly individuals. An RSV vaccine tailored towards an elderly population will need to maximize the immune response elicited in order to overcome age-related defects in the immune system. In this article, we review the hurdles that must be overcome to successfully develop an RSV vaccine for use in the elderly, and discuss the vaccine candidates currently being tested in this highly susceptible population.


Molecules ◽  
2021 ◽  
Vol 26 (9) ◽  
pp. 2607
Author(s):  
Yuzhen Gao ◽  
Jingjing Cao ◽  
Pan Xing ◽  
Ralf Altmeyer ◽  
Youming Zhang

Respiratory syncytial virus (RSV) is a major pathogen that causes severe lower respiratory tract infection in infants, the elderly and the immunocompromised worldwide. At present no approved specific drugs or vaccines are available to treat this pathogen. Recently, several promising candidates targeting RSV entry and multiplication steps are under investigation. However, it is possible to lead to drug resistance under the long-term treatment. Therapeutic combinations constitute an alternative to prevent resistance and reduce antiviral doses. Therefore, we tested in vitro two-drug combinations of fusion inhibitors (GS5806, Ziresovir and BMS433771) and RNA-dependent RNA polymerase complex (RdRp) inhibitors (ALS8176, RSV604, and Cyclopamine). The statistical program MacSynergy II was employed to determine synergism, additivity or antagonism between drugs. From the result, we found that combinations of ALS8176 and Ziresovir or GS5806 exhibit additive effects against RSV in vitro, with interaction volume of 50 µM2% and 31 µM2% at 95% confidence interval, respectively. On the other hand, all combinations between fusion inhibitors showed antagonistic effects against RSV in vitro, with volume of antagonism ranging from −50 µM2 % to −176 µM2 % at 95% confidence interval. Over all, our results suggest the potentially therapeutic combinations in combating RSV in vitro could be considered for further animal and clinical evaluations.


Pathogens ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 47
Author(s):  
Catalina A. Andrade ◽  
Alexis M. Kalergis ◽  
Karen Bohmwald

Respiratory infections are among the major public health burdens, especially during winter. Along these lines, the human respiratory syncytial virus (hRSV) is the principal viral agent causing acute lower respiratory tract infections leading to hospitalization. The pulmonary manifestations due to hRSV infection are bronchiolitis and pneumonia, where the population most affected are infants and the elderly. However, recent evidence suggests that hRSV infection can impact the mother and fetus during pregnancy. Studies have indicated that hRSV can infect different cell types from the placenta and even cross the placenta barrier and infect the fetus. In addition, it is known that infections during the gestational period can lead to severe consequences for the development of the fetus due not only to a direct viral infection but also because of maternal immune activation (MIA). Furthermore, it has been described that the development of the central nervous system (CNS) of the fetus can be affected by the inflammatory environment of the uterus caused by viral infections. Increasing evidence supports the notion that hRSV could invade the CNS and infect nervous cells, such as microglia, neurons, and astrocytes, promoting neuroinflammation. Moreover, it has been described that the hRSV infection can provoke neurological manifestations, including cognitive impairment and behavioral alterations. Here, we will review the potential effect of hRSV in brain development and the potential long-term neurological sequelae.


F1000Research ◽  
2019 ◽  
Vol 8 ◽  
pp. 1837 ◽  
Author(s):  
Rinat Nuriev ◽  
Cecilia Johansson

Respiratory syncytial virus (RSV) can cause severe lower respiratory tract infections especially in infants, immunocompromised individuals and the elderly and is the most common cause of infant hospitalisation in the developed world. The immune responses against RSV are crucial for viral control and clearance but, if dysregulated, can also result in immunopathology and impaired gas exchange. Lung immunity to RSV and other respiratory viruses begins with the recruitment of immune cells from the bloodstream into the lungs. This inflammatory process is controlled largely by chemokines, which are small proteins that are produced in response to innate immune detection of the virus or the infection process. These chemokines serve as chemoattractants for granulocytes, monocytes, lymphocytes and other leukocytes. In this review, we highlight recent advances in the field of RSV infection and disease, focusing on how chemokines regulate virus-induced inflammation.


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