scholarly journals EFFECT OF p30 RECOMBINANT PROTEIN ON AFRICAN SWINE FEVER VIRUS IN VITRO REPRODUCTION

Author(s):  
Ali Mazloum ◽  
I. Yu. Zhukov ◽  
A. S. Pershin ◽  
A. S. Igolkin ◽  
N. N. Vlasova

African swine fever specific prevention means have not been developed yet. However, it is necessary to study the function of definite viral proteins, their role in immune response morphogenesis and induction to determine the components to be included into ASF protection drugs. It was established that p54 and p30 proteins participate in virus penetration and internalization and are able to induce protective antibodies in immunized pigs. The inoculation of these proteins into ASFV-infected cell culture has an impact on virus reproduction to different extents. The results of the study of purified recombinant protein p30 effect, derived from E. coli clone, containing pET32b(+)/р30 plasmid, on ASFV in vitro reproduction are presented. The greatest decrease, including complete inhibition of virus reproduction, was observed when 300 ng of p30 were inoculated into porcine spleen and marrow primary cell cultures, infected with the ASFV Krasnodar 07/17 isolate at the dose of 100 HAU per plate (~ 0.01 HAU per cell). It was noted that if the mixture of p30 and p54 was inoculated into a sample, the virus reproduction was greater compared to the use of only p30.

2018 ◽  
pp. 8-12
Author(s):  
Ali Mazloum ◽  
N. G. Zinyakov ◽  
A. S. Igolkin ◽  
N. N. Vlasova

Results of cloning X69R, A179L, E248R, I215L and DP96R genes of ASF virus Krasnodar 07/17 isolate and analysis of their nucleotide sequences are presented. Obtained clones were added to the previously constructed clone library comprising clones of 8 genes of Krasnodar 06/12 isolate. Clones containing X69R, A179L, E248R, I215L and DP96R genes of ASF virus Krasnodar 07/17 isolate will be used for recombinant protein obtaining and testing for their effect on in vitro virus reproduction and their role in the virus infectivity, level of clinical manifestations and virulence. Prokaryotic vector, pJET1.2/ blunt, was used. Thus, the clone library available at the FGBI “ARRIAH” Reference Laboratory for African swine fever was supplemented by pJET1.2-X69R, pJET1.2-A179L, pJET1.2-E248R, pJET1.2-I215L and pJET1.2-DP96R plasmid constructions containing 5 genes of ASF virus Krasnodar 07/17 isolate. Proportion of cloned virus genes was 3.01% of Krasnodar 07/17 isolate genome, hence, total amount of the clone library has reached 7.82%.


Author(s):  
Ali Mazloum ◽  
N. G. Zinyakov ◽  
A. S. Igolkin ◽  
N. N. Vlasova

Results of cloning X69R, A179L, E248R, I215L and DP96R genes of ASF virus Krasnodar 07/17 isolate and analysis of their nucleotide sequences are presented. Obtained clones were added to the previously constructed clone library comprising clones of 8 genes of Krasnodar 06/12 isolate. Clones containing X69R, A179L, E248R, I215L and DP96R genes of ASF virus Krasnodar 07/17 isolate will be used for recombinant protein obtaining and testing for their effect on in vitro virus reproduction and their role in the virus infectivity, level of clinical manifestations and virulence. Prokaryotic vector, pJET1.2/ blunt, was used. Thus, the clone library available at the FGBI “ARRIAH” Reference Laboratory for African swine fever was supplemented by pJET1.2-X69R, pJET1.2-A179L, pJET1.2-E248R, pJET1.2-I215L and pJET1.2-DP96R plasmid constructions containing 5 genes of ASF virus Krasnodar 07/17 isolate. Proportion of cloned virus genes was 3.01% of Krasnodar 07/17 isolate genome, hence, total amount of the clone library has reached 7.82%.


2019 ◽  
pp. 23-28 ◽  
Author(s):  
A. S. Pershin ◽  
I. V. Shevchenko ◽  
A. S. Igolkin ◽  
Ye. V. Aronova ◽  
N. N. Vlasova

A characteristic feature of African swine fever virus (ASFV) is the ability to escape from host immune response, affecting macrophages and replicating in them. Besides, ASFV - specific antibodies do not completely neutralize the virus. Cytokines are important factors for various viral infection pathologies. The virulence of ASFV isolates may depend on the capacity to regulate cytokine expression by macrophages. Thus, when comparing in vitro and in vivo cytokine production by macrophages, it was established that infection with low virulent virus isolates leads to an immune response with a predominance of cytokines involved in cellular immunity, such as INF-α and IL-12p40, as compared with infection with highly virulent isolates. The aim of this paper was to study the effect of African swine fever virus on the production of IL-10, a pleiotropic cytokine that inhibits synthesis of cytokines and shows a strong antiinflammatory effect. For this, 12 piglets were experimentally infected intramuscularly with a continuous cell culture-adapted ASFV isolate Vero25 at a dose of 10 HAdU per animal followed by control infection of surviving animals with the reference virus isolate Arm 07 at a dose of 1,000 HAdU per animal. Temperature measurements were taken and blood sampling to obtain serum was conducted during the experiment. IL-10 amount in blood sera was determined using Invitrogen test systems (Thermo Fisher, USA). A higher IL-10 level (15.8–173 pg/ml) was observed in blood sera of dead animals infected with a moderately virulent virus, as compared with surviving pigs (4–5 pg/ml). No correlation between the speed of appearance of specific antibodies and IL-10 serum levels has been established. No noticeable effect of the IL-10 serum level prior to infection on the survival rate of animals has been observed. Further studies are needed to establish a causal relationship, including study of the expression of various cytokines during infection with both low- and highly virulent virus isolates.


Viruses ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 2198
Author(s):  
Elisabeth Wöhnke ◽  
Walter Fuchs ◽  
Luise Hartmann ◽  
Ulrike Blohm ◽  
Sandra Blome ◽  
...  

African swine fever virus (ASFV), causing an OIE-notifiable viral disease of swine, is spreading over the Eurasian continent and threatening the global pig industry. Here, we conducted the first proteome analysis of ASFV-infected primary porcine monocyte-derived macrophages (moMΦ). In parallel to moMΦ isolated from different pigs, the stable porcine cell line WSL-R was infected with a recombinant of ASFV genotype IX strain “Kenya1033”. The outcome of the infections was compared via quantitative mass spectrometry (MS)-based proteome analysis. Major differences with respect to the expression of viral proteins or the host cell response were not observed. However, cell-specific expression of some individual viral proteins did occur. The observed modulations of the host proteome were mainly related to cell characteristics and function. Overall, we conclude that both infection models are suitable for use in the study of ASFV infection in vitro.


2007 ◽  
Vol 88 (9) ◽  
pp. 2426-2434 ◽  
Author(s):  
Ana Luísa Reis ◽  
R. M. E. Parkhouse ◽  
Ana Raquel Penedos ◽  
Carlos Martins ◽  
Alexandre Leitão

The protective immune response to African swine fever virus (ASFV) includes both cellular and serological components. In this study, the role of antibodies in the pathogenicity and diagnosis of African swine fever (ASF) was explored. Accordingly, total and Ig isotype antibody responses against the 12 viral proteins previously demonstrated to be the main targets of serological immunity were evaluated in longitudinally collected sera from pigs infected experimentally with the non-pathogenic ASFV/NH/P68 isolate. Strong total IgG antibody responses were observed against viral proteins E183L/p54, K205R/‘unassigned’, A104R/histone-like and B602L/‘unassigned’; therefore, IgM, IgG1 and IgG2 responses to these proteins were also determined. One protein stimulating IgM (K205R) may have practical potential for the detection of recently infected animals. There was a clear trend towards an IgG1 response to all of the proteins. This may reflect a dominant Th2-controlled immune response. In order to identify possible correlations between these serological responses and the pathogenesis of ASF, total IgG responses to the 12 recombinant proteins were compared in asymptomatic and chronically infected animals. For the proteins NP419L/DNA ligase, CP312R, B646L/p73, K196R/thymidine kinase and K205R, the antibody titres were significantly higher in animals developing lesions. One exception was the antibody response to the A104R/histone-like protein, which was higher in asymptomatic than in chronically infected pigs, suggesting that antibodies against this protein might be an indicator of an effective immune response or that this response is somehow involved in protection.


2021 ◽  
pp. 105081
Author(s):  
Zhao Huang ◽  
Lang Gong ◽  
Zezhong Zheng ◽  
Qi Gao ◽  
Xiongnan Chen ◽  
...  

Vaccines ◽  
2021 ◽  
Vol 9 (1) ◽  
pp. 29
Author(s):  
Laia Bosch-Camós ◽  
Elisabet López ◽  
María Jesús Navas ◽  
Sonia Pina-Pedrero ◽  
Francesc Accensi ◽  
...  

The development of subunit vaccines against African swine fever (ASF) is mainly hindered by the lack of knowledge regarding the specific ASF virus (ASFV) antigens involved in protection. As a good example, the identity of ASFV-specific CD8+ T-cell determinants remains largely unknown, despite their protective role being established a long time ago. Aiming to identify them, we implemented the IFNγ ELISpot as readout assay, using as effector cells peripheral blood mononuclear cells (PBMCs) from pigs surviving experimental challenge with Georgia2007/1. As stimuli for the ELISpot, ASFV-specific peptides or full-length proteins identified by three complementary strategies were used. In silico prediction of specific CD8+ T-cell epitopes allowed identifying a 19-mer peptide from MGF100-1L, as frequently recognized by surviving pigs. Complementarily, the repertoire of SLA I-bound peptides identified in ASFV-infected porcine alveolar macrophages (PAMs), allowed the characterization of five additional SLA I-restricted ASFV-specific epitopes. Finally, in vitro stimulation studies using fibroblasts transfected with plasmids encoding full-length ASFV proteins, led to the identification of MGF505-7R, A238L and MGF100-1L as promiscuously recognized antigens. Interestingly, each one of these proteins contain individual peptides recognized by surviving pigs. Identification of the same ASFV determinants by means of such different approaches reinforce the results presented here.


Viruses ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 255
Author(s):  
Jingyuan Zhang ◽  
Yanyan Zhang ◽  
Teng Chen ◽  
Jinjin Yang ◽  
Huixian Yue ◽  
...  

African swine fever (ASF), caused by the African swine fever virus (ASFV), is a major epidemic disease endangering the swine industry. Although a number of vaccine candidates have been reported, none are commercially available yet. To explore the effect of unknown genes on the biological characteristics of ASFV and the possibility of a gene-deleted isolate as a vaccine candidate, the strain SY18ΔL7-11, with deletions of L7L–L11L genes from ASFV SY18, was constructed, and its biological properties were analyzed. The results show that deletion of genes L7L-L11L did not affect replication of the virus in vitro. Virulence of SY18△L7-11 was significantly reduced, as 11 of the 12 pigs survived for 28 days after intramuscular inoculation with a low dose (103 TCID50) or a high dose (106 TCID50) of SY18ΔL7-11. All 11 surviving pigs were completely protected against challenge with the parental ASFV SY18 on 28 days postinoculation (dpi). Transient fever and/or irregularly low levels of genomic DNA in the blood were monitored in some pigs after inoculation. No ASF clinical signs or viremia were monitored after challenge. Antibodies to ASFV were induced in all pigs from 14 to 21 days postinoculation. IFN-γ was detected in most of the inoculated pigs, which is usually inhibited in ASFV-infected pigs. Overall, the results demonstrate that SY18ΔL7-11 is a candidate for further constructing safer vaccine(s), with better joint deletions of other gene(s) related to virulence.


2021 ◽  
Author(s):  
Tai L Ng ◽  
Erika J Olson ◽  
Tae Yeon Yoo ◽  
H. Sloane Weiss ◽  
Yukiye Koide ◽  
...  

Suppression of the host innate immune response is a critical aspect of viral replication. Upon infection, viruses may introduce one or more proteins that inhibit key immune pathways, such as the type I interferon pathway. However, the ability to predict and evaluate viral protein bioactivity on targeted pathways remains challenging and is typically done on a single virus/gene basis. Here, we present a medium-throughput high-content cell-based assay to reveal the immunosuppressive effects of viral proteins. To test the predictive power of our approach, we developed a library of 800 genes encoding known, predicted, and uncharacterized human viral genes. We find that previously known immune suppressors from numerous viral families such as Picornaviridae and Flaviviridae recorded positive responses. These include a number of viral proteases for which we further confirmed that innate immune suppression depends on protease activity. A class of predicted inhibitors encoded by Rhabdoviridae viruses was demonstrated to block nuclear transport, and several previously uncharacterized proteins from uncultivated viruses were shown to inhibit nuclear transport of the transcription factors NF-kB and IRF3. We propose that this pathway-based assay, together with early sequencing, gene synthesis, and viral infection studies, could partly serve as the basis for rapid in vitro characterization of novel viral proteins.


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