Recombinant Protein p30 for Serological Diagnosis of African Swine Fever by Immunoblotting Assay.

This article is devoted to the development and evaluation of the immunoblotting test system for serological diagnosis of African swine fever (ASF), based on the highly purified recombinant p30 of ASF virus (ASFV) strain Stavropol 01/08 (Stavropol 2008), representative of the ASFV currently circulating in the Russian Federation. The main project stages are as follows: (i) cloning of the central hydrophilic region of the ASFV gene CP204L (p30) into a prokaryotic vector; (ii) expression and chromatographic purification of the recombinant product p30 with thioredoxin and poly-histidine site (p30e1_TrxA_6xHis); (iii) development of the immunoblotting test system (Rec p30-IB) using the highly purified recombinant p30; and (iv) evaluation of Rec p30-IB using sera and organ samples from domestic pigs and wild boars experimentally or naturally infected by ASFV. Testing of the Rec p30-IB showed the diagnostic specificity and sensitivity of the assay to be 98.75% and 100.00%, respectively. High sensitivity of the Rec p30-IB allowed the detection of ASFV-specific antibodies in samples of organs of the immune system and blood sera, collected from domestic pigs and wild boars, starting from 6 to 8 days post-infection, regardless of virus virulence, seroimmunotype and geographic origin of the samples (East Europe, South Europe, West Europe, Central and south-east Africa).

[Immunosuppression in dogs and pigs infected with canine distemper virus].

Immunosuppression manifesting itself as leukopenia and a considerably lower lymphocyte proliferative response to T- and B-cell mitogens develops in pigs and dogs within 2-3 weeks after intramuscular or oral infection with canine distemper virus (CDV). CDV antigens are detectable in the oral secretions of the animals within 2-2.5 week after infection.

[Antigenic diversity of African swine fever viruses].

Data on the seroimmunotypic and hemadsorbing characteristics of African swine fever virus (ASF) are summarized. According to the results of immunological sampling in pigs and those of hemagglutination inhibition test, the known ASFV strains and isolates were divided into 11 groups, 8 were characterized as seroimmunogroups having their specific reference strains. A 110-140-kD ASFV serotype-specific nonstructural major glycoprotein was identified. It is suggested that it is the glycoprotein that corresponds to the genetic engineering detected virus-specific homolog of lymphocyte membrane protein CD2, gene deletion of which results in the loss of hemadsorbing properties by ASFV.

[Immunity in listeriosis]. / Immunitet pri listerioze.

In this review modern concepts on the formation of specific immunity to listeriosis are presented. Numerous data indicate that in Listeria monocytogenes virulence and the capacity for inducing specific protection is ensured by the protein listeriolysin O. The importance of gamma-interferon, tumor necrosis factor alpha, interleukin 12 and other mediators in ensuring the differentiation of (CD4(+) T-cells into Th1-helpers and cytotoxic T-lymphocytes in animals infected with L. monocytogenes is described in detail. The safety and effective preparations for specific prophylaxis of listeriosis were not developed. Hopeful results have been obtained in experiments on the immunization of mice with killed bacteria with listeriolysin O or interleukin 12. Works describing the use of modified L. monocytogenes strains as vectors for the creation of vaccines against different infections seem to show good prospects.

[Distemper of carnivore: Proliferative activity of lymphocytes in sick and vaccinated dogs]. / Chuma plotoiadnykh: Proliferativnaia aktivnost' limfotsitov u bol'nykh i vaktsinirovannykh sobak.

Effect of inoculation with canine distemper virus (CDV) strains of various virulence or vaccination with commercial polyvalent preparations on the immune status of puppies has been studied. Serum interferon concentration did not change, irrespective of the strain appurtenance of CDV, while the concentration of tumor necrosis factor-alpha decreased on days 4-14 after the virus inoculation. According to the lymphocyte stimulation test (LST), virulent strain Snyder Hill and reactogenic variant U were characterized by a pronounced immunosuppressive effect. Vaccine strain VNiiViM-88 exerted a stimulating effect in LST. Vanguard 5/L vaccine suppressed the immunity for up to 2 weeks. Vacchum, VNiiViM, and experimental vaccine manufactured by a joint-stock company Vetzverotsentr+ activated the mitogen-induced lymphocyte blastogenesis.

[Glycoproteins from the African swine fever virus]. / Glikoproteiny virusa afrikanskoi chumy svinei.

The composition of African swine fever virus (ASFV) glycoproteins was studied. Isolate-specific major gp 110-140 was identified by radioimmunoprecipitation in lysate of porcine bone marrow cells infected with hemadsorbing virus strains. Carbohydrates constitute about 50% of the total mass of gp 110-140. A quantitative method is proposed for identification of the serologic relationships between ASFV hemadsorbing strains. A possible role of ASFV glycoprotein carbohydrates in the hemadsorption, virulence, and immunogenicity is discussed.

[The functional role of the glycosylation of viral components]. / Funktsional'naia rol' glikozilirovaniia virusnykh komponentov.

An inhibitory analysis of the role of glycosylation and glycoproteins in the manifestations of the most important properties of African swine virus was carried out using a set of strains and variants with contrasting characteristics. Glycoproteins were shown to realize some virus functions such as virulence and its variability, intracellular transport and exocytosis of virions, hemadsorption, but not immunological recognition of the infected cells by cytotoxic T-lymphocytes.

[Immune reactions to the African swine fever virus]. / Immunnye reaktsii na virus afrikanskoi chumy svinei.

Host immune reactions to African swine fever virus variants differing in their virulence were studied comparatively. Their obvious variabilities in antibody induction to some polypeptides active in antibody-dependent cell cytotoxicity and cytotoxic T-lymphocytes were demonstrated. T-helpers of immune pig splenocytes were found to recognize the cells infected with avirulent but not virulent virus variants. The described differences were not connected with the changes in SLA-1 antigen expression in the infected cells but correlated with induction of host resistance, chronic or acute course of the disease with fatal outcome.