Antigenic variants among street rabies virus isolates from France, Africa, Madagascar and Asia. Preliminary results with antinucleocapsid monoclonal antibodies

A panel of monoclonal antibodies directed against the nucleocapsid antigens of rabies virus allowed a rapid characterization of isolates by an indirect immunofluorescence test on brain smears of infected animals. Analysis of 77 isolates (71 from animals and 6 from humans) showed a great diversity. Isolates from different areas showed different patterns of reactivity. No relation was found between animal species and antigenic patterns specificity.     

Antigenic variants of rabies virus in isolates from eastern, central and northern Canada.

Street rabies virus isolated from 51 specimens from Ontario, Quebec, Manitoba and the Northwest Territories have been typed by a panel of 36 antinucleocapsid monoclonal antibodies. Three main groups were found. The first group comprised those terrestrial mammals originating in Ontario, Quebec and the Northwest Territories. The second group was found in terrestrial mammals from Manitoba. The third heterogenous group was made up of bats from Ontario.     

Antigenic characterization of street rabies virus isolates from Nigeria using monoclonal antibodies

Twenty isolates of street rabies virus were recovered in mouse neutroblastoma cells from 84 rabies suspect brain specimens from Nigeria dogs and a cat. They were characterized with the Tübingen monoclonal antibody panels directed against nucleocapsid and glycoprotein antigens. Antigenic variations were detected both with antinucleocapsid (anti-NC) and antiglycoprotein (anti-GP) monoclonal antibodies (mabs). One isolate reacted positively with anti-NC mab P41 which hitherto has been known to react positively with polar rabies. Another isolate did not react with anti-NC mab 187.5; a reaction normally seen with ERA/SAD strains of rabies virus. With anti-GP mabs it was possible to group the isolates by their area of origin. Isolates from Plateau State were not neutralized by anti-GP mabs ERA 543 and P44.7.2. The isolates studied had glycoprotein antigenic patterns different from the pattern for low egg passage (LEP) Flury strain vaccine virus used in Nigeria for immunization of dogs.     

Antigenic characterisation of virus isolates from vaccinated dogs dying of rabies

Four rabies virus isolates from dogs that succumbed to rabies infection in Nigeria within one year of anti-rabies vaccination were characterised by monoclonal antibodies (MAbs). The samples were screened for rabies and rabies-related viral antigens by the indirect fluorescent antibody test, performed with MAb 502-2, which recognises the nucleocapsid (NC) protein of all known Lyssaviruses and with MAb 422-5 which identifies African rabies-related viruses. All four canine virus isolates displayed positive fluorescence with MAb 502-2 and were negative with MAb 422-5. In the anti-NC MAb characterisation with a panel of 34 additional MAbs, all isolates displayed positive staining with 32 of the MAbs, were negative with MAb 102-27 and all displayed poor immunofluorescence with MAb 377-7. On the basis of reactivity with a panel of 40 anti-glycoprotein (G) MAbs the isolates were separated into four distinct viral subtypes. None of these canine isolates was identified as the common attenuated Flury LEP rabies strain used for domestic animal vaccination and none resembled other previously characterised rabies viruses from Nigeria.     

狂犬病病毒HepFlury株P蛋白单克隆抗体的制备及间接免疫荧光检测方法的建立

本研究以原核表达的融合型的重组蛋白pET32a(+)-P(狂犬病病毒HepFlury株P蛋白)免疫6~8周龄的BALB/c小鼠,取脾细胞和SP2/0按常规杂交瘤技术进行细胞融合,经间接免疫荧光方法(IFA)筛选及对mAb进行初步鉴定。经3次亚克隆后获得1株稳定分泌表达的杂交瘤细胞株5G8。     

Comparison of visual microscopic and computer-automated fluorescence detection of rabies virus neutralizing antibodies.

The rapid fluorescent focus inhibition test (RFFIT) and the fluorescent antibody virus neutralization test (FAVNT) are both diagnostic tests for determining levels of rabies neutralizing antibodies. An automated method for determining fluorescence has been implemented to reduce the work time required for fluorescent visual microscopic observations. The automated method offers several advantages over conventional visual observation, such as the ability to rapidly test many samples. The antibody titers obtained with automated techniques were similar to those obtained with both the RFFIT (n = 165, r = 0.93, P < 0.001) and the FAVNT (n = 52, r = 0.99, P < 0.001).     

The persistence of rabies virus antibodies in the sera of fox cubs

The persistence of maternal antibodies transfer from rabies-immune vixens to their fox cubs was studied. Eight vixens (Vulpes vulpes) were vaccinated 1 month before pregnancy with Lysvulpen vaccine for oral vaccination of foxes. Twenty-one were foxes born at the first half of April. The geometrical mean titre of rabies neutralizing antibodies of fox cubs sampled in May was 1.31 IU/ml and has dropped successively to 0.54 IU/ml in June samples and to 0.18 IU/ml in July samples. It has been proven that the duration of rabies maternal antibodies in fox cubs was limited to 2 months after birth.     

Monoclonal antibody characterization of rabies virus isolates from Russia, Finland and Estonia

Five different rabies virus variants were identified among rabies virus-positive samples from Russia, Finland and Estonia, using a panel of five anti-nucleocapsid monoclonal antibodies. Two rabies virus isolates showed a different reaction pattern, suggesting the presence of a new antigenic variant. The results were compared with the data obtained by other research groups.     

Antigenic variation of porcine transmissible gastroenteritis virus detected by monoclonal antibodies

Mouse myeloma cells (SP2/O) were fused with spleen cells from BALB/c mice immunized with detergent-solubilized antigen of purified virus, and 21 monoclonal (MC) antibodies reactive in enzyme-linked immunosorbent assay with the TO-163 strain of porcine transmissible gastroenteritis (TGE) virus were obtained. Of these MC antibodies, 14, 6 and 1 were IgG1, IgG2a and IgM, respectively. All of the MC antibodies contained light chains of the kappa type. Of these MC antibodies, 8 were found to have neutralization (NT) activity against the TO-163 strain. Comparison of 7 strains of TGE virus by NT tests using our panel of MC antibodies confirmed their close antigenic relationships, but also revealed the occurrence of distinct antigenic differences. These results suggest that there may be at least 6 different epitopes involved in NT reaction on the virion of the TO-163 strain. This notion was confirmed by the competitive binding assay.     

Antigenic relationships of foot-and-mouth disease virus serotype Asia-1 isolates demonstrated by monoclonal antibodies.

A panel (26) of monoclonal antibodies (MAbs) was elicited against three distinct isolates of foot-and-mouth disease virus (FMDV) serotype Asia-1. Each MAb was characterized according to the location of its epitope: Class I, restricted to the intact virion (140S); Class II, restricted to 140S and the virion protein subunit (12Sps); Class III, available on 140S, 12Sps and virus protein 1; Class IV, restricted to 12Sps. In addition, the MAbs were further categorized by isotype, neutralization of viral infectivity, capacity to bind in radioimmunoassay and precipitation in the Ouchterlony reaction. Neutralization of FMDV infectivity by a MAb of the IgA isotype is reported for the first time. A minimum of seven distinct neutralization epitopes were described on FMDV Asia-1. Some of the neutralizing MAbs bound FMDVs in addition to those that they neutralized. The MAbs defined epitopes common to FMDV serotypes Asia-1, A, O1 and C but neutralizing capacity was restricted to serotype Asia-1. Class IV MAbs defined epitopes highly conserved throughout the FMDV serotypes. Identification of FMDV neutralization epitopes makes possible the direct selection of optimal FMDV strains for vaccine fabrication. In addition, these data are crucial to the design of future synthetic vaccines.     

猪戊型肝炎病毒单克隆抗体的抗原识别位点分析

采用ELISA叠加试验,对6株具有ELISA反应特性的猪戊型肝炎病毒(SHEV)单克隆抗体(McAb-αC11、αC12、γH1、γF8、BC4和CH8)的抗原识别位点进行检测。抗体反应增值结果表明,6株单抗分别针对4个不同抗原位点,McAb-γH1,BC4,CH8识别的位点各不相同,其中McAb-γH1、BC4识别的位点有部分重叠,McAb-αC11、αC12,γF8识别同一位点,位于γH1,BC4识别位点的重叠区内。     

Antigenic differentiation of pestivirus strains with monoclonal antibodies against hog cholera virus

Thirty-one bovine viral diarrhoea virus (BVDV) or border disease virus (BDV) strains and 94 hog cholera virus (HCV) strains were grown in cell culture, and characterized by immunostaining with 13 monoclonal antibodies (MAbs) and one polyclonal serum (PAb) against HCV. All 125 strains were recognized by the PAb. None of the BVDV or BDV strains were detected by the 13 MAbs. Seven MAbs detected all 94 HCV strains. Six other MAbs detected heterogeneity among and within HCV strains. The MAbs are useful tools in differentiating between HCV and BVDV infections in pigs, and can also be used to differentiate infections induced by HCV field strains from infections induced by the "Chinese" strain of vaccine virus.     

Major antigenic groups of rabies virus in Canada determined by anti-nucleocapsid monoclonal antibodies

A total of 123 rabies virus isolates from various geographical areas in Canada were characterized by a panel of 43 anti-nucleocapsid monoclonal antibodies. Four major antigenic groups are found in terrestrial mammals: "Canadian Arctic" from Ontario, Quebec and the Northwest Territories; "south-eastern Georgian Bay" from Ontario; "south mid-central skunk" from Alberta, Saskatchewan and Manitoba; and "Brook's, Alberta skunk" from a restricted area in Alberta. Bat isolates can be divided into 4 major antigenic groups: "B-1" in Eptesicus fuscus from Ontario; "B-2" in a variety of bat species from British Columbia eastward into Ontario; "B-3" in Myotis spp. from Ontario and New Brunswick; and "B-4" in E. fuscus from Alberta and Saskatchewan. A single case of bat to horse transmission of rabies virus is recorded. These street isolates are compared with isolates of fixed virus. Epidemiological aspects are discussed.     

Monoclonal antibodies to the Sp strain of infectious pancreatic necrosis virus

Twelve hybrids secreting antibody to the Sp serotype of infectious pancreatic necrosis virus (IPNV) were isolated from the fusion of murine myeloma cells and spleen cells from mice immunized with pelleted virus. All of the monoclonal antibodies possessed the kappa (K) light chain isotype. Nine contained the mu (M), two had the gamma 2a (G2a), and one had the gamma 1 (G1) heavy chain isotype. Using an enzyme-linked immunosorbent assay (ELISA), 10 antibodies were found to be broadly reactive against partially purified representatives of the three serotypes of IPNV, the Sp, Ab, and VR-299 strains. The other two antibodies reacted with the Sp serotype alone. Characterization by immunostaining of viral polypeptides electrophoretically transferred to nitrocellulose sheets was possible only with IgG type antibodies. One of the specific monoclonal antibodies was shown to be directed against the major capsid protein while the other specific monoclonal antibody and the broadly reacting one reacted with the low molecular weight viral polypeptides.     

Antigenic heterogeneity of sialodacryoadenitis virus isolates.

Seventeen field isolates of sialodacryoadenitis (SDA) virus had been isolated from the lung of rats with clinical SDA during epizootics of SDA from 1976 to 1978 in the research laboratory. Based on their neutralization patterns against antisera to strains 681, 930-10, Lu-3, Lu-4 and Lu-7, these isolates were divided into 3 antigenic groups. The first group consisted of 8 isolates which were neutralized by 4 out of 5 antisera at high serum dilution. The second group consisted of 6 isolates which were neutralized by only 2 antisera at high serum dilution. The third group exhibited intermediate neutralization pattern and 3 isolates belonged to it. Considering the time course of virus isolation, it was concluded that three antigenically different SDA viruses had been spread irregularly and ocassionally two had been spread simultaneously in an animal house of rats during the several epizootics of SDA.