Rinderpest Virus Antigens Research Articles

Vaccination of cattle with attenuated rinderpest virus stimulates CD4+ T cell responses with broad viral antigen specificity

The immune responses of cattle inoculated with either a virulent or an attenuated vaccine strain of rinderpest virus (RPV) were examined by measuring the proliferation of peripheral blood mononuclear cells (PBMC) to whole RPV antigen preparations and to individual RPV major structural proteins expressed using recombinant adenoviruses. Responses to the T cell mitogen concanavalin A (ConA) were also measured as a control to monitor non-specific effects of infection with RPV on T cell responses. Infection with the vaccine strain of RPV was found to induce a strong CD4(+) T cell response. A specific response was detected to all RPV proteins tested, namely the haemagglutinin (H), fusion (F), nucleocapsid (N) and matrix (M) proteins, in animals vaccinated with the attenuated strain of the virus. No one protein was found to be dominant with respect to the induction of T cell proliferative responses. As expected, vaccination of cattle with an unrelated virus vaccine, a capripox vaccine, failed to produce a response to RPV antigens. While profound suppression of T cell responses was observed following infection with the virulent strain of RPV, no evidence of impairment of T cell responsiveness was observed following RPV vaccination, or on subsequent challenge of vaccinated animals with virulent virus.

Serological evidence of morbillivirus infection in small cetaceans from the Southeast Pacific

The presence of morbillivirus-specific serum antibodies was examined by an indirect enzyme linked immunosorbent assay (iELISA) and virus neutralization tests in serum samples from 30 dusky dolphins ( Lagenorhynchus obscurus), 8 long-snouted common dolphins ( Delphinus capensis), 2 inshore and 6 offshore bottlenose dolphins ( Tursiops truncatus) and 20 Burmeister's porpoises ( Phocoena spinipinnis) taken in fisheries off central Peru in 1993–1995. The sera from six dusky dolphins, one common dolphin and three offshore bottlenose dolphins were positive on a coat of dolphin morbillivirus (DMV) antigen in the iELISA. Several of these sera were also positive when tested against peste des petits ruminants and rinderpest virus antigen. Porpoise morbillivirus and/or DMV neutralizing antibodies were detected in the sera of two bottlenose and three dusky dolphins that reacted positively with DMV antigen in iELISA and also in the sera of one common, one dusky and one bottlenose dolphin that were negative in the iELISA. These results strongly suggest that viruses closely related, or identical, to the cetacean morbillivirus present in the North Atlantic and the Mediterranean Sea infect several species of Delphinidae of the Southeastern Pacific. No convincing morbillivirus-specific antibody positive reactions were detected in the sera from either the Burmeister's porpoises or the inshore bottlenose dolphins.

Protective vaccination of ferrets against canine distemper with recombinant pox virus vaccines expressing the H or F genes of rinderpest virus

Abstract Objective To investigate the ability of rinderpest virus (RPV) antigens, expressed in pox virus vectors, to protect against canine distemper virus (CDV) infection in ferrets. Animals Ferrets (Mustela putorius; n = 27) with no previous exposure to CDV. Procedure Ferrets were inoculated intradermally with recombinant vaccinia viruses expressing the H gene of RPV, the F gene of RPV, the H and F genes of RPV, or a fowlpox virus recombinant expressing both genes. Two ferrets were vaccinated SC with CDV vaccine as positive controls, and 1 group was left unvaccinated as a negative control. Blood was obtained from ferrets biweekly; antibody titer to RPV was detected by ELISA, and CDV antibody titer was measured by serum neutralization testing and ELISA. Results Partial protection was seen in all groups, with vRVFH vaccination being the most protective (60%). Conclusions and Clinical Relevance A single inoculation with a vaccinia virus expressing the H and F genes of RPV was able to protect 60% of the vaccinated ferrets challenge exposed with a high dose of CDV. These results indicate the ability of RPV antigens expressed by vaccinia virus to protect ferrets against a related morbillivirus. Further, they document the safety and efficacy of a recombinant vaccinia virus vaccine for ferrets. Such vaccines may be useful given the susceptibility of ferrets to CDV and the problem of maternal antibody interfering with vaccination of young animals. (Am J Vet Res 1997;58:590–593)

Effect of gamma irradiation on reactivity of rinderpest virus antigen with bovine immune serum in enzyme-linked immunosorbent assays and virus neutralization and indirect fluorescent-antibody tests

Gamma irradiation effectively inactivated gradient-purified rinderpest virus. Irradiated antigen and sera remained functional in enzyme-linked immunosorbent assays, virus neutralization tests, and indirect fluorescent-antibody tests. Irradiation, however, led to a dose-dependent decrease in reactivity, particularly significant (P < 0.05) when both reagents were irradiated. To avoid false-positive reactions, only one reagent (serum or antigen) may be irradiated.

Identification of epitope expression on the internal proteins of rinderpest virus which is dependant upon virion maturation events

Monoclonal antibodies (MAb) identified the existence of both maturation-dependent and maturation-independent epitopes on rinderpest virus antigens. The former were divided into (i) post-maturation antigenic determinants, which were dependent upon the maturation of viral antigen into complete virions; and (ii) pre-maturation antigenic determinants, which were only expressed on what appeared to be immature particles before ‘budding’ into the extracellular environment. Epitope expression could be related to the kinetics of virus production, with the ‘post-maturation’ sites requiring the production of mature/infectious virions, but the ‘pre-maturation’ sites being lost when mature virus was formed (these ‘pre-maturation’ determinants were strongly cell-associated). MAb against the different virion proteins of measles virus, when reacting with rinderpest virus did not demonstrate the same relationship to virion maturation as did the anti-rinderpest virus MAb: the anti-measles virus MAb detected maturation-independent epitopes. This work demonstrates the caution which should be taken when preparing antigens for diagnostic and epidemiological purposes, especially when MAb are being used to identify antigenic differences between isolates, and/or to compare antigenically isolates with vaccine viruses.

The Production of Peste des Petits Ruminants Hyperimmune Sera in Rabbits and their Application in Virus Diagnosis

Hyperimmune sera were produced by serial inoculation of rabbits with Vero cell-adapted, sucrose gradient-purified Nigerian peste des petits ruminants virus (PPRV) isolate. Two antisera produced, neutralized the homologous PPRV but not the heterologous rinderpest Kabette "O" virus. The antisera gave strong precipitin lines with purified PPRV antigens and were used to detect PPRV and rinderpest virus antigens from ante-mortem secretions and post-mortem tissue homogenates from PPR and rinderpest virus infected goats and cattle by the agar gel precipitation tests (AGPT). The hyperimmune sera gave good titration curves with both purified Nigerian goat and the United Arab Emirate wildlife PPRV isolates in the indirect enzyme linked immunosorbent assay (ELISA). Results of indirect ELISA showed that although there were some cross reactions with the rinderpest, canine-distemper and measles viruses, at 1:100 dilution, the antisera would give a positive signal with only the homologous PPR virus.

Rinderpest virus antigen DNA application as a DNA probe for potential disease diagnosis and recombinant protein production or virus production for vaccine production

Rinderpest virus antigen DNA application as a DNA probe for potential disease diagnosis and recombinant protein production or virus production for vaccine production

The suitability of different microtitre plates for detection of antibody to virus antigens by indirect ELISA

To optimize enzyme linked immunosorbent assays (ELlSAs) for the detection of virus-specific antibodies, a range of commercially available microtitre plates was evaluated for their ability to bind virus antigen. Rinderpest virus and foot-and-mouth disease virus were investigated as target antigens. Binding capacity for antigen, binding ratios (attachment of specific antibody versus that of non-immune antibody) and the variation in the results of the tests within and between plates were measured. Binding capacity was found to be greater with rinderpest virus (RPV) antigen than with foot-and-mouth disease virus (FMDV) antigen, although higher binding ratios were obtained with FMDV antigen. Variation within and between plates was generally less with RPV antigen than with FMDV antigen. One plate could not be said to out-perform the other plates in all tests. For our purpose, that is the detection of monoclonal antibody production against a variety of virus antigens, a number of plates were found to be suitable (e.g. Dynatech M129B, Flow 77-172-05 and Nunc 4-39454). The differences in the performances of the microtitre plates with these two virus antigens highlights the need for consideration of the solid phase as part of the standardization procedures for ELISAs.

Assay sensitivity and differentiation of monoclonal antibody specificity in ELISA with different coating buffers

Buffers of different pH and ionic strength were employed as coating buffers for antigen adsorption to microtitre plates. Their efficiency for coating plates with rinderpest virus (RPV) and foot-and-mouth disease virus (FMDV) antigens was studied by ELISA with polyclonal and monoclonal antibody preparations. While the adsorption and detection of RPV antigen with polyclonal antiserum was highly dependent on the ionic strength and pH of coating buffer, adsorption of antigenically active FMDV antigen was relatively unaffected by the buffering conditions. Both antigens were adsorbed optimally in 0·01 m phosphate buffer, pH 8·0. When monoclonal antibodies were used to detect antigen, there was a greater degree of dependence on the coating buffer than that found with polyclonal antisera. Moreover, when they were used to detect antigen adsorbed under several buffering conditions, monoclonal antibodies showed a variety of preferred buffers. The usefulness of this differential reactivity in distinguishing epitope specificity is demonstrated.

Development and distribution of rinderpest virus antigen in experimentally infected goats.

Three goats, experimentally infected with rinderpest virus were examined for the development and distribution of precipitating antigens in various tissues and secretions using the agar gel immunodiffusion test. Virus antigens were detected in ocular secretions and lymph node biopsies from the second to the fourth and fifth days of pyrexia, respectively, but were not detected in nasal secretions. Precipitating antigens were demonstrated in various lymphoid organs, the lung and abomasum of a goat killed on the fourth day of pyrexia. These findings are discussed in relation to the epidemiology of rinderpest in goats in Africa.

Development and stability of rinderpest virus antigens in cattle tears and lymph nodes.

Diffusible rinderpest virus antigens were demonstrated in increasing quantities in ocular and lymph node biopsies from rinderpest-infected cattle using agar gel immunodiffusion (AGID) and counterimmunoelectrophoresis (CIEP) tests. Positive samples were detected from the second day of pyrexia to two days after death. The antigens in ocular secretions and lymph nodes were thermolabile being destroyed within five minutes at 56 degrees C and within two weeks at 4 degrees C.

Detection of rinderpest virus antigens in vitro and in vivo by direct immunofluorescence

Cell-culture attenuated and virulent strains of rinderpest virus (RV) were inoculated on to bovine kidney cell cultures. A direct immunofluorescent antibody test detected RV antigens in cell cultures within one to three days after inoculation whereas RV cytopathic effects usually took three to nine days to develop. Cells containing RV antigens were also detected in impression smears and frozen sections of tissues collected from RV infected animals at post mortem examination, and in smears of lymph node biopsies taken from cattle with clinical rinderpest. These techniques may offer additional methods for rapid diagnosis of rinderpest.

The use of the direct immunoperoxidase test to detect the multiplication of rinderpest virus in bovine kidney cell culture

The direct immunoperoxidase test has been used to detect rinderpest virus antigens in infected bovine kidney cell cultures to study the multiplication of the virus. Infected bovine kidney coverslip cultures were sequentially tested with peroxidase-labelled, anti-rinderpest globulins at 3, 6, 24, 48, 72, 96, 120 and 144 h post-infection. The progressive virus-specific cytopathic changes compared well with the increase in the number of cells showing the presence of viral antigens when tested by the direct immunoperoxidase test. The specificity of the reaction was confirmed by using negative and antiserum-blocked BK cell cultures on coverslips.