• Journal of Veterinary Science
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• v.22 no.4
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• pp.45.1-45.13
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• 2021

Background: Peste des petits ruminants (PPR) is an infectious disease caused by the peste des petits ruminants virus (PPRV) that mainly produces respiratory symptoms in affected animals, resulting in great losses in the world's agriculture industry every year. Single-domain variable heavy chain (VHH) antibody fragments, also referred to as nanobodies, have high expression yields and other advantages including ease of purification and high solubility. Objectives: The purpose of this study is to obtain a single-domain antibody with good reactivity and high specificity against PPRV. Methods: A VHH cDNA library was established by immunizing camels with PPRV vaccine, and the capacity and diversity of the library were examined. Four PPRV VHHs were selected, and the biological activity and antigen-binding capacity of the four VHHs were identified by western blot, indirect immunofluorescence, and enzyme-linked immunosorbent assay (ELISA) analyses. ELISA was used to identify whether the four VHHs were specific for PPRV, and VHH neutralization tests were carried out. ELISA and western blot analyses were used to identify which PPRV protein was targeted by VHH2. Results: The PPRV cDNA library was constructed successfully. The library capacity was greater than 2.0 × 10⁶ cfu/mL, and the inserted fragment size was approximately 400 bp to 2000 bp. The average length of the cDNA library fragment was about 1000 bp, and the recombination rate was approximately 100%. Four single-domain antibody sequences were selected, and proteins expressed in the supernatant were obtained. The four VHHs were shown to have biological activity, close affinity to PPRV, and no cross-reaction with common sheep diseases. All four VHHs had neutralization activity, and VHH2 was specific to the PPRV M protein. Conclusions: The results of this preliminary research of PPRV VHHs showed that four screened VHH antibodies could be useful in future applications. This study provided new materials for inclusion in PPRV research.

• Korean Journal of Veterinary Service
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• v.33 no.1
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• pp.1-6
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• 2010

Monoclonal antibody (mAb)-based enzyme immune-slide assay (EISA) was used for the detection of Peste des petits ruminants (PPR) virus from field samples collected from a natural outbreak. The clinicopathological study was undertaken to diagnose the case primarily of PPR. Antigen was detected from discharges and faeces of infected goats and swabs of postmortem lesions prepared on glass slide or glass plate using acetone fixation. Nasal discharge collected at the early stage of disease course or lung is an appropriate ante- or postmortem sample for this technique, respectively. Convalescent polyclonal sera collected from recovered animals which were diagnosed as PPR by EISA showed high antibody titer against PPR by C-ELISA, demonstrating the satisfactory specificity of the test. Therefore, EISA is a sensitive and specific assay to confirm PPR infection both in field and laboratory conditions and especially suitable for developing country.

• Journal of Veterinary Science
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• v.25 no.2
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• pp.21.1-21.15
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• 2024

Background: Peste des petits ruminants (PPR) is a contagious and fatal disease of sheep and goats. PPR virus (PPRV) infection induces endoplasmic reticulum (ER) stress-mediated unfolded protein response (UPR). The activation of UPR signaling pathways and their impact on apoptosis and virus replication remains controversial. Objectives: To investigate the role of PPRV-induced ER stress and the IRE1-XBP1 and IRE1-JNK pathways and their impact on apoptosis and virus replication. Methods: The cell viability and virus replication were assessed by 3-(4,5-Dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide assay, immunofluorescence assay, and Western blot. The expression of ER stress biomarker GRP78, IRE1, and its downstream molecules, PPRV-N protein, and apoptosis-related proteins was detected by Western blot and quantitative reverse transcription-polymerase chain reaction, respectively. 4-Phenylbutyric acid (4-PBA) and STF-083010 were respectively used to inhibit ER stress and IRE1 signaling pathway. Results: The expression of GRP78, IRE1α, p-IRE1α, XBP1s, JNK, p-JNK, caspase-3, caspase-9, Bax and PPRV-N were significantly up-regulated in PPRV-infected cells, the expression of Bcl-2 was significantly down-regulated. Due to 4-PBA treatment, the expression of GRP78, p-IRE1α, XBP1s, p-JNK, caspase-3, caspase-9, Bax, and PPRV-N were significantly downregulated, the expression of Bcl-2 was significantly up-regulated. Moreover, in PPRV-infected cells, the expression of p-IRE1α, p-JNK, Bax, and PPRV-N was significantly decreased, and the expression of Bcl-2 was increased in the presence of STF-083010. Conclusions: PPRV infection induces ER stress and IRE1 activation, resulting in apoptosis and enhancement of virus replication through IRE1-XBP1s and IRE1-JNK pathways.

• Journal of Veterinary Science
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• v.24 no.5
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• pp.55.1-55.12
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• 2023

Background: Peste des petits ruminants (PPR), caused by the PPR virus (PPRV), is an acute and fatal contagious disease that mainly infects goats, sheep, and other artiodactyls. Peripheral blood mononuclear cells (PBMCs) are considered the primary innate immune cells. Objectives: PBMCs derived from goats were infected with PPRV and analyzed to detect the relationship between PPRV replication and apoptosis or the inflammatory response. Methods: Quantitative real-time polymerase chain reaction was used to identify PPRV replication and cytokines expression. Flow cytometry was conducted to detect apoptosis and the differentiation of CD4⁺ and CD8⁺ T cells after PPRV infection. Results: PPRV stimulated the differentiation of CD4⁺ and CD8⁺ T cells. In addition, PPRV induced apoptosis in goat PBMCs. Furthermore, apoptosis and the inflammatory response induced by PPRV could be suppressed by Z-VAD-FMK and Z-YVAD-FMK, respectively. Moreover, the virus titer of PPRV was attenuated by inhibiting caspase-1-dependent apoptosis and inflammation. Conclusions: This study showed that apoptosis and the inflammatory response play an essential role in PPR viral replication in vitro, providing a new mechanism related to the cell host response.

• Journal of Animal Science and Technology
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• v.57 no.1
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• pp.2.1-2.5
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• 2015

Among the main intimidation to the sheep and goat population, PPR outbreaks are causing huge losses especially in endemic areas. During recent times, six outbreaks of PPR were confirmed at semi-organized goat farms/herds in various regions of Punjab province and Islamabad capital territory (ICT), Pakistan. The disease started after introduction of new animals at these farms with no history of previous PPR vaccination. The clinical signs appeared affecting respiratory and enteric systems and spread quickly. Disease caused mortality of 10-20% and morbidity of 20-40% within a time period of four weeks. Morbidity and mortality rates were 30.38% (86/283) and 15.55% (44/283), respectively. Three treatment regimes were executed to demonstrate the role of vaccination during outbreak at these farms. First was to use only the broad spectrum antibiotics (Penicillin & Streptomycin and/or Trimethoprim and Sulfadiazine) at two farms (Texilla and Attock). Second treatment regime was to use the same broad spectrum antibiotic along with extensive fluid therapy (Farms at ICT-1 and ICT-2). The third regime was to use of broad spectrum antibiotic plus fluid therapy along with vaccinating the herd against PPR during first week of outbreak (ICT-3 and ICT-4). The third scheme of treatment gave the better results as there was no mortality in third week post-outbreak. Therefore, it is suggested to give proper importance to PPR vaccination along with conventional symptomatic treatment when dealing the PPR outbreaks in endemic disease conditions.