Anti-neoplastic effect of avian reovirus σ C protein on Rous sarcoma virus-induced tumors in chicken

Abstract

Summary. -This study investigated the anti-neoplastic potential of avian reovirus σC (sigma C) protein on Rous sarcoma virus-induced fibrosarcoma in chicken. The recombinant vector expressing σC protein was injected intra-tumorally into specific pathogen free chicken with fibro-sarcoma at the dose 100µg per bird, while control birds were mock-treated with 100µg of empty vector per bird. Recombinant σC protein induced apoptosis in tumors of treated birds resulting in progressive tumor regression, while similar changes were absent in tumors of mock-treated controls. The σC protein-induced apoptosis in tumors was quantified by flow cytometry and the mean level of apoptosis up to 66% was observed in treated tumors, whereas any significant level of apoptosis was absent in mock-treated controls.Keywords: avian reovirus; Rous sarcoma virus; tumors; σC protein; apoptosis E-mail: uma@kvasu.ac.in; phone: +91-487-2370344-275. Abbreviations: ARV(s) = avian reovirus(es); AO/EtBr = acridine orange/ethidium bromide; CEF = chicken embryonic fibroblast; H&E = hematoxylin and eosin; MRV = mammalian reovirus; MAb = monoclonal antibody; σC = sigma C, σ1 = sigma 1; SPF = specific pathogen free; RSV = Rous sarcoma virus

Recombinant Newcastle Disease Virus (NDV) Expressing Sigma C Protein of Avian Reovirus (ARV) Protects against Both ARV and NDV in Chickens

“…The recombinant NDV strain R2B rescued by reverse genetics was available in the Recombinant DNA Laboratory, Division of Veterinary Biotechnology, Indian Veterinary Research Institute, Bareilly, India. An Indian field isolate of ARV (VA-1) was obtained from the Avian Diseases Section, Indian Veterinary Research Institute [48] and was propagated in primary chicken embryo fibroblast culture. One day-old fertile specific-pathogen-free (SPF) eggs, were purchased from Venky’s India Pvt.…”

“…To determine the protective efficacy of the recombinant viruses, birds (n = 6) from groups one, two, three and five were challenged with virulent NDV (10 5 ELD 50 /mL/bird) and birds (n = 6) from group one, three, four and five were challenged with virulent ARV (10 5 TCID 50 /mL/bird) [48] at 62 days of age. Following the challenge, birds were observed for 10 days to study for the appearance of clinical signs of both NDV and ARV infection and the surviving birds were sacrificed humanely.…”

Critical role of eukaryotic elongation factor 1 alpha 1 (EEF1A1) in avian reovirus sigma-C-induced apoptosis and inhibition of viral growth

“…ARV infection causes apoptosis in cultured cells [2,8,21,30] and is induced by the ARV rC protein [10,21,22]. In a recent publication, rC was injected into Rous sarcoma virus-induced tumors in chickens to induce apoptosis with some success [23]. Our data show that expression of a rC-GFP fusion protein induced apoptosis in DF-1 cells (Fig.…”

“…Although ARV C is known as an apoptosis inducer [10,21,22], and intra-tumor injection of recombinant rC has been shown to induce regression of virus-induced fibrosarcoma in chickens [23], the exact mechanism of rCinduced apoptosis is still unclear. In this study, we found that the cellular protein eukaryotic elongation factor 1 alpha 1 (EEF1A1) interacted with rC via the portion of rC including aa 210-246.…”