Pro-inflammatory cytokine and apoptotic gene mRNA levels against lentogenic and velogenic Newcastle disease virus pathotypes in in-vivo and in-vitro biological systems
INDIAN JOURNAL OF ANIMAL RESEARCH
Authors: Rajasekaran, Ranjani; Kirubaharan, J. John; Vidhya, M.; Shilpa, P.; Chandran, N. Daniel Joy
Abstract
Knowledge on the influence of pro-inflammatory cytokine and apoptotic gene mRNA levels in the pathogenesis of Indian field isolates of Newcastle disease virus (NDV) is little. In this study, cytokine mRNA levels were elucidated in spleen of chickens (in-vivo) and chicken embryo fibroblast cells (in-vitro) infected with lentogenic D58 strain and viscerotropic velogenic D165 isolate until five days post infection (dpi). In spleen of chickens infected with D165, maximum upregulation of pro-inflammatory cytokines (IL-1 beta, IL-6, TNF-alpha), chemokine (IL-8) and apoptotic gene (Caspase-8) at 3dpi correlated with the onset of severe clinical signs and necrotic histopathological lesions in spleen, proventriculus, intestine and caecal tonsil of chickens. Similarly, in CEF cells infected with D165, upregulation of pro-inflammatory cytokine and apoptotic gene mRNA levels correlated with the appearance of CPE. In spleen of chickens and CEF cells infected with D58, there was comparatively minimal upregulation of pro-inflammatory cytokine and apoptotic gene mRNA levels which did not cause histopathological changes in tissues and CPE formation in CEF cells. In both in-vivo and in-vitro systems, upregulation of anti-inflammatory cytokine IL-10 showed inhibitory effects on the mRNA levels of pro-inflammatory cytokines. Thus, this study reports variation in the cytokine mRNA levels elucidated in response to two different pathotypes isolated from India and associates the same with the clinical signs and pathological lesions produced during the course of ND.
Construction of a novel DNA vaccine candidate targeting F gene of genotype VII Newcastle disease virus and chicken IL-18 delivered by Salmonella
JOURNAL OF APPLIED MICROBIOLOGY
Authors: Gao, X.; Xu, K.; Yang, G.; Shi, C.; Huang, H.; Wang, J.; Yang, W.; Liu, J.; Liu, Q.; Kang, Y.; Jiang, Y.; Wang, C.
Abstract
Aims Genotype VII Newcastle disease (ND) is one of the most epidemic and serious infectious diseases in the poultry industry. A novel vaccine targeting VII Newcastle disease virus (NDV) is still proving elusive. Methods and Results In this study, we constructed regulated delayed lysis Salmonella strains expressing either a fusion protein (F) alone under an eukaryotic CMV promoter or together with chicken IL-18 (chIL-18) as a molecular adjuvant under prokaryotic P-trc promoter, named pYL1 and pYL23 respectively. Oral immunization with recombinant strains induced NDV-specific serum IgG antibodies in both pYL1- and pYL23-immunized chickens. The presence of chIL-18 significantly increased lymphocyte proliferation in immunized chickens, as well as the percentages of CD3(+)CD4(+) and CD3(+)CD8(+) T cells in serum, even if a statistically significant difference did not exist. After a virulent challenge, pYL23 immunization provided about 80% protection at day 10 postinfection, compared with 60% of protection offered by pYL1 immunization and 100% protection in the inactivated vaccine group, indicating the enhanced immune response provided by chIL-18, which was also confirmed by histochemical analysis. Conclusions Recombinant lysis Salmonella-vectored DNA vaccine could provide us a novel potential option for controlling NDV infection. Significance and Impact of the Study This study took use of a regulated delayed lysis Salmonella vector for the design of an orally administrated vaccine against NDV.