Improving the potency of DNA vaccine against Chicken Anemia Virus (CAV) by fusing VP1 protein of CAV to Marek's Disease Virus (MDV) Type-1 VP22 protein

Studies have shown that the VP22 gene of Marek’s Disease Virus type-1 (MDV-1) has the property of movement between cells from the original cell of expression into the neighboring cells. The ability to facilitate the spreading of the linked proteins was used to improve the potency of the constructed DNA vaccines against chicken anemia virus (CAV). The VP1 and VP2 genes of CAV isolate SMSC-1 were amplified and inserted into eukaryotic co-expression vector, pBudCE4.1 to construct pBudVP2-VP1. We also constructed pBudVP2-VP1/VP22 encoding CAV VP2 and the VP22 of MDV-1 linked to the CAV VP1. In vitro expression of the genes was confirmed by using RT- PCR, Western blot and indirect immunofluorescence. The vaccines were then tested in 2-week-old SPF chickens which were inoculated with the DNA plasmid constructs by the intramuscular route. After in vivo expression studies, immune responses of the immunized chickens were evaluated pre- and post-immunization. Chickens vaccinated with pBudVP2-VP1/VP22 exhibited a significant increase in antibody titers to CAV and also proliferation induction of splenocytes in comparison to the chickens vaccinated with pBudVP2-VP1. Furthermore, the pBudVP2-VP1/VP22-vaccinated group showed higher level of the Th1 cytokines IL-2 and IFN-g. This study showed that MDV-1 VP22 gene is capable of enhancing the potency of DNA vaccine against CAV when fused with the CAV VP1 gene

Neonatal feed restriction modulates circulating levels of corticosterone and expression of glucocorticoid receptor and heat shock protein 70 in aged Japanese quail exposed to acute heat stress.

This study aimed to determine the effect of neonatal feed restriction on plasma corticosterone concentration (CORT), hippocampal glucocorticoid receptor (GR) expression, and heat shock protein (Hsp) 70 expression in aged male Japanese quail subjected to acute heat stress. Equal numbers of chicks were subjected to either ad libitum feeding (AL) or 60% feed restriction on d 4, 5, and 6 (FR). At 21 (young) and 270 (aged) d of age, birds were exposed to 43 ± 1°C for 1 h. Blood and hippocampus samples were collected to determine CORT and Hsp 70 and GR expressions before heat stress and following 1 h of heat stress, 1 h of post-heat stress recovery, and 2 h of post-heat stress recovery. With the use of real-time PCR and enzyme immunoassay, we examined the hippocampal expression of GR and Hsp 70 and CORT. The GR expression of the young birds increased following heat stress and remained consistent throughout the period of recovery. Conversely, no significant changes were noted on GR expression of aged birds. Although both young and aged birds had similar CORT before and during heat stress, the latter exhibited greater values following 1 and 2 h of recovery. Within the young group, feeding regimens had no significant effect on Hsp 70 expression. However, neonatal feed restriction improved Hsp 70 expression in aged birds. Neonatal feed restriction, compared with the AL group, resulted in higher CORT on d 21 but the converse was noted on d 270. Neonatal feed restriction appears to set a robust reactive hypothalamo-pituitary-adrenal response allowing the development of adaptive, healthy, and resilient phenotypes in aged quail as measured by a higher hippocampal Hsp 70 expression along with lower CORT

Effects of agitation speed, temperature, carbon and nitrogen sources on the growth of recombinant Lactococcus lactis NZ9000 carrying domain 1 of aerolysin gene

Lactococcus lactis is a Gram-positive bacterium widely used in the production of buttermilk and cheese. Recently, the bacterium becomes famous as the genetically modified organism can be used alive for the treatment of disease. In this study, different cultural conditions based on agitation speed and temperature on the growth of recombinant L. lactis NZ9000 harboring domain 1 of aerolysin gene (NHD1Aer) were investigated using shake flask experiment. The effect of different carbon (glucose, sucrose and lactose) and nitrogen (yeast extract, peptone, NH4Cl, (NH4)2SO4, and urea) sources in M17 medium on the cell accumulation were also tested. The results showed that the highest cell concentration (3.22 g/L, μm = 0.58 h-1) was obtained when the cultivation was incubated at 27°C and at agitation of 100 rpm. The cells growth was markedly improved when utilizing glucose and peptone/yeast extract as carbon and nitrogen sources, respectively. The aerolysin gene in the cells after four generation time was extracted and then analyzed using agarose gel electrophoresis. The results obtained showed a 250 bp band amplified of domain 1 of the aerolysin gene.Keywords: Aerolysin, Lactococcus lactis, fermentation, one-factor-at-a-timeAfrican Journal of Biotechnology Vol. 9(33), pp. 5392-5398, 16 August, 201

Physiological responses of 3 chicken breeds to acute heat stress.

Domestic animals have been modified by selecting individuals exhibiting desirable traits and culling the others. To investigate the alterations introduced by domestication and selective breeding in heat stress response, 2 experiments were conducted using Red Jungle Fowl (RJF), village fowl (VF), and commercial broilers (CB). In experiment 1, RJF, VF, and CB of a common chronological age (30 d old) were exposed to 36 ± 1°C for 3 h. In experiment 2, RJF, VF, and CB of common BW (930 ± 15 g) were subjected to similar procedures as in experiment 1. Heat treatment significantly increased body temperature, heterophil:lymphocyte ratio, and plasma corticosterone concentration in CB but not in VF and RJF. In both experiments and irrespective of stage of heat treatment, RJF showed lower heterophil:lymphocyte ratio, higher plasma corticosterone concentration, and higher heat shock protein 70 expression than VF and CB. It can be concluded that selective breeding for phenotypic traits in the domestication process has resulted in alterations in the physiology of CB and concomitantly the ability to withstand high ambient temperature compared with RJF and VF. In other words, domestication and selective breeding are leading to individuals that are more susceptible to stress rather than resistant. It is also apparent that genetic differences in body size and age per se may not determine breed or strain variations in response to heat stress

Improved Protection from Velogenic Newcastle Disease Virus Challenge Following Multiple Immunizations With Plasmid DNA Encoding for F And HN Genes

Specific-pathogen free (SPF) chicken were inoculated with the plasmid combination and challenged with velogenic NDV. The antibody level against NVD was measured using commercial enzyme linked immunosorbent assay (ELISA). In the first immunization regimen, SPF chickens inoculated twice with NDV-F or NDV-HN constructs elicited antibody responses 1 week after the second injection. However, the levels of the antibody were low and did not confer significant protection from the lethal challenge. In addition, admininistration of the plasmid constructs with Freund’s adjuvant did not improve the level of protection. In the second immunization regimen, chickens inoculsted trice with the plasmid constructs emulsified with Freund”s adjuvant induced significant antibody titers after the third injection. Three out of nine (33.3 %) chickensvaccinated with pEGFP-HN, five of ten (50.0%) chicken vaccinated with pEGFP-F and nine of ten (90.0%) chicken vaccinated with combined pEGFP-F and pEGFP-HN were protected from the challenge. No significant differences in the levels of protection were observed when the chicken were vaccinated with linearized pEGFP-F. the results suggested that more than two injections with both F and HN encoding plasmid DNA were required to induce level of antibodies for protection against velogenic NDV in chickens

Improved protocol for the preparation of tetraselmis suecica axenic culture and adaptation to heterotrophic cultivation.

The effectiveness of various physical and chemical methods for the removal of contaminants from the microal-gae, Tetraselmis suecica, culture was investigated. The information obtained was used as the basis for the development of improved protocol for the preparation of axenic culture to be adapted to heterotrophic cultivation. Repeated centrifugation and rinsing effectively removed the free bacterial contaminants from the microalgae culture while sonication helped to loosen up the tightly attached bacterial contaminants on the microalgae cells. Removal of bacterial spores was accom- plished using a mixture of two antibiotics, 5 mg/mL vancomycine and 10 mg/mL neomycine. Walne medium formulation with natural seawater was preferred for the enhancement of growth of T. suecica. Adaptation of growth from photoautot- rophic to heterotrophic conditions was achieved by the repeated cultivation of photoautotrophic culture with sequential reduction in illumination time, and finally the culture was inoculated into the medium containing 10 g/L glucose, incu- bated in total darkness to obtain heterotrophic cells. Changes in the morphology and composition of T. suecica cells dur- ing the adaptation from photoautotrophic to heterotrophic condition, as examined under Transmission Electron Micro- scope, were also reported

Lactobacillus acidophilus as a live vehicle for oral immunization against chicken anemia virus.

The AcmA binding domains of Lactococcus lactis were used to display the VP1 protein of chicken anemia virus (CAV) on Lactobacillus acidophilus. One and two repeats of the cell wall binding domain of acmA gene were amplified from L. lactis MG1363 genome and then inserted into co-expression vector, pBudCE4.1. The VP1 gene of CAV was then fused to the acmA sequences and the VP2 gene was cloned into the second MCS of the same vector before transformation into Escherichia coli. The expressed recombinant proteins were purified using a His-tag affinity column and mixed with a culture of L. acidophilus. Whole cell ELISA and immunofluorescence assay showed the binding of the recombinant VP1 protein on the surface of the bacterial cells. The lactobacilli cells carrying the CAV VP1 protein were used to immunize specific pathogen-free chickens through the oral route. A moderate level of neutralizing antibody to CAV was detected in the serum of the immunized chickens. A VP1-specific proliferative response was observed in splenocytes of the chickens after oral immunization. The vaccinated groups also showed increased levels of Th1 cytokines interleukin (IL)-2, IL-12, and IFN-γ. These observations suggest that L. acidophilus can be used in the delivery of vaccines to chickens

Anti-breast cancer effects of live, heat-killed and cytoplasmic fractions of Enterococcus faecalis and Stuphylococcus hominis isolated from human breast milk

Development of tumour that is resistant to chemotherapeutics and synthetic drugs, coupled with their life-threatening side effects and the adverse effects of surgery and hormone therapies, led to increased research on probiotics' anticancer potentials. The current study investigated the potential of live, heat-killed cells (HKC) and the cytoplasmic fractions (CF) of Enterococcus faecalis and Staphylococcus hominis as anti-breast cancer agents. MCF-7 cell line was treated with 25, 50, 100 and 200 μg/mL each of live, HKC and CF of the bacteria; and cytotoxicity was evaluated for 24, 48 and 72 h using MTT assay. The morphological features of the treated cells were examined by fluorescence microscopy. The stage of cell cycle arrest and apoptosis were quantified by flow cytometry. The bacterial effect on non-malignant breast epithelial cell line, MCF-10A, was assessed using MTT assay for 24, 48 and 72 h. All the three forms of the bacteria caused a significant decrease in MCF-7 (up to 33.29%) cell proliferation in concentration- and time-dependent manner. Morphological features of apoptosis like cell death, cell shrinkage and membrane blebbing were observed. Flow cytometry analyses suggested that about 34.60% of treated MCF-7 was undergoing apoptosis. A strong anti-proliferative activity was efficiently induced through sub-G1 accumulation (up to 83.17%) in treated MCF-7 and decreased number in the G0/G1 phase (74.39%). MCF-10A cells treated with both bacteria showed no significant difference with the untreated (>90% viability). These bacteria can be used as good alternative nutraceutical with promising therapeutic indexes for breast cancer because of their non-cytotoxic effects to normal cells