Effects of Three Kinds of Chinese Medicine Polysaccharides on the Immune Effect of Newcastle Disease Vaccine

240 14-day-old healthy and non-immune Roman chicken were randomly divided into 8 groups, including blank control group （BC group）, immune control group （IC group）, and immunity groups of each Chinese medicine. On the day of the first immunity, 3 d before the second immunity, the day of the second immunity and 3 d after the second immunity, high-dose concentration and low-dose concen- tration of Astragalus polysaccharide （ASP）, Epimedium polysaccharide （EPP） and Isatis roots polysaccharide （IRPS） were used for the immunity groups of each Chi- nese medicine using the gavage, and 0.5 ml for each chick, and the equivalent normal saline was used for the blank control group and vaccine control group. On the 7^th, 14^th, 21^st and 28^th day after the first immunity, 10 chicken of each group were randomly got and weighed, and the antibody titer and the changes of the pro- liferation of T lymphocyte were measured. The results showed that 3 kinds of Chi- nese medicine polysaccharides all can increase the weight of chicken, improve HI antibody titer of Newcastle disease, and promote the proliferation of peripheral T lymphocyte, in which the effect of IRPS at low dosage is the best.

Study on Inactivated Vaccine in Oil Emulsion Against Newcastle Disease and Fowl Cholera IV——Field Test of Vaccine

[ Objective] The aim of this study was to evaluate the clinical effect of the inactivated vaccine in oil emulsion against Newcastle disease and Fowl cholera, and provide conditions for combined prevention and control of Newcastle disease and Fowl cholera. [ Method] The mixture of avian pasteurella multocida （type A） virulent strain 1502 and Newcastle disease virus attenuated strain La Sota was prepared into five batches of the inactivated vaccine in oil emulsion to use in the field test for assessing its safety and effects on immune protection of chicken, duck and goose. [ Result] The field safety test showed that there was no adverse reaction in the vaccinated chickens, ducks and geese. The field test of immune effect for chickens suggested that the titers of hemagglutination inhibition antibody for Nescastle disease virus （ ND-HI ） in 7 - 14 day- old chickens and 60 -90 day-old young chickens were 2 -3 log2 higher than the control group after being vaccinated for 3 weeks, which could last for more than 4 months. The protection rate against avian pasteurella multocida was over 75.0% and its immune effect could last for 6 months. The field test of immune effect for duck and goose indicated that the titers of ND-HI antibody were all higher than 4.2 log2 in vaccinated ducks and geese while lower than 2 log2 in the control group after being vaccinated for 3 weeks. The protection rate against avian pasteurella multocida in vaccinated ducks and geese was higher than 75.0% and 62.5% respectively. [ Conclusion] The binary vaccine is safe for poultry and has good immune effects.

Immunological Adjuvant Function of Aluminium Phosphate and Chicken IL-18 in NDV F Gene Vaccine

[Objective] This study aimed to investigate the immunological adjuvant function of aluminium phosphate and chicken IL-18 in NDV F gene vaccine. [Method] The vaccine （0.2 ml） containing aluminum phosphate adjuvant （90 μg）, pcDNA/F （200μg）, and pcDNA/chlL-18 （200 μg） was prepared. The 7 d old chick- ens to be tested were randomly divided into six groups （12 chickens in each group） and immunized through intramuscular injection with inactivated Newcastle disease vaccines, pcDNA/F＋pcDNA/chlL-18＋phosphate aluminum, pcDNA/F, pcDNA/F.＋pcDNA/ chlL-18, pcDNA/F＋aluminum phosphate, and physiological saline respectively; the secondary immunization was conducted with the same dose when the chickens were 21 d old. Their blood was sampled 0, 7, 14, 21, 28 d after first immunization. Anti- body titer was detected with ELISA and T cell transformation rate was measured with MIT. Experimental chicken will be challenged with 30 LD50 NDV virulence 28 d after first immunization. [Result] The survival rate of the chickens immunized with pcDNA/F＋aluminium phosphate＋pcDNA/chlL-18 achieved 8/12, higher than that of those immunized with pcDNA/F 4/12 and pcDNA/F＋pcDNA/chlL-18 （6/12）. The NDV antibody titer of the chickens immunized with pcDNA/F＋ aluminum phosphate, pcD- NA/F＋pcDNA/chlL-18 and pcDNA/F＋pcDNA/chlL-18＋aluminum phosphate is not differ- ent （P〉0.05）, but significantly lower than that of the chickens immunized with tradi- tional vaccine （P〈0.05）. The T cell transformation rate of the chickens immunized with pcDNA/F＋pcDNA/chlL-18＋aluminium phosphate was obviously higher than that of the chickens immunized with pcDNA/F （P〈0.05）. The T cell transformation rates of chickens immunized with pcDNA/F and the traditional vaccine showed no signifi- cant difference （P〉0.05）. [Conclusion] Combination of aluminium phosphate and pcD- NA/chlL-18 can significantly enhance the immune effect of NDV F gene vaccine.

Characterization of Pigeon Paramyxoviruses (Newcastle disease virus) Isolated in Kazakhstan in 2005

Isolates of Newcastle disease virus (NDV) from deceased wild and domestic pigeons in Kazakhstan were obtained from the Almaty region during 2005 and were genotypically analyzed by using reverse transcription polymerase chain reaction (RT-PCR) with primers specific to the viral fusion (F) protein gene. Part of the amplified F protein DNA product (nucleotide sequence 47-422) and the deduced amino acid sequences were compared phylogenetically with those from strains previously reported in other geographic regions. Phylogenetic analysis indicated that the Kazakhstanian pigeon paramyxovirus type 1 (PPMV-1) isolates belong to genotype VI or 4bii. To our knowledge, this is the first reported VI isolates that possess the sequences of 112 GKRQKR116* F117 within the F0 protein. The information is fundamental to improving the efficiency of control strategies and vaccine development for NDV.

Optimization of Sonication Process for High Newcastle Disease Virus （NDV） Titer

Cell disruption focuses on obtaining a desired bioproduct within a cell, and it is the cell wall that must be disrupted to allow access to the contents of the cell. In animal cells, the plasma membrane is the only barrier separating cell contents from the environment. Sound waves from sonication, a mechanical technique for cell disintegration, have been used to disrupt as well as to aggregate cells as a step towards purification of a desired bioproduct. In the present study, an improved sonication process for the high yield of Newcastle disease virus （NDV） propagated in tissue culture was described. DF-I cell was cultured in 25cm^2 T flask. When cells were about 80% confluent, a lentogenic strain of NDV （F strain） was used to infect the cell monolayer. With evident cytopathic effect, cells were subjected to cycles of freeze-thaw before sonicating with varying combinations of amplitude, temperature and time. Cells were sonicated using a water bath Sonicator, Jac Ultrasonic 1505 JEIO TECH 4 KHz. From ANOVA analysis, a significant interaction between sonication time and amplitude was observed. This also corresponds to the highest F value observed.

Epitope variation in the Newcastle disease virus HN gene under antibody immune selective pressure in cell culture

The influence of antibody immune selective pressure on Newcastle disease virus (NDV) HN and F gene mutations was studied in cell cultures.NDV field strain TZ060107 was inoculated into chicken embryo fibroblast cells and continuously passaged with (group A) or without (group B) anti-NDV monospecific serum.Each group contained three independent passage series.HN and F genes were amplified and sequenced for the 10th,20th,30th,40th and 50th generations of each serial passage,and compared with the original strain.The results demonstrated that increased HN gene mutations were observed in group A with the antibody than in group B without the antibody.The nonsynonymous (NS) to synonymous (S) mutations ratio was 6 for group A,significantly higher than 3.4 in group B.In group A with the antibody,there were five stable NS mutations in HN gene,three of which (related to aa#353,521 and 568) were related to known epitopes.There were two stable NS mutations in F gene in group A,but no stable NS mutations in group B.The NS/S ratios of F gene were less than 2.5 for both groups A and B.Our results suggested that the antibody strongly influenced HN gene mutations,while the F gene was less influenced by the same antibody.