Identification of an additional N-glycosylation site and thermostable mutations within the hemagglutinin-neuraminidase gene of the Newcastle disease virus belonging to the VII.1.1 sub-genotype

Newcastle disease virus (NDV) is considered one of the most devastating avian viral patho-gens affecting the avian population, and it causes a significant economic burden on the poultry industry worldwide. The study aimed to gain deeper understanding of the molecular and phylogenetic analyses of the complete hemagglutinin-neuraminidase (HN) coding region among NDV isolates. The samples were obtained from different parts of Iran from July 2017 to February 2020, were used for phylogenic analysis in this study. The results confirmed the predominance of sub-genotype VII.1.1, previously known as sub-genotype VIIL, which is circulating in commercial broiler farms of Iran. Identification of (a) an additional N-glycosylation site (NIS) at position 144; (b) mutations S315P and I369V which are related to increasing the viral thermostability; (C) cysteine residues at positions 123; (d) amino acid substitutions in the HN antigenic sites, especially the mutations I514V and E347Q, as well as the other mutant within HN binding sites of the VII.1.1 sub-genotype, suggests the idea that this new sub-genotype of NDV may possess a high level of pathogenicity and virulence compared to other NDV sub-genotypes. In conclusion, the results indicate the presence of an additional NIS at position 144, which may alter the virulence of the isolates. Furthermore, the presence of the thermostable mutations (S315P and I369V) and the other amino acid substitutions among the VII.1.1 sub-genotype isolates may have an impact on the vaccine immunity against this new NDV sub-genotype.

Molecular characterization and phylogenetic study of the hemagglutinin-neuraminidase gene of newcastle disease virus isolated from peacock (Pavo cristatus) and Turkey (Meleagris) and its comparison with broiler isolates

Newcastle disease has been endemic within the Iranian poultry industry for decades. However, the genetic nature of the circulating Hemagglutinin-Neuraminidase (HN) gene among Iranian domesticated bird populations is broadly unexplored. The presented study was carried out to gain insights into the biological and molecular characterization of four complete HN genes isolated from turkey, peacock, and broiler isolates in Iran between 2018 and 2020. The phylogenetic analysis revealed that the isolates belong to the Newcastle disease virus (NDV) subgenotype VII.1.1, previously known as VIIL. Further analysis demonstrated the thermostable substitutions S315P and I369V within the isolates. Finding the N-glycosylation site (NIS) at positions 144-146 and the cysteine residue 123 might influence the fusogenicity abilities of the isolates, while identification of multiple amino acid substitutions in both antigenic sites, especially I514V and E347Q, and the binding sites of the HN protein, raised concern about the pathogenicity of the isolates. In addition, the annual rate of change based on the HN gene of Iranian NDV was calculated at about 1.8088E-3 between 2011 and 2020. In conclusion, a new NDV variant with multiple site mutagenesis is circulating not only among chickens but also in turkey and captive birds such as peafowls, and failure of routine vaccination programs could be attributed to the differences between circulating NDV strains and those used in vaccine manufacturing. Therefore, future legislation aimed at providing vaster vaccination cover and biosecurity plans will be needed to control the spread of circulating NDV strains.

Genomic and comparative clinico-pathological assessment of two Pakistani pigeon-derived newcastle disease virus sub-genotypes XXI.1.1 and XXI.1.2 isolated in 2017

Pigeon paramyxovirus type-1 (PPMV-1) is an antigenic-variant of Newcastle disease virus (NDV) which is associated with infection in Columbidae family. In this study, we isolated two pigeon-derived strains pi/Pak/Lhr/SA_1/17 (designed as SA_1) and pi/Pak/Lhr/SA_2/17 (designed as SA_2) from diseased pigeons collected in Punjab province in 2017. We performed the whole genome, phylogenetic analysis and comparative clinico-pathological evaluation of two viruses in pigeons. Phylogenetic analysis based on fusion (F) gene and complete genome sequences showed that SA_1 belonged to sub-genotype XXI.1.1 and SA_2 clustered in sub-genotype XXI.1.2. SA_1 and SA_2 viruses contributed to morbidity and mortality in pigeons. Remarkably, although the two viruses resulted in comparatively similar pattern of pathogenesis and replication ability in various tissues of infected pigeons, SA_2 could cause more severe histopathological lesions and had comparatively high replication ability in pigeons than SA_1. Moreover, pigeons infected with SA_2 had higher shedding efficiency than that of pigeons infected with SA_1. Moreover, several aa substitutions in the major functional domains of the F and HN proteins might be contributed to the pathogenic differences between the two isolates in pigeons. Overall, these findings provide us with important insight into the epidemiology and evolution of PPMV-1 in Pakistan and laid the foundation for the further elucidation of the mechanism underlying the pathogenic difference of PPMV-1 in pigeons.

Molecular Characterization and Phylogenetic Analysis of Marek's Disease Virus in Iran

Marek's disease (MD) is a highly contagious, lymphoproliferative poultry disease caused by the oncogenic herpesvirus, serotype 1 Marek's disease virus (MDV-1), or Gallid herpesvirus 2 (GaHV-2). MDV strains have shown a continued evolution of virulence leading to immune failure, and MD cases continue to occur or surge. Meq, the major MDV-1 oncoprotein, induces T-cell neoplastic transformation through several mechanisms including inhibition of apoptosis, cell cycle regulation, and serum-anchorage independent growth. There is no current information on the MDV serotypes and pathotypes circulating in vaccinated commercial farms in Iran, where the birds are vaccinated at the hatchery with GaHV-2 and Meleagrid herpesvirus 1 (MeHV-1) vaccines. This study reports the molecular characterization of a GaHV-2 strain detected in 19 flocks of Iranian layer farms exhibiting MDV-1-like clinical signs and visceral lymphomas. Based on sequencing and phylogenetic analysis of the Meq gene, the Iranian GaHV-2 isolates could be divided into two separate clades regarding molecular features. The clade containing strains was closely related to Italian, Indian, and Hungarian virulent isolates, and the clade was related to American very virulent plus (vv+) isolates. For the first time, the MDV-1 virus was characterized by an outbreak in poultry flocks in Iran. Although MDV-1 strains obtained in Iran's present outbreak are presumably related to virulent (v) and vv+ pathotypes based on nucleotide, amino acid, and phylogenetic analysis of the viruses, they are not confirmed so far. Thus, it is highly recommended to perform further analyses to demonstrate the pathotype characteristics in vivo.

Characterisation, whole-genome sequencing and phylogenetic analysis of three H3N2 avian influenza viruses isolated from domestic ducks at live poultry markets of Iran, 2017: First report

BACKGROUND

Avian influenza type A viruses (AIV) can infect a broad range of hosts including human and birds, making them an important viral pathogen with zoonotic potential. Ducks are a known reservoir for many avian viruses including the AIV.

OBJECTIVES

To sequence the entire genome of duck-derived H3N2 and ran comprehensive phylogenetic analysis on them to study their origin.

METHODS

In this study, 962 cloacal swabs were collected from domestic ducks at several live poultry markets (LPMs) of Gilan, Mazandaran and Golestan provinces of Iran in the year 2017.

RESULTS

Preliminary assays such as haemagglutination inhibition assay (HI), Neuraminidase Inhibition assay(NI) and RT-qPCR suggested that 0.5% of the birds were infected by H3 low pathogenic influenza viruses (LPAI). Three isolates were selected for whole genome sequencing. The cleavage site of the HA genes showed a PEKQTR/GLF motif, an indicator of LPAI. Furthermore, BLAST and phylogenetic analyses of the HA gene showed high homology to the Eurasian lineage of H3N8 AIV (95.5%-97.1% to several European and East Asian isolates). However, the NA genes showed high homology (at most 96.5-96.9%) to those belonging to AIV N2 subtype. Furthermore, internal genes showed high homology (96%-98%) to a variety of duck-origin subtypes and glycoprotein combinations, which were different for each segment. This showed a complex reassortment between different subtypes.

DISCUSSION

This report is the first whole genome sequencing and complete characterisation of H3N2 AIV from Iran.

CONCLUSION

Such surveillance should continue to study the evolution and possible emergence of viruses with pandemic potential.

Molecular characterisation and phylogenetic study of the fusion gene of Newcastle disease viruses isolated from broiler farms of Iran in 2018-2019

Avian orthoavulavirus, commonly known as Newcastle disease virus (NDV) has been a constant threat for the poultry industry of Iran for decades. Recently, a couple of preliminary studies on backyard and commercial chicken suggested that a major subgenotype circulating in Iran may be VII(L) subgenotype, which is now known as VII.1.1 according to the new classification system. The unique subgenotype was not reported from other parts of the world and was slightly (≥3%) different from the closest group that was VIId. The study was conducted between July 2018 and March 2019 to determine the exact NDV genotypes/subgenotypes circulating in Iranian broiler poultry farms; five-hundred and forty chickens were sampled from thirty-six broiler farms located in eighteen provinces of Iran. As other genotypes/subgenotypes such as XIII and VI.2 are circulating in neighbouring countries, border provinces were also sampled. The F gene of the NDV isolates was sequenced and phylogenetic analysis was conducted. All the isolates clustered under the VII.1.1 group. The evolutionary analysis also revealed that the distances were between 0.0 and 0.7% meaning that the Iranian NDV circulating in broiler farms were not only of VII.1.1 sub-genotype, but also genetically very identical, indicating that the routine control measures for ND in Iran were not able to prevent the circulating NDVs. Although stricter biosecurity measures have been really effective in developed countries, surveillance of NDV to determine the circulating genotypes might also help us to implement better vaccination strategies in the future.

Report of a new meq gene size: The first study on genetic characterisation of Marek's disease viruses circulating in Iranian commercial layer and backyard chicken

1. In recent months, several outbreaks with clinical signs of MDV-1 were reported in Iranian parent and laying hen farms, in addition to backyard chickens. Several meq gene sequences from these outbreaks were amplified and molecularly characterised.2. The meq protein sequences revealed three different sizes, namely the standard 339 aa, a shorter form of 338 aa lacking a proline residue at position 191, and a very short (vs) size of 265 aa. Based on sequence and size, the 265 aa meq has never been reported from international research groups before. The protein has only one PPPP repeat motif suggesting it belongs to a highly virulent strain.3. The standard meq sequences showed 100% BLAST identity to the vv+ isolate Polen5. However, the 338 aa form clustered to the clade usually reported from North America.4. This is the first report on genetic analysis of MDV-1 from Iran, but further study is required to obtain a better picture of the diversity and prevalence of different MDV-1 strains circulating in the country's farms, backyard poultry and other bird species.

Circulation of at Least Six Distinct Groups of Pigeon-Derived Newcastle Disease Virus in Iran Between 1996 and 2019

According to the latest Newcastle disease virus (NDV) classification system, Iranian PPMV-1 isolates were classified as either XXI.1.1 or XXI.2 subgenotypes only. However, a few recent studies have suggested the possible existence of other Iranian PPMV-1 genotypes/subgenotypes. Recently, we isolated a PPMV-1 closely related to the African origin subgenotype VI.2.1.2 from an ill captive pigeon in a park aviary in central Tehran (Pg/IR/AMMM160/2019). This subgenotype had never been reported from Iran or neighboring countries. We also isolated a subgenotype VII.1.1 NDV (Pg/IR/AMMM117/2018), usually reported from non-pigeon birds in Iran. The nucleotide distance of AMMM117 was 1.0-2.5% compared to other Iranian subgenotypes VII.1.1 isolates. However, usually the same year VII.1.1 viruses that we isolate from Iranian poultry farms show negligible distances (0.0-0.5%). More isolates are required to study if this difference is due to subgenotype VII.1.1 being circulated and mutated in pigeons. Here, we also characterized two other isolates, namely Pg/IR/AMMM168/2019 and Pg/IR/MAM39/2017. The latter is the first Iranian subgenotype XXI.1.1 to be featured in the NDV datasets of the international NDV consortium. We also investigated the phylogenetic relation of all the published Iranian pigeon-derived NDV to date and updated the grouping according to the latest classification system. We have concluded that at least six different groups of pigeon-derived NDV have been circulating in Iran since 1996, four of which have been reported from just one city over the last seven years. This study suggests that the Iranian pigeon-origin NDV have been more diverse than the Iranian poultry-derived NDV in recent years.

Nutraceuticals: Transformation of Conventional Foods into Health Promoters/Disease Preventers and Safety Considerations

Nutraceuticals are essential food constituents that provide nutritional benefits as well as medicinal effects. The benefits of these foods are due to the presence of active compounds such as carotenoids, collagen hydrolysate, and dietary fibers. Nutraceuticals have been found to positively affect cardiovascular and immune system health and have a role in infection and cancer prevention. Nutraceuticals can be categorized into different classes based on their nature and mode of action. In this review, different classifications of nutraceuticals and their potential therapeutic activity, such as anti-cancer, antioxidant, anti-inflammatory and anti-lipid activity in disease will be reviewed. Moreover, the different mechanisms of action of these products, applications, and safety upon consumers including current trends and future prospect of nutraceuticals will be included.

Rapid Generation of a Recombinant Genotype VIII Newcastle Disease Virus (NDV) Using Full-Length Synthetic cDNA

Rescue of (-)ssRNA viruses involves the sequential assembly and cloning of the full-length cDNA, which is often a challenging and time-consuming process. The objective of this study was to develop a novel method to rapidly clone the full-length cDNA of a very virulent NDV by only one assembly step. A completely synthetic 15 kb cDNA of a Malaysian genotype VIII NDV known as strain AF2240-I with additional flanking BsmBI sites was synthesised. However, to completely follow the rule-of-six, the additional G residues that are traditionally added after the T7 promoter transcription initiation site were not synthesised. The synthetic fragment was then cloned into low-copy number transcription vector pOLTV5-phiX between the T7 promoter and HDV Rz sequences through digestion with BbsI. The construct was co-transfected with helper plasmids into BSRT7/5 cells. A recombinant NDV called rAF was successfully rescued using transfection supernatant harvested as early as 16 h post-transfection. Virus from each passage showed an intracerebral pathogenicity index (ICPI) and a mean death time (MDT) similar to the parent strain AF2240-I. Moreover, rAF possessed an introduced mutation which was maintained for several passages. The entire rescue using the one-step assembly procedure was completed within a few weeks, which is extremely fast compared to previously used methods.

An Overview of the Potential Therapeutic Applications of Essential Oils

The emergence of antimicrobial resistance (AMR) has urged researchers to explore therapeutic alternatives, one of which includes the use of natural plant products such as essential oils (EO). In fact, EO obtained from clove, oregano, thymus, cinnamon bark, rosemary, eucalyptus, and lavender have been shown to present significant inhibitory effects on bacteria, fungi, and viruses; many studies have been done to measure EO efficacy against microorganisms. The strategy of combinatory effects via conventional and non-conventional methods revealed that the combined effects of EO-EO or EO-antibiotic exhibit enhanced efficacy. This paper aims to review the antimicrobial effects of EO, modes of EO action (membrane disruption, efflux inhibition, increase membrane permeability, and decrease in intracellular ATP), and their compounds' potential as effective agents against bacteria, fungi, and viruses. It is hoped that the integration of EO applications in this work can be used to consider EO for future clinical applications.

Complete genome sequence of a subgenotype XXI.1.1 pigeon paramyxovirus type 1 virus (PPMV‑1) isolated from Iran in 2018 and phylogenetic analysis of a possible novel, but unassigned, PPMV-1 group isolated in 2014

Newcastle disease (ND) is one of the most serious infectious and contagious viral diseases in avian species. Recently, several ND outbreaks in pigeon caused by pigeon paramyxovirus serotype-1 (PPMV-1) have been reported from Iran, but unfortunately, phylogenetic studies have been mostly conducted on partial sequence of NDV fusion (F) gene. In addition, a complete genome data of Iranian PPMV-1 strains are not available. In the present study, a PPMV-1, named Avian avulavirus 1/pigeon/Iran/UT-EGV/2018, isolated from an infected pigeon, was subjected to whole-genome sequencing. The isolate showed an MDT of 74 h, thus categorizing it as mesogenic. The phylogenetic analysis based on the F gene sequence revealed the isolate belongs to XXI.1.1 subgenotype (min 0.9 % and max 3 %). To our knowledge, our study is the first study to publish the complete genome of a PPMV-1 from Iran. According to BLAST results, the whole genome of UT-EGV had high homology with some Russian, Egyptian and Ukrainian strains (the highest was 96.55 %). Additionally, we conducted a phylogenetic analysis on five PPMV-1 that we isolated in 2014 to find that they may belong to a completely unreported subgenotype (6 % distance when compared as a group). The information obtained from this study can be useful in preventive measures, including constructing an effective vaccine against PPMV-1 in Iran.

Ongoing genetic evolution of H9N2 avian influenza viruses in Iranian industrial poultry farms

Despite the use of wide-scale vaccination programmes against the H9N2 virus, enzootic outbreaks of H9N2 avian influenza (AI) have often occurred and caused serious nationwide economic losses, particularly in broiler chickens. In this study, the haemagglutinin (HA) and neuraminidase (NA) genes of nine recent H9N2s and a common vaccine strain were fully sequenced and compared with other representative Iranian viruses. Phylogenetic analysis revealed that all Iranian viruses were grouped into the G1 sub-lineage with different clusters in which recent isolates (2014-2017) formed a distinct cluster compared to the vaccine group (1998-2004). All Iranian H9N2s exhibited low pathogenicity AI connecting peptide feature with an R/KSSR motif. Amino acid 226, located in the 220 loop of the receptor binding site, was leucine among the recent Iranian viruses, a characteristic of human influenza viruses. With an overall gradual increase in the genetic diversity of H9N2s, Bayesian skyline plots of Iranian HA and NA genes depicted a fluctuation and a relative stable situation, respectively. It is recommended to apply constant surveillance to assess any increase in viral human adaptation and evolutionary changes in circulating field H9N2s. Moreover, antigenic characterisation of the prevailing H9N2 viruses seems to be necessary for evaluating the possible antigenic drift from the vaccine strain.

Virotherapy: Current Trends and Future Prospects for Treatment of Colon and Rectal Malignancies

Colorectal cancer (CRC) is one of the most common malignancies. In recent decades, early diagnosis and conventional therapies have resulted in a significant reduction in mortality. However, late stage metastatic disease still has very limited effective treatment options. There is a growing interest in using viruses to help target therapies to tumour sites. In recent years the evolution of immunotherapy has emphasised the importance of directing the immune system to eliminate tumour cells; we aim to give a state-of-the-art over-view of the diverse viruses that have been investigated as potential oncolytic agents for the treatment of CRC.

Rescue of recombinant Newcastle disease virus: a promising vector with two decades of intensive vaccine research

Two decades have passed since the first reverse genetics system for the rescue of recombinant Newcastle disease virus was developed. Since then, the recombinant Newcastle disease virus vector has shown promising results as a safe and potent vector for development of many vaccines for both avian and human use. Herein, we review several technical topics that would be useful to further understanding of this technology. First, the effect of using helper plasmids encoding proteins belonging to strains other than the full-length cDNA and the possible incorporation of these expressed proteins into progeny virus will be discussed. Then, we will discuss the effect of removal of additional G residues from the T7 initiation sequence and finally, we will review different ways to improve rescue efficiency.

Characterization and full genome sequencing of a velogenic Newcastle disease virus (NDV) strain Ck/IR/Beh/2011 belonging to subgenotype VII(L)

Avian avulavirus 1, better known as Newcastle disease virus (NDV), causes substantial loss to the poultry industry in many developing countries. In this study we have characterized and fully sequenced the genome of a velogenic NDV strain named Beh (Ck/IR/Beh/2011) that has been used in our lab for a number of challenge and immunological studies over the last few years. This strain was isolated from poultry in the city of Behshahr, Mazandaran Province, Iran after an outbreak reported in the region in 2011. The intracerebral pathogenicity index (ICPI) was 1.8 in one-day-old chicks, characteristic of a velogenic NDV strain. Later, the virus was purified using a sucrose gradient centrifugation and used for next-generation sequencing (NGS). The results showed that the genome length was 15192 bp, similar to those of class II velogenic strains. In addition, the phylogenetic analysis based on the complete F gene showed that the NDV strain Beh has an F protein cleavage site 112RRQKR↓ F117 and belongs to the newly identified subgenotype VII(L). Based on the biological and genetic characterization, NDV strain Beh is now the best documented reference isolate representing the novel subgenotype VII(L) in Iran. Keywords: NDV; NGS; velogenic strain, subgenotype VII(L); phylogenetic analysis.

NDV subgenotype VII(L) is currently circulating in commercial broiler farms of Iran, 2017-2018

BACKGROUND

Based on our previous work, it was discovered that some Newcastle disease virus (NDV) isolates from backyard poultry between 2011 and 2013 in Iran formed a new separate cluster when phylogenetic analysis based on the complete F gene sequence was carried out. The novel cluster was designated subgenotype VII(L) and published.

AIM

In the current study, for further validation, we initiated a comprehensive epidemiological study to identify the dominant NDV genotype(s) circulating within the country. Collection of samples was executed between October 2017 and February 2018 from 108 commercial broiler farms which reported clinical signs of respiratory disease in their broilers.

RESULT

We report that 38 of the farms (> 35%) tested positive for NDV. The complete F gene sequences of seven of the isolates are shown as representative sequences in this study. According to the phylogenetic tree constructed, the recent broiler farm isolates clustered into the newly designated cluster VII(L) together with the older Iranian backyard poultry isolates in our previous work. All the sequences shared the same virulence-associated F cleavage site of ₁₁₂RRQKR↓F₁₁₇.

CONCLUSION

Our phylogenetic analysis suggested that the NDV subgenotype VII(L) may have been derived from subgenotype VIId, and contrary to popular belief, subgenotype VIId may not be the dominant subgenotype in Iran. Tracking of the subgenotype on BLAST suggested that the NDV subgenotype VII(L), although previously unidentified, may have been circulating in this region as an endemic virus for at least a decade. Other NDV genotypes, however, have also been reported in Iran in recent years. Hence, ongoing study is aimed at determining the exact dominant NDV genotypes and subgenotypes in the country. This will be crucial in effective mitigation of outbreaks in Iranian broiler farms.

Full sequence analysis of hemagglutinin and neuraminidase genes and proteins of highly pathogenic avian influenza H5N1 virus detected in Iran, 2015

Over the last two decades, the highly pathogenic avian influenza H5N1 virus has gained a lot of attention due to its zoonotic and mutative nature. Iran is among the countries significantly affected by the virus as it hosts migratory birds during seasonal migration. In this study, the molecular characterizations of hemagglutinin (HA) and neuraminidase (NA) genes and proteins of H5N1 strain A/chicken/Iran/8/2015 detected in backyard poultry, Mazandaran province, were investigated. Phylogenetic analysis classified this virus as a member of subclade 2.3.2.1c, with the cleavage site motif of "PQRERRRK-R/GLF". HA carried a few mutations altering affinity to mammalian cells; however, the virus was categorized as avian. NA protein had the 20-amino acid deletion at aa position 49-69 similar to those isolated since 2000. Mutations of H253Y and H274Y contributing to antiviral resistance were present in NA. From this analysis, it can be concluded that the wild migratory birds flying from Western Asia to Eastern Africa are probably the main carriers of seasonal H5N1 in the country.

Prevalence of avian influenza (H9N2) in commercial quail, partridge, and turkey farms in Iran, 2014-2015

Avian influenza virus (AIV) H9N2 subtype is endemic in Iran and causes substantial economic loss to the growing poultry industry within the country. In this study, a cross-sectional analysis was carried out to determine the sero-prevalence of H9N2 in several commercial farms between the years 2014 and 2015. The comparison of the mean of serum titers and the ratio of sero-positive birds between all units were analyzed using one-way ANOVA test. In 2014, a total of 77 farms (58 turkey farms, 14 quail farms, and 5 partridge farms) and 894 birds (682 turkeys, 154 quails, and 58 partridges) were sampled while in 2015, a total of 69 farms (54 turkey farms, 8 quail farms, and 7 partridge farms) and 856 birds (675 turkeys, 105 quails, and 76 partridges) were sampled. Of that, 52 of 77 sampled farms (67.5%) and 437 of 894 samples (48.9%) were positive for H9N2 in 2014 while. Forty-one of 69 farms (59.4%) and 307 of 856 sera (35.9%) were positive in 2015. Furthermore, the mean titer of partridge farms was significantly lower than that of turkey farms (p < 0.01) and the mean percentage of sero-positive turkey farms was significantly higher than partridge farms (p < 0.01) in 2014. In 2015, no significant difference was observed between the mean sera titer amongst farms and percentage of sero-positive birds (p > 0.05). Our results indicated that H9N2 is circulating in these farms. Since many more such farms are being established for operations, in addition to the threat of emergence and continuous reemergence of the disease in these farms, enhanced veterinary biosecurity measures on farms are required for mitigation.

Rescue of recombinant Newcastle disease virus: a short history of how it all started

Reverse genetics of viruses has come a long way, and many recombinant viruses have been generated since the first successful "rescues" were reported in the late 1970s. Recombinant Newcastle disease virus (rNDV), a non-segmented negative-sense RNA virus (NSNSV), was first rescued in 1999 using a reverse genetics approach similar to that reported for other recombinant viruses of the order Mononegavirales a few years before. The route from an original NDV isolate to the generation of its recombinant counterpart requires many steps that have to be sequentially and carefully completed. Background knowledge of each of these steps is essential because it allows one to make the best choices for fulfilling the specific requirements of the final recombinant virus. We have previously reviewed the latest strategies in cloning the NDV full-length cDNA into transcription vectors and the use of different RNA polymerase systems for the generation of viral RNA from plasmid DNA. In this article, we review a number of discoveries on the mechanism of transcription and replication of NDV, including a brief history behind the discovery of its RNP complex. This includes the generation of artificial and functional RNP constructs, in combination with the smart use of available knowledge and technologies that ultimately resulted in rescue of the first rNDV.

Rescue of recombinant Newcastle disease virus: current cloning strategies and RNA polymerase provision systems

Since the first rescue of a recombinant Newcastle disease virus (rNDV) in the late 1990s, many more rNDVs have been rescued by researchers around the world. Regardless of methodology, the main principle behind rescue of the virus has remained the same, i.e., the formation of a functional replication complex by simultaneously providing the full-length viral RNA and the viral NP, P and L proteins. However, different strategies have been reported for the insertion of the full-length genome into a suitable transcription vector, which remains the most challenging step of the rescue. Moreover, several systems have been published for provision of the DNA-dependent RNA polymerase, which is needed for transcription of viral RNA (vRNA) from the transfected plasmid DNA. The aim of this article is to consolidate all of the current cDNA assembly strategies and transcription systems used in rescue of rNDV in order to attain a better understanding of the advantages and disadvantages of each approach.

The effect of high level natural ionizing radiation on expression of PSA, CA19-9 and CEA tumor markers in blood serum of inhabitants of Ramsar, Iran

Since several high level natural radiation areas (HLNRAs) exist on our planet, considerable attention has been drawn to health issues that may develop as the result of visiting or living in such places. City of Ramsar in Iran is an HNLRA, and is a tourist attraction mainly due to its hot spas. However, the growing awareness over its natural radiation sources has prompted widespread scientific investigation at national level. In this study, using an ELISA method, the level of expression of three tumor markers known as carcinoembryonic antigen (CEA), prostate-specific antigen (PSA) and carcino antigen 19-9 (CA19-9) in blood serum of 40 local men of Ramsar (subject group) was investigated and compared to 40 men from the city of Noshahr (control group). Noshahr was previously identified as a normal level natural radiation area (NLNRA) that is some 85 km far from Ramsar. According to statistical analysis, there was a significant difference in the levels of PSA and CA19-9 markers between the two groups (p < 0.001) with those of Ramsar being considerably higher. CEA level did not show any difference. Although some of the volunteers tested positive to the markers, they were in good health as confirmed by the physician. Moreover, the high number of positive markers in Noshahr was considerable. Therefore, future study is needed to further validate this result and to determine the level of positivity to tumor markers in both cities.

NDV-induced apoptosis in absence of Bax; evidence of involvement of apoptotic proteins upstream of mitochondria

Background

Recently it was shown that following infection of HeLa cells with Newcastle disease virus (NDV), the matrix (M) protein binds to Bax and subsequently the intrinsic pathway of apoptosis is activated. Moreover, there was very little alteration on mRNA and protein levels of Bax and Bcl-2 after infection with NDV.

Finding

In order to further investigate the role of members of the Bcl-2 family, Bax-knockout and wild-type HCT116 cells were infected with NDV strain AF2240. Although both cells underwent apoptosis through the activation of the intrinsic pathway and the release of cytochrome c from mitochondria, the percentage of dead Bax-knockout cells was significantly lower than wt cells (more than 10% at 48 h post-infection). In a parallel experiment, the effect of NDV on HT29 cells, that are originally Bcl-2-free, was studied. Apoptosis in HT29 cells was associated with Bax redistribution from cytoplasm to mitochondria, similar to that of HeLa and wt HCT116 cells.

Conclusion

Although the presence of Bax during NDV-induced apoptosis contributes to a faster cell death, it was concluded that other apoptotic protein(s) upstream of mitochondria are also involved since cancer cells die whether in the presence or absence of Bax. Therefore, the classic Bax/Bcl-2 ratio may not be a major determinant in NDV-induced apoptosis.

Increase in concentration of soluble HLA-G in high-quality embryos after intracytoplasmic sperm injection

Non-invasive methods are normally preferred to conventional invasive methods when selecting suitable embryos to improve pregnancy rates after assisted reproduction techniques. One of the most recognized non-invasive methods is to examine the supernatants of embryo culture media. Soluble human leukocyte antigen, class I, G (sHLA-G) antigen is a non-classical class I molecule that has been widely considered as a marker of pregnancy failure or implantation success. In the current study of some Iranian patients, we examined the concentration of sHLA-G at different time points after intracytoplasmic sperm injection and compared the rates to the morphology and quality of the selected embryos. We showed that the concentration of sHLA-G increases over time in high-quality embryos. We conclude that there is a positive relationship between morphology, quality, and sHLA-G concentration. We suggest that this relationship can be used to increase the chance of a successful pregnancy.

Newcastle disease virus infection promotes Bax redistribution to mitochondria and cell death in HeLa cells

BACKGROUND/AIMS

Newcastle disease virus (NDV) is an avian paramyxovirus that has gained a lot of interest in cancer viro-therapeutic applications because of its ability to selectively induce apoptosis in human cancer cells. However, the underlying mechanisms by which NDV induces apoptosis in human cancer cells are still not entirely understood.

METHODS

In this study we examined the effect of a Malaysian velogenic strain of NDV, known as AF2240, on some elements of the intrinsic pathway of apoptosis.

RESULTS

We show that NDV infection leads to conformational change of Bax protein. This is associated with the translocation of Bax from the cytoplasm to mitochondria and the release of cytochrome c into the cytoplasm. Interestingly, the level of Bcl-2 protein was not affected by NDV treatment.

CONCLUSION

We have shown that Bax conformational change and subcellular distribution is involved in the intrinsic pathway of apoptosis induced by NDV.