R. Nategh - Academia.edu (original) (raw)

Papers by R. Nategh

Iranian journal of microbiology, 2011

Each year, Enteroviruses infect millions of people and cause different diseases. The agents are u... more Each year, Enteroviruses infect millions of people and cause different diseases. The agents are usually detected using cell culture. RD (Rhabdomyosarcoma) and L20B (L cells) are among the recommended cells by the World Health Organisation (WHO) for this purpose. Even though cell culture is the most common method used in diagnosing Enteroviruses in stool specimens, this particular method poses some problems, which include false positive or negative results, lack of a unique cell line for diagnosing all Enterovirus types in addition to being time consuming. For these reasons, an attempt was made to find better techniques of Enterovirus detection. RT-PCR (Reverse Transcriptase Polymerase Chain Reaction) is a technique used in place of the cell culture method. In this study, the cell culture method was compared with RT-PCR for detection of Enteroviruses in stool specimens. First, the chloroform treated stool samples were inoculated onto five cell lines, including RD, L20B, Hep-2 (Human ...

Eastern Mediterranean health journal = La revue de santé de la Méditerranée orientale = al-Majallah al-ṣiḥḥīyah li-sharq al-mutawassiṭ, 2004

To better understand the annual distribution of influenza virus in our country, we isolated and t... more To better understand the annual distribution of influenza virus in our country, we isolated and typed 45 viruses from 1043 patients with acute respiratory illnesses in a 10-year study conducted by the National Influenza Centre of the Islamic Republic of Iran. The seasonal distribution of influenza typically ran from November to April. Type A influenza was most common during the winters of 1991-92, 1997-98 and 2000-01 and type B influenza was most common during 1992-5 and 1996-97. Both type A and type B viruses circulated in 1995-96 and 1998-2000. A serological survey based on haemagglutination inhibition test confirmed our findings. The annual pattern of strains isolated was similar to the worldwide pattern during the same interval.

Virology, 2000

We have studied 52 new HHV8 strains by sequencing the complete hypervariable K1 gene and genotypi... more We have studied 52 new HHV8 strains by sequencing the complete hypervariable K1 gene and genotyping the K14.1/K15 loci located at both sides, respectively, of the viral genome. The samples originated from 49 patients with Kaposi's sarcoma (KS; 32 patients), multicentric Castleman's disease (MCD; 12 patients), or primary effusion lymphoma (PEL; 5 patients). Among these patients, 32 were of African origin (West and Central African countries and Creoles from French Guiana) and the 17 others were mostly French homosexuals. Comprehensive phylogenetic studies allowed the identification of distinct groups within the three already known main subtypes. Interestingly, two new sequences that did not cluster within a known subtype or group could be considered as prototypes of early/ancient variants of the C subtype and A/C set, respectively. Among the 32 African strains, the majority were either of the B subtype (13 cases) or of the A5 group (11 cases), indicating that this latter genotype is frequent and widespread in Africa. In contrast, a subtype C strain infected most of the 17 other patients. PCR-based genotyping of the K14.1/K15 loci revealed an overall predominance of P subtype, except in the A5 and B K1 groups, in which the P and M alleles were equally represented. The implications of these data on the evolution and spread of HHV8 among human African populations are discussed.

Vaccine, 2006

During mass campaign for measles/rubella vaccination on December 2003 in Iran, many pregnant wome... more During mass campaign for measles/rubella vaccination on December 2003 in Iran, many pregnant women have vaccinated mistakenly. These women were grouped to susceptible and immune against rubella before vaccination by the status of IgG avidity response to rubella vaccine, then susceptible women were followed up to delivery time and their neonates were followed up to one year. In five neonates that were born from susceptible women, rubella-specific IgM has detected in cord blood sera, but they have not shown signs compatible to congenital rubella syndrome.

Journal of Clinical Virology, 2007

Background: The live-attenuated oral polio vaccine used to interrupt poliovirus transmission is g... more Background: The live-attenuated oral polio vaccine used to interrupt poliovirus transmission is genetically unstable. Reversion of some attenuating mutations, which normally occurs during vaccine strain replication in some recipients, and can rarely cause vaccine-associated paralytic poliomyelitis (VAPP). The poliovirus eradication program designed by the World Health Organization (WHO) includes immunization with OPV in addition to careful surveillance of all acute-flaccid paralysis (AFP) cases. Objectives: In Iran we last isolated imported wild poliovirus in 2000 and the immunization coverage was 100% in 2002. During 2001, there were three AFP cases with residual paralysis from which Sabin-like type 1 polioviruses were isolated in our national polio laboratory. Study design: The complete VP 1 region of the three isolates was sequenced and amino acid substitutions associated with these neurovirulent isolates were recorded. Results: These isolates had either 4, 2 or 1 nucleotide substitution(s) in the VP 1 region, corresponding to amino acid change in the VP 1 of isolate 1 of either (H 149 −→Y), (T 106 −→A) or (I 90 −→L), respectively.

Journal of Clinical Virology, 2009

Background: The 66 serotypes of human enteroviruses (EVs) are classified into four species A-D, b... more Background: The 66 serotypes of human enteroviruses (EVs) are classified into four species A-D, based on phylogenetic relationships in multiple genome regions. Partial VP 1 amplification and sequence analysis are reliable methods for identifying non-polio enterovirus serotypes, especially in negative cell culture specimens from patients with residual paralysis. Objectives: In Iran during the years 2000-2002, there were 29 residual paralysis cases with negative cell (RD, HEp 2 and L 20 B) culture results. Study design: The genomic RNA was extracted from stool specimens from cases of residual paralysis and detected by amplification of the 5 -nontranslated region using RT-PCR with Pan-EV primers. Partial VP 1 amplification by semi-nested RT-PCR (snRT-PCR) and sequence analysis were done. Results: Specimens from the 29 culture-negative cases contained echoviruses of six different serotypes. Conclusions: The global eradication of wild polioviruses is near and study of non-polio enteroviruses, which can cause poliomyelitis, is increasingly important to understand their pathogenesis. The VP 1 sequences, derived from the snRT-PCR products, allowed rapid molecular analysis of these non-polio strains.

International Journal of Infectious Diseases, 2008

e469 bated in a 5-10% CO2 atmosphere at 37 • C for at least 48 hours.

Current HIV Research, 2014

Despite numerous and tremendous achievements in the development and standardization of HIV vaccin... more Despite numerous and tremendous achievements in the development and standardization of HIV vaccines, there are still lots of vague concepts in HIV vaccinology. Various approaches have been applied to design an efficient HIV vaccine. Due to their lack of replication ability and expression of native antigens at the same time virus-like particles, such as previously introduced mzNL4-3 HIV-1 VLPs are among the highlighted candidates in this field. On the other part, application of adjuvants is an inseparable strategy in the vaccine development researches. Archaeosomes are liposomal adjuvants with intensifiying features of T helper 1 and cytotoxic T-cells responses. Archaeosomes derived from Methanobrevibacter smithii has been shown to enhance MHC class I-dependent antigen presentation and hence, are to be advantageous in the development of vaccines against viral infections. Herein, we have studied efficiency of mzNL4-3 VLPs entrapped in M. smithii archaeosomes as an HIV-1 vaccine candidate to induce humoral and cellular responses in BALB/c mice. Analysis of total and subtype-specific anti-Env IgG antibody, as well as, cytokine secretion pattern revealed an efficient promotion of anti-HIV specific T helper 1 responses in immunized animals. This finding was evidenced by the significant dominance of IgG2a subtype in the sera and considerable secretion of IFN-γ by specifically induced splenocytes of mice immunized with VLP-containing archaeosomes (VLP+ Archaeosome). In addition, ELISpot assay verified these results and indicated the significantly higher frequency of IFN-γ secreting splenocytes in immunized models. The ratio of IFN-γ to IL-4 spot forming cells (SFCs) in the VLP+ Archaeosome immunized mice was also higher than that of the other groups immunized with either VLP-free archaeosomes or VLPs formulated with complete/incomplete Freund's adjuvants. These results propound M. smithii archaeosomes-entrapped mzNL4-3 VLPs as a promising immunogen which specifically induces and augments T-helper 1 oriented responses against HIV antigens.

BMC Research Notes, 2011

Background: Initial data on the molecular epidemiology of HCV infection in Cyprus showed a highly... more Background: Initial data on the molecular epidemiology of HCV infection in Cyprus showed a highly polyphyletic infection and multiple points of introduction into the general population. The continuation and expansion of this investigation is presented here including high risk groups. Findings: The samples include additional subjects from the general population, a group of inmates and HIV/HCV coinfected individuals, whose strains were amplified by RT-PCR and sequenced in partial Core-E1 and NS5B regions. The results confirm the broad genotype distribution and polyphyletic infection on the island, and no new subtypes were found. Monophyletic clusters between strains of the prisoners and the injecting drug users imply sharing of infected equipment, and highlight the risk of widespread transmission in these cohorts, although no spill-over to the general population was observed. Conclusions: The results of this study underline the impact of population movements and high-risk population groups on the changing molecular epidemiology of HCV, with strains moving to Europe from Asia, Africa and Eastern Europe by means of immigration and modern transmission routes.

Archives of Virology, 2010

Influenza virus infections cause severe illness worldwide. Vaccination reduces the morbidity and ... more Influenza virus infections cause severe illness worldwide. Vaccination reduces the morbidity and mortality of influenza. The efficacy of vaccines varies due to antigenic differences between the circulating influenza strains and the vaccine. Neuraminidase inhibitors are effective for prophylaxis and treatment of influenza infections, and the emergence of drug resistant mutants is an important challenge. Full-length nucleotide and deduced amino acid sequences of the hemagglutinin and neuraminidase genes of three 2009 pandemic influenza A/H1N1 isolates were compared with the vaccine strain and some strains from different countries. Phylogenetic analysis for hemagglutinin and neuraminidase showed they were related to their vaccine strain, with an average of 99.56 and 99.53% sequence identity, respectively. No genetic indication of resistance to neuraminidase inhibitors was found. Although genomic analysis of hemagglutinin and neuraminidase genes of Iranian strains in comparison to the corresponding vaccine strain revealed some mutations, none of these were identified in functionally important receptor-binding sites.

American Journal of Infection Control, 2006

Background: Prevention of congenital rubella syndrome (CRS) is the main goal of rubella immunizat... more Background: Prevention of congenital rubella syndrome (CRS) is the main goal of rubella immunization. The World Health Organization (WHO) recommends that countries undertaking measles elimination should take the opportunity to eliminate rubella as well through use of measles-rubella (MR) or measles-mumps-rubella (MMR) vaccine in their childhood immunization programs and campaigns. On December 2003, during a mass campaign for measles-rubella vaccination in Iran, more than 33 million doses of vaccine were administered to 5-to 25-year-old males and females. Methods: In this study, immunoglobulin (Ig)G avidity assay was used to evaluate the rubella vaccine produced immunity among susceptible populations. Results: Findings indicated that 61.9% of vaccinees (1202 out of 1940) were immune against rubella before vaccination, and 38.1% (738 out of 1940) were susceptible to rubella before vaccination. Our results also showed that 98% of the susceptible group (723 out of 738) acquired immunity against rubella after vaccination, and 2% of them (15 out of 738) did not acquire vaccineinduced immunity to rubella. Conclusion: Findings revealed that mass vaccination in December 2003 provided appropriate immune coverage among vaccinees. Also, rubella vaccine induced favorable immunity in a part of the childbearing age female (15-25 years) population, which could prevent congenital rubella syndrome among those females. (Am J Infect Control

Acta Virologica, 2009

Adamantanes have been used for the prophylaxis and treatment of Influenza A virus (IAV) infection... more Adamantanes have been used for the prophylaxis and treatment of Influenza A virus (IAV) infections worldwide. However, they have limited use because of increasing number of resistant viruses during recent years. In investigating the frequency of amantadine-resistant IAVs (H3N2) circulating in Iran in 2005-2008, we found that M2 sequences of recently circulating viruses that were amantadine-resistant contained a Ser31Asn mutation. Thus, adamantanes should not be used for treatment or prophylaxis of recent IAVs (H3N2) infections. In future, their potential use will depend on the resistance of circulating viruses.

Virus Research, 2013

An insect High-Five cell line was generated constitutively and stably expressing the VP2 protein ... more An insect High-Five cell line was generated constitutively and stably expressing the VP2 protein of rotavirus RF strain leading to the formation of core-like particles. The integration of the VP2 gene was confirmed by PCR, Real-time PCR and Southern blot, and the protein expression was confirmed by Western blot and immunofluorescence microscopy. Integrity and self assembly of VP2 as core-like particles was demonstrated by electron microscopy. The High-Five cell system stably expressing rotavirus corelike particles can be applied to the study of viral protein structure and functions; it may be useful for vaccine development, gene therapy and drug delivery.

Iranian journal of microbiology, 2011

Each year, Enteroviruses infect millions of people and cause different diseases. The agents are u... more Each year, Enteroviruses infect millions of people and cause different diseases. The agents are usually detected using cell culture. RD (Rhabdomyosarcoma) and L20B (L cells) are among the recommended cells by the World Health Organisation (WHO) for this purpose. Even though cell culture is the most common method used in diagnosing Enteroviruses in stool specimens, this particular method poses some problems, which include false positive or negative results, lack of a unique cell line for diagnosing all Enterovirus types in addition to being time consuming. For these reasons, an attempt was made to find better techniques of Enterovirus detection. RT-PCR (Reverse Transcriptase Polymerase Chain Reaction) is a technique used in place of the cell culture method. In this study, the cell culture method was compared with RT-PCR for detection of Enteroviruses in stool specimens. First, the chloroform treated stool samples were inoculated onto five cell lines, including RD, L20B, Hep-2 (Human ...

Eastern Mediterranean health journal = La revue de santé de la Méditerranée orientale = al-Majallah al-ṣiḥḥīyah li-sharq al-mutawassiṭ, 2004

To better understand the annual distribution of influenza virus in our country, we isolated and t... more To better understand the annual distribution of influenza virus in our country, we isolated and typed 45 viruses from 1043 patients with acute respiratory illnesses in a 10-year study conducted by the National Influenza Centre of the Islamic Republic of Iran. The seasonal distribution of influenza typically ran from November to April. Type A influenza was most common during the winters of 1991-92, 1997-98 and 2000-01 and type B influenza was most common during 1992-5 and 1996-97. Both type A and type B viruses circulated in 1995-96 and 1998-2000. A serological survey based on haemagglutination inhibition test confirmed our findings. The annual pattern of strains isolated was similar to the worldwide pattern during the same interval.

Virology, 2000

We have studied 52 new HHV8 strains by sequencing the complete hypervariable K1 gene and genotypi... more We have studied 52 new HHV8 strains by sequencing the complete hypervariable K1 gene and genotyping the K14.1/K15 loci located at both sides, respectively, of the viral genome. The samples originated from 49 patients with Kaposi's sarcoma (KS; 32 patients), multicentric Castleman's disease (MCD; 12 patients), or primary effusion lymphoma (PEL; 5 patients). Among these patients, 32 were of African origin (West and Central African countries and Creoles from French Guiana) and the 17 others were mostly French homosexuals. Comprehensive phylogenetic studies allowed the identification of distinct groups within the three already known main subtypes. Interestingly, two new sequences that did not cluster within a known subtype or group could be considered as prototypes of early/ancient variants of the C subtype and A/C set, respectively. Among the 32 African strains, the majority were either of the B subtype (13 cases) or of the A5 group (11 cases), indicating that this latter genotype is frequent and widespread in Africa. In contrast, a subtype C strain infected most of the 17 other patients. PCR-based genotyping of the K14.1/K15 loci revealed an overall predominance of P subtype, except in the A5 and B K1 groups, in which the P and M alleles were equally represented. The implications of these data on the evolution and spread of HHV8 among human African populations are discussed.

Vaccine, 2006

During mass campaign for measles/rubella vaccination on December 2003 in Iran, many pregnant wome... more During mass campaign for measles/rubella vaccination on December 2003 in Iran, many pregnant women have vaccinated mistakenly. These women were grouped to susceptible and immune against rubella before vaccination by the status of IgG avidity response to rubella vaccine, then susceptible women were followed up to delivery time and their neonates were followed up to one year. In five neonates that were born from susceptible women, rubella-specific IgM has detected in cord blood sera, but they have not shown signs compatible to congenital rubella syndrome.

Journal of Clinical Virology, 2007

Background: The live-attenuated oral polio vaccine used to interrupt poliovirus transmission is g... more Background: The live-attenuated oral polio vaccine used to interrupt poliovirus transmission is genetically unstable. Reversion of some attenuating mutations, which normally occurs during vaccine strain replication in some recipients, and can rarely cause vaccine-associated paralytic poliomyelitis (VAPP). The poliovirus eradication program designed by the World Health Organization (WHO) includes immunization with OPV in addition to careful surveillance of all acute-flaccid paralysis (AFP) cases. Objectives: In Iran we last isolated imported wild poliovirus in 2000 and the immunization coverage was 100% in 2002. During 2001, there were three AFP cases with residual paralysis from which Sabin-like type 1 polioviruses were isolated in our national polio laboratory. Study design: The complete VP 1 region of the three isolates was sequenced and amino acid substitutions associated with these neurovirulent isolates were recorded. Results: These isolates had either 4, 2 or 1 nucleotide substitution(s) in the VP 1 region, corresponding to amino acid change in the VP 1 of isolate 1 of either (H 149 −→Y), (T 106 −→A) or (I 90 −→L), respectively.

Journal of Clinical Virology, 2009

Background: The 66 serotypes of human enteroviruses (EVs) are classified into four species A-D, b... more Background: The 66 serotypes of human enteroviruses (EVs) are classified into four species A-D, based on phylogenetic relationships in multiple genome regions. Partial VP 1 amplification and sequence analysis are reliable methods for identifying non-polio enterovirus serotypes, especially in negative cell culture specimens from patients with residual paralysis. Objectives: In Iran during the years 2000-2002, there were 29 residual paralysis cases with negative cell (RD, HEp 2 and L 20 B) culture results. Study design: The genomic RNA was extracted from stool specimens from cases of residual paralysis and detected by amplification of the 5 -nontranslated region using RT-PCR with Pan-EV primers. Partial VP 1 amplification by semi-nested RT-PCR (snRT-PCR) and sequence analysis were done. Results: Specimens from the 29 culture-negative cases contained echoviruses of six different serotypes. Conclusions: The global eradication of wild polioviruses is near and study of non-polio enteroviruses, which can cause poliomyelitis, is increasingly important to understand their pathogenesis. The VP 1 sequences, derived from the snRT-PCR products, allowed rapid molecular analysis of these non-polio strains.

International Journal of Infectious Diseases, 2008

e469 bated in a 5-10% CO2 atmosphere at 37 • C for at least 48 hours.

Current HIV Research, 2014

Despite numerous and tremendous achievements in the development and standardization of HIV vaccin... more Despite numerous and tremendous achievements in the development and standardization of HIV vaccines, there are still lots of vague concepts in HIV vaccinology. Various approaches have been applied to design an efficient HIV vaccine. Due to their lack of replication ability and expression of native antigens at the same time virus-like particles, such as previously introduced mzNL4-3 HIV-1 VLPs are among the highlighted candidates in this field. On the other part, application of adjuvants is an inseparable strategy in the vaccine development researches. Archaeosomes are liposomal adjuvants with intensifiying features of T helper 1 and cytotoxic T-cells responses. Archaeosomes derived from Methanobrevibacter smithii has been shown to enhance MHC class I-dependent antigen presentation and hence, are to be advantageous in the development of vaccines against viral infections. Herein, we have studied efficiency of mzNL4-3 VLPs entrapped in M. smithii archaeosomes as an HIV-1 vaccine candidate to induce humoral and cellular responses in BALB/c mice. Analysis of total and subtype-specific anti-Env IgG antibody, as well as, cytokine secretion pattern revealed an efficient promotion of anti-HIV specific T helper 1 responses in immunized animals. This finding was evidenced by the significant dominance of IgG2a subtype in the sera and considerable secretion of IFN-γ by specifically induced splenocytes of mice immunized with VLP-containing archaeosomes (VLP+ Archaeosome). In addition, ELISpot assay verified these results and indicated the significantly higher frequency of IFN-γ secreting splenocytes in immunized models. The ratio of IFN-γ to IL-4 spot forming cells (SFCs) in the VLP+ Archaeosome immunized mice was also higher than that of the other groups immunized with either VLP-free archaeosomes or VLPs formulated with complete/incomplete Freund's adjuvants. These results propound M. smithii archaeosomes-entrapped mzNL4-3 VLPs as a promising immunogen which specifically induces and augments T-helper 1 oriented responses against HIV antigens.

BMC Research Notes, 2011

Background: Initial data on the molecular epidemiology of HCV infection in Cyprus showed a highly... more Background: Initial data on the molecular epidemiology of HCV infection in Cyprus showed a highly polyphyletic infection and multiple points of introduction into the general population. The continuation and expansion of this investigation is presented here including high risk groups. Findings: The samples include additional subjects from the general population, a group of inmates and HIV/HCV coinfected individuals, whose strains were amplified by RT-PCR and sequenced in partial Core-E1 and NS5B regions. The results confirm the broad genotype distribution and polyphyletic infection on the island, and no new subtypes were found. Monophyletic clusters between strains of the prisoners and the injecting drug users imply sharing of infected equipment, and highlight the risk of widespread transmission in these cohorts, although no spill-over to the general population was observed. Conclusions: The results of this study underline the impact of population movements and high-risk population groups on the changing molecular epidemiology of HCV, with strains moving to Europe from Asia, Africa and Eastern Europe by means of immigration and modern transmission routes.

Archives of Virology, 2010

Influenza virus infections cause severe illness worldwide. Vaccination reduces the morbidity and ... more Influenza virus infections cause severe illness worldwide. Vaccination reduces the morbidity and mortality of influenza. The efficacy of vaccines varies due to antigenic differences between the circulating influenza strains and the vaccine. Neuraminidase inhibitors are effective for prophylaxis and treatment of influenza infections, and the emergence of drug resistant mutants is an important challenge. Full-length nucleotide and deduced amino acid sequences of the hemagglutinin and neuraminidase genes of three 2009 pandemic influenza A/H1N1 isolates were compared with the vaccine strain and some strains from different countries. Phylogenetic analysis for hemagglutinin and neuraminidase showed they were related to their vaccine strain, with an average of 99.56 and 99.53% sequence identity, respectively. No genetic indication of resistance to neuraminidase inhibitors was found. Although genomic analysis of hemagglutinin and neuraminidase genes of Iranian strains in comparison to the corresponding vaccine strain revealed some mutations, none of these were identified in functionally important receptor-binding sites.

American Journal of Infection Control, 2006

Background: Prevention of congenital rubella syndrome (CRS) is the main goal of rubella immunizat... more Background: Prevention of congenital rubella syndrome (CRS) is the main goal of rubella immunization. The World Health Organization (WHO) recommends that countries undertaking measles elimination should take the opportunity to eliminate rubella as well through use of measles-rubella (MR) or measles-mumps-rubella (MMR) vaccine in their childhood immunization programs and campaigns. On December 2003, during a mass campaign for measles-rubella vaccination in Iran, more than 33 million doses of vaccine were administered to 5-to 25-year-old males and females. Methods: In this study, immunoglobulin (Ig)G avidity assay was used to evaluate the rubella vaccine produced immunity among susceptible populations. Results: Findings indicated that 61.9% of vaccinees (1202 out of 1940) were immune against rubella before vaccination, and 38.1% (738 out of 1940) were susceptible to rubella before vaccination. Our results also showed that 98% of the susceptible group (723 out of 738) acquired immunity against rubella after vaccination, and 2% of them (15 out of 738) did not acquire vaccineinduced immunity to rubella. Conclusion: Findings revealed that mass vaccination in December 2003 provided appropriate immune coverage among vaccinees. Also, rubella vaccine induced favorable immunity in a part of the childbearing age female (15-25 years) population, which could prevent congenital rubella syndrome among those females. (Am J Infect Control

Acta Virologica, 2009

Adamantanes have been used for the prophylaxis and treatment of Influenza A virus (IAV) infection... more Adamantanes have been used for the prophylaxis and treatment of Influenza A virus (IAV) infections worldwide. However, they have limited use because of increasing number of resistant viruses during recent years. In investigating the frequency of amantadine-resistant IAVs (H3N2) circulating in Iran in 2005-2008, we found that M2 sequences of recently circulating viruses that were amantadine-resistant contained a Ser31Asn mutation. Thus, adamantanes should not be used for treatment or prophylaxis of recent IAVs (H3N2) infections. In future, their potential use will depend on the resistance of circulating viruses.

Virus Research, 2013

An insect High-Five cell line was generated constitutively and stably expressing the VP2 protein ... more An insect High-Five cell line was generated constitutively and stably expressing the VP2 protein of rotavirus RF strain leading to the formation of core-like particles. The integration of the VP2 gene was confirmed by PCR, Real-time PCR and Southern blot, and the protein expression was confirmed by Western blot and immunofluorescence microscopy. Integrity and self assembly of VP2 as core-like particles was demonstrated by electron microscopy. The High-Five cell system stably expressing rotavirus corelike particles can be applied to the study of viral protein structure and functions; it may be useful for vaccine development, gene therapy and drug delivery.