Pathologic and immunologic characteristics of coxsackievirus A16 infection in rhesus macaques.

Coxsackievirus A16 (CV-A16) causes human hand, foot and mouth disease, but its pathogenesis is unclear. In rhesus macaques, CV-A16 infection causes characteristic vesicles in the oral mucosa and limbs as well as viremia and positive viral loads in the tissues, suggesting that these animals reflect the pathologic process of the infection. An immunologic analysis indicated a defective immune response, which included undetectable neutralizing antibodies and IFN-γ-specific memory T-cells in macaques infected with CV-A16.

The Structure, Pathogenicity and Immunogenicity of Two Virion Fractions Harvested from Cell Cultures Infected with the CA16 Virus.

Objectives: To investigate the biological characteristics of the two types of virion fractions of Coxsackievirus A 16 (CA16), which include the real virion fraction and pseudo-virion fraction in their structure, pathogenicity and immunogenicity.

Methods: We obtained the two CA16 virion fractions by density gradient centrifugation. The morphology of virion fractions was analyzed by electron microscopy, while the antigenic characteristics and immunogenicity of two virion fractions were determined by ELISA, SDS-PAGE, Western blot, qRT-PCR, and the mouse model of immune response.

Immunity and clinical efficacy of an inactivated enterovirus 71 vaccine in healthy Chinese children: a report of further observations.

Background: To investigate the long-term effects on immunity of an inactivated enterovirus 71 (EV71) vaccine and its protective efficacy.

Methods: A sub-cohort of 1,100 volunteers from Guangxi Province in China was eligible for enrolment and randomly administered either the EV71 vaccine or a placebo on days 0 and 28 in a phase III clinical trial and then observed for the following 2 years with approval by an independent ethics committee of Guangxi Zhuang Autonomous Region, China. Serum samples from the 350 participants who provided a full series of blood samples (at all the sampling points) within the 2-year period were collected.

[Heat effect stability of inactivated enterovirus 71 vaccine].

Objective: To investigate the effect of temperature on the stability of intermediate and final products of inactivated enterovirus 71 vaccine, which was prepared in human diploid cells.

Methods: The different batches of harvest viral cultures, the vaccine stock solutions and the final productions of inactivated enterovirus 71 vaccine were stored at different temperatures. The samples of viral culture stored at -20°C or 4°C were harvested at 0, 6, 12 and 24 months later.

Comparative study of the immunogenicity in mice and monkeys of an inactivated CA16 vaccine made from a human diploid cell line.

The coxsackie A16 virus (CA16), along with enterovirus 71 (EV71), is a primary pathogen that causes hand, foot, and mouth disease (HFMD). To control HFMD, CA16, and EV71 vaccines are needed. In this study, an experimental inactivated CA16 vaccine was prepared using human diploid cells, and the vaccine's immunogenicity was analyzed in mice and rhesus monkeys.

An inactivated enterovirus 71 vaccine in healthy children.

Background: Enterovirus 71 (EV71) is a major cause of hand, foot, and mouth disease in children and may be fatal. A vaccine against EV71 is needed.

Methods: We conducted a randomized, double-blind, placebo-controlled phase 3 trial involving healthy children 6 to 71 months of age in Guangxi Zhuang Autonomous Region, China.

Study of the integrated immune response induced by an inactivated EV71 vaccine.

Unlabelled: Enterovirus 71 (EV71), a major causative agent of hand-foot-and-mouth disease (HFMD), causes outbreaks among children in the Asia-Pacific region. A vaccine is urgently needed. Based on successful pre-clinical work, phase I and II clinical trials of an inactivated EV71 vaccine, which included the participants of 288 and 660 respectively, have been conducted.

Comparative analysis of the immunogenicity and protective effects of inactivated EV71 vaccines in mice.

Background: Enterovirus 71 (EV71) is the major causative agent of hand, foot, and mouth disease (HFMD). Three inactivated EV71 whole-virus vaccines of different strains developed by different manufacturers in mainland China have recently entered clinical trials. Although several studies on these vaccines have been published, a study directly comparing the immunogenicity and protective effects among them has not been carried out, which makes evaluating their relative effectiveness difficult.

The effect of enterovirus 71 immunization on neuropathogenesis and protein expression profiles in the thalamus of infected rhesus neonates.

Enterovirus 71 (EV71) is a major pathogen that causes hand-foot-mouth disease (HFMD). Our previous studies have demonstrated that the complete process of pathogenesis, which may include tissue damage induced by host inflammatory responses and direct tissue damage caused by viral infection, can be observed in the central nervous system (CNS) of animals infected in the laboratory with EV71. Based on these observations, the neuropathogenesis and protein expression profiles in the thalamic tissues of EV71-infected animals were further analyzed in the present study.

Analysis of the Th1/Th2 reaction in the immune response induced by EV71 inactivated vaccine in neonatal rhesus monkeys.

Although clinical trials for the enterovirus type 71 (EV71) inactivated vaccine have been progressing, the potential mechanism of EV71 infection and its associated pathogenesis are not well-characterized in terms of comprehensive analysis of the induced immune response, which is generally recognized as an important indicator of the safety of vaccines. To investigate the Th1/Th2 response following viral challenge in neonatal rhesus monkeys immunized with different doses of EV71 inactivated vaccines, the variety of different Th1 and Th2 cytokines in the organs or tissues of the monkeys were identified. The results suggest that depending on the viral challenge, the Th1/Th2 reaction induced by different doses of EV71 inactivated vaccine varies.

A comparative study of the characteristics of two Coxsackie A virus type 16 strains (genotype B).

Coxsackie A virus is one of the major pathogens associated with hand, foot and mouth disease (HFMD). The etiological characteristics of Coxsackie A virus type 16 (CA16) are thought to correlate with the pathological process of its infection. Two CA16 strains that were isolated from a severe HFMD patient presented with different plaque forms.

Establishing China's national standards of antigen content and neutralizing antibody responses for evaluation of enterovirus 71 (EV71) vaccines.

Enterovirus 71 (EV71) is a highly infectious agent that causes hand-foot-mouth disease (HFMD) in humans. Effective vaccination against EV71 infection is critically important, given the recent outbreak of HFMD in the Asia-Pacific region, where it has shown significant mortality and morbidity. There is currently no approved anti-viral therapy available to treat the disease.

Immunoprotection elicited by an enterovirus type 71 experimental inactivated vaccine in mice and rhesus monkeys.

A number of commonly recognized public health issues are associated with EV71 infection, including the induction of severe cases of hand-foot-and-mouth disease (HFMD). Because of such issues, research and development of EV71 vaccine candidates is of growing importance. In the present study, an experimental EV71 inactivated vaccine was prepared, and its corresponding immunogenicity was analyzed.

Pathogenesis study of enterovirus 71 infection in rhesus monkeys.

Enterovirus 71 (EV71), a major pathogen that is responsible for causing hand-foot-and-mouth disease (HFMD) worldwide, is a member of the Human Enterovirus species A, family Picornaviridae. HFMD that is caused by EV71 is usually characterized by vesicular lesions on the skin and oral mucosa and high morbidity rates in children; additionally, occasional fatal cases have been reported involving brainstem encephalitis and myelitis associated with cardiopulmonary collapse. Although viral pathogenesis in humans is unclear, previous animal studies have indicated that EV71, inoculated via various routes, is capable of targeting and injuring the central nervous system (CNS).

Neonatal rhesus monkey is a potential animal model for studying pathogenesis of EV71 infection.

Data from limited autopsies of human patients demonstrate that pathological changes in EV71-infected fatal cases are principally characterized by clear inflammatory lesions in different parts of the CNS; nearly identical changes were found in murine, cynomolgus and rhesus monkey studies which provide evidence of using animal models to investigate the mechanisms of EV71 pathogenesis. Our work uses neonatal rhesus monkeys to investigate a possible model of EV71 pathogenesis and concludes that this model could be applied to provide objective indicators which include clinical manifestations, virus dynamic distribution and pathological changes for observation and evaluation in interpreting the complete process of EV71 infection. This induced systemic infection and other collected indicators in neonatal monkeys could be repeated; the transmission appears to involve infecting new monkeys by contact with feces of infected animals.

Optimized development of a candidate strain of inactivated EV71 vaccine and analysis of its immunogenicity in rhesus monkeys.

Enterovirus type 71 (EV71) is one of the main etiologic agents responsible for periodic epidemics of hand-foot-and-mouth disease (HFMD). The prevention and control of EV71 epidemics with effective anti-viral agents and vaccines is very important for public health. Because the pathogenesis of EV71 in the human body is not completely clear and genetic variations in the virus during its replication are difficult to control, we have focused on the development of an inactivated whole-virus vaccine.

A comparison of the biological characteristics of EV71 C4 subtypes from different epidemic strains.

The comparative analysis of the biological characterization and the genetic background study of EV71 circulating strains is commonly recognized as basic work necessary for development of an effective EV71 vaccine. In this study, we sequenced five EV71 circulating strains, isolated from Fuyang, Hefei, Kunming and Shenzhen city of China and named them FY-23, FY-22, H44, K9 and S1 respectively. The sequence alignment demonstrated their genotypes be C4.

Identification and development of a promising novel mumps vaccine candidate strain.

Mumps epidemics are usually caused by airborne transmission of mumps virus (MuV) and have high morbidity in non-immunized children. Epidemiological studies in many regions of China show that the genotype F viral strain is the most prevalent. However, the genotype A strain is currently used to prepare vaccines.

Egress of HSV-1 capsid requires the interaction of VP26 and a cellular tetraspanin membrane protein.

HSV-1 viral capsid maturation and egress from the nucleus constitutes a self-controlled process of interactions between host cytoplasmic membrane proteins and viral capsid proteins. In this study, a member of the tetraspanin superfamily, CTMP-7, was shown to physically interact with HSV-1 protein VP26, and the VP26-CTMP-7 complex was detected both in vivo and in vitro. The interaction of VP26 with CTMP-7 plays an essential role in normal HSV-1 replication.

Herpes simplex virus type 1 tegument protein VP22 is capable of modulating the transcription of viral TK and gC genes via interaction with viral ICP0.

VP22, a tegument protein of herpes simplex virus type 1 (HSV-1), is present in many copies in one virion and undergoes different types of post-translational modification. VP22 is believed to have certain functions in viral infection apart from virus assembly. Here we show that VP22 physically interacted with infected cell polypeptide 0 (ICP0) and colocalized in the nucleus, indicating that VP22 could be functionally involved in the modulation of viral transcription through interaction with ICP0.

The transactivating effect of HSV-1 ICP0 is enhanced by its interaction with the PCAF component of histone acetyltransferase.

ICP0 is a multifunctional protein that plays diverse roles in herpes simplex virus type 1 (HSV-1) infection. It can promote the lytic replication of HSV-1 and activate a variety of viral or cellular genes when introduced into cells by transfection or infection. However, the exact mechanism of ICP0 action is not fully understood.

Transcriptional regulation of the Herpes Simplex Virus 1alpha-gene by the viral immediate-early protein ICP22 in association with VP16.

Herpes Simplex Virus 1 (HSV1) is capable of inducing two forms of infection in individuals, and the establishment of which type of infection occurs is linked to the transcriptional activation of viral alpha genes. One of the HSV1 alpha genes, ICP22, is known to have multiple functions during virus replication, but its distinct roles are still unclear. This study showed that ICP22 functions as a general repressor for certain viral and cellular promoters, and this transcriptional repression by ICP22 is independent of the specific upstream promoter element, as shown using the CAT enzyme assay system.

Immunogenicity and safety of a novel formalin-inactivated and alum-adjuvanted candidate subunit vaccine for mumps.

While an attenuated vaccine against mumps has played a role in controlling the epidemic of this disease worldwide, some problems with efficacy and safety of the vaccine are still present. In the work described here, a novel mumps vaccine with good immunity and safety was developed by selecting an antigen component of the mumps virus. The results suggest that this purified antigen vaccine is immunogenic in animals and is capable of inducing a specific neutralizing antibody response against viral HN, but not against other viral proteins.

Immediate-early gene product ICP22 inhibits the trans-transcription activating function of P53-mdm-2.

As a product of HSVI immediate-early gene, ICP22 is capable of interacting with various cellular transcriptive and regulatory molecules during viral infection so as to impact the normal cellular molecular mechanism. ICP22 expressed in transfected cells can push the cells' entering into S phase with binding to mdm-1 promoter region and impact its trans-transcription activating effect by P53. Consequently, the MDM-2 binds to P53, and the degradation effects by the ubiquitous pathway are decreased, improving indirectly the P53 levels in cells and making the cells progress into the S phase.

Using interferon-alpha to block expression of cellular ribosome subunit S24 variant 2 in human fibroblasts inhibits translation of the poliovirus genome.

Studies about the proteins induced by interferon (IFN-)-alpha stimulation have provided some data on their mechanism of antiviral effect. These proteins were confirmed to contribute to antiviral functions. In this study, IFN-alpha stimulation of human fibroblasts was shown to induce the inhibition of S24 variant 2 (a structural component of the ribosomal small subunit) at the mRNA and protein levels, implying a possible antiviral mechanism for IFN-alpha in human fibroblasts.