DNA, Viral ; analysis ; Drug Resistance, Viral ; Hepatitis B ; drug therapy ; immunology ; virology ; Humans ; Viral Load

EV71 infection has become a serious public health threat especially among young children. Yet, at present, no specific antiviral drug against EV71 infection is available. A number of scientists are studying various kinds of vaccines, including inactivated vaccine, virus-like particle vaccine, DNA vaccine, synthetic peptide vaccines, and transgenic oral vaccine. This article reviews the recent advancement in the design of various kinds of vaccine against EV71 as well as their prospective usefulness, effectiveness, weakness and developments in the foreground.
Enterovirus A, Human ; immunology ; Hand, Foot and Mouth Disease ; immunology ; prevention & control ; Humans ; Vaccines, Attenuated ; immunology ; Vaccines, DNA ; immunology ; Vaccines, Inactivated ; immunology ; Vaccines, Synthetic ; immunology ; Viral Vaccines ; immunology

Animals ; DNA, Complementary ; genetics ; Genome, Viral ; Humans ; Influenza Vaccines ; genetics ; immunology ; Orthomyxoviridae ; genetics ; immunology ; RNA, Viral ; genetics

Six recombinant plasmids co-expressing the wild-type GP5 gene or the codon-optimized GP5 gene (containing pan-DR epitope) of porcine reproductive and respiratory syndrome virus (PRRSV) and the E2 gene of classical swine fever virus (CSFV) or the E2 fused with the UL49 of pseudorabies virus (PrV) were constructed based on the suicidal DNA vaccine pSFV1CS-E2 described previously. Expression of GP5 and E2 was confirmed by indirect immunofluorescence assay. The immunogenicity of six plasmids was evaluated in BALB/c mouse model. For the six plasmids, low-level of E2 and GP5 protein specific antibodies could be detected in the sera of the immunized mice. Specific lymphoproliferative responses to the PRRSV or CSFV stimulation were induced in the splenocytes of the immunized mice as demonstrated by CFSE staining assay and WST-8 assay. Antigen specific IFN-gamma and L-4 secretion was detected in the splenocytes of some immunized mice by cytokine ELSIA. Fusion with the PrV UL49 in the suicidal vaccines induced significantly higher lymphoproliferative responses and cytokine secretion. Taken together, the suicidal DNA vaccines co-expressing GP5 and E2 could induce PRRSV and CSFV specific humoral and cell-mediated immune responses.
Animals ; Antibodies, Viral ; blood ; Antibody Formation ; Cytokines ; blood ; Female ; Immunity, Cellular ; Lymphocytes ; immunology ; Mice ; Mice, Inbred BALB C ; Random Allocation ; Vaccines, DNA ; biosynthesis ; immunology ; Viral Envelope Proteins ; genetics ; immunology ; Viral Structural Proteins ; genetics ; immunology ; Viral Vaccines ; biosynthesis ; immunology

Hepatitis C virus (HCV) core protein is considered to be an attractive candidate for development of protective HCV vaccines. However, this protein may attenuate the induction of systemic immune responses due to its immunomodulatory properties. In this study, we constructed a HCV core gene-containing eukaryotic expression plamid pCI-C, and an in vivo-inducible prokaryotic expression plasmid pZW-C, and transformed the recombinant plasmids into an attenuated Salmonella typhimurium aroA strain SL7207. The resulting bacterial strains SL7207/pCI-C and SL7207/pZW-C were used to orally immunize BALB/c mice, and the immune responses specific to HCV core protein were assessed. Immunization with the recombinant bacteria SL7207/pCI-C led to a persistent drop in percentage of CD3 CD4 T cells, and induced a weak anti-core IgG production. Splenocytes from SL7207/pCI-C immunized mice developed a relatively weak proliferation response and inferior cytotoxic activity compared to those from the mice immunized with bacteria SL7207/pZW-C. Boost immunization with SL7207/ pCI-C yielded limited improvement in immune strength, while the boost with bacteria SL7207/pZW-C significantly enhanced the immune response. These results suggest that de novo synthesis of native HCV core protein may blunt the induction of immune responses. Attenuated S. typhimurium carrying HCV core protein could efficiently activate systemic cellular and humoral responses, and may be a promising strategy for the development of core-based HCV vaccines.
Animals ; Hepacivirus ; genetics ; immunology ; Mice ; Plasmids ; genetics ; Salmonella typhimurium ; genetics ; metabolism ; Vaccines, DNA ; immunology ; Viral Core Proteins ; genetics ; immunology ; Viral Hepatitis Vaccines ; genetics ; immunology

BACKGROUNDTo observe the LMP2 specific cellular and humoral immune responses after immunization with recombinant adenovirus Ad-LMP2 in rhesus.

METHODSThe rhesuses were immunized with Ad-LMP2 through intra muscular injection in three groups, high dosage (4.5 x 10(11) VP/kg), medium dosage (1.5 x 10(11) VP/kg) and low dosage (0.5 x 10(11) VP/kg) groups. They were totally immunized six times at intervals of 5 days. The specific cellular immune responses were tested during the 7th week by ELISPOT after immunization. And the titers of anti-LMP2 antibody were tested by EIA throughout the period of immunization.

RESULTSLMP2 induced specific cellular and humoral immune responses in all three dosage group. The potency of immune responses was related with the dosage of immunization. Higher dosage elicited more potent immune response. Both the neutralizing antibody to adenovirus and anti-LMP2 antibody could be detected from 2 weeks after immunization. They would reach the peak during 3-4 weeks after immunization, then declined during the 7th week after immunization.

CONCLUSIONThe recombinant adenovirus LMP2 could induce specific cellular and humoral responses in rhesus after immunization.

Adenoviridae ; genetics ; Animals ; Antibodies, Viral ; blood ; Antibody Formation ; immunology ; Female ; Immunization ; methods ; Macaca mulatta ; Male ; Recombinant Fusion Proteins ; genetics ; immunology ; T-Lymphocytes, Cytotoxic ; immunology ; Vaccines, DNA ; genetics ; immunology ; Viral Matrix Proteins ; genetics ; immunology ; Viral Vaccines ; genetics ; immunology

Humans ; Membrane Glycoproteins ; immunology ; SARS Virus ; immunology ; Severe Acute Respiratory Syndrome ; prevention & control ; Spike Glycoprotein, Coronavirus ; Vaccines, DNA ; immunology ; Vaccines, Inactivated ; immunology ; Vaccines, Synthetic ; immunology ; Viral Envelope Proteins ; immunology ; Viral Vaccines ; immunology ; Virion ; immunology

To enhance the immuogenicity of DNA vaccines expressing the GP5 protein of Porcine Reproductive and Respiratory Syndrome Virus (PRRSV), the tegument protein VP22 (encoded by VP22 gene) of Bovine Herpesvirus 1 (BHV-1), which has been demonstrated to exhibit the unusual protein transduction property, was fused to N-terminus of GP5 of DNA vaccine construct pCI-ORF5M, resulting in pCI-VP22-ORF5M expressing VP22-GP5 fusion protein. The expression of VP22-GP5 fusion protein was confirmed by both indirect immunofluorescence assay (IFA) and Western blot. To investigate its immunogenicity, BALB/c mice were immunized with the fusion expression plasmid pCI-VP22-ORF5M and non-fusion expression plasmid pCI-ORF5M, respectively. The GP5-specific ELISA antibodies, neutralizing antibodies and lymphocyte proliferative responses were evaluated at various time points after primary immunization. The results showed that GP5-specific ELISA antibodies, neutralizing antibodies, and lymphocyte proliferative responses induced by DNA vaccine pCI-VP22-ORF5M were higher significantly than those of DNA vaccine pCI-ORF5M, indicating that fusion expression with BHV-1 VP22 significantly enhances the immuogenicity of DNA vaccine expressing the PRRSV GP5 protein, and that this strategy may also be useful to develop more efficient DNA vaccines against other pathogens.
Animals ; Antigens, Viral ; genetics ; immunology ; Artificial Gene Fusion ; Female ; Mice ; Mice, Inbred BALB C ; Porcine Reproductive and Respiratory Syndrome ; prevention & control ; Random Allocation ; Vaccines, DNA ; genetics ; immunology ; Viral Envelope Proteins ; genetics ; immunology ; Viral Structural Proteins ; genetics ; Viral Vaccines ; genetics ; immunology

OBJECTIVETo investigate hepatitis E virus (HEV) infection among pigs in Henan province.

METHODSA total of 623 swine sera, collected from 5 districts, were divided into two groups, under 3-month of age and over 3-month of age. They were tested for HEV antigen and antibody by using ELISAs, respectively. The sera positive for HEV antigen were tested for HEV RNA with RT-PCR. The positive products of RT-PCR were cloned and sequenced.

RESULTSThe positive rates of anti-HEV antibody of the groups under 3-month and over 3-month of age were 90.27% and 92.55%, respectively, without statistical difference, while those of HEV antigen were 15.93% and 5.69%, respectively, with significant difference. The positive rates of anti-HEV antibody and HEV antigen were significantly different among different districts. HEV RNA was detectable in 5 of 47 HEV antigen positive samples. The sequence analysis showed that in 4 of 5 specimens the sequence belonged to genotype 4 while in the remaining one the sequence was genotype 1.

CONCLUSIONThe prevalence rate of HEV infection in pigs was high in Henan province and the rate differed in different districts.

Animals ; Antibodies, Viral ; analysis ; immunology ; Antigens, Viral ; analysis ; immunology ; China ; Genotype ; Hepatitis E ; epidemiology ; immunology ; veterinary ; virology ; Hepatitis E virus ; genetics ; immunology ; isolation & purification ; Phylogeny ; RNA, Viral ; analysis ; genetics ; Sequence Analysis, DNA ; Swine ; virology ; Swine Diseases ; epidemiology ; immunology ; virology

In 1990, it was reported that the naked DNA encoding an antigen (so-called DNA vaccine) transduced directly into the muscle is able to induce immune responses just like antigen inoculation. Since then, a number of DNA vaccines against different diseases have been developed and shown to induce different levels of specific humoral and/or cell-mediated immunity. Efforts have been made to develop effective DNA vaccines against classical swine fever (CSF). This review covered the following aspects in the development and application of CSF DNA vaccines: construction and evaluation, application of adjuvants, combination with other vaccines and the existing problems and solutions.
Adjuvants, Immunologic ; pharmacology ; Animals ; Classical Swine Fever ; prevention & control ; Swine ; Vaccines, DNA ; biosynthesis ; immunology ; Viral Envelope Proteins ; genetics ; immunology ; Viral Vaccines ; biosynthesis ; immunology