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Eucalyptus is a large genus of the Myrtaceae family with high value in various fields of industry. Recently, attention has been focused on the functional properties of Eucalyptus extracts. These extracts have been traditionally used to combat various infectious diseases, and volatile oils are usually considered to play a major role. But the positive effects of non-volatile acylphloroglucinols, a class of specialized metabolites with relatively high content in Eucalyptus, should not be neglected. Herein, non-volatile acylphloroglucinols from leaves of Eucalyptus robusta were evaluated for their abilities to inhibit Zika virus (ZIKV) which is associated with severe neurological damage and complications. The results showed eucalyprobusone G, a new symmetrical acylphloroglucinol dimer, possessed the significant ability to inhibit ZIKV without inducing cytotoxicity. The EC50 values of eucalyprobusone G against the African lineage (MR766) and Asian lineage (SZ-WIV01) of ZIKV were 0.43 ± 0.08 and 10.10 ± 3.84 μM which were 110 times and 5.8 times better than those of the reference compound ribavirin, respectively. Further action mode research showed that eucalyprobusone G impairs the viral binding and RdRp activity of NS5. The results broaden the functional properties of Eucalyptus robusta and indicate acylphloroglucinol dimers could be developed as anti-ZIKV agents.

HIV-1 depends on host-cell-encoded factors to complete its life cycle. A comprehensive understanding of how HIV-1 manipulates host machineries during viral infection can facilitate the identification of host targets for antiviral drugs or gene therapy. The cellular protein Naf1 (HIV-1 Nef-associated factor 1) is a CRM1-dependent nucleo-cytoplasmic shuttling protein, and has been identified to regulate multiple receptor-mediated signal pathways in inflammation. The cytoplasm-located Naf1 can inhibit NF-κB activation through binding to A20, and the loss of Naf1 controlled NF-κB activation is associated with multiple autoimmune diseases. However, the effect of Naf1 on HIV-1 mRNA expression has not been characterized. In this study we found that the nucleus-located Naf1 could promote nuclear export of unspliced HIV-1 gag mRNA. We demonstrated that the association between Naf1 and CRM1 was required for this function as the inhibition or knockdown of CRM1 expression significantly impaired Naf1-promoted HIV-1 production. The mutation of Naf1 nuclear export signals (NESs) that account for CRM1 recruitment for nuclear export decreased Naf1 function. Additionally, the mutation of the nuclear localization signal (NLS) of Naf1 diminished its ability to promote HIV-1 production, demonstrating that the shuttling property of Naf1 is required for this function. Our results reveal a novel role of Naf1 in enhancing HIV-1 production, and provide a potential therapeutic target for controlling HIV-1 infection.

P-selectin glycoprotein ligand-1 (PSGL-1) has been proved to serve as the functional receptor for enterovirus 71 (EV71). We found the abundant expression of PSGL-1 on monocyte-derived dendritic cells (MDDCs). However, we have previously demonstrated that MDDCs did not support efficient replication of EV71. Dendritic cells (DCs) have been described to be subverted by various viruses including EV71 for viral dissemination, we thus explore the potential contribution of PSGL-1 on DC-mediated EV71 transmission. We found that the cell-surface-expressing PSGL-1 on MDDCs mediated EV71 binding, and intriguingly, these loaded-viruses on MDDCs could be transferred to encountered target cells; Prior-treatment with PSGL-1 antibodies or interference with PSGL-1 expression diminished MDDC-mediated EV71 transfer and rescued virus-induced cell death. Our data uncover a novel role of PSGL-1 in DC-mediated EV71 spread, and provide an insight into blocking primary EV71 infection.

To obtain full-length FKN nucleotide sequences of homonids including human, chimpanzee, gorilla, orangutan and gibbon, and Old World Monkeys including macaque and leaf monkey and make phylogenetic analysis, three exons of FKN were amplified by degenerated PCR using obtained peripheral blood cells DNA as template which was extracted from homonids and Old World Monkeys. After extracting and purifying from agarose gels, PCR products were sequenced and then spliced by using BioEdit. All the FKN sequences were aligned and compared the percent identity by using DNAStar. The phylogenetic tree was constructed using maximum evolution approach in Mega. The negative selection sites were analyzed by using Datamonkey. There is an apparent 30 bp nucleotides deletion mutation in homonids FKN comparing to that of Old World Monkeys besides other point mutations. Homology of nucleotide sequence between human and chimpanzee, gorilla, orangutan, gibbon, macaque and leaf monkey is 99.2%, 98.4%, 98.1%, 96.5%, 95.9% and 93.8%, respectively. Homology of amino acid sequence of them is 98.5%, 98.0%, 97.7%, 94.7%, 93.7% and 90.5%, respectively. In the same time, the genealogical relationship of human is a lot closer to chimpanzee than it is to gorilla and other apes. It is generally agreed that the evolution rule of FKN gene is in accord with that of the higher primates. In addition, Datamonkey shows that there are 3 negative selection sites 53Q, 84D and 239N in FKN. The full-length FKN gene of human, chimpanzee, gorilla, orangutan, gibbon, macaque and leaf monkey were sequenced successfully, and the FKN sequences analysis lays the foundation for further studying its evolution in immunological function in higher primates and the relation between its structure and function.

Objectives: To investigate cyclin E, pl6ink4a, and Ki67 as possible diagnostic biomarkers for cervical preneoplasia, and to evaluate its significance for screening human papillomavirus (HPV)-infected patients who are at high risk of developing cervical carcinoma. Methods: The expressions of cyclin E, pl6ink4a, and Ki67 were examined in 266 cervical exfoliated epithelial specimens using immunohistochemical analysis; simultaneously, HPV type 16/18 DNA status were detected by PCR. Results: Overexpression of cyclin E was observed in low-grade squamous intraepithelial lesion (LSIL) (92.4% P < 0.005), and pl6ink4a and Ki67 were overexpressed in high-grade squamous intraepithelial lesion (HSIL) (92.0% and 89.8%, respectively). Conclusions: Cyclin E, pl6ink4a, and Ki67 may be used as diagnostic biomarkers for HPV-related cervical neoplastic lesions. In addition, this technique can be used for screening patients at high risk of developing cervical carcinoma.

Four hundred forty-six serum samples from HBsAg-positive chronic hepatitis B patients were collected from five areas in China (eastern coastal city, Shanghai; southwestern inland city, Chengdu; mid-inland city, Wuhan; southern island city, Haikou; and northeastern city, Changchun). Precore stop codon variants (e-minus mutants) were screened using a rapid method of polymerase chain reaction (PCR) amplification of a precore and partial core gene fragment (nucleotides 1785–2172), followed by dot-blot hybridization with specific oligonucleotide probes (M0, and M1 + M2). The sequence of the M0 probe covered the distal precore region of wild-type virus (nucleotides 1887–1908), and the sequences of the M1 and M2 probes were from sequences mutated at nt. 1898, (TGGTAG) with or without additional change at nt. 1901. A significantly lower incidence of the precore stop codon was found in anti-HBe-positive serum samples from Haikou (17.6%), whereas in other areas the percentages of this mutation in anti-HBe positive sera ranged from 47.4% to 78.9%. In HBeAg-positive samples, the rate of e-minus mutant in coexistence with wild-type virus was low in specimens from Haikou (9.5%) and Changchun (2.9%) compared to other areas in China. In contrast, coexistence of mutant and wild-type virus was frequently detected in samples from Wuhan (50.0%). J Med Virol 51:85–89, 1997. © 1997 Wiley-Liss, Inc.

One-day-old ducklings experimentally infected with duck hepatitis B virus (DHBV) were found to be immunologically tolerant to virus antigens (DHBsAg, DHBcAg), with no humoral or cellular immune responses being detected. When immunized with virus antigens in Freund's complete adjuvant, no immune responses could be induced. Rabbit anti-DHBs sera were complexed to a solid matrix (Staphylococcus aureus Cowan A strain) and purified DHBsAg was bound to this complex to form a solid matrix antibody-antigen (SMAA) complex. This SMAA was used as an immunogen to immunize the tolerant ducks. After three injections, in 12 of 17 ducks serum DHBV DNA became absent and serum DHBsAg was cleared. In eight of 16 ducks, low titres of anti-DHBs could be detected. The SMAA approach shows potential for application in immunoregulatory treatment for chronically infected hepatitis B patients.

Viral myocarditis is a common cardiovascular disease, which has greatly threatened human health. However, up to now, the pathogenesis of viral myocarditis has been unclear, which leads to the lack of its effective treatments. To investigate the role of chemokines in pathogenesis of viral myocarditis, mRNA expression for a panel of 19 chemokines detected by RT-PCR in myocardial tissue of BALB/c mice that were inoculated intraperitoneally with coxsackievirus B3. Moreover primary cultured cardiac myocytes were infected with coxsackievirus B3 following extraction of RNA, from myocytes the expression of 19 chemokines was detected by by RT-PCR. Our results showed that there was much difference in the expression pattern of chemokines in myocardial tissue between infected mice with viral myocarditis and uninfected control mice. The expression of chemokines was varied significantly in clusters in myocardium post coxsackievirus B3 infection. There were also complexity and imbalance in the change of the expression of chemokines. In the meantime, Coxsackievirus B3 infection also influenced the expression pattern of chemokines in cardiac myocytes in vitro. However the expression of monocyte chemoattractant protein-1 alone was upregulated in cardiac myocytes post coxsackievirus B3 infection in the 19 detected chemokines. The chemokine expression pattern changed in complexity and imbalance manner both in myocardium and in primary cultured cardiac myocytes after coxsackievirus B3 infection. Coxsackievirus B3 infection may start viral myocarditis by regulating the expression pattern of chemokines in cardiac myocytes. MCP-1 may be one of key chemokines in the initial stage of viral myocarditis.

To obtain full-length FKN nucleotide sequences of homonids including human, chimpanzee, gorilla, orangutan and gibbon, and Old World Monkeys including macaque and leaf monkey and make phylogenetic analysis, three exons of FKN were amplified by degenerated PCR using obtained peripheral blood cells DNA as template which was extracted from homonids and Old World Monkeys. After extracting and purifying from agarose gels, PCR products were sequenced and then spliced by using BioEdit. All the FKN sequences were aligned and compared the percent identity by using DNAStar. The phylogenetic tree was constructed using maximum evolution approach in Mega. The negative selection sites were analyzed by using Datamonkey. There is an apparent 30 bp nucleotides deletion mutation in homonids FKN comparing to that of Old World Monkeys besides other point mutations. Homology of nucleotide sequence between human and chimpanzee, gorilla, orangutan, gibbon, macaque and leaf monkey is 99.2%, 98.4%, 98.1%, 96.5%, 95.9% and 93.8%, respectively. Homology of amino acid sequence of them is 98.5%, 98.0%, 97.7%, 94.7%, 93.7% and 90.5%, respectively. In the same time, the genealogical relationship of human is a lot closer to chimpanzee than it is to gorilla and other apes. It is generally agreed that the evolution rule of FKN gene is in accord with that of the higher primates. In addition, Datamonkey shows that there are 3 negative selection sites 53Q, 84D and 239N in FKN. The full-length FKN gene of human, chimpanzee, gorilla, orangutan, gibbon, macaque and leaf monkey were sequenced successfully, and the FKN sequences analysis lays the foundation for further studying its evolution in immunological function in higher primates and the relation between its structure and function.

Several examples have shown that C3d3, when fused to a corresponding antigen, had a strong adjuvant effect on certain specific antibody production. In a previous study, we attempted to prove that this was the case of the human chorionic gonadotrophin beta chain (hCGbeta)-induced immunity following DNA vaccination. However, we found that C3d3 when fused to hCGbeta inhibited rather than enhanced the antigen-specific immune response. In the present study, using hCGbeta DNA vaccine preparations, we demonstrated that C3d3 inhibited the antigen-specific humoral antibody response and several other immune responses, such as the hCGbeta specific lymphoproliferation. Such inhibitory effects of C3d3 were not related to the expression level of the target protein, the gender of the test mice, or the vector used. Contrastingly, C3d3 fused with the envelope protein of hepatitis B virus (PreS2/S) used as a control system resulted in the enhancement of both humoral and cell-mediated antigen-specific immune responses against HBV-preS2/S, which was consistent with other groups' adjuvant-effect findings. We further showed that the mechanisms involved in the inhibitory effect of C3d3 might be possible due to impairing the function of antigen presenting B lymphocytes and reducing the expression of transcription factors (T-bet and GATA-3) and cytokine IL-4. Collectively, unlike its usual expected adjuvant function, the fusion of C3d3 with the tumor-associated antigen hCGbeta was found to inhibit both humoral and cell-mediated antigen-specific immune responses. These findings indicate that research concerning tumor immune escapes and vaccine designs require further extensive attention.

To explore the inhibitory effects of IP10 on the experimental tumor metastases of a mammary carcinoma cell line 4T1 in vivo.4T1 cells were transfected with pcDNA3-IP10 plasmid and the positive clones (IP10-4T1) were screened in the presence of G418. The parental 4T1 cells and 4T1 cells transfected with pcDNA3 (pcDNA3-4T1) were used as controls. The expression of IP10 mRNA was examined with RT-PCR. The chemotactic activity of the cell-cultured supernatant for the activated lymphocytes was assessed with chemotaxis assay. All BALB/c mice were divided into 3 equal groups: IP10-4T1, parental 4T1 and pcDNA3-4T1 (6 mice in each group). Seven days after mice were inoculated with 2 x 10(6) 4T1, pcDNA3-4T1 or IP10-4T1 cells, 1 x 10(5) 4T1 cells were injected into mice in tail vein. On day 14 tumors were sectioned. On day 28 mice were sacrificed and the lung weight, metastatic forci on the lung surface, disseminated metastases in the lungs and the number of clonogenic metastases of 4T1 cells were observed. The splenocytes were isolated from tumor-bearing mice, and the cytotoxicity of the splenocytes was evaluated by CFSE/7-AAD method.The transcription of IP10 mRNA increased in IP10-4T1 cells compared to parental 4T1 and pcDNA3-4T1 cells (P = 0.002). Moreover, accumulated lymphocytes migrated to the supernatants of IP10-4T1 cells, which can be abrogated by anti-CXCR3 (P0.05). Compared to controls, inoculation of IP10-4T1 cells resulted in the decreased disseminated metastases as indicated by dramatically reduced lung metastatic forci on the surface of the lungs; the lung weight was lighter (IP10-4T1, 0.27 +/- 0.02 g v.s. 4T1, 0.48 +/- 0.08 g and pcDNA3-4T1, 0.43 +/- 0.16 g, P = 0.021); the number of clonogenic metastatic 4T1 cells enumerated in ten fields decreased greatly (IP10-4T1, 2.6 +/- 1.7 v.s. 4T1, 34 +/- 6.3 and pcDNA3-4T1, 33 +/- 2.3, P0.05); histological assay showed that metastasis was not found in the lungs of the 4/6 of mice in IP10-4T1 group, and was seen in all the mice of parental 4T1 and pcDNA3-4T1 groups. The splenocytes from the mice inoculated with IP10-4T1 cells exhibited stronger cytotoxic activity against 4T1 target cells at different ratios of effector versus target cells (3:1, 9:1, 27:1) than controls (P0.05).IP10 expressed locally could inhibit disseminated metastasis of circulating 4T1 tumor cells by enhancing anti-tumor cellular immune responses.

To investigate the role of CXCR4 in the metastasis of human lung cancer and its possible mechanism.Lung cancer cells of the lines 95C and 95D with high or low metastatic potential were transfeted with CXCR4 antisense plasmid pcDNA-ASX4, whole length eukaryotic expression plasmid pcDNA-CXCR4 (95D-ASX4 and 95C-X4 cell lines), and corresponding plasmid pcDNA3 (95C-pC and 95D-pC cell lines). 95C, 95C-pC, 95C-X4, 95D, and 95D-pC cells were injected subcutaneously into Balb/c nu/nu mice, 4 approximately 5 mice in a group. The mice were observed twice a week. Ten weeks later the mice were killed and the tumor in situ and the lungs were taken out to undergo histological examination. The effect of CXCR4 expression on the cell migration, MMP-2 activity, adhesion and GRO-a expression of lung cancer cells were detected by chemotaxis and chemoinvasion assay, zymography, adhesion assay and RT-PCR respectively. The polymerization of F-actin was measured by FACS and confocal microcopy. Western blotting was used to detect the phospharylation of ERK1/2 in 85D cellsMetastasis was not found in the mice injected with 95C and 95C-pC cells, and was seen in 2/5 of the mice injected with 95C-X4 cells, 3/4 of the mice injected with 95D and 95D-pC cells, 2/5 of the mice injected with 95D-ASX4 cells, however, the number of metastatic nodes in the lungs of 95D-ASX4 group was significantly less than those in the 95D and 95D-pC groups (P = 0.044). SDF-1a, a CXCR4 specific ligand, induced the migratory response and F-actin polymerization in the lung cancer cells; SDF-1a promoted the MMP-2 activity, the adhesion to vascular endothelial cells and GRO-a expression; and neutralizing CXCR4 antibody inhibited these effects to some degree. Moreover, SDF-1a induced the phosphorylation of ERK1/2 in human lung cancer cells.Metastasis of human lung cancer depends on, to some degree, the interaction of CXCR4 and SDF-1 that are involved in this process by regulating the active locomotion, MMP-2 activity, adhesion ability or GRO-a expression.

To confirm the relations between the expression of cyclin E, p16ink4, ki67 and HPV16/18 infection using cervical exfoliated cells, and evaluate the usefulness of cyclin E, p16ink4 and ki67 as biomarkers for screening of cervical carcinomas.The expression of cyclin E, p16ink4 oncoproteins and ki67 proliferative activity was evaluated immunohistochemically in 78 cervical exfoliated epithelial specimens. Human papillomavirus type16 and 18 (HPV16/18) infection was assessed by polymerase chain reaction (PCR) using type specific primers.Cyclin E, p16ink4 and ki67 were all overexpressed in cervical preneoplasia and neoplasia cells, compared with little expressed in ASCUS (P less than 0.005). Overexpression of cyclin E was observed in CIN, (P less than 0.01), p16ink4 and ki67 overexpressed in invasive carcinoma(100 percent and 90.9 percent respectively). The degree of p16ink4 and ki67 expression correlated well with the degree of cervical neoplasia (P less than 0.005). HPV16 infection was assessed at all stages of cervical neoplasia samples, and a significant relationship with the degree of cervical epithelial lession was observed at the same time. The expression level of p16ink4 and ki67 seemed to be more closely associated with HPV16 infection than cyclin E did (rs=1.0 vs rs=0.4). HPV18 was found positive in only 1 case in CIN1 and in 4 cases in CIN2-3. Therefore no significance was found on statistical analysis (P less than 0.005).Cyclin E, p16ink4 and ki67 should be regarded as useful biomarkers of HPV-related cervical neoplasias, and be used for screening patients at high risk for developing cervical carcinomas. Moreover, cyclin E might be a significant cytologic marker for the primary screening of cervical carcinomas.

To enhance the efficiency of the expression of target gene in eukaryotic cells, one of the strongest prokaryotic expression systems, the T7 RNA polymerase and T7 promoter, was introduced into eukaryotic cells. A duel-plasmid gene expression system of T7 bacteriophage components was developed; one containing the T7 phage RNA polymerase gene under the control of eukaryotic promoter CMV (pCMV-T7pol) and the other (pT7IRES) containing the T7 promoter and T7 terminator as well as EMCV IRES. To test the feasibility of this plasmid system for eukaryotic expression, hepatitis B virus envelop HBV preS2/S was used to construct pT7IRES-HBs. The target genes were expressed efficiently by the eukaryonized prokaryotic expression system in a variety of the cells indicating C2C12, SP2/0, NIH3T3 and BALB/c 3T3, suggesting the potential applications of the expression system in gene therapy and gene immunization.

To investigate effects of anti-dsDNA autoantibodies on growth of tumor in vitro and in vivo.BALB/c mice were inoculated with inactivated tumor cells and challenged s.c. with SP 2/0 and Wehi 164 tumor cells four weeks after the last inoculation. The naïve mice were inoculated with SP 2/0 tumor cells immediately after incubating with sera derived from the immunized mice at week 6. Then the tumor size was examined. In vitro, the cytotoxicity of anti-dsDNA autoantibodies to tumor cells was analysed. Furthermore, apoptosis of SP 2/0 and Wehi 164 tumor cells induced by anti-dsDNA autoantibodies was examined by FACS.In vivo study showed that the growth of SP 2/0 and Wehi 164 tumors were inhibited in mice with anti-dsDNA autoantibodies, but not in mice lack of anti-dsDNA autoantibodies. In vitro, apoptosis of SP 2/0 and Wehi 164 tumor cells was induced when the tumor cells were incubated with the sera containing anti-dsDNA autoantibodies. Statistical analysis showed that the ability of anti-dsDNA autoantibodies to induce apoptosis of SP 2/0 and Wehi 164 tumor cells was significantly correlated with affinity (r = 0.990, P0.01 and r = 0.901, P0.05).Anti-dsDNA autoantibodies have inhibitory effect on tumor cells via inducing apoptosis.

To investigate the pathophysiological role of CXCL16 in immunological liver injury induced by Bacille de Calmette et Guerin (BCG) and lipopolysaccharides (LPS).Immunological liver injury was induced by BCG and LPS in mice, and the expression of CXCL16 was detected in the liver tissues by real-time quantitative PCR and immunohistochemical examination. The relationship of the expression of CXCL16 and the extent of hepatic necrosis was investigated histopathologically and immunohistochemically. Mononuclear cells were isolated from the liver tissues and their numbers were counted; T lymphocytes populations in the liver tissue were also analyzed with FACS.The immunological liver injury model was successfully created. Up-regulation of CXCL16 in injured livers correlated with the extent of liver injury and the amountmononuclear cell infiltrations.These findings suggest that up-regulation of CXCL16 was closely correlated with liver injury extent during the immunological liver injury induced by BCG-LPS in mice, and intrahepatic recruitment of specific lymphocytes might be an important mechanism of liver injury.

To construct a plasmid which efficiently express short peptides in DNA immunization.The plasmid containing peptide-expressing cassette (PEC) was constructed and its effect in DNA immunization was investigated, using a DHBV B cell epitope as the short peptide. The peptide in vitro was detected by DOT-EIA. The BALB/c mice were immunized with the empty plasmid or the recombinant plasmid, and the specific antibodies against the epitope in the sera of the mice were determined by ELISA.The plasmid containing peptide-expressing cassette (PEC) was successfully constructed. Recombinant epitope-based plasmid could efficiently express the short peptide in vitro and induce immune response against it in DNA immunization.The constructed vector provides highly efficient short peptide expression in DNA immunization.

To investigate whether P28 derived from C3d can enhance the immune response to HBV-preS2/S induced by directly injection of naked plasmids containing variable repeats of P28 and HBV-preS2/S in fusion form.One to four copies of C3d-P28 coding gene, amplified by PCR and modified by restriction endonucleases digestion, were subcloned into a eukaryotic expression vector pVAON33 to construct pVAON33-P28, pVAON33-P28.2, pVAON33-P28.3 and pVAON33-P28.4 (pVAON33-P28.[1-4]). HBV-preS2/S coding sequence was then introduced into the pVAON33-P28.[1-4] and identified by both PCR and DNA sequencing. BALB/c mice were primed by intramuscular gene immunization with 100 microg different recombinant plasmids on day 0 and were boosted by subcutaneous inoculation with HBsAg protein (1 microg) 12 wk post-priming. The levels and avidity of specific IgG in sera collected at the indicated times from each group were determined by ELISA and NaSCN-displacement ELISA, respectively.HBsAg specific antibody response was elicited in groups primed with plasmids pVAON33-S2/S-P28.[1-4] and pVAON33-S2/S. However, the response against HBsAg in the groups primed with pVAON33-S2/S-P28.[1-4] was significantly higher than that in pVAON33-S2/S group, the highest level of the specific antibody response was observed in the groups primed with pVAON33-S2/S-P28.4 (P0.01). After secondary immunization with specific antigen, the acceleration of antibody levels was significantly higher and faster in the mice primed with DNA expressing preS2/S-P28 fusions than that with DNA expressing preS2/S only (P0.05). Interestingly, mice primed with DNA expressing preS2/S-P28.4 fusions maintained the highest levels of anti-HBs antibodies in all animals. The avidity assay showed that the avidity index (AI) collected at 18 wk from mice primed with pVAON33-S2/S-P28.3 and pVAON33-S2/S-P28.4 were significantly higher than that from preS2/S-DNA vaccinated mice (P0.01).Different repeats of C3d-P28 can enhance both humoral immune response and avidity maturation of specific antibodies induced by gene immunization, in which four copies of C3d-P28 may be necessary to achieve the most modest antibody response.

To investigate whether P28 derived from complement C3d can enhance the cell-mediated immunoresponse to HBV-preS2/S induced by direct injection of naked plasmid DNA containing four tandem repeats of C3d-P28 gene and HBV-preS2/S gene existed in fusion form.Four copies of gene coding for C3d-P28, amplified by PCR and cut by restriction endonucleases digestion, were subcloned into a eukaryotic expression vector pVAON33 to construct pVAON33-P28.4. HBV-preS2/S gene was then introduced into the pVAON33 and pVAON33-P28.4 respectively to form pVAON33-S2/S and pVAON33-S2/S-P28.4. The recombinant plasmids were identified by PCR and restriction endonucleases digestion as well as DNA sequencing. BALB/c mice were immunized i.m. three times at 3 weeks' intervals with 100 microg of pVAON33-S2/S DNA, pVAON33-S2/S-P28.4 and mock DNA, respectively. Splenocytes from immunized mice were stimulated by HBsAg and then harvested to analyze the specific lymphocytic proliferative response and CTL cytotoxic activity by (3)H-TdR incorporation assay and isotopic release analysis, respectively.Specific lymphocytic proliferation and CTL cytotoxic activity against HBV-preS2/S were observed in mice immunized by both pVAON33-S2/S and pVAON33-S2/S-P28.4 in dose-dependent form. Specific lymphocytic proliferation and CTL response in mice immunized by pVAON33-S2/S-P28.4 were markedly stronger than those in mice immunized by pVAON33-S2/S.A C3d-P28 can enhance the cell-mediated immunoresponse induced by HBV-preS2/S gene immunization.

To induce Coxsackie virus B type 3 (CVB3)-specific immune response by using a DNA vaccine containing CVB3-VP1 and to observe its protection against CVB3 challenge.The gene coding for VP1 was obtained by RT-PCR and then was cloned into plasmid pcDNA3 to construct pcDNA3-VP1. In-vitro expression of VP1 was performed by transfection of pcDNA3-VP1 into Hela cells. Expressed product was detected by ELISA. BALB/c mice were immunized intramuscularly with 50 microg DNA three times, and challenged by 5xLD(50) CVB3 four weeks after the last immunization.pcDNA3-VP1 had been constructed and the expression product was detected in the culture supernatant of Hela cells 24 hours after transfection. CVB3-specific IgM and IgG elicited in the mice immunized with pcDNA3-VP1 were significantly higher than those in the control mice immunized with pcDNA3. Specific proliferation of the splenic lymphocytes and activity of CVB3-specific CTLs from the pcDNA3-VP1 immunized mice were much stronger than those in the controls. pcDNA3-VP1 could protect 33.3% mice from lethal CVB3 challenge, while control mice only survived 6.7 days. Infiltration of inflammatory cells or unusual proliferation of connective tissue, indicating ongoing myocarditis or fibrosis, were not found in pcDNA3-VP1 immunized mice, but did exist in control mice.Intramuscular immunization with pcDNA3-VP1 may be a promising approach against CVB3 infection.

To enhance the effect of chitosan-pcDNA3-VP1 DNA vaccine to prevent onset of coxsackievirus B3 (CVB3)-induced myocarditis.HA-pLys16 "carrier peptide" containing "endosome fusogenic peptide" and poly-Lysine was synthesized and complexed with DNA and chitosan sequentially, resulting chitosan-pcDNA3-VP1-HApLys16 vaccine. It was administrated to BALB/c mice with a total dose of 200 micro g pcDNA3-VP1. Mice were infected with 3 (LD(50) CVB3 3 weeks later to induce myocarditis. Loss of body weight, body/heart weight ratio, outlook and HE staining of heart tissues was observed and compared as an indicative of severity of myocarditis.chitosan-pcDNA3-VP1-HApLys16 vaccine intranasal immunization enhanced secretion of mucosal sIgA. After 3 x LD(50) CVB3 infection, pcDNA3 immunized mice groups lost their 5.75% weight following CVB3 infection, while chitosan-pcDNA3-VP1 and chitosan-pcDNA3-VP1-HApLys16 immunized mice increased their body weight by 1.75% and 5.44%. Body/heart weight ratio of chitosan-pcDNA3-VP1-HAplys16 group reached 193.77 suggesting lightened myocarditis. No myonecrosis or infiltrating immune cells existed in heart of chitosan-pcDNA3-VP1-HAplys16 immunized mice, and 1/6 of incidence and very light myocarditis were seen in chitosan-pcDNA3-VP1 immunized mice. While in pcDNA3 immunized mice 6/6 incidence and extremely severe myocarditis were observed. Heart from pcDNA3-immunized mice was bigger than normal ones and had a lot of white stripes, which were not observed in that of chitosan-pcDNA3-VP1 and chitosan-pcDNA3-VP1-HApLys16 immunized mice.Novel chitosan-pcDNA3-VP1-HApLys16 vaccine containing "endosome fusogenic peptide" could more effectively prevent CVB3-induced myocarditis than chitosan-pcDNA3-VP1 vaccine.

To investigate the roles of B7 antisense peptide (B7AP) in blocking the CD28-B7 pathway and inducing the allogeneic chimerism.B7 antisense peptide was synthesized by solid phase synthetic methods and purified with HPLC. The C57BL/6 splenocytes of mice were pre-treated by B7AP, and subsequently injected in travenously to BALB/c mice. Three days later the mice were injected with fresh-made bone marrow cells derived from C57BL/6 mice. The B7 expression and allogeneic chimerism were analyzed with FACS. The lymphocyte proliferation reaction and the mice pinna cardiac transplantation model were exerted to study the relation between chimerism and prolongation of allograft in vitro and in vivo.Lymphoproliferation of the splenocytes derived from BALB/c mice immunized with the B7AP pretreated C57BL/6 splenocytes versus splenocytes from C57BL/6 mice was inhibited dramatically with a inhibition rates up to 43%. Under this condition, the allogeneic chimerism was successfully induced after BMT. Both the chimerism and the survival of allogeneic cardiac grafts were prolonged over 100 days (n = 6).Synthetic B7 antisense peptide can induce allogeneic chimerism in mice and consequently prolong the survival of allogeneic cardiac grafts.

T cell anergy has been successfully induced under different conditions in cloned CD4(+) T cells, but induction of T cell anergy in vivo has been difficult and controversial. Due to the low frequency of naturally occurring T cell population with specificity to a defined antigen, it is very difficult to study anergy of naïve T cells without prior in vivo priming which complicates the interpretation of experimental data. To solve this problem, we adopted the HNT-TCR transgenic mice which have homogeneous antigen specific CD4(+) T cell population. In this study, we generated an influenza virus hemagglutinin (HA) peptide-specific CD4(+) T cell clone from the HNT-TCR transgenic mice and induced anergy using APCs which were treated with the crosslinker, ECDI (1-ethyl-3-3(3-dimethylaminopropyl) carbodiimide). The proliferative response of the cloned or freshly purified naïve CD4(+) transgenic T cells after treatment with ECDI-treated APCs and the HA peptide antigen was monitored as the index of anergy induction. The results showed that anergy was successfully induced in the cloned HNT-TCR transgenic CD4(+) T cells. It was determined that the induced anergy was antigen- and MHC-specific. By contrast, anergy was not observed in freshly purified naïve CD4(+) transgenic T cells under the same conditions. The results suggest that naïve CD4(+) T cells may have different anergy inducing requirements, or that cloned CD4(+) T cells may have certain priming or in vitro cloning artifact which makes them more susceptible to anergy induction. We propose that induction of T cell anergy may depend on the T cell growth, activation and differentiation state or cloning conditions. The results from the present study may have important implications for the study of the mechanism(s) underlying T cell anergy induction in vivo and for applications of immune tolerance based therapy.

SIP24/24p3 is a secreted murine acute phase protein which has been speculated to play an anti-inflammatory role in vivo. Recently SIP24/24p3 has been found to be able to specifically induce apoptosis in leukocytes. By using (35)S metabolic labeling method, we studied the regulation of SIP24/24p3 by glucocorticoid and pro-inflammatory cytokines IL-6 and TNF-alpha in cultured Balb/c 3T3 and BNL cells. The following results were observed: (1) dexamethasone induced the expression of SIP24/24p3 in both Balb/c 3T3 and BNL cells, the induction was more significant in BNL cells; (2) dexamethasone and IL-6 synergistically induced the expression of SIP24/24p3 in both Balb/c 3T3 and BNL cells; (3) in Balb/c 3T3 cells dexamethasone and TNF-alpha acted synergistically to induce the expression of SIP24/24p3, whereas in BNL cells dexamethasone and TNF-alpha induced the expression of SIP24/24p3 in an additive manner; (4) dexamethasone and IL-6/TNF-alpha acted synergistically in Balb/c 3T3 cells and additively in BNL cells to induce the expression of SIP24/24p3. The inducibility of SIP24/24p3 by multiple factors will help to explain its highly specific expression in vivo. The difference in the expression patterns of SIP24/24p3 in different cell types is also suggestive to its expression and regulation in hepatic and extrahepatic tissues. Finally, the fact that SIP24/24p3 protein can be induced by both pro-inflammatory as well as anti-inflammatory factors is indicative of the important role of SIP24/24p3 in the entire acute phase response process.

To investigate the specific anti-tumor immunity induced by gene immunization with ectopic hCG encoding gene.BALB/c mice were immunized with plasmid TR421-hCGbeta coding for hCGbeta and mock DNA for 3 times at 3 weekly intervals. The level of specific anti-hCGbeta IgG antibody in the serum was determined by ELISA at the indicated time in the two groups. The growth inhibitory activity of the sera against tumor cells was examined in vitro by [(3)H]-Thymidine incorporation assay. Specific lympho-proliferation versus hCGbeta was detected by [(3)H]-Thymidine incorporation assay with hCGbeta protein or inactivated SP2/0-hCGbeta cells as specific stimulating antigen. Cytotoxic T lymphocyte (CTL) activity of the splenocytes derived from the immunized mice was measured by [(3)H]-Thymidine release assay. Protective assay was performed by subcutaneous inoculation of SP2/0-hCGbeta cells into the immunized mice. The weight and formation rate of the tumor were evaluated after challenge.All mice immunized with plasmid TR421-hCGbeta developed high level of anti-hCGbeta antibodies, which could inhibit the growth of Hela cells and SP2/0-hCGbeta cells compared with the serum from animals immunized with mock DNA (P0.05). The high-level specific lympho-proliferation against hCGbeta protein or/and inactivated SP2/0-hCGbeta cells were shown in TR421-hCGbeta immunized mice, whereas no significant proliferative activity was found in mock DNA immunized animals (P0.01). A strong cytotoxic activity against SP2/0-hCGbeta in TR421-hCGbeta immunized mice was found. Inoculation of SP2/0-hCGbeta cells into the mice immunized with mock DNA developed large tumors within 25 days. But a marked reduction of tumor weight and formation rate was found after the tumor cells challenge in the mice immunized with TR421-hCGbeta plasmid DNA (P0.01).The gene immunization of ectopic hCGbeta encoding gene, eliciting high-level of specific humoral and cellular immune responses, could inhibit the growth of tumor cells harboring ectopic hCGbeta in vitro and in vivo.

To investigate the role of Coxsackievirus group B type 3 (CVB3) infection on the expression profile of chemokines (ChKs) in myocardial tissue/cells.CVB3 was inoculated into male BALB/c intraperitoneally and primary neonatal myocardial cells of BALB/c to establish CVB3 infection models in vivo and in vitro, where the expression profile of ChKs was detected at different time points post-infection as well as under different loading of CVB3 qualitatively and quantitatively by RT-PCR.The expression of MIP-2 and IP-10 was induced post-infection, while SDF-1, MCP-1, MCP-2, MCP-3, MCP-5, MDC, FKN and Ltn were constitutively expressed in myocardial tissue. The expression of MCP-1, MCP-2, MCP-3, MCP-5, MDC and Ltn increased 1.8, 1.9, 3.7, 1.7, 1.3 and 1.2 folds post-infection higher than that of uninfected control (P0.01). There was not significant difference in the expression of SDF-1 and FKN between infected myocardial tissue and uninfected myocardial tissue (P0.05). The expression of Eot was not detected in infected and uninfected myocardial tissue. Every chemokine had different expression at different infection time points. For example, the expression of MIP-2 at the 4th day was 1.1 and 1.5 times than that of the 7th and 14th day (P0.01). IP-10 showed similar expression between the 4th and 7th days (P0.05), which is 2.47 and 2.54 times compared to that of the 9th day (P0.01). And the expression of MCP-1 at the 14th day post-infection was 1.3, 1.2 and 1.0 times comparing to that of the 4th, 7th, 9th day post-infection, which showed statistical meaning. The expression of MCP-2 at the 4th was 1.4, 1.5 and 2.2 times comparing to that of the 7th, 9th, 14th day, and moreover, the expression was lower than that of the basal expression. The expression of MCP-1 and MCP-3 was up-regulated significantly, which occurred at different time points post-infection in vitro. While the expression of MIP-2 and MCP-5 was down-regulated in vitro. The expression patterns of MCP-2, MCP-3, MCP-5 and MDC were consistent with CVB3 loading. But that of the others (FKN, SDF-1, et al) were inconsistent with CVB3 loading. There was a correlation between change patterns of MCP-3 and CVB3 loading post-infection (r = 0.881, P0.05) within 14 days after infection. The varied expression trend of MCP-1 and MCP-3 was similar to the titer of anti-CVB3 antibody (r = 0.913, P = 0.031), while the expression of MCP-2, MCP-5 and MDC shows contrary change. There was not a significant correlation between change patterns of other ChKs (IP-10, SDF-1, et al) and the titer of anti-CVB3 antibody. A positive correlation between anti-CVB3 antibody and MCP-1 (r = 0.976, P0.05) was showed.The expression level and kind of ChKs in vivo and in vitro was varied significantly in clusters after CVB3 infection. The ChKs changed in clusters consisted of the expression profiles of ChKs. There were complexity and unbalance in the change of the expression of ChKs in every expression profile. It suggested that CVB3 infection could regulate the expression of ChKs in myocardial tissue/cells likely in different ways.

Recently, increasing attention is being paid to the viral etiology of atherosclerosis (AS). Human cytomegalovirus (HCMV) is thought to be the most possible etiological factor of AS. In our study, artery vascular tissue specimens derived from 75 patients with AS were studied for detection of HCMV immediately early (IE) and later (L) gene fragments by polymerase chain reaction (PCR) and in situ hybridization; sera collected from the same patients were examined for HCMV specific IgG and IgM by enzyme-linked immunosorbent assay (ELISA). Twenty two normal arterial tissues and sera were used as controls. We found that the positive rate of HCMV L and IE gene fragments were significantly higher in AS patients than those in controls. HCMV DNA were mainly observed in nucleus of endothelial cells and muscularis under intima as well as smooth muscle of media of AS area, rarely found in controls. These results suggested that HCMV infection may relate to the pathogenesis of AS; and the artery itself may be the site of HCMV latency. In addition, higher levels of HCMV IgG and IgM were found to be associated with virus persistence, indicating that a periodically active latent infection or a continuously active infection is presented in AS patients.

Background: Enterovirus 71 (EV71) is the main causative agent of hand, foot and mouth disease that occurs in young children. Neither antiviral agents nor vaccines are available for efficiently combating viral infection. Study of EV71–host interplay is important for understanding viral infection and developing strategies for prevention and therapy. Here the interactions of EV71 with human dendritic cells were analyzed. Methods: EV71 capture, endocytosis, infection, and degradation in monocyte-derived dendritic cells (MDDCs) were detected by Flow cytometry or real-time (RT-) PCR, and MDDCs-mediated EV71 trans-infection of RD cells was determined via coculture system. Cell morphology or viability was monitored with microscopy or flow cytometry. SiRNA interference was used to knock down gene expression. Results: MDDCs can bind EV71, but these loaded-EV71 particles in MDDCs underwent a rapid degradation in the absence of efficient replication; once the captured EV71 encountered susceptible cells, MDDCs efficiently transferred surface-bound viruses to target cells. The molecule of DC-SIGN (DC-specific intercellular adhesion molecule-3 grabbing nonintegrin) mediated viral binding and transfer, because interference of DC-SIGN expression with specific siRNAs reduced EV71 binding and impaired MDDC-mediated viral trans-infection, and exogenous expression of DC-SIGN molecule on Raji cell initiated viral binding and subsequent transmission. Conclusion: MDDCs could bind efficiently EV71 viruses through viral binding to DC-SIGN molecule, and these captured-viruses could be transferred to susceptible cells for robust infection. The novel finding of DC-mediated EV71 dissemination might facilitate elucidation of EV71 primary infection and benefit searching for new clues for preventing viruses from initial infection.

Recently, more and more studies suggested a new, possible role of markers of infection and inflammation beyond traditional cardiovascular risk factors, in the development and progression of atherosclerosis. Our aim was to study the mechanism of MCMV infection contributing to atherogenesis. ApoE knockout C57BL/6 mice were fed with hypercholesterol diet and inoculated ip with 3×10 pfu/100 μl MCMV. The plasma concentrations of cholesterol and the expression of MCP-1, GRO-α, FKN, RANTES, IL-4 and IFN-γ were detected in the atherosclerosis lesion. Results showed that the concentration of plasma cholesterol increased over 500 mg/dl and distinct atherosclerotic plaque could be observed in aorta after 12 weeks with hypercholesterol diet. In MCMV infection, impressive atherosclerotic plaques were observed in the aorta and the infiltration of inflammatory cells in endothelium were significantly enhanced. RT-PCR results showed that MCMV infection could induce the expression of MCP-1, GRO-α, FKN and RANTES on the atherosclerotic lesion and correlated with the atherosclerotic plaque. The local expression of cytokine IFN-γ was enhanced in MCMV infection. Our findings showed that MCMV infection contributed to atherogenesis probably by inducing expression of chemokines and immune response deviation to Th1 response. Surely, there will be other pathways involved the atherogenesis.