第711回 千葉医学会例会・第20回 佐藤外科例会 32.

<p>It obtained by maximum likelihood method using HKY+<i>Г</i>+I as nucleotides' substitution model. Triangleshows the position of cluster C which is detailed in (A). See <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0162492#pone.0162492.g001" target="_blank">Fig 1</a> legend for more details.</p

Designing and Construction of a Multiepitope-Based DNA Vaccine to Induce Protective Immunity against Hepatitis C Virus

Abstract Background: Hypervariability of hepatitis C virus (HCV) proteins is an important obstacle to design an efficient vaccine for the infection. To construct a protective vaccine against HCV, a DNA vaccine containing conserved epitopes of the virus was designed. To enhance the induced immune responses, adjuvant activity of N-terminal domain of gp96 (NT(gp96)) was used. Materials and Methods: A multi-epitope (PT) DNA vaccine encoding four HCV immunodominant cytotoxic T lymphocyte epitopes (HLA-A2 and H2-Dd) from Core, E2, NS3 and NS5B antigens in addition to a T-helper CD4+ epitope from NS3 protein and a B-cell epitope from E2 protein was designed and constructed. Then, NT(gp96) was fused to the PT DNA (PT-NT(gp96)). The stimulated cellular and humoral immune responses of PT and PT-NT(gp96) were evaluated in mice model. Results: According to multicolor flow cytometry assay, the frequency of CD8+ T-cells producing IFNγ and TNFα in the splenocytes of immunized mice with PT-NT(gp96) (6.8%, 4%) was significantly higher than those of immunized with PT (0.9% , 0.8%), respectively. The same results have obtained in hepatic lymphocytes of the vaccinated mice. The level of IgG, IgG1 and IgG2a in the mice vaccinated with PT-NT (gp96) was significantly higher than the value obtained from the mice immunized with PT. Conclusion: The results showed that PT DNA vaccine induces immune responses in mice model. Fusion of NT (gp96) to PT DNA vaccine causes to enhance cellular and humoral immune responses against HCV compared to sole PT vaccine

HCV Core/NS3 Protein Immunization with “N-Terminal Heat Shock gp96 Protein (rNT (gp96))” Induced Strong and Sustained Th1-Type Cytokines in Immunized Mice

Feeble cellular responses induced by T cell-based vaccines are a major challenge for the development of an effective vaccine against Hepatitis C virus (HCV) infection. To address this challenge, the potential of N-terminal fragment of gp96 heat shock protein (rNT (gp96) as an adjuvant was evaluated and compared to that of the CpG (as a recognized Th1-type adjuvant) in the formulation of HCV core/NS3 antigens in three immunization strategies of protein/protein, DNA/DNA, and DNA/protein. Immunized mice were evaluated for elicited immune responses in week 3 (W3) and 11 post-immunizations. Our results demonstrated that the protein (subunit) vaccine formulated with rNT (gp96) in protein/protein strategy (core/NS3 + gp96) was significantly more efficient than CpG oligodeoxynucleotides (CpG ODN) formulation and all other immunization strategies in the induction of Th1-type cytokines. This group of mice (core/NS3 + gp96) also elicited a high level of anti-Core-NS3 total immunoglobulin G (IgG) with dominant IgG2a isotype at W3. Thus, the co-administration of recombinant NT (gp96) protein with rHCV proteins might be a promising approach in the formulation of HCV subunit vaccine candidates for induction of high levels of Th1 cytokines and humoral responses

Epidemic History of Hepatitis C Virus among Patients with Inherited Bleeding Disorders in Iran.

The high rate of hepatitis C virus (HCV) infection among transfusion related risk groups such as patients with inherited bleeding disorders highlighting the investigation on prevalent subtypes and their epidemic history among this group. In this study, 166 new HCV NS5B sequences isolated from patients with inherited bleeding disorders together with 29 sequences related to hemophiliacs obtained from a previous study on diversity of HCV in Iran were analyzed. The most prevalent subtype was 1a (65%), followed by 3a (18.7%),1b (14.5%),4(1.2%) and 2k (0.6%). Subtypes 1a and 3a showed exponential expansion during the 20th century. Whereas expansion of 3a started around 20 years earlier than 1a among the study patients, the epidemic growth of 1a revealed a delay of about 10 years compared with that found for this subtype in developed countries. Our results supported the view that the spread of 3a reached the plateau 10 years prior to the screening of blood donors for HCV. Rather, 1a reached the plateau when screening program was implemented. The differences observed in the epidemic behavior of HCV-1a and 3a may be associated with different transmission routes of two subtypes. Indeed, expansion of 1a was more commonly linked to blood transfusion, while 3a was more strongly associated to drug use and specially IDU after 1960. Our findings also showed HCV transmission through blood products has effectively been controlled from late 1990s. In conclusion, the implementation of strategies such as standard surveillance programs and subsiding antiviral treatments seems to be essential to both prevent new HCV infections and to decline the current and future HCV disease among Iranian patients with inherited bleeding disorders

HCV Core/NS3 Protein Immunization with “N-Terminal Heat Shock gp96 Protein (rNT (gp96))” Induced Strong and Sustained Th1-Type Cytokines in Immunized Mice

Feeble cellular responses induced by T cell-based vaccines are a major challenge for the development of an effective vaccine against Hepatitis C virus (HCV) infection. To address this challenge, the potential of N-terminal fragment of gp96 heat shock protein (rNT (gp96) as an adjuvant was evaluated and compared to that of the CpG (as a recognized Th1-type adjuvant) in the formulation of HCV core/NS3 antigens in three immunization strategies of protein/protein, DNA/DNA, and DNA/protein. Immunized mice were evaluated for elicited immune responses in week 3 (W3) and 11 post-immunizations. Our results demonstrated that the protein (subunit) vaccine formulated with rNT (gp96) in protein/protein strategy (core/NS3 + gp96) was significantly more efficient than CpG oligodeoxynucleotides (CpG ODN) formulation and all other immunization strategies in the induction of Th1-type cytokines. This group of mice (core/NS3 + gp96) also elicited a high level of anti-Core-NS3 total immunoglobulin G (IgG) with dominant IgG2a isotype at W3. Thus, the co-administration of recombinant NT (gp96) protein with rHCV proteins might be a promising approach in the formulation of HCV subunit vaccine candidates for induction of high levels of Th1 cytokines and humoral responses

Estimated dates of HCV subtypes origin, as obtained under model combinations A to F.

<p>(A) Subtype 1a, cluster A. (B) subtype 1b, cluster B. (C) subtype 3a, cluster D. (D) subtype 3a, cluster E (see text for further details). The bars show the 95% credible intervals of each estimate.</p

Estimated evolutionary of each subtype (median and 95% confidence intervals).

<p>Estimated evolutionary of each subtype (median and 95% confidence intervals).</p