Home About us Contact
|
Home About us Contact | ||
|
|
||
Recombinant Vaccine (recombinant + vaccine)
Selected AbstractsAdult hepatitis B vaccination using a novel triple antigen recombinant vaccineHEPATOLOGY, Issue 2 2001Michael D. Young Present hepatitis B vaccines use multidose prolonged regimens, which even healthcare workers at risk do not always complete. Moreover, when vaccination is completed there remain some who fail to achieve adequate protection. The protection of adults at risk could be improved if there were a more potent vaccine and/or a shorter vaccination regimen available. Vaccine-naive adults were randomized to vaccination with either Engerix-B (SmithKline Biologicals, Rixensart, Belgium) or a novel triple antigen (S, pre-S1, and pre-S2) recombinant vaccine (Hepacare; Medeva Pharma Plc, Speke, UK). The primary efficacy parameter was the degree of seroprotection 6 or 7 months (26 ± 2 weeks) after beginning vaccination. A total of 304 adults entered the study. Of these, 16 failed to complete the study (9 on Hepacare and 7 on Engerix-B). With the Engerix-B standard (0, 1, 6) regimen, 88% of subjects were protected by month 7, whereas with the triple antigen vaccine a 2-dose regimen (0, 1) provided equivalent protection (91%) within 6 months and a 3-dose (0, 1, 6) regimen was significantly superior (98% seroprotected by 7 months after starting vaccination P < .001). With adults at risk for a suboptimal response (i.e., older adults, the obese, men, and smokers) the triple antigen vaccine produced a greater degree of protection. The vaccines had similar safety profiles. Both vaccines were well tolerated. In healthy normal adults, a triple antigen hepatitis B vaccine containing S and pre-S antigens produced an enhanced immunologic response and was as effective as a 2- and 3-dose regimen. [source] Double-dose double-phase use of second generation hepatitis B virus vaccine in patients after living donor liver transplantation: Not an effective measure in transplant recipientsHEPATOLOGY RESEARCH, Issue 1 2009Noriyo Yamashiki Aims:, Post-transplant active immunization for chronic hepatitis B patients has been attempted in several studies with controversial results. We assessed the effect of a double-dose double-phase vaccination regimen among partial living donor liver recipients. Methods:, Eighteen patients who underwent liver transplantation (LT) for chronic hepatitis B and two non-hepatitis B virus (HBV)-infected patients who received hepatitis B core antibody (HBcAb)-positive donor organs were recruited 18,78 months after LT. All were on hepatitis B immunoglobulin (HBIG) mono-prophylaxis before and throughout vaccination, to maintain hepatitis B surface antibody (HBsAb) titers of more than 100 IU/mL. Recombinant hepatitis B surface antigen vaccine (40 µg) was administered intramuscularly during weeks 0, 4, 8, 24, 28 and 32. Results:, The patients consisted of 15 males and five females with a median age of 52 (39,59) years. None developed a sufficient HBsAb titer above 500 IU/mL by week 48. In two patients whose maximum HBsAb titer increased to above 300 IU/mL, we attempted to skip HBIG, but shortly thereafter the titer dropped below 100 IU/mL and HBIG administration was resumed. Although the HBIG dose was reduced during and after vaccination, cessation of administration was not achieved. Conclusion:, Double-dose double-phase use of second generation recombinant vaccine was not effective in this study population. The selected population should be targeted for a conventional vaccine regimen, and different approaches, such as strong adjuvant or pre-S containing protein, should be further tested in a larger number of patients after LT for chronic hepatitis B. [source] Association of cytokine genetic polymorphisms with the humoral immune response to recombinant vaccine against HBV in infantsJOURNAL OF MEDICAL VIROLOGY, Issue 6 2010Luciana Conci Macedo Abstract The prevention of hepatitis B by vaccination is one the most efficient tools to avoid the transmission of the virus, although a considerable variability to the anti-HBsAg antibody response has been described. Recently, polymorphisms of cytokine regulating genes have been described which seem to influence the immune response to various antigens. This article's objective was to evaluate the influence of cytokine genetic polymorphisms onto the humoral immune response to hepatitis B vaccine in infants. Vaccinated children were classified according to the level of anti-HBsAg antibody titles. The genotyping for TNF (,308), TGFB1 (+869, +915), IL-10 (,1082, ,819, ,592), IL-6 (,174), and IFNG (+874) was accomplished by the PCR-SSP technique. The TNF (,308) allele A presented a lower but not statistically significant frequency at 5% level in high responder patients (3.7% vs. 12.3%, P,=,0.0919). The same was seen for the TNF (,308) genotype GA (7.4% vs. 24.5%, P,=,0.0757). Further studies in other populations and evaluation of a greater number of individuals may contribute for a better understanding of the cytokine gene polymorphism influence in general and TNF polymorphism more specifically in the humoral immune response to the HBsAg vaccination in newborn children. J. Med. Virol. 82:929,933, 2010. © 2010 Wiley-Liss, Inc. [source] Immunomodulatory properties of Lactobacillus plantarum and its use as a recombinant vaccine against mite allergyALLERGY, Issue 3 2009P. Rigaux Background:, Selected lactic acid bacteria were reported to prevent atopic dermatitis and experimental asthma but the mechanisms of their immunomodulatory effects are not fully elucidated. In this study, the signaling pathways triggered by Lactobacillus plantarum NCIMB8826 were investigated and the potential use of this strain producing a variant of the mite allergen Der p 1 as live vaccine vehicle was evaluated. Methods:, Mouse bone marrow-derived dendritic cells were stimulated with wild-type or a L. plantarum teichoic acid mutant to evaluate the secretion of cytokines. A recombinant L. plantarum expressing Der p 1 was engineered, its in vitro immunomodulatory properties were characterized and its prophylactic potential was evaluated in a Der p 1-sensitization murine model. Results:, Mouse dendritic cells stimulated by L. plantarum triggered the release of interleukin-10 (IL-10), IL-12 p40, IL-12 p70 and tumor necrosis factor-alpha (TNF-,). IL-12 p40 secretion was dependent on nuclear factor-,B (NF-,B), mitogen-activated protein (MAP) kinases, Toll-like receptor 2 (TLR2), TLR9 and on the bacterial teichoic acid composition. Recombinant L. plantarum producing Der p 1 exhibited similar immunostimulatory properties as wild-type. Prophylactic intranasal pretreatment of mice with this recombinant strain prevented the development of the typical Th2-biased allergic response by a drastic reduction of specific IgE and the induction of protective allergen-specific IgG2a antibodies. Moreover, both wild-type or recombinant L. plantarum reduced airway eosinophilia following aerosolized allergen exposure and IL-5 secretion upon allergen restimulation. Conclusion:, By combining both Th1-type immunostimulatory properties and an efficient allergen delivery capacity, recombinant L. plantarum producing Der p 1 represents a promising vaccine against house dust mite allergy. [source] Production of Hepatitis B Surface Antigen in Recombinant Plant Systems: An UpdateBIOTECHNOLOGY PROGRESS, Issue 3 2007G. B. Sunil Kumar There is a growing interest to develop oral vaccines for infectious diseases, as it is the most convenient and effective way to attain mucosal immunity. Hepatitis B continues to be a major infectious disease in many developing countries despite the availability of recombinant vaccine. On a global scenario, Hepatitis B Virus infection is probably the single most prevalent cause of persistent viraemia in humans. There are about 350 million chronic carriers of HBV, which is about 5% of the total world population. It is estimated that 75,100 million of them will die of liver cirrhosis and/or hepatocellular carcinoma. Progress in plant genetic engineering has enabled the transfer of useful genes for desirable traits. The recent trend is to use this technique to exploit plants as biofactories for the production of therapeutic proteins including vaccines. Rapid progress has been made in this area to develop plant-based vaccines for hepatitis B. This review describes the expression, characterization, and immunogenicity studies of hepatitis B vaccines produced in recombinant plant systems and their implications for developing a plant-based vaccine. [source] Both CD4+ and CD8+ T cell epitopes fused to heat shock cognate protein 70 (hsc70) can function to eradicate tumorsCANCER SCIENCE, Issue 5 2008Shusaku Mizukami Vaccination with heat shock proteins (HSP) protects mice from challenge with the tumor from which the HSP were isolated. The antigenicity of HSP vaccination is thought to result from HSP-associated endogenous major histocompatibility complex class I peptides or their precursors. The vaccination effect can be achieved in an adjuvant-free manner and is mediated by CD8+ T cells, indicating that HSP can act as a natural adjuvant and cross-prime T cells in vivo. We previously devised a recombinant vaccine composed of a CD8+ T cell epitope fused to the carboxyl-terminus of hsc70 and demonstrated efficient generation of antigen-specific cytotoxic T lymphocyte (CTL) after vaccination with a few micrograms of the hsc70-CTL epitope fusion protein. The present study aimed to determine if the fusion protein vaccine could control tumor growth in vivo and whether simultaneous fusion of a CD4+ T cell epitope to the amino terminus of the hsc70-CTL epitope would be a more potent vaccine compared to the CTL epitope alone. Ovalbumin (OVA),derived 8 mer peptide, OVA257-264, and 16mer peptide, OVA265-280, were used as CD8+ and CD4+ T cell epitopes, respectively. Vaccination with hsc70-OVA257-264 generated peptide specific CTL more effectively than a peptide plus incomplete Freund's adjuvant combination, and suppressed growth of OVA expressing EL4 (E.G7) and B16 melanoma tumor cells. Addition of OVA265-280 to the amino-terminus of hsc70-OVA257-264 (OVA265-280 -hsc70-OVA257-264) enhanced the generation of the OVA257-264 -specific CTL population, leading to better eradication of MO5 lung metastasis compared to hsc70-OVA257-264. Our results suggest that fusion of both CD4+ and CD8+ T cell epitopes to hsc70 enhances tumor immunity beyond the effect of the CD8+ T cell epitope alone. (Cancer Sci 2008; 99: 1008,1015) [source] Synthetic bacterial lipopeptide analogs facilitate naive CD4+ T,cell differentiation and enhance antigen-specific HLA-II-restricted responsesEUROPEAN JOURNAL OF IMMUNOLOGY, Issue 8 2005Mascia Ghielmetti Abstract Synthetic di- and tri-palmitoylated bacterial lipopeptide analogs (BLpA) can enhance HLA-I-restricted immune responses. Here we show that BLpA indirectly promote antigen-driven differentiation of naive CD4+ T,lymphocytes in vitro, with mechanisms that require DC and are inhibited by CTLA-4/Ig. In mixed cultures of cord blood-derived PBMC and allogeneic DC, P3CSK4 lipopeptide facilitated the transition from CCR7+/CD45RA+/CD62L+ to CCR7,/CD45RA,/CD62Ldim T,cells with kinetics significantly exceeding those obtained with the unlipidated CSK4 analog. Moreover, P3CSK4 and P2CSK4, but neither the mono-palmitoylated PCSK4 analog nor the CSK4 peptide, increased the frequency of IFN-,-producing T,cells expanded under similar conditions. Along with this, P2CSK4 and P3CSK4, but not PCSK4, restored the in vitro antigenicity of MDP-OspA, a non-immunogenic analog of Borrelia burgdorferi major outer surface lipoprotein,A, and enhanced the frequency of in vitro expanded T,cells specific for the tetanus toxoid (TT) and hepatitis,B surface antigen (HBsAg) peptides TT947,967 and HBsAg19,33 and for TT. Altogether, BLpA bearing at least two ester-bonded palmitoyl side chains indirectly enhance antigen-driven CD4+ T,cell differentiation. BLpA adjuvanticity is independent of covalent bonding to Ag and Ag formulation. This information may be helpful to generate more potent recombinant vaccines. [source] A potent adjuvant effect of CD40 antibody attached to antigenIMMUNOLOGY, Issue 1 2003Tom A. Barr Summary There is great potential for novel vaccines based on recombinant proteins and synthetic peptides. Unfortunately these antigens often lack the immunogenicity of whole, killed pathogens used in traditional vaccines. Thus there is strong interest in the identification of immunological adjuvants with low reactogenicity, but high potency, to enhance immune responses and realize the potential of these new vaccine strategies. CD40 antibodies have been shown to have adjuvant effects when administered at very high doses. These large doses are impractical and induce a cascade of cytokine release giving rise to septic shock-like symptoms, as well as splenomegaly and polyclonal antibody production. We show here that a very small amount of CD40 antibody can exhibit potent adjuvant effects when attached to soluble antigen. The lack of detectable systemic effects indicates that this method may be a powerful and practical means of enhancing the efficacy of recombinant vaccines. [source] Anchorage to the cytosolic face of the endoplasmic reticulum membrane: a new strategy to stabilize a cytosolic recombinant antigen in plantsPLANT BIOTECHNOLOGY JOURNAL, Issue 6 2008Alessandra Barbante Summary The levels of accumulation of recombinant vaccines in transgenic plants are protein specific and strongly influenced by the subcellular compartment of destination. The human immunodeficiency virus protein Nef (negative factor), a promising target for the development of an antiviral vaccine, is a cytosolic protein that accumulates to low levels in transgenic tobacco and is even more unstable when introduced into the secretory pathway, probably because of folding defects in the non-cytosolic environment. To improve Nef accumulation, a new strategy was developed to anchor the molecule to the cytosolic face of the endoplasmic reticulum (ER) membrane. For this purpose, the Nef sequence was fused to the C-terminal domain of mammalian ER cytochrome b5, a long-lived, tail-anchored (TA) protein. This consistently increased Nef accumulation by more than threefold in many independent transgenic tobacco plants. Real-time polymerase chain reaction of mRNA levels and protein pulse-chase analysis indicated that the increase was not caused by higher transcript levels but by enhanced protein stability. Subcellular fractionation and immunocytochemistry indicated that Nef-TA accumulated on the ER membrane. Over-expression of mammalian or plant ER cytochrome b5 caused the formation of stacked membrane structures, as observed previously in similar experiments performed in mammalian cells; however, Nef-TA did not alter membrane organization in tobacco cells. Finally, Nef could be removed in vitro by its tail-anchor, taking advantage of an engineered thrombin cleavage site. These results open up the way to use tail-anchors to improve foreign protein stability in the plant cytosol without perturbing cellular functions. [source] Surface-exposed expression of Edwardsiella tarda EseB in live attenuated Vibrio anguillarum based on novel surface display systemsAQUACULTURE RESEARCH, Issue 13 2009Qiyao Wang Abstract Live, attenuated Vibrio anguillarum strains can serve as vectors for the delivery of heterologous antigens for development of multivalent recombinant vaccines. Based on the outer membrane anchoring elements of V. anguillarum, we have previously constructed several efficient surface display systems Lpp-Omporf1, Lpp-OmpU, Lpp-Omp26La, Wza-Omporf1, Wza-OmpU and Wza-Omp26La. In this study, with these constructed surface display systems, a putative antigen protein EseB from pathogenic Edwardsiella tarda was successfully expressed on the surface of an attenuated V. anguillarum strain to get multivalent vaccine candidates. Further immune protection evaluation in zebra fish (Danio rerio) demonstrated that the V. anguillarum EseB-display strain AV/pW-26La-B could trigger full protection against V. anguillarum infection and early protection against E. tarda infection in the immunized fish. These results suggest that surface display of heterologous protective antigens in attenuated V. anguillarum could be used as a tool to develop potential V. anguillarum vector vaccine. [source] | |||||||||||||||||||||||||