Comparison of the efficacy of early versus late viral proteins in vaccination against SIV.

The immune response against early regulatory proteins of simian- and human immunodeficiency virus (SIV, HIV) has been associated with a milder course of infection. Here, we directly compared vaccination with Tat/Rev versus Pol/Gag. Challenge infection with SIVmac32H (pJ5) suggested that vaccination with Tat/Rev induced cellular immune responses that enabled cynomolgus macaques to more efficiently control SIV replication than the vaccine-induced immune responses against Pol/Gag. Vaccination with Tat/Rev resulted in reduced plasma SIV loads compared with control (P=0.058) or Pol/Gag-vaccinated (P

Intradermal Electroporation of Naked Replicon RNA Elicits Strong Immune Responses

RNA-based vaccines represent an interesting immunization modality, but suffer from poor stability and a lack of efficient and clinically feasible delivery technologies. This study evaluates the immunogenic potential of naked in vitro transcribed Semliki Forest virus replicon RNA (RREP) delivered intradermally in combination with electroporation. Replicon-immunized mice showed a strong cellular and humoral response, contrary to mice immunized with regular mRNA. RREP-elicited induction of interferon-γ secreting CD8+ T cells and antibody responses were significantly increased by electroporation. CD8+ T cell responses remained substantial five weeks post vaccination, and antigen-specific CD8+ T cells with phenotypic characteristics of both effector and central memory cells were identified. The immune response during the contraction phase was further increased by a booster immunization, and the proportion of effector memory cells increased significantly. These results demonstrate that naked RREP delivered via intradermal electroporation constitute an immunogenic, safe and attractive alternative immunization strategy to DNA-based vaccines

Protective Efficacy of Serially Up-Ranked Subdominant CD8+ T Cell Epitopes against Virus Challenges

Immunodominance in T cell responses to complex antigens like viruses is still incompletely understood. Some data indicate that the dominant responses to viruses are not necessarily the most protective, while other data imply that dominant responses are the most important. The issue is of considerable importance to the rational design of vaccines, particularly against variable escaping viruses like human immunodeficiency virus type 1 and hepatitis C virus. Here, we showed that sequential inactivation of dominant epitopes up-ranks the remaining subdominant determinants. Importantly, we demonstrated that subdominant epitopes can induce robust responses and protect against whole viruses if they are allowed at least once in the vaccination regimen to locally or temporally dominate T cell induction. Therefore, refocusing T cell immune responses away from highly variable determinants recognized during natural virus infection towards subdominant, but conserved regions is possible and merits evaluation in humans

Enhanced simian immunodeficiency virus-specific immune responses in macaques induced by priming with recombinant Semliki Forest virus and boosting with modified vaccinia virus Ankara

The immunogenicity of two vector-based vaccines, either given alone or in a prime-boost regimen, was investigated. Cynomolgus macaques were immunised with modified vaccinia virus Ankara (MVA) expressing simian immunodeficiency virus (SIV)macJ5 env, gag-pol, nef, rev, and tat genes (MVA-SIVmac) or primed with a Semliki forest virus (SFV) vaccine expressing the same genes (SFV-SIVmac) and boosted with MVA-SIVmac. Generally, antibody responses, T-cell proliferative responses and cytotoxic T-cell responses remained low or undetectable in vaccinees receiving MVA-SIVmac or SFV-SIVmac alone. In contrast, monkeys who first received SFV-SIVmac twice and then were boosted with MVA-SIVmac showed increased antibody responses as well as high T-cell proliferative responses. Three of these vaccinees had cytotoxic T-lymphocytes directed against three or four of the gene products. No evidence of protection was seen against an intrarectal heterologous SIVsm challenge given 3 months after the last immunisation. The study demonstrates a prime-boost strategy that efficiently induces both humoral and cellular immune responses. © 2001 Elsevier Science Ltd. All rights reserved.SCOPUS: ar.jinfo:eu-repo/semantics/publishe

Cloning of human IL-12 p40 and p35 DNA into the Semliki Forest virus vector: expression of IL-12 in human tumor cells.

IL-12 can enhance the development of effective immune responses against tumors as well as against certain infectious agents. It is therefore a potential candidate for therapeutic use in cancer therapy and in the design of vaccines against several infectious diseases. Several studies have demonstrated that IL-12 could efficiently induce tumor regression in animal models. To investigate the antitumor effect of direct gene transfer of human IL-12 into tumors, human IL-12 p35 and p40 cDNAs were cloned into the Semliki Forest virus (SFV) vector pSFV1. In order to express the two subunits from the same vector, the p35 and the p40 cDNAs were cloned into pSFV1, each under the control of a subgenomic SFV promoter. Recombinant RNA produced by in vitro transcription of SFV-IL-12 construct, was packaged into SFV viral particles with the use of a non-packageable helper RNA. We show that human tumor cell lines infected in vitro in vivo with recombinant SFV-IL-12 viral particles secrete high levels of biologically active heterodimeric p35/p40 IL-12, as demonstrated using ELISA and biological assays.Journal ArticleResearch Support, Non-U.S. Gov'tinfo:eu-repo/semantics/publishe

Role of nanocellulose in tailoring electroanalytical performance of hybrid nanocellulose/multiwalled carbon nanotube electrodes

Publisher Copyright: © 2022, The Author(s).Nanocellulose has emerged as a promising green dispersant for carbon nanotubes (CNTs), and there is an increasing trend in developing nanocellulose/CNT hybrid materials for electrochemical detection of various small molecules. However, there have been very few comprehensive studies investigating the role of nanocellulosic material properties upon the electroanalytical performance of the resultant hybrid electrodes. In this work, we demonstrate the influence of both nanocellulose functionalization and geometry, utilizing sulfated cellulose nanocrystals, sulfated cellulose nanofibers, and TEMPO-oxidized cellulose nanofibers. Transmission electron microscopy tomography enables direct visualization of the effect of nanocellulosic materials on the hybrid architectures. High resolution X-ray absorption spectroscopy verifies that the chemical nature of CNTs in the different hybrids is unmodified. Electroanalytical performances of the different nanocellulose/CNT hybrid electrodes are critically evaluated using physiologically relevant biomolecules with different charge such as, dopamine (cationic), paracetamol (neutral), and uric acid (anionic). The hybrid electrode containing fibrillar nanocellulose geometry with a high degree of sulfate group functionalization provides the highest electroanalytical sensitivity and strongest enrichment towards all studied analytes. These results clearly demonstrate for the first time, the extent of tailorability upon the electroanalytical response of nanocellulose/CNT hybrid electrodes towards different biomolecules, offered simply by the choice of nanocellulosic materials.Peer reviewe

A vaccine strategy utilizing a combination of three different chimeric vectors which share specific vaccine antigens

SCOPUS: ar.jFLWINinfo:eu-repo/semantics/publishe

Protection against lethal simian immunodeficiency virus SIVsmmPBj14 disease by a recombinant Semliki forest virus gp160 vaccine and by a gp120 subunit vaccine

SCOPUS: ar.jinfo:eu-repo/semantics/publishe

Small-angle scattering study of structural changes in the microfibril network of nanocellulose during enzymatic hydrolysis

The hydrolysis of nanofibrillated cellulose (NFC), consisting of individual cellulose fibrils, was followed using small-angle scattering techniques in order to reveal changes in the substrate structure caused by cellulose degrading enzymes. In particular, the nanoscale structure of the network of cellulose fibrils was characterized with the combination of small-angle neutron scattering and small-angle x-ray scattering. In the nanocellulose with higher xylan content, the interfibrillar distance was shown to remain unchanged during enzymatic degradation, whereas the distance increased in the nanocellulose with lower xylan content. The limiting effect of xylan on the hydrolysis and a faster hydrolysis of the more thoroughly fibrillated segments of the NFC network could be observed. Despite the extensive fibrillation of the raw material, however, the hydrolysis was eventually limited by the aggregated and heterogeneous structure of the substrate