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1.
《Vaccine》2023,41(10):1684-1693
Oil-in-water emulsion-based adjuvants have demonstrated acceptable safety in many disease indications, while their adjuvant activities for vaccines still need to be improved. Recently, the strategy of combining adjuvants with multiple types of immunostimulants has been shown to enhance immune responses. In this study, astragalus polysaccharides were combined with simvastatin as an immunostimulant to construct a compound O/W emulsion adjuvant. The formulations were optimized according to the OVA-specific antibody responses induced in mice. For this reason, high (5 mg/mL), medium (2.5 mg/mL), and low (1.25 mg/mL) concentrations of astragalus polysaccharides and high (10 mg/mL), medium (1 mg/mL), and low (0.1 mg/mL) concentrations of simvastatin were selected. The final optimal formulation of the immunostimulant was a high concentration of astragalus polysaccharides combined with a medium concentration of simvastatin. The optimal compound O/W emulsion adjuvant could induce effective humoral and cellular immune responses that were stronger and more stable than those induced by aluminum adjuvant and Freund's adjuvant. The OVA/HAPS-MSim-OE induced dramatically strong and persistent IgG expressions and Th1-polarized immune responses. What’s more, the highest CD4+/CD8+lymphocyte ratios were observed in OVA/HAPS-MSim-OE group. In addition, compound O/W emulsion adjuvant groups significantly promoted the secretion of IFN-γ and IL-6, which also indicated that the compound O/W emulsion adjuvants could induce both enhanced Th1 and Th2-mediated immune responses but prefer the Th1-mediated ones. This study would contribute to an interesting and promising direction in the development of emulsion-based adjuvants.  相似文献   

2.
《Vaccine》2019,37(35):4963-4974
Vaccination is the most efficient strategy to protect from infectious diseases and the induction of a protective immune response not only depends on the nature of the antigen, but is also influenced by the vaccination strategy and the co-administration of adjuvants. Therefore, the precise monitoring of adjuvant candidates and their immune modulatory properties is a crucial step in vaccine development. Here, one central aspect is the induction of appropriate humoral and cellular effector mechanisms.In our study we performed a direct comparison of two promising candidates in adjuvant development, the STING activator bis-(3,5)-cyclic dimeric adenosine monophosphate (c-di-AMP) and the Toll-like receptor ligand formulation poly(I:C)/CpG. These were evaluated in C57BL/6 mice using the model antigen ovalbumin (OVA) in subcutaneous vaccination with soluble protein as well as in a dendritic cell (DC) targeting approach (αDEC-OVA). Strikingly, c-di-AMP as compared to poly(I:C)/CpG resulted in significantly higher antigen-specific IgG antibody levels when used in immunization with soluble OVA as well as in antigen targeting to DC. In vaccination with soluble OVA, c-di-AMP induced a significantly stronger CTL, Th1 and IFNγ-producing CD8+ memory T cell response than poly(I:C)/CpG. The response was CTL and Th1 cell dominated, a profile shared by both adjuvants. In the context of targeting OVA to DC, c-di-AMP induced significantly increased Th1 and Th2 cell responses as compared to poly(I:C)/CpG. Interestingly, the Th1 response dominated the overall T cell response only when c-di-AMP was used, indicating a distinct modulatory property of c-di-AMP when the DC targeting immunization approach was exploited.Taken together, we describe superior properties of c-di-AMP as compared to poly(I:C)/CpG in subcutaneous vaccination with soluble antigen as well as antigen targeting to DC. This indicates exceptionally effective adjuvant properties for c-di-AMP and provides compelling evidence of its potential for further adjuvant development, especially also when using DC targeting approaches.  相似文献   

3.
《Vaccine》2020,38(39):6141-6152
Influenza vaccination is considered the most valuable means to prevent and control seasonal influenza infections, which causes various clinical symptoms, ranging from mild cough and fever to even death. Among various influenza vaccine types, the inactivated subunit type is known to provide improved safety with reduced reactogenicity. However, there are some drawbacks associated with inactivated subunit type vaccines, with the main ones being its low immunogenicity and the induction of Th2-biased immune responses. In this study, we investigated the role of a single-stranded RNA (ssRNA) derived from the intergenic region in the internal ribosome entry site of the Cricket paralysis virus as an adjuvant rather than the universal vaccine for a seasonal inactivated subunit influenza vaccine. The ssRNA adjuvant stimulated not only well-balanced cellular (indicated by IgG2a, IFN-γ, IL-2, and TNF-α) and humoral (indicated by IgG1 and IL-4) immune responses but also a mucosal immune response (indicated by IgA), a key protector against respiratory virus infections. It also increases the HI titer, the surrogate marker of influenza vaccine efficacy. Furthermore, ssRNA adjuvant confers cross-protective immune responses against heterologous influenza virus infection while promoting enhanced viral clearance. Moreover, ssRNA adjuvant increases the number of memory CD4+ and CD8+ T cells, which can be expected to induce long-term immune responses. Therefore, this ssRNA-adjuvanted seasonal inactivated subunit influenza vaccine might be the best influenza vaccine generating robust humoral and cellular immune responses and conferring cross-protective and long-term immunity.  相似文献   

4.
《Vaccine》2020,38(19):3537-3544
BackgroundVaccination is the most effective approach to prevent infection with highly pathogenic avian influenza (HPAI). Adjuvants are often used to induce effective immune responses and overcome the immunological weakness of recombinant HPAI antigens. Given the logistical challenges of immunization to HPAI during pandemic situations, vaccines administered via the intramuscular (I.M.) route would be of value.MethodsA new formulation of nanoemulsion adjuvant (NE02) suitable for I.M. vaccination was developed. This NE02 was evaluated alone and in combination with CpG to develop H5 immune responses in mouse and ferret models. Measures of recombinant H5 (rH5) specific immunity evaluated included serum IgG and IgG subclasses, bronchoalveolar lavage fluid IgA, and cytokines. The activation of NF-kB was also analyzed. The efficacy of the vaccine was assessed by performing hemagglutination inhibition (HAI), virus neutralization (VN) assays, and viral challenges in ferrets.ResultsI.M. vaccination with rH5-NE02 significantly increased rH5-specific IgG and protected ferrets in the viral challenge model providing complete protection and sterile immunity in all animals tested. Combining NE02 and CpG produced accelerated antibody responses and this was accompanied by an elevation of IFN-γ and IL-17 responses and the downregulation of IL-5. The combination also caused a synergistic effect on NF-kB activation. In immunized ferrets after viral challenge, the rH5-NE02 + CpG vaccine via I.M. achieved at least 75% and 88% seroconversion of HAI and VN antibody responses, respectively, and improved body temperature stabilization and weight loss over NE02 alone.ConclusionsThe I.M. injection of NE02 adjuvanted rH5 elicits strong and broad immune responses against H5 antigens and effectively protects animals from lethal H5 challenge. Combining this adjuvant with CpG enhanced immune responses and provided improvements in outcomes to viral challenge in ferrets. The results suggest that combinations of adjuvants may be useful to enhance H5 immune responses and improve protection against influenza infection.  相似文献   

5.
《Vaccine》2022,40(10):1448-1457
The generation of DCs with augmented functions is a strategy for obtaining satisfactory clinical outcomes in tumor immunotherapy. We developed a novel synthetic adjuvant comprising a liposome conjugated with a DC-targeting Toll-like-receptor ligand and a pH-sensitive polymer for augmenting cross-presentation. In an in vitro study using mouse DCs, these liposomes were selectively incorporated into DCs, significantly enhanced DC function and activated immune responses to present an epitope of the incorporated antigen on the major histocompatibility complex class I molecules. Immunization of mice with liposomes encapsulating a tumor antigen significantly enhanced antigen-specific cytotoxicity. In tumor-bearing mice, vaccination with liposomes encapsulating a tumor antigen elicited complete tumor remission. Furthermore, vaccination significantly enhanced cytotoxicity, targeting not only the vaccinated antigen but also the other antigens of the tumor cell. These results indicate that liposomes are an ideal adjuvant to develop DCs with considerably high potential to elicit antigen-specific immune responses; they are a promising tool for cancer therapy with neoantigen vaccination.  相似文献   

6.
《Vaccine》2021,39(11):1583-1592
Targeted delivery of antigen to antigen-presenting cells (APCs) enhances antigen presentation and thus, is a potent strategy for making more efficacious vaccines. This can be achieved by use of antibodies with specificity for endocytic surface molecules expressed on the APC. We aimed to compare two different antibody-antigen fusion modes in their ability to induce T-cell responses; first, exchange of immunoglobulin (Ig) constant domain loops with a T-cell epitope (Troybody), and second, fusion of T-cell epitope or whole antigen to the antibody C-terminus. Although both strategies are well-established, they have not previously been compared using the same system. We found that both antibody-antigen fusion modes led to presentation of the T-cell epitope. The strength of the T-cell responses varied, however, with the most efficient Troybody inducing CD4 T-cell proliferation and cytokine secretion at 10–100-fold lower concentration than the antibodies carrying antigen fused to the C-terminus, both in vitro and after intravenous injection in mice. Furthermore, we exchanged this loop with an MHCI-restricted T-cell epitope, and the resulting antibody enabled efficient cross-presentation to CD8 T cells in vivo. Targeting of antigen to APCs by use of such antibody-antigen fusions is thus an attractive vaccination strategy for increased activation of both CD4 and CD8 peptide-specific T cells.  相似文献   

7.
《Vaccine》2019,37(42):6208-6220
Seasonal influenza vaccines represent a positive intervention to limit the spread of the virus and protect public health. Yet continual influenza evolution and its ability to evade immunity pose a constant threat. For these reasons, vaccines with improved potency and breadth of protection remain an important need. We previously developed a next-generation influenza vaccine that displays the trimeric influenza hemagglutinin (HA) on a ferritin nanoparticle (NP) to optimize its presentation. Similar to other vaccines, HA-nanoparticle vaccine efficacy is increased by the inclusion of adjuvants during immunization. To identify the optimal adjuvants to enhance influenza immunity, we systematically analyzed TLR agonists for their ability to elicit immune responses. HA-NPs were compatible with nearly all adjuvants tested, including TLR2, TLR4, TLR7/8, and TLR9 agonists, squalene oil-in-water mixtures, and STING agonists. In addition, we chemically conjugated TLR7/8 and TLR9 ligands directly to the HA-ferritin nanoparticle. These TLR agonist-conjugated nanoparticles induced stronger antibody responses than nanoparticles alone, which allowed the use of a 5000-fold-lower dose of adjuvant than traditional admixtures. One candidate, the oil-in-water adjuvant AF03, was also tested in non-human primates and showed strong induction of neutralizing responses against both matched and heterologous H1N1 viruses. These data suggest that AF03, along with certain TLR agonists, enhance strong neutralizing antibody responses following influenza vaccination and may improve the breadth, potency, and ultimately vaccine protection in humans.  相似文献   

8.
《Vaccine》2019,37(22):2952-2959
CD8+ T cells are known to control infections, but their role in preventing latent infection from establishing has not been thoroughly investigated.We hypothesized that a potent CD8+ T cell response patrolling the mucosal viral entry points could kill the first infected cells and thereby abrogate the infection before latency is established.To investigate this, replication deficient adenovirus serotype 5 vectors encoding murine γ-herpesvirus-68 CD8+ T cell epitopes linked to the T cell adjuvant Invariant chain, were developed. We show that intranasal vaccination of mice reduces the risk of establishment of latent infection from multiple intranasal ID50 challenges with murine γ-herpesvirus-68 by 81% per exposure at 14 days post vaccination. Protection waned over time, but immune responses were extended by heterologous prime-boost vaccination applied simultaneously intramuscularly and intranasally, and animals vaccinated 66 days prior to challenge showed a strong trend of long-term protection.Our data provides evidence that CD8+ T cells are able to protect against establishment of latent infection. Although the protective efficacy is difficult to maintain over time, this proof-of-concept study suggests a role for a CD8+ T cell arm in future vaccine strategies against latent human viral infections caused by pathogens such as HIV and multiple herpes virus.  相似文献   

9.
《Vaccine》2020,38(3):699-704
ObjectiveThis study aimed to investigate whether systemic immunization with a 13-valent pneumococcal conjugate vaccine (PCV13) followed by intranasal (IN) immunization with phosphorylcholine (PC) can boost immune response against Streptococcus pneumoniae.Materials and methodsTwo weeks after the intraperitoneal (IP) injection of PCV13, mice were divided into two groups (mice requiring another IP injection of PCV13 and mice requiring PC-keyhole limpet hemocyanin IN immunization in combination with cholera toxin as a mucosal adjuvant) to compare the magnitude of systemic and mucosal immune responses against S. pneumoniae and PC.ResultsSerum immunoglobulin (Ig) G antibody titer against the vaccine strains of S. pneumoniae was similar between the PCV13 systemic immunization group and PC IN immunization group, while the serum IgG antibody titer against PC was significantly higher in the PC IN immunization group. PC-specific IgA antibody titer in the nasal lavage and PC-specific IgA-producing cell number in the nasal mucosa were also significantly higher in the PC IN immunization group. Induction of PC-specific IgA in the PC IN immunization group enhanced the clearance of bacteria from the middle ear.ConclusionAdditional IN immunization with PC after PCV13 immunization, which is currently conducted under a periodic vaccination program, can produce a booster effect comparable to that achieved by additional systemic immunization as well as PC-specific mucosal immune response, thereby providing protection against S. pneumoniae serotypes not contained in PCV13.  相似文献   

10.
《Vaccine》2021,39(37):5295-5301
Strong quantitative and functional antibody responses to the quadrivalent human papillomavirus (HPV) vaccine were reported in mid-adult aged men, but there are limited data on the avidity of the antibody response and the memory B-cell response following vaccination. Although circulating antibodies induced by vaccination are believed to be the main mediators of protection against infection, evaluation of avidity of antibodies and memory B cell responses are critical for a better understanding of the vaccine immunogenicity mechanisms. Both the modified enzyme-linked immunosorbent assay (ELISA) and the enzyme-linked immunosorbent spot (ELISpot) assay are tools to measure the humoral and cellular immune responses post vaccination to characterize vaccine immunogenicity. The avidity of HPV-16 and HPV-18 specific IgG in the serum of mid-adult aged men (N = 126) who received three quadrivalent HPV vaccine doses was examined using a modified ELISA. HPV-16 memory B-cell responses were assessed via ELISpot at month 0 (prior to vaccination) and 1-month post-dose three of the vaccine (month 7). The quadrivalent vaccine induced an increase in HPV-16 and HPV-18 antibody avidity at month 7. HPV-18 avidity levels moderately correlated with anti-HPV-18 antibody titers, but no association was observed for HPV-16 antibody titers and avidity levels. The HPV-16-specific memory B-cell response was induced following three vaccine doses, however, no association with anti-HPV-16 antibody avidity was observed. Three doses of quadrivalent HPV vaccine increased antibody affinity maturation for HPV-16/18 and increased the frequency of anti-HPV-16 memory B-cells in mid-adult aged men.  相似文献   

11.
《Vaccine》2019,37(31):4364-4369
Duck hepatitis A virus (DHAV) is the major pathogen of duck viral hepatitis, which has caused great economic losses to duck breeding industry. As an effective delivery tool for protein antigens, Lactococcus lactis (L. lactis) has been successfully used to stimulate mucosal and systemic immune response. In this study, a recombinant L. lactis named NZ3900-VP1 was constructed, which could express VP1 protein of DHAV type 3 (DHAV-3) by using a nisin-controlled expression (NICE) system. The animal experiment in both mice and ducklings were performed to detect the immune response and protection effect of oral vaccination by the recombinant L. lactis. The results showed that oral vaccination with L. lactis NZ3900-VP1 significantly induced specific anti-VP1 IgG antibodies and mucosal secretory immunoglobulin A (sIgA) of DHAV-3 in mice and ducklings, and cytokines including interleukin-2 (IL-2), interferon gamma (IFN-γ), interleukin-10 (IL-10) and interleukin-4 (IL-4). Notably, the ducklings vaccinated with L. lactis NZ3900-VP1 were effectively protected when facing natural infestation of DHAV-3, which indicated that the recombinant L. lactis could serve as an effective vaccine to prevent DHAV-3 infection in ducklings.  相似文献   

12.
《Vaccine》2020,38(50):7989-7997
Pharmacological therapies for the treatment of cocaine addiction have had disappointing efficacy, and the lack of recent developments in the clinical care of cocaine-addicted patients indicates a need for novel treatment strategies. Recent studies have shown that vaccination against cocaine to elicit production of antibodies that reduce concentrations of free drug in the blood is a promising method to protect against the effects of cocaine and reduce rates of relapse. However, the poorly immunogenic nature of cocaine remains a major hurdle to active immunization. Therefore, we hypothesized that strategies to increase targeted exposure of cocaine to the immune system may produce a more effective vaccine. To specifically direct an immune response against cocaine, in the present study we have conjugated a cocaine analog to a dendrimer-based nanoparticle carrier with MHC II-binding moieties that previously has been shown to activate antigen-presenting cells necessary for antibody production. This strategy produced a rapid, prolonged, and high affinity anti-cocaine antibody response without the need for an adjuvant. Surprisingly, additional evaluation using multiple adjuvant formulations in two strains of inbred mice found adjuvants were either functionally redundant or deleterious in the vaccination against cocaine using this platform. The use of conditioned place preference in rats after administration of this vaccine provided proof of concept for the ability of this vaccine to diminish cocaine reward. Together these data demonstrate the intrinsic efficacy of an immune-targeting dendrimer-based cocaine vaccine, with a vast potential for design of future vaccines against other poorly immunogenic antigens by substitution of the conjugated cargo.  相似文献   

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15.
《Vaccine》2020,38(48):7645-7653
The development of a Chagaś disease vaccine has yet the need for the identification of novel combinations of antigens and adjuvants. Here, the performance of TcTASV-C proteins that are virulence factors of trypomastigotes and belong to a novel surface protein family specific for T. cruzi, have been evaluated as antigens for a prophylactic vaccine. Several immunization schemes in which TcTASV-C was combined with aluminum hydroxide, saponin and/or U-Omp19 were assayed. Aluminum hydroxide and saponin were assayed together to trigger different pathways of the immune response simultaneously. U-Omp19 is a promising novel adjuvant able to promote a Th1 immune response with IFNg production, thus an interesting molecule to be tested as adjuvant for the control of T. cruzi infection. Therefore, U-Omp19 was added to the aluminum hydroxide-saponin formulation as well as assayed individually with TcTASV-C. The immunization with TcTASV-C and U-Omp19 had the best performance as a prophylactic vaccine. Mice presented the lowest parasitemias and improved survival by 40% after being challenged with a highly virulent T. cruzi strain, which promoted 100% mortality in all other immunized groups. Immunization with TcTASV-C and U-Omp19 triggered cellular responses with IFN-γ and IL-17 production and with lytic antibodies that could explain the protection achieved by this vaccination scheme. To our knowledge, this is the first time that U-Omp19 is tested with a defined T. cruzi antigen in a vaccine formulation.  相似文献   

16.
《Vaccine》2019,37(26):3472-3477
Adjuvants are substances that enhance adaptive immune response to antigen. Development of a safe and effective immunostimulant adjuvant is essential for the efficacy of a vaccine to protect against infectious pathogens. Purple non-sulfur photosynthetic bacteria exhibited nontoxic natural lipid A variants that are distinct in their chemical structures from that of the Escherichia coli-type lipid A. In this study, the adjuvant efficacy of attenuated lipid A variants and their corresponding lipopolysaccharides (LPSs), derived from purple photosynthetic bacteria (Rhodocyclus tenuis and Rhodobacter sphaeroides) were evaluated. LPS was extracted using modified phenol-chloroform-petroleum ether method and lipid A was separated by mild acid hydrolysis. Trinitrophenol (TNP) was conjugated to hen egg albumin (TNP-HEA) and used as haptenic antigen. The LPS and lipid A adjuvant candidates were formulated in oil-in-water emulsion (OIWE) and evaluated to elicit anti-TNP IgG against TNP-HEA conjugate in BALB/c female mice. The anti-TNP IgG titers were measured using ELISA. The intact LPS-based adjuvants present in OIWE formulation showed significantly higher efficacy to elicit anti-TNP IgG titers against TNP-HEA conjugate compared to their corresponding lipid A-based adjuvants. As expected, the OIWE formulations of all LPS- and lipid A-based adjuvant candidates showed higher activities compared to the aqueous formulations. Slow reduction in the levels of anti-TNP IgG antibodies in the serum was observed over 4 months after immunization using the LPS- and lipid A-based adjuvant candidates which may provide a long protection against pathogens. The attenuated LPSs and lipid A’s from the photosynthetic bacteria showed promising results to develop novel safe and effective adjuvants that can evoke the immune response. The most promising adjuvant candidate was the LPS-based adjuvant from R. tenuis.  相似文献   

17.
《Vaccine》2021,39(16):2214-2223
IntroductionStudies on the cross-protective effect of HPV bivalent and quadrivalent vaccines demonstrated inconsistent findings against additional HPV types covered by the nonavalent vaccine. The objective of this study was to conduct a systematic literature review to assess the consistency and durability of the cross-protective neutralizing antibody immune responses of the currently licensed bivalent and quadrivalent vaccines to non-vaccine HPV types targeted by the nonavalent vaccine (HPV 6, 11, 31, 33, 45, 52, and 58).MethodsPubMed and EMBASE databases were searched from 2008 to 2019 to identify studies reporting antibody/immune response after vaccination with either the bivalent, quadrivalent, or nonavalent vaccine. Key outcomes were seroconversion, seropositivity or geometric mean titers against HPV types 6, 11, 31, 33, 45, 52, and 58.ResultsEighteen publications met inclusion criteria, reporting on 14 interventional and five observational studies. Across all studies, immune responses to non-vaccine high-risk HPV types after bivalent vaccination were higher than baseline or quadrivalent vaccine. Nonavalent vaccine elicited near total seroconversion to HPV types 31, 33, 45, 52, and 58, with seropositivity remaining near 100% up to 24 months post-dose 1. In contrast, bivalent and quadrivalent vaccination resulted in lower seroconversion levels for non-vaccine types, which waned over time.ConclusionsThe cross-protection antibody/immune response among participants having received all three doses of bivalent or quadrivalent vaccine is not comparable to the specific response elicited by HPV vaccine types. Even in cases where a statistically significant cross-reactive immunological response is reported, long-term data on the duration of the response beyond two years are very limited. Further, the lack of a standard for assays limits comparability of results between studies.  相似文献   

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20.
《Vaccine》2019,37(40):5954-5961
L-HBsAg is a third-generation hepatitis vaccine capable of inducing antibodies in non-responders and thus providing potentially therapeutic treatment. In this study, L-HBsAg was administered using microneedles (MN) without an adjuvant to induce intradermal (ID) immunization, and the efficacy of ID immunization was compared with that of intramuscular (IM) immunization that uses a conventional formulation with an adjuvant of aluminum hydroxide (L-HBsAg-AL-IM).The L-HBsAg was dip-coated onto 800-μm-long microneedles made of polylactic acid (PLA). Delivery efficiency and administration time were determined through in vitro experiments using porcine skin. The denaturation of the formulation against sterilization by gamma rays was observed. A storage test and a freeze-thaw cycle test of the microneedles with trehalose as a stabilizer (L-HBsAg-MN-Tre) were observed. An antibody titer of L-HBsAg-MN-Tre was compared with that of the conventional IM immunization of the L-HBsAg solution with aluminum hydroxide (L-HBsAg-AL-IM).The formulation containing L-HBsAg was located on the upper third of the microneedle tips. The formulation on the MN was dissolved and delivered within 30 min of insertion into porcine skin in vitro. Trehalose was selected as a stabilizer, and the stabilizing effect increased with the increase of trehalose content in the solidified formulation. L-HBsAg-MN with 15% of trehalose was stable for 7 days at 40 °C and showed increased stability compared to the conventional liquid formulations. L-HBsAg-MN-Tre showed improved stability during the freeze-thaw cycle. The antibody titer of L-HBsAg-MN-Tre at 28 days was higher than that of L-HBsAg-AL-IM.ID administration of L-HBsAg-MN-Tre showed better efficacy and improved thermal and freeze thaw stability compared to L-HBsAg-AL-IM. Therefore, L-HBsAg-MN-Tre administration showed the possibility of ID delivery of L-HBsAg without the use of an adjuvant for the efficacy, convenience, and safety of pediatric vaccination.  相似文献   

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