Immune Safety Research Articles

Silver Nanoparticles Attenuate the Antimicrobial Activity of the Innate Immune System by Inhibiting Neutrophil-Mediated Phagocytosis and Reactive Oxygen Species Production.

PurposeDespite the extensive development of antibacterial biomaterials, there are few reports on the effects of materials on the antibacterial ability of the immune system, and in particular of neutrophils. In this study, we observe differences between the in vivo and in vitro anti-infective efficacies of silver nanoparticles (AgNPs). The present study was designed to further explore the mechanism for this inconsistency using ex vivo models and in vitro experiments.MethodsAgNPs were synthesized using the polyol process and characterized by transmission electron microscopy and X-ray photoelectron spectroscopy. The antibacterial ability of AgNPs and neutrophils was tested by the spread-plate method. The infected air pouch model was prepared to detect the antimicrobial ability of AgNPs in vivo. Furthermore, blood-AgNPs-bacteria co-culture model and reactive oxygen species (ROS) measurement were used to evaluate the effect of AgNPs to neutrophil-mediated phagocytosis and ROS production.ResultsThe antibacterial experiments in vitro showed that AgNPs had superior antibacterial properties in cell compatible concentration. While, AgNPs had no significant antibacterial effect in vivo, and pathological section in AgNPs group indicated less neutrophil infiltration in inflammatory site than S. aureus group. Furthermore, AgNPs were found to reduce the phagocytosis of neutrophils and inhibit their ability to produce ROS and superoxide during ex vivo and in vitro experiments.ConclusionThis study selects AgNPs as the representative of inorganic nano-biomaterials and reveals the phenomenon and the mechanism underlying the significant AgNPs-induced inhibition of the antibacterial ability of neutrophils, and may have a certain enlightening effect on the development of biomaterials in the future. In the fabrication of antibacterial biomaterials, however, attention should be paid to both cell and immune system safety to make the antibacterial properties of the biomaterials and innate immune system complement each other and jointly promote the host’s ability to resist the invasion of pathogenic microorganisms.

Immune Modulation Effects of Lactobacillus casei Variety rhamnosus on Enterocytes and Intestinal Stem Cells in a 5-FU-Induced Mucositis Mouse Model.

Background Intestinal mucositis remains one of the most deleterious side effects in cancer patients undergoing chemotherapy. We hypothesize that the probiotics could preserve gut ecology, ameliorate inflammation, and protect epithelia via immune modulations of enterocytes and intestinal stem cells. Our aim is to characterize these changes and the safety of probiotics via a 5-fluorouracil- (5-FU-) induced intestinal mucositis mouse model. Methods 5-FU-injected BALB/c mice were either orally administrated with saline or probiotic suspension of Lactobacillus casei variety rhamnosus (Lcr35). Diarrhea scores, serum proinflammatory cytokines, and T-cell subtypes were assessed. Immunostaining analyses for the proliferation of intestinal stem cells CD44 and Ki67 were processed. Samples of blood and internal organs were investigated for bacterial translocation. Results Diarrhea was attenuated after oral Lcr35 administration. Serum proinflammatory cytokines were significantly increased in the 5-FU group and were reversed by Lcr35. A tremendous rise of the CD3+/CD8+ count and a significant decrease of CD3+CD4+/CD3+CD8+ ratios were found in the 5-FU group and were both reversed by Lcr35. 5-FU significantly stimulated the expression of CD44 stem cells, and the expression was restored by Lcr35. 5-FU could increase the number of Ki67 proliferative cells. No bacterial translocation was found in this study. Conclusions Our results showed that 5-FU caused intestinal inflammation mainly via Th1 and Th17 responses. 5-FU could stimulate stem cells and proliferation cells in a mouse model. We demonstrate chemotherapy could decrease immune competence. Probiotics were shown to modulate the immune response. This is the first study to analyze the immune modulation effects and safety of Lactobacillus strain on enterocytes and intestinal stem cells in a mouse model.

Tdap booster to adolescents with juvenile idiopathic arthritis on and off anti-TNF agents is safe and immunogenic

Introduction: The response to vaccines in juvenile idiopathic arthritis (JIA) patients on and off anti-tumor necrosis factor (anti-TNF) agents remains highly discussed. There are no published studies on the immune response following a Tdap booster dose in JIA patients so far. ObjectiveTo evaluate the immune response and safety after a Tdap booster in JIA patients and in healthy adolescents. MethodsNineteen adolescents with JIA according to the ILAR criteria on anti-TNF medication, 19 adolescents with JIA off anti-TNF medication, and 27 healthy adolescents (control group) were compared after a Tdap booster. Adverse events and disease activity were evaluated. Lymphocyte immunophenotyping was performed by flow cytometry. Tetanus, diphtheria and pertussis toxin antibodies were assessed by ELISA; whole blood was stimulated with whole-cell pertussis, and supernatants were assessed for cytokines by xMAP. ResultsThe three groups showed a similar frequency of adverse events. There was no disease reactivation after the Tdap booster. Tetanus, diphtheria and pertussis antibodies showed a significant response when D0 and D14 concentrations were compared in both JIA groups and controls. Over time, a different pattern of response to the Tdap booster was observed among the groups for tetanus antibodies (p = 0.005) but not for diphtheria and pertussis antibodies. In contrast to the protection attained for tetanus and diphtheria, in the three groups, not all individuals showed pertussis seroconversion at either D14 or D28. In addition, the seroconversion of three subjects with JIA on anti-TNF medication was not maintained at D28. JIA patients off anti-TNF showed a higher percentage of naive CD8 + T cells (p = 0.007) and central memory CD8 + cells (p = 0.003) and a lower percentage of effector CD8 + T cells (p = 0.003) and NK cell numbers (p = 0.018) than the control group. The JIA group off anti-TNF medication had fewer B lymphocytes than both the JIA group on anti-TNF medication and the control group (p = 0.016). Cellular immunity to Bordetella pertussis showed that IFNγ levels were significantly lower in both JIA groups than in the control group (p = 0.003), IL10 levels were higher in the JIA off anti-TNF group (p = 0.009), IL17A and IL5 levels were lower in the JIA on anti-TNF group than in the control group (p = 0.018 and p = 0.016, respectively); however, an increase in IFNγ (p = 0.008), IL17A (p = 0.030) and TNFα (p = 0.041) levels was observed at D14 in both patient groups. Both JIA groups showed higher levels of IL21 than the control group (p = 0.023). ConclusionWe conclude that individuals with JIA on or off anti-TNF agents showed a good response to a booster dose for the three antigens studied in the absence of major adverse events and without the reactivation of the disease.

EFFECT OF THE PREPARATION «PROSTIMUL» ON IMMUNE STATUS, PRODUCTIVITY AND SAFETY OF RETARDED IN GROWTH PIGS

The article presents the results of studies on the effect of Prostimul containing cytokines of the type 1, vitamins A, E, and C on the immune status, productivity, and safety of pigs that lag behind in growth and development. It was found that the drug, administered twice with an interval of 48 hours was followed by an increase in the immune status of animals, which was manifested by increasing in the serum the level of total protein, gamma globulins, total immunoglobulins, lysozymic and complementary activity, as well as the absorptive and digestive function of phagocytes, and a decrease in the level of circulating immune complexes and their pathogenicity. The use of Prostimul, accompanied by an increase in the immune status of pigs that retard in growth and devel-opment, had a positive effect on their productivity and safety. This allows the drug to be recommended for a wide use in industrial pig farming.

Adequate tetanus but poor diphtheria and pertussis response to a Tdap booster in adolescents with juvenile systemic lupus erythematosus.

Reports on vaccine responses in immunocompromised patients, such as juvenile systemic lupus erythematosus (jSLE), have shown highly variable results. To compare the immune response and safety after a Tdap booster in 26 jSLE patients and 26 matched healthy adolescents.Methodology: Adverse events and disease activity were evaluated. Lymphocyte immunophenotyping was performed by flow cytometry. Tetanus, diphtheria and pertussis toxin antibodies were assessed by ELISA; whole blood was stimulated with whole cell pertussis and supernatants were assessed for cytokines by xMAP. Both groups showed a similar frequency of adverse events. There was no evidence of disease reactivation after Tdap booster in the jSLE cohort. Both groups showed a significant increase in antibody titers for all three antigens on D14 and D28 (p < 0.001). jSLE patients had a significantly lower increase in diphtheria titers than the control group (p = 0.007). jSLE patients had a distinct titer increase of tetanus and pertussis antibodies when compared to controls (p = 0.004 and p < 0.001, respectively). There was a lower frequency of pertussis seroconversion in the jSLE group on D14 (p = 0.009), D28 (p = 0.023), D12m (p = 0.015) and D24m (p = 0.004). Cellular immune response to Bordetella pertussis showed significantly lower levels of IFNγ (p < 0.001) and higher levels of IL10, IL12, IL21 and TNFα in jSLE patients than controls. jSLE patients had good response to Tdap booster dose for the tetanus antigen, but not for diphtheria and pertussis. This vaccine was safe in relation to adverse events and absence of disease reactivation.

Is Viral Vector Gene Delivery More Effective Using Biomaterials?

Gene delivery has been extensively investigated for introducing foreign genetic material into cells to promote expression of therapeutic proteins or to silence relevant genes. This approach can regulate genetic or epigenetic disorders, offering an attractive alternative to pharmacological therapy or invasive protein delivery options. However, the exciting potential of viral gene therapy has yet to be fully realized, with a number of clinical trials failing to deliver optimal therapeutic outcomes. Reasons for this include difficulty in achieving localized delivery, and subsequently lower efficacy at the target site, as well as poor or inconsistent transduction efficiency. Thus, ongoing efforts are focused on improving local viral delivery and enhancing its efficiency. Recently, biomaterials have been exploited as an option for more controlled, targeted and programmable gene delivery. There is a growing body of literature demonstrating the efficacy of biomaterials and their potential advantages over other delivery strategies. This review explores current limitations of gene delivery and the progress of biomaterial-mediated gene delivery. The combination of biomaterials and gene vectors holds the potential to surmount major challenges, including the uncontrolled release of viral vectors with random delivery duration, poorly localized viral delivery with associated off-target effects, limited viral tropism, and immune safety concerns.

The Race for a COVID-19 Vaccine: Current Trials, Novel Technologies, and Future Directions.

Summary:The Coronavirus Disease 2019 (COVID-19) pandemic has presented a major threat to public health worldwide alongside unprecedented global economic and social implications. In the absence of a “gold standard” treatment, the rapid development of a safe and effective vaccine is considered the most promising way to control the pandemic. In recent years, traditional vaccine technologies have seemed insufficient to provide global protection against the rapid spread of emerging pandemics. Therefore, the establishment of novel approaches that are independent of whole pathogen cultivation, cost-effective, and able to be rapidly developed and produced on a large scale are of paramount importance for global health. This article summarizes the current efforts to develop a COVID-19 vaccine, including the ongoing and future anticipated clinical trials. We also provide plastic and reconstructive surgeons with insight into the novel technologies currently utilized for COVID-19 vaccine development, focusing on the very promising viral-vector-based and gene-based vaccine technologies. Each platform has its own advantages and disadvantages related to its efficacy and ability to induce certain immune responses, manufacturing capacity, and safety for human use. Once the fundamental key challenges have been addressed for viral-vector-based and gene-based vaccines, these novel technologies may become helpful in winning the fight against COVID-19 and transforming the future of health care.

Construction of a Live-Attenuated Vaccine Strain of Yersinia pestis EV76-B-SHUΔpla and Evaluation of Its Protection Efficacy in a Mouse Model by Aerosolized Intratracheal Inoculation.

Plague, which is caused by Yersinia pestis, is one of the most dangerous infectious diseases. No FDA-approved vaccine against plague is available for human use at present. To improve the immune safety of Y. pestis EV76 based live attenuated vaccine and to explore the feasibility of aerosolized intratracheal inoculation (i.t.) route for vaccine delivery, a plasminogen activator protease (pla) gene deletion mutant of the attenuated Y. pestis strain EV76-B-SHU was constructed, and its residual virulence and protective efficacy were evaluated in a mouse model via aerosolized intratracheal inoculation (i.t.) or via subcutaneous injection (s.c.). The residual virulence of EV76-B-SHUΔpla was significantly reduced compared to that of the parental strain EV76-B-SHU following i.t. and s.c. infection. The EV76-B-SHUΔpla induced higher levels of mucosal antibody sIgA in the bronchoalveolar lavage fluid of mice immunized by i.t. but not by s.c.. Moreover, after lethal challenge with Y. pestis biovar Microtus strain 201 (avirulent in humans), the protective efficacy and bacterial clearance ability of the EV76-B-SHUΔpla-i.t. group were comparable to those of the EV76-B-SHUΔpla-s.c. and EV76-B-SHU immunized groups. Thus, the EV76-B-SHUΔpla represents an excellent live-attenuated vaccine candidate against pneumonic plague and aerosolized i.t. represents a promising immunization route in mouse model.

Research progress on immune efficacy, safety, vaccination intention and immunization strategy of domestic enterovirus 71 vaccine after its marketing

Enterovirus 71 (EV71) is one of the main pathogens of hand, foot and mouth disease (HFMD) and the main pathogen of severe HFMD. In 2015, three EV71 vaccines were successively marketed in China as powerful prevention and control tools for HFMD caused by EV71. To understand the efficacy, immunogenicity, safety and quality stability of the domestic EV71 vaccine after entering into the market and analyze potential problems in its application, this article incorporates research regarding the immune effect, population effect, safety, quality testing and evaluation results, vaccination willingness and vaccination behavior survey to explore the vaccination strategies for the donll stic EV71 vaccine. EV71 vaccine has good immunogenicity, safety, protective efficacy, and good quality stability after entering into the market, however, only a few study focused on its safety when inoculating with other immunization planning vaccines simultaneously. Strengthen safety monitoring and discuss the safety of the EV71 vaccine especially when simultaneously inoculate with other immunization program vaccines are still necessary. Enterovirus evolution and recombination, whilst the probable impact of the EV71 vaccine can be the reason for future changes of HFMD epidemic strains, hence continuous monitoring of antigenic mutations and genetic evolution of enterovirus should be responded to. Encouraging the R&D of polyvalent vaccines against HFMD is also necessary. Parents' lack of HFMD and EV71 vaccine knowledge was common, therefore HFMD knowledge should be strengthened at the same time when introducing the EV71 vaccine to the public. Also, it should be emphasized that the EV71 vaccine can only prevent HFMD caused by EV71.

Immune checkpoint inhibitor efficacy and safety in older non-small cell lung cancer patients.

Immune checkpoint inhibitors offer longer survival than chemotherapy in several clinical trials for advanced non-small cell lung cancer. In subset analyses of clinical trials, immune checkpoint inhibitors extended survival in patients aged ≥65years, but the effects in patients aged ≥75years are controversial. We performed multicenter, collaborative and retrospective analyses of immune checkpoint inhibitor efficacy and safety in non-small cell lung cancer patients aged ≥75years. We retrospectively studied 434 advanced non-small cell lung cancer patients who received immune checkpoint inhibitors from December 2015 to December 2017, and retrospectively applied the Geriatric (G) 8 screening tool with medical records. Of the 434 patients who received immune checkpoint inhibitors, 100 were aged ≥75years. Five patients with performance status 3 were omitted from the final analysis. Immune checkpoint inhibitors were given as a first-line treatment to 20 patients. The objective response rates, median progression-free survival rates and median survival times were 35.0%, 6.1months and 10.7months for first-line treatment, and 20.0%, 2.9months and 14.7months for second- or later-line treatments, respectively. The median modified G8 score was 11.0. The median survival time was longer in the high modified G8 (≥12.0) group than in the low modified G8 (≤11.0) group (18.7 vs. 8.7months; P=0.02). Likewise, the median survival time was 15.5months (performance status 0-1) vs. 3.2months (performance status 2) (P<0.01). The grade≥2 immune-related adverse events incidence was 36.8%. In this study, immune checkpoint inhibitors were effective and tolerable for patients aged ≥75years. The modified G8 screening tool and performance status were associated with the outcome of older non-small cell lung cancer patients treated with immune checkpoint inhibitors.

Abstract 589: Immune biomarker profiling and safety evaluation response to 4-1BB antibody (Urelumab) in humanized 4-1BB mice

Abstract 4-1BB (CD137) belongs to the TNFR superfamily and is expressed by activated CD4 helper T cells, B cells, natural killer cells, natural killer T cells, dendritic cells and Treg cells. 4-1BB is a potential therapeutic target as it enhances tumor rejection by upregulating T cells following activation and its engagement increases T cell proliferation and pro-inflammatory cytokine production. However, the liver toxicity associated with over immune activation has obstructed the clinical development of 4-1BB targeting therapies. To address the issue, Biocytogen has developed humanized B-h4-1BB mice as an efficient platform of both in vivo MOA and safety studies of 4-1BB antibody. In B-h4-1BB mice, murine colon cancer MC38 cells were subcutaneously implanted. Biomarkers, such as, mCD45, mCD3, mCD4, mCD8, mNK, mFoxp3, mCD11b, and etc., were profiled after the treatment with an 4-1BB antibody (Urelumab). FACS, IHC, and IF data showed that Urelumab have increased the ratio of CD8+ T cell, but on the other hand decreased Treg cell, the PD-1 and Tim3 (T cell exhausted marker) upon treatment. Toxicity have also been with the treatment of Urelumab using this model. The blood chemistry assays showed that the high dose Urelumab had toxicity effects compared with the control group and WT C57BL/6 mice. Based on these findings, we conclude that the B-h4-1BB humanized mouse model is a powerful platform for both MOA (biomarker) discovery and safety evaluation of 4-1BB antibody. Citation Format: Jie Xiang, Dirui Li, Hao Yang, Gary Ng, Yuelei Shen. Immune biomarker profiling and safety evaluation response to 4-1BB antibody (Urelumab) in humanized 4-1BB mice [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 589.

Advancements in the Field of Vaccines and Immunization

“Vaccines and Immunization” is a global platform to discuss and learn Vaccines and Immunization, Vaccine Preventable Diseases, Plant-Based Vaccines, Types of Immunology, Immunoresearch & Immunotechnology, Autoimmune & Inflammatory Diseases, Immune Diseases, Making a Session Plan, Giving Vaccinations, HIV Vaccines, Vaccines Production and Development, Vaccines for Immune Mediated Diseases, Vaccine Safety & Efficacy. Vaccines are antigenic substance prepared from the causative agent of a disease or a synthetic substitute, used to provide immunity against one or several diseases. Vaccine stimulates the immune system so that it can recognize the disease and protect from future infection.

Toward High-Dimensional Single-Cell Analysis of Graphene Oxide Biological Impact: Tracking on Immune Cells by Single-Cell Mass Cytometry.

Considering the potential exposure to graphene, the most investigated nanomaterial, the assessment of the impact on human health has become an urgent need. The deep understanding of nanomaterial safety is today possible by high-throughput single-cell technologies. Single-cell mass cytometry (cytometry by time-of flight, CyTOF) shows an unparalleled ability to phenotypically and functionally profile complex cellular systems, in particular related to the immune system, as recently also proved for graphene impact. The next challenge is to track the graphene distribution at the single-cell level. Therefore, graphene oxide (GO) is functionalized with AgInS2 nanocrystals (GO-In), allowing to trace GO immune-cell interactions via the indium (115 In) channel. Indium is specifically chosen to avoid overlaps with the commercial panels (>30 immune markers). As a proof of concept, the GO-In CyTOF tracking is performed at the single-cell level on blood immune subpopulations, showing the GO interaction with monocytes and B cells, therefore guiding future immune studies. The proposed approach can be applied not only to the immune safety assessment of the multitude of graphene physical and chemical parameters, but also for graphene applications in neuroscience. Moreover, this approach can be translated to other 2D emerging materials and will likely advance the understanding of their toxicology.

Changes in immune cell profile, clinical and safety outcomes in fingolimod-treated patients with relapsing multiple sclerosis in the FLUENT study (4249)

Changes in immune cell profile, clinical and safety outcomes in fingolimod-treated patients with relapsing multiple sclerosis in the FLUENT study (4249)

CD28/4-1BB CD123 CAR T cells in blastic plasmacytoid dendritic cell neoplasm.

Blastic plasmacytoid dendritic cell neoplasm (BPDCN) is associated with a remarkably poor prognosis and with no treatment consensus. The identification of relevant therapeutic targets is challenging. Here, we investigated the immune functions, antileukemia efficacy and safety of CD28/4-1BB CAR T cells targeting CD123 the interleukin (IL)-3 receptor alpha chain which is overexpressed on BPDCN. We demonstrated that both retroviral and lentiviral engineering CD28/4-1BB CD123 CAR T cells exhibit effector functions against BPDCN cells through CD123 antigen recognition and that they efficiently kill BPDCN cell lines and BPDCN-derived PDX cells. In vivo, CD28/4-1BB CD123 CAR T-cell therapy displayed strong efficacy by promoting a decrease of BPDCN blast burden. Furthermore we showed that T cells from BPDCN patient transduced with CD28/4-1BB CD123 CAR successfully eliminate autologous BPDCN blasts in vitro. Finally, we demonstrated in humanized mouse models that these effector CAR T cells exert low or no cytotoxicity against various subsets of normal cells with low CD123 expression, indicating a potentially low on-target/off-tumor toxicity effect. Collectively, our data support the further evaluation for clinical assessment of CD28/4-1BB CD123 CAR T cells in BPDCN neoplasm.

Improved immune responses and safety of foot-and-mouth disease vaccine containing immunostimulating components in pigs.

BackgroundThe quality of a vaccine depends strongly on the effects of the adjuvants applied simultaneously with the antigen in the vaccine. The adjuvants enhance the protective effect of the vaccine against a viral challenge. Conversely, oil-type adjuvants leave oil residue inside the bodies of the injected animals that can produce a local reaction in the muscle. The long-term immunogenicity of mice after vaccination was examined. ISA206 or ISA15 oil adjuvants maintained the best immunity, protective capability, and safety among the oil adjuvants in the experimental group.ObjectivesThis study screened the adjuvant composites aimed at enhancing foot-and-mouth disease (FMD) immunity. The C-type lectin or toll-like receptor (TLR) agonist showed the most improved protection rate.MethodsExperimental vaccines were fabricated by mixing various known oil adjuvants and composites that can act as immunogenic adjuvants (gel, saponin, and other components) and examined the enhancement effect on the vaccine.ResultsThe water in oil (W/O) and water in oil in water (W/O/W) adjuvants showed better immune effects than the oil in water (O/W) adjuvants, which have a small volume of oil component. The W/O type left the largest amount of oil residue, followed by W/O/W and O/W types. In the mouse model, intramuscular inoculation showed a better protection rate than subcutaneous inoculation. Moreover, the protective effect was particularly weak in the case of inoculation in fatty tissue. The initial immune reaction and persistence of long-term immunity were also confirmed in an immune reaction on pigs.ConclusionsThe new experimental vaccine with immunostimulants produces improved immune responses and safety in pigs than general oil-adjuvanted vaccines.

A multiple peptides vaccine against COVID-19 designed from the nucleocapsid phosphoprotein (N) and Spike Glycoprotein (S) via the immunoinformatics approach

Due to the current Coronavirus (COVID-19) pandemic, the rapid discovery of a safe and effective vaccine is an essential issue. Consequently, this study aims to predict a potential COVID-19 peptide-based vaccine utilizing the Nucleocapsid phosphoprotein (N) and Spike Glycoprotein (S) via the Immunoinformatics approach. To achieve this goal, several Immune Epitope Database (IEDB) tools, molecular docking, and safety prediction servers were used. According to the results, The Spike peptide SQCVNLTTRTQLPPAYTNSFTRGVY is predicted to have the highest binding affinity to the B-Cells. The Spike peptide FTISVTTEI has the highest binding affinity to the Major Histocompatibility Complex class 1 (MHC I) Human Leukocyte Allele HLA-B*1503 (according to the MDockPeP and HPEPDOCK servers, docking scores were −153.9 and −229.356, respectively). The Nucleocapsid peptides KTFPPTEPK and RWYFYYLGTGPEAGL have the highest binding affinity to the MHC I HLA-A0202 allele and the three the Major Histocompatibility Complex class 2 (MHC II) Human Leukocyte Allele HLA-DPA1*01:03/DPB1*02:01, HLA-DQA1*01:02/DQB1-*06:02, HLA-DRB1, respectively. Docking scores of peptide KTFPPTEPK were −153.9 and −220.876. In contrast, docking scores of peptide RWYFYYLGTGPEAGL were ranged from 218 to 318. Furthermore, those peptides were predicted as non-toxic and non-allergen. Therefore, the combination of those peptides is predicted to stimulate better immunological responses with respectable safety.

RETRACTED ARTICLE: Therapeutic effect of nanoliposomal PCSK9 vaccine in a mouse model of atherosclerosis

BackgroundProprotein convertase subtilisin/kexin 9 (PCSK9) is an important regulator of low-density lipoprotein receptor (LDLR) and plasma levels of LDL cholesterol (LDL-C). PCSK9 inhibition is an efficient therapeutic approach for the treatment of dyslipidemia. We tested the therapeutic effect of a PCSK9 vaccine on dyslipidemia and atherosclerosis.MethodsLipid film hydration method was used to prepare negatively charged nanoliposomes as a vaccine delivery system. An immunogenic peptide called immunogenic fused PCSK9-tetanus (IFPT) was incorporated on the surface of nanoliposomes using DSPE-PEG-maleimide lipid (L-IFPT) and adsorbed to Alhydrogel® (L-IFPTA+). The prepared vaccine formulation (L-IFPTA+) and empty liposomes (negative control) were inoculated four times with bi-weekly intervals in C57BL/6 mice on the background of a severe atherogenic diet and poloxamer 407 (thrice weekly) injection. Antibody titers were evaluated 2 weeks after each vaccination and at the end of the study in vaccinated mice. Effects of anti-PCSK9 vaccination on plasma concentrations of PCSK9 and its interaction with LDLR were determined using ELISA. To evaluate the inflammatory response, interferon-gamma (IFN-γ)- and interleukin (IL)-10-producing splenic cells were assayed using ELISpot analysis.ResultsL-IFPTA+ vaccine induced a high IgG antibody response against PCSK9 peptide in the vaccinated hypercholesterolemic mice. L-IFPTA+-induced antibodies specifically targeted PCSK9 and decreased its plasma consecration by up to 58.5% (− 164.7 ± 9.6 ng/mL, p = 0.0001) compared with the control. PCSK9-LDLR binding assay showed that generated antibodies could inhibit PCSK9-LDLR interaction. The L-IFPTA+ vaccine reduced total cholesterol, LDL-C, and VLDL-C by up to 44.7%, 51.7%, and 19.2%, respectively, after the fourth vaccination booster, compared with the control group at week 8. Long-term studies of vaccinated hypercholesterolemic mice revealed that the L-IFPTA+ vaccine was able to induce a long-lasting humoral immune response against PCSK9 peptide, which was paralleled by a significant decrease of LDL-C by up to 42% over 16 weeks post-prime immunization compared to control. Splenocytes isolated from the vaccinated group showed increased IL-10-producing cells and decreased IFN-γ-producing cells when compared with control and naive mice, suggesting the immune safety of the vaccine.ConclusionsL-IFPTA+ vaccine could generate long-lasting, functional, and safe PCSK9-specific antibodies in C57BL/6 mice with severe atherosclerosis, which was accompanied by long-term therapeutic effect against hypercholesterolemia and atherosclerosis.

2723. Immunogenicity and Safety of a Quadrivalent Meningococcal Conjugate Vaccine (MenACYW-TT) Administered in Adolescents 10–17 Years of Age

BackgroundThe MenACYW-TT conjugate vaccine is a quadrivalent meningococcal vaccine that contains tetanus toxoid as carrier protein. The vaccine is intended for global use in all age groups (i.e., individuals 6 weeks of age and older). This Phase III study evaluated the immune lot consistency, and safety and immunogenicity of the vaccine when compared with a licensed quadrivalent meningococcal conjugate vaccine in individuals 10–55 years of age.MethodsA randomized, modified double-blind, multi-center study (NCT02842853) was conducted in the United States. The study evaluated 3344 meningococcal vaccine naïve adolescents and adults, who were randomly assigned to receive either a single dose of one of the three lots of MenACYW-TT conjugate vaccine or single dose of Menactra® [MenACWY-D]. Serum bactericidal assay with human complement (hSBA) and baby rabbit complement (rSBA) was used to measure antibodies against serogroups A, C, W and Y at baseline before vaccination (Day 0) and 30 days post-vaccination. Safety data were collected up to 6 months post-vaccination. Herein we report the performance of MenACYW-TT in adolescents 10 through 17 years of age (n = 1504).ResultsImmune equivalence was demonstrated across all 3 lots of MenACYW-TT conjugate vaccine based on geometric mean titers (GMTs) for all serogroups. Non-inferiority of immune responses, based on percentages of participants achieving hSBA vaccine seroresponse, was demonstrated between MenACYW-TT and MenACWY-D for all four serogroups at Day 30 compared with baseline. The proportions of individuals (10–17 years) with hSBA ≥ 1:8 following MenACYW-TT administration were higher than those after MenACWY-D administration for all four serogroups (A: 96.2% vs. 89.0%; C: 98.5% vs. 74.7%; W: 98.3% vs. 93.7%; Y: 99.1% vs. 94.3%). A similar trend was observed for post vaccination GMTs in adolescent participants. Reactogenicity profiles were comparable across study groups. Most unsolicited adverse events were of grade 1 or grade 2 intensity. No vaccine-related serious adverse events were reported.ConclusionMenACYW-TT vaccine was well tolerated and demonstrated a non-inferior immune response compared with the licensed MenACWY-D vaccine when administered as a single dose to meningococcal vaccine naïve adolescents.Disclosures All authors: No reported disclosures.

2719. Immunogenicity and Safety of a Quadrivalent Meningococcal Conjugate Vaccine (MenACYW-TT) Administered in Adults 18–55 Years of Age

BackgroundThe MenACYW-TT conjugate vaccine is a quadrivalent meningococcal vaccine that contains tetanus toxoid as carrier protein. The vaccine is intended for global use in all age groups (i.e., individuals 6 weeks of age and older). This Phase III study evaluated the immune lot consistency, and safety and immunogenicity of the vaccine when compared with a licensed quadrivalent meningococcal conjugate vaccine in individuals 10–55 years of age.MethodsA randomized, modified double-blind, multi-center study (NCT02842853) was conducted in the United States. The study evaluated 3344 meningococcal vaccine naïve adolescents and adults, who were randomly assigned to receive either a single dose of one of the three lots of MenACYW-TT conjugate vaccine or single dose of Menactra® [MenACWY-D]. Serum bactericidal assay with human complement (hSBA) and rabbit complement (rSBA) was used to measure antibodies against serogroups A, C, W, and Y at baseline before vaccination (Day 0) and 30 days post-vaccination. Safety data were collected up to 6 months post-vaccination. Herein we report the performance of MenACYW-TT in adults 18 through 55 years of age (n = 1,807).ResultsImmune equivalence was demonstrated across all 3 lots of MenACYW-TT conjugate vaccine based on geometric mean titers (GMTs) for all serogroups. Non-inferiority of immune responses, based on percentages of participants achieving hSBA vaccine seroresponse, was demonstrated between MenACYW-TT and MenACWY-D for all four serogroups at Day 30 compared with baseline. The proportions of individuals (18–55 years) with hSBA ≥ 1:8 following MenACYW-TT administration were higher than those after MenACWY-D administration for all four serogroups (A: 93.5% vs. 88.1%; C: 93.5% vs. 77.8%; W: 94.5% vs. 80.2%; Y: 98.6% vs. 81.2%). A similar trend was observed for post vaccination GMTs in adult participants. Reactogenicity profiles were comparable across study groups. Most unsolicited adverse events were of grade 1 or grade 2 intensity. No vaccine-related serious adverse events were reported.ConclusionMenACYW-TT vaccine was well tolerated and demonstrated a non-inferior immune response compared with the licensed MenACWY-D vaccine when administered as a single dose to meningococcal vaccine naïve adults.Disclosures All authors: No reported disclosures.