Ad Vectors Research Articles

Intranasal delivery of a recombinant adenovirus vaccine encoding the PEDV COE elicits potent mucosal and systemic antibody responses in mice.

Porcine epidemic diarrhea virus (PEDV) is an enteropathogenic coronavirus that causes substantial economic loss to the global pig industry. The emergence of PEDV variants has increased the need for new vaccines, as commercial vaccines confer inferior protection against currently circulating strains. It is well established that the induction of mucosal immunity is crucial for PEDV vaccines to provide better protection against PEDV infection. In this study, we constructed a recombinant adenovirus expressing the core neutralization epitope (COE) of G2b PEDV based on human adenovirus serotype 5 (Ad5). We evaluated the effects of different administration routes and doses of vaccine immunogenicity in Balb/c mice. Both intramuscular (IM) and intranasal (IN) administration elicited significant humoral responses, including COE-specific IgG in serum and mucosal secretions, along with serum-neutralizing antibodies. Moreover, IN delivery was more potent than IM in stimulating IgA in serum and mucosal samples and in dampening the immune response to the Ad5 vector. The immune response was stronger after high versus low dose IM injection, whereas no significant difference was observed between high and low IN doses. In summary, our findings provide important insights for developing novel PEDV vaccines.IMPORTANCEPorcine epidemic diarrhea (PED) is a highly contagious disease that has severe economic implications for the pork industry. Developing an effective vaccine against PEDV remains a necessity. Here, we generated a recombinant adenovirus vaccine based on Ad5 to express the COE protein of PEDV (rAd5-PEDV-COE) and systematically evaluated the immunogenicity of the adenovirus-vectored vaccine using different administration routes (intramuscular and intranasal) and doses in a mouse model. Our results show that rAd5-PEDV-COE induced potent systemic humoral response regardless of the dose or immunization route. Notably, intranasal delivery was superior to induce peripheral and mucosal IgA antibodies compared with intramuscular injection. Our data provide valuable insights into designing novel PEDV vaccines.

Evaluation of the correlation between nuclear localization levels and genome editing efficiencies of Cas12a fused with nuclear localization signals

Genome editing technology using the CRISPR-Cas system is attracting much attention not only as a promising experimental tool for analysis of genome functions, but also as a novel therapeutic approach for genetic disorders. Among the various types of Cas proteins, Cas12a is expected to be a promising gene editing tool due to its unique properties, including low off-target effects. As Cas proteins are of prokaryotic origin, they need to be fused with appropriate localization signals to perform their function in eukaryotic cells. Cas12a proteins fused with a nuclear localization signal (NLS) have been developed so far, but the relation between the nuclear localization activity and the genome editing efficiency has not been fully elucidated. Here, utilizing two Cas12a orthologs, AsCas12a and LbCas12a, with various number of NLSs derived from various origins, we revealed that the improved nuclear localization resulted in increased genome editing efficiencies when expressed using adenovirus (Ad) vector in cultured cells. However, when they were expressed in mouse liver, the improvement of the nuclear localization activity was not necessarily required to achieve the maximum genome editing efficiency four weeks after Ad vector administration. These data indicated that the optimized NLS modification of Cas12a proteins in in vitro situations differed from that in in vivo.

FastAd: A versatile toolkit for rapid generation of single adenoviruses or diverse adenoviral vector libraries

Adenoviruses (Ads) are potent gene delivery vectors for in vitro and in vivo applications. However, current methods for their construction are time-consuming and inefficient, limiting their rapid production and utility in generating complex genetic libraries. Here, we introduce FastAd, a rapid and easy-to-use technology for inserting recombinant “donor” DNA directly into infectious “receiver” Ads in mammalian cells by the concerted action of two efficient recombinases: Cre and Bxb1. Subsequently, the resulting mixed recombinant Ad population is subjected to negative selections by flippase (FLP) recombinase to remove viruses that missed the initial recombination. With this approach, recombinant Ad production time is reduced from two months to 10 days or less. FastAd can be applied for inserting complex genetic DNA libraries into Ad genomes, as evidenced by the generation of barcode libraries with over 3 million unique clones from a T25 flask-scale of transfection. Furthermore, we leveraged FastAd to construct an Ad library containing a comprehensive genome-wide CRISPR/Cas9 guide RNA (gRNA) library and demonstrated its effectiveness in uncovering novel virus-host interactions. In summary, FastAd enables the rapid generation of single Ad vectors or complex genetic libraries, facilitating not only novel applications of Ad vectors but also research in foundational Ad biology.

Transplacental delivery of factor IX Fc-fusion protein ameliorates bleeding phenotype of newborn hemophilia B mice

Hemophilia B is an inherited hemorrhagic disorder characterized by a deficiency of blood coagulation factor IX (FIX) that results in abnormal blood coagulation. The blood coagulation is already evident in hemophiliacs at the fetal stage, and thus intracranial hemorrhage and other bleeding complications can occur at birth, leading to sequelae. Therefore, it is important to develop effective treatments for hemophiliacs in utero. In this study, in order to transplacentally deliver FIX from pregnant mice to their fetuses, an improved adenovirus (Ad) vector expressing human FIX fused with the IgG Fc domain (FIX Fc fusion protein), which plays a crucial role in neonatal Fc receptor (FcRn)-mediated transcytosis across the placenta, was intravenously administered to E13.5 pregnant mice. Significant levels of FIX Fc fusion protein were detected in 0-day-old newborn mice whose mothers were administered an Ad vector expressing FIX Fc fusion protein. Wild-type FIX overexpressed in the pregnant mice was not delivered to the fetuses. Plasma FIX levels in the newborn mice were relatively well correlated with those in their mothers, although transplacental delivery efficiencies of FIX Fc fusion protein were slightly reduced when the FIX Fc fusion protein was highly expressed in the mother mice. Plasma FIX levels in the newborn mice were about 3.6–6.4% of those in their mothers, Transplacental delivery of FIX Fc fusion protein to their fetuses successfully improved the blood clotting ability in the newborn mice.

A pseudotyped adenovirus serotype 5 vector with serotype 49 fiber knob is an effective vector for vaccine and gene therapy applications

Adenoviruses (Ad) have demonstrated significant success as replication-deficient (RD) viral vectored vaccines, as well as broad potential across gene therapy and cancer therapy. Ad vectors transduce human cells via direct interactions between the viral fiber knob and cell surface receptors, with secondary cellular integrin interactions. Ad receptor usage is diverse across the extensive phylogeny. Commonly studied human Ad serotype 5 (Ad5), and chimpanzee Ad-derived vector “ChAdOx1” in licensed ChAdOx1 nCoV-19 vaccine, both form primary interactions with the Coxsackie and Adenovirus Receptor (CAR), which is expressed on human epithelial cells and erythrocytes. CAR usage is suboptimal for targeted gene delivery to cells with low/negative CAR expression, including human dendritic cells (DCs) and vascular smooth muscle cells (VSMCs). We evaluated the performance of a RD Ad5 vector pseudotyped with the fiber knob of human Ad serotype 49, termed Ad5/49K vector. Ad5/49K demonstrated superior transduction of murine and human DCs over Ad5, which translated into significantly increased T cell immunogenicity when evaluated in a mouse cancer vaccine model using 5T4 tumour-associated antigen. Additionally, Ad5/49K exhibited enhanced transduction of primary human VSMCs. These data highlight the potential of Ad5/49K vector for both vascular gene therapy applications and as a potent vaccine vector.

A Simple and Versatile Method for Ex Vivo Monitoring of Goat Vaginal Mucosa Transduction by Viral Vector Vaccines.

Goat may represent a valid large animal model for human pathogens and new vaccines testing. Appropriate vaccine administration is a critical component of a successful immunization program. The wrong route of administration may reduce the efficacy of the vaccine, whereas the proper administration strategy can enhance it. Viral vectors have been employed successfully for goat and sheep immunization; however, no data concerning the vaginal route are available. A viral vector's ability to transduce the site of inoculation is of primary interest. In this study, a fast and reliable ex vivo assay for testing the transduction capability of an Ad5-based vector when intravaginally administered was developed. An Ad5 vector delivering an expression cassette with a bicistronic reporter gene, Ad5-CMV-turboGFP-IRES-Luc2, was constructed. We demonstrated Ad5-CMV-turboGFP-IRES-Luc2's ability to transduce caprine vaginal mucosa by ex vivo bioluminescent imaging (BLI) employing a simple CCD camera apparatus for chemiluminescence western immunoblotting. These data, though simple, provide valuable insights into developing a vaginal immunization strategy using a viral vector-based vaccine to protect against pathogens causing genital diseases.

Development of a novel adenovirus serotype 35 vector vaccine possessing an RGD peptide in the fiber knob and the E4 orf 4, 6, and 6/7 regions of adenovirus serotype 5

Adenovirus (Ad) vectors based on human adenovirus serotype 5 (Ad5) have attracted significant attention as vaccine vectors for infectious diseases. However, the effectiveness of Ad5 vectors as vaccines is often inhibited by the anti-Ad5 neutralizing antibodies retained by many adults. To overcome this drawback, we focused on human adenovirus serotype 35 (Ad35) vectors with low seroprevalence in adults. Although Ad35 vectors can circumvent anti-Ad5 neutralizing antibodies, vector yields of Ad35 vectors are often inferior to those of Ad5 vectors. In this study, we developed novel Ad35 vectors containing the Ad5 E4 orf 4, 6, and 6/7 or the Ad5 E4 orf 6 and 6/7 for efficient vector production, and compared their properties. These E4-modified Ad35 vectors efficiently propagated to a similar extent at virus titers comparable to those of Ad5 vectors. An Ad35 vector containing the Ad5 E4 orf 4, 6, and 6/7 mediated more efficient transduction than that containing the Ad5 E4 orf 6 and 6/7 in human cultured cells. Furthermore, insertion of an arginine-glycine-aspartate (RGD) peptide in the fiber region of an Ad35 vector containing the Ad5 E4 orf 4, 6, and 6/7 significantly improved the transgene product-specific antibody production following intramuscular administration in mice. The Ad35 vector containing the RGD peptide mediated efficient vaccine effects even in the mice pre-immunized with an Ad5.

Development of an Improved Adenovirus Vector and Its Application to the Treatment of Lifestyle-Related Diseases.

The number of patients with lifestyle-related diseases such as type 2 diabetes mellitus (T2DM) and metabolic dysfunction-associated steatotic liver disease (MASLD), formerly known as non-alcoholic fatty liver disease (NAFLD), has continued to increase worldwide. Therefore, development of innovative therapeutic methods targeting lifestyle-related diseases is required. Gene therapy has attracted considerable attention as an advanced medical treatment. Safe and high-performance vectors are essential for the practical application of gene therapy. Replication-incompetent adenovirus (Ad) vectors are widely used in clinical gene therapy and basic research. Here, we developed a novel Ad vector, named Ad-E4-122aT, exhibiting higher and longer-term transgene expression and lower hepatotoxicity than conventional Ad vectors. We also elucidated the mechanisms underlying Ad vector-induced hepatotoxicity during the early phase using Ad-E4-122aT. Next, we examined the therapeutic effects of the genes of interest, namely zinc finger AN1-type domain 3 (ZFAND3), lipoprotein lipase (LPL), and lysophospholipid acyltransferase 10 (LPLAT10), on lifestyle-related diseases using Ad-E4-122aT. We showed that the overexpression of ZFAND3 in the liver improved glucose tolerance and insulin resistance. Liver-specific LPL overexpression suppressed hepatic lipid accumulation and improved glucose metabolism. LPLAT10 overexpression in the liver suppressed postprandial hyperglycemia by increasing glucose-stimulated insulin secretion. Furthermore, we also focused on foods to advance research on the pathophysiology and treatment of lifestyle-related diseases. Cranberry and calamondin, which are promising functional foods, attenuated the progression of MASLD/NAFLD. Our findings will aid the development of new therapeutic methods, including gene therapy, for lifestyle-related diseases such as T2DM and MASLD/NAFLD.

Efficacy, Effectiveness, and Safety of COVID-19 Vaccine Compared to Placebo in Preventing COVID-19 Infection among 12-17 Years Old: A Systematic Review.

The World Health Organization recently revised their recommendations and considered healthy children and adolescents as low priority group for COVID-19 vaccine. This review comprehensively assessed existing clinical evidence on COVID-19 vaccine in 12-17 years old. Included in this review were any type of study that investigated the efficacy, immunogenicity, safety, and effectiveness of COVID-19 vaccine on protection against SARS-COV-2 infection in 12-17 years old. Various electronic databases were searched up to March 15, 2023. Studies were screened, data extracted, risk of bias appraised, and certainty of evidence was judged using GRADE. Review Manager 5.4 was used to estimate pooled effects. Difference between the two groups was described as mean difference for continuous variables and as relative risk or odds ratio for categorical variables. There were six randomized controlled trials and 16 effectiveness studies (8 cohorts and 8 case control). Low certainty evidence showed that BNT162b2 (Pfizer) was effective, immunogenic, and safe in healthy adolescents. There were 15 effectiveness studies on BNT162b2 (Pfizer) in healthy adolescent and one on immunocompromised patients. It was protective against infection with any of the variants, with higher protection against Delta than Omicron. BNT162b2 is protective against hospitalization and emergency and urgent care (high certainty); and critical care and MIS-C (low). Very low certainty evidence noted that BNT 162b2 was also immunogenic in 12-21 years old with rheumatic diseases while on immunomodulatory treatment but with possible increased exacerbation of illness. Low certainty evidence demonstrated that mRNA-1273 (Moderna) was effective, immunogenic, and safe. Low to very low certainty evidence were noted on the safety and immunogenicity of two vector base vaccines (ChAdOx1-19 and Ad5 vector COVID vaccine) and two inactivated vaccines (CoronaVac and BBIBP CorV). There is presently low certainty evidence on the use of RNA vaccines in 12-17 years old. The recommendation on its use is weak. There is presently insufficient evidence for the use of inactivated and vector-based COVID-19 vaccines. Different countries should consider whether to vaccinate healthy adolescent without comprising the other recommended immunization and health priorities that are crucial for this age group. Other factors including cost-effectiveness of vaccination and disease burden should be accounted.

Prophylactic treatment with PEGylated bovine IFNλ3 effectively bridges the gap in vaccine-induced immunity against FMD in cattle.

Foot-and-mouth disease (FMD) is a vesicular disease of cloven-hoofed animals with devastating economic implications. The current FMD vaccine, routinely used in enzootic countries, requires at least 7 days to induce protection. However, FMD vaccination is typically not recommended for use in non-enzootic areas, underscoring the need to develop new fast-acting therapies for FMD control during outbreaks. Interferons (IFNs) are among the immune system's first line of defense against viral infections. Bovine type III IFN delivered by a replication defective adenovirus (Ad) vector has effectively blocked FMD in cattle. However, the limited duration of protection-usually only 1-3 days post-treatment (dpt)-diminishes its utility as a field therapeutic. Here, we test whether polyethylene glycosylation (PEGylation) of recombinant bovine IFNλ3 (PEGboIFNλ3) can extend the duration of IFN-induced prevention of FMDV infection in both vaccinated and unvaccinated cattle. We treated groups of heifers with PEGboIFNλ3 alone or in combination with an adenovirus-based FMD O1Manisa vaccine (Adt-O1M) at either 3 or 5 days prior to challenge with homologous wild type FMDV. We found that pre-treatment with PEGboIFNλ3 was highly effective at preventing clinical FMD when administered at either time point, with or without co-administration of Adt-O1M vaccine. PEGboIFNλ3 protein was detectable systemically for >10 days and antiviral activity for 4 days following administration. Furthermore, in combination with Adt-O1M vaccine, we observed a strong induction of FMDV-specific IFNγ+ T cell response, demonstrating its adjuvanticity when co-administered with a vaccine. Our results demonstrate the promise of this modified IFN as a pre-exposure prophylactic therapy for use in emergency outbreak scenarios.

340 Anti-CD20 attenuates lung humoral and cellular immune responses: implications for gene therapy in Cystic Fibrosis

OBJECTIVES/GOALS: Re-administration of inhaled gene therapies has the potential to overcome low correction efficiencies and limiting immune responses observed in previous trials of gene therapy for Cystic Fibrosis. We therefore tested the hypothesis that pre-treatment with a B-cell depleting α ± CD20 antibody would permit vector re-administration. METHODS/STUDY POPULATION: We first selected Adenoviral (Ad) vectors to study initially due to their well-known ability to elicit potent immune responses. Mice were dosed with a depleting α ± CD20 antibody or isotype control 2 days prior to delivery of Ad-Luc. 4 weeks later, mice were euthanized to assess the development of anti-vector immune responses. Flow cytometry and single-cell RNA sequencing were used to evaluate the development of lung-resident memory cells. Serum and airway antibody responses were assessed by ELISA. After 4 weeks, mice were dosed with Ad-LacZ and euthanized 3 days later to assess efficiency of second-round gene transfer by β-galactosidase activity assay. Similar methods were used in a pilot experiment with Adeno-associated virus vector (AAV), but with euthanasia 3 weeks after secondary gene transfer. RESULTS/ANTICIPATED RESULTS: Delivery of Ad vectors leads to the development of lung-resident memory B and T-cells. The depletion of B-cells prior to first-round vector delivery attenuated airway T-cell infiltration and serum IgG production, abrogated mucosal IgG and IgA production, and completely rescued secondary gene transfer. Genetically modified mouse models suggest secreted antibodies are critical in prevention of vector redosing. AAV vectors were found to be less immunogenic than Ad vectors, with only partial reduction of second-round gene transfer. However, anti-CD20 provided no benefit for AAV redelivery. DISCUSSION/SIGNIFICANCE: Mucosal humoral immunity is critical in preventing re-administration of Adenoviral vectors. Impairment of B-cell responses by α ± CD20 treatment prior to vector delivery allows re-administration and may help overcome low efficiencies of CF gene therapy. AAV vectors may be less susceptible to neutralization by pre-existing immunity.

Development of adenoviral vectors that transduce Purkinje cells and other cerebellar cell-types in the cerebellum of a humanized mouse model

Viral vector gene therapy has immense promise for treating central nervous system (CNS) disorders. Although adeno-associated virus vectors (AAVs) have had success, their small packaging capacity limits their utility to treat the root cause of many CNS disorders. Adenoviral vectors (Ad) have tremendous potential for CNS gene therapy approaches. Currently, the most common vectors utilize the Group C Ad5 serotype capsid proteins, which rely on the Coxsackievirus-Adenovirus receptor (CAR) to infect cells. However, these Ad5 vectors are unable to transduce many neuronal cell types that are dysfunctional in many CNS disorders. The human CD46 (hCD46) receptor is widely expressed throughout the human CNS and is the primary attachment receptor for many Ad serotypes. Therefore, to overcome the current limitations of Ad vectors to treat CNS disorders, we created chimeric first generation Ad vectors that utilize the hCD46 receptor. Using a "humanized" hCD46 mouse model, we demonstrate these Ad vectors transduce cerebellar cell types, including Purkinje cells, that are refractory to Ad5 transduction. Since Ad vector transduction properties are dependent on their capsid proteins, these chimeric first generation Ad vectors open new avenues for high-capacity helper-dependent adenovirus (HdAd) gene therapy approaches for cerebellar disorders and multiple neurological disorders.

The investigation of the dynamics of changes in neutralizing antibody titers against type 5 adenovirus in the context of vaccination against a new coronavirus infection

This research focuses on analyzing the dynamics of neutralizing antibody (nAbs) titers against type 5 adenovirus (Ad5) in the adult population of Russia following vaccination against the novel coronavirus infection with recombinant adenovirus type-5 COVID-19 vaccine (CanSino Biologics, China). The impact of the Ad5 vector on nAb titers was investigated using 302 blood serum samples from individuals who received a single dose of the Ad5-nCoV vector vaccine. The research revealed that 33.8% of adults in Russia had pre-existing anti-Ad5 nAbs before the pandemic. Notably, 40% of vaccinated individuals did not exhibit an increase in nAbs titers upon receiving the Ad5-based vaccine. However, in the group with no or low titers of anti-Ad5 nAbs (1:10–1:40), a significant 8-16-fold increase in nAb titers to Ad5 was observed.

Advances of Recombinant Adenoviral Vectors in Preclinical and Clinical Applications.

Adenoviruses (Ad) have the potential to induce severe infections in vulnerable patient groups. Therefore, understanding Ad biology and antiviral processes is important to comprehend the signaling cascades during an infection and to initiate appropriate diagnostic and therapeutic interventions. In addition, Ad vector-based vaccines have revealed significant potential in generating robust immune protection and recombinant Ad vectors facilitate efficient gene transfer to treat genetic diseases and are used as oncolytic viruses to treat cancer. Continuous improvements in gene delivery capacity, coupled with advancements in production methods, have enabled widespread application in cancer therapy, vaccine development, and gene therapy on a large scale. This review provides a comprehensive overview of the virus biology, and several aspects of recombinant Ad vectors, as well as the development of Ad vector, are discussed. Moreover, we focus on those Ads that were used in preclinical and clinical applications including regenerative medicine, vaccine development, genome engineering, treatment of genetic diseases, and virotherapy in tumor treatment.

Phase 2A trial of Ad5.F35-GUCY2C-PADRE vaccine for recurrence prevention in gastrointestinal (GI) adenocarcinomas post definitive surgery and adjuvant therapies.

TPS235 Background: A significant proportion of patients with GI adenocarcinomas remain at high risk of recurrence despite adjuvant therapies. Guanylyl cyclase C (GUCY2C) is expressed by normal intestinal cells and immunologically compartmentalized. Its overexpression in GI adenocarcinomas makes it an appealing target for anti-cancer therapies. We previously completed a phase I study of the Ad5-GUCY2C-PADRE vaccine in patients (pts) where it was safe and well tolerated (NCT01972737). Pre-existing neutralizing antibodies (NAbs) to the Ad5 vector opposed vaccine-induced immune responses. To overcome this challenge, we generated a GUCY2C vaccine employing a chimeric viral vector composed of the Ad5 capsid and Ad35 fiber protein (Ad5.F35). The extracellular domain of GUCY2C, along with the PADRE CD4+ helper T-cell epitope, were cloned into the Ad5.F35 viral vector to generate a replication-incompetent vaccine. Preclinical studies showed that Ad5.F35-GUCY2C-PADRE was less sensitive to pre-existing Ad5-specific immunity. Methods: This is a Phase 2A, dose-finding, single-center, open-label, randomized trial (NCT04111172) to evaluate the safety and immunogenic activity of three dose levels of Ad5.F35-GUCY2C-PADRE vaccine in adult pts with select solid tumors (colorectal, pancreatic, gastric, esophageal, or small bowel) who are at risk of relapse post definitive surgery and adjuvant therapy. Pts must enroll at 4-24 weeks from completion of standard therapies. Other key eligibility requirements include ECOG status of 0-1 and adequate organ function. Pts are randomized to one of three dose levels (1011 vp or viral particles, 1012 vp, or 5x1012 vp) with stratification by disease type. After completing an initial safety run-in for 9 pts (3 pts in each arm), the study will recruit up to 81 pts in total (27 in each arm). Pts will receive three successive doses of vaccine (4 weeks apart) and will undergo end-of-treatment assessment 4 weeks after their last vaccine. Pts are followed for disease status by scheduled follow-up until 2 years or recurrence, whichever occurs first. An interim futility analysis will be performed after 15 patients have completed treatment in each arm based on the Simon minimax design. Study objectives include assessment of safety and tolerability (primary), as well as T-cell and antibody responses to GUCY2C (secondary). Additional exploratory objectives include evaluating the relationship between NAbs and immune responses to GUCY2C, GUCY2C protein expression in tumors, circulating tumor DNA kinetics in relation to vaccination, and disease-free and overall survival (where applicable). Prespecified safety run-in has been completed without dose limiting toxicities; second stage accrual began in November 2021, and 43 out of 81 pts have been enrolled. Study enrollment is ongoing. Clinical trial information: NCT04111172 .

Overexpression of lysophospholipid acyltransferase, LPLAT10/LPCAT4/LPEAT2, in the mouse liver increases glucose-stimulated insulin secretion.

Postprandial hyperglycemia is an early indicator of impaired glucose tolerance that leads to type 2 diabetes mellitus (T2DM). Alterations in the fatty acid composition of phospholipids have been implicated in diseases such as T2DM and nonalcoholic fatty liver disease. Lysophospholipid acyltransferase 10 (LPLAT10, also called LPCAT4 and LPEAT2) plays a role in remodeling fatty acyl chains of phospholipids; however, its relationship with metabolic diseases has not been fully elucidated. LPLAT10 expression is low in the liver, the main organ that regulates metabolism, under normal conditions. Here, we investigated whether overexpression of LPLAT10 in the liver leads to improved glucose metabolism. For overexpression, we generated an LPLAT10-expressing adenovirus (Ad) vector (Ad-LPLAT10) using an improved Ad vector. Postprandial hyperglycemia was suppressed by the induction of glucose-stimulated insulin secretion in Ad-LPLAT10-treated mice compared with that in control Ad vector-treated mice. Hepatic and serum levels of phosphatidylcholine 40:7, containing C18:1 and C22:6, were increased in Ad-LPLAT10-treated mice. Serum from Ad-LPLAT10-treated mice showed increased glucose-stimulated insulin secretion in mouse insulinoma MIN6 cells. These results indicate that changes in hepatic phosphatidylcholine species due to liver-specific LPLAT10 overexpression affect the pancreas and increase glucose-stimulated insulin secretion. Our findings highlight LPLAT10 as a potential novel therapeutic target for T2DM.

Immunogenicity and protective efficacy of recombinant adenovirus expressing a novel genotype G2b PEDV spike protein in protecting newborn piglets against PEDV.

Porcine epidemic diarrhea (PED) is a highly infectious and economically significant gastrointestinal disorder that affects pigs of all ages. Preventing and controlling PED is achieved by immunizing sows with vaccines, enabling passive piglet immunization via colostrum. The prevalence of G2b porcine epidemic diarrhea virus (PEDV) continues in China despite the use of commercial vaccines, raising questions regarding current vaccine efficacy and the need for novel vaccine development. Adenovirus serotype 5 (Ad5) has several advantages, including high transduction efficiency, a wide range of host cells, and the ability to infect cells at various stages. In this study, we expressed the immunogenic proteins of spike (S) using an Ad5 vector and generated a PED vaccine candidate by inducing significant humoral immunity. The rAd5-PEDV-S prevented PED-induced weight loss, diarrhea, and intestinal damage in piglets. This novel vaccine candidate strain possesses the potential for use in the pig breeding industry.

Modulation of microglial function by neuronal expression of the Alzheimer multifactorial therapeutic agent E2F4DN is mediated by a soluble factor

AbstractBackgroundAlzheimer’s disease (AD) is a neurodegenerative disorder in which altered immune response is an important etiological factor (Cell Rep. 2019;27:1293.e6‐1306.e6, Nature 2019;575:669‐673). The transcription factor E2F4 regulates gene networks affected in AD (Interdiscip. Sci. 2019;11:226‐236), thus constituting a potential target for intervention. Neuronal expression of a dominant negative form of E2F4 (E2F4DN), which cannot be phosphorylated in two conserved Thr residues, can attenuate microgliosis in a mouse model of AD (Neurotherapeutics 2021;18:2484‐2503, Mol. Neurobiol. 2022;59:3016‐30392), as evidenced by the reduction of area occupied by microglia (i.e. Iba1‐positive cells). Communication between neurons and microglia is essential to regulate microglial activation and neuroprotection. The loss of this communication can cause microglia overactivation and produce persistent inflammation, finally resulting in the exacerbation of the neuropathology (Neural Regen. Res. 2019;14:1499‐1502).MethodMouse cortical neurons were cultured and maintained for 9 days in vitro (DIV) for maturation. Neurons were then transfected with an E2F4DN adenoviral (Ad5) vector, or a control EGFP Ad5 vector. After 48 h, rat microglia were treated for 24 hours with the conditioned media, and then fixed and immunostained with the microglia marker Iba1. The size of these cells was analyzed as a readout of the glial inflammatory activity (Sci. Rep. 2017;7:1576).ResultMicroglial cell size was analyzed from images obtained in the fluorescence microscope. This would determine if any soluble factor secreted by neurons that express E2F4DN, but not by neurons that express EGFP, is capable of inducing morphological changes that may reflect functional changes in this cell type. A reduction in the size of microglia was observed when the conditioned medium came from neurons expressing E2F4DN. These results show the existence of a differential communication mechanism between neurons and microglia depending on the expression of E2F4DN.ConclusionWe suggest that there is an E2F4DN‐dependent neuron‐microglia communication based on soluble factors such as those described by Simon et al. (Neuroscience 2019;405:24‐34). Altogether, our data are consistent with a beneficial immune response elicited by neurons expressing E2F4DN, a molecule proposed as a multifactorial therapeutic agent against AD.

Abstract B004: Neoantigen adenoviral cancer vaccine generates improved CD8+ T-cell responses compared to adjuvanted peptide vaccine

Abstract Development of large, functional CD8+ T cell responses is crucial for successful cancer vaccine therapeutics. Neoantigens have demonstrated their potential as cancer vaccine immunogens, but improvements in delivery method are still necessary. In this work, we characterized five candidate Adenovirus Serotype 26 (Ad26) cancer vaccines for prophylactic efficacy in the MC-38 cancer model. All five single shot vaccines generated cellular immune responses at a higher level than prime boost peptide vaccination. The vaccines generated varying degrees of protection against tumor growth. The best Ad26 vaccine candidates showed improved protection compared to long synthetic peptide vaccines containing the same immunogens, the current standard in the field. Ad26 expressing seven neoantigens conjugated to the Herpes Viral Protein 22 (VP22) (Ad26.VP22.7Epi) was found to reduce tumor growth the most. Ad26.VP227Epi was compared to peptide vaccination in immune recall post challenge studies, in both the spleen and the tumor. Both Ad26.VP22.7Epi and Peptide showed a clear recall response after challenge in the spleen. This response was primarily focused on the Adpgk neoantigen but Ad26.VP22.7Epi additionally induced responses to the Irgq neoantigen while the peptide vaccine had stronger responses against the Reps1 neoantigen. The Ad26.VP227Epi vaccine generated increased numbers of infiltrating CD8+ T-cells, IFN+ CD8+ T-cells, and CD107a+ CD8+ T-cells, which all correlated with reduced tumor growth. We used single cell RNA-seq (scRNA-seq) to characterize tumor infiltrating lymphocyte populations (defined as CD45+) generated by the two platforms. We found that both Ad26.VP22.7Epi and Peptide induced higher numbers of infiltrating CD8+ T-cells within the tumor as compared to Sham. Single-cell analysis also showed higher numbers of tumor infiltrating Tregs in peptide vaccinated mice. Higher numbers of CD8+ T-cells correlated with protection as expected but interestingly increased numbers of Tregs positively correlated with tumor volume only among vaccinated mice, which could further explain differences between Ad vector and peptide vaccination. Differential gene expression analysis of CD8+ T-cells showed an upregulation of Th1 pathways and general T cell activation when comparing Ad vector vaccinated mice to peptide vaccinated. Peptide vaccinated CD8+ T-cells showed upregulation in the IL-10 pathway, potentially caused by an increased Tregs. Further investigation of these differences among CD8+ T cell and Treg populations could further elucidate potential mechanisms explaining the differences in platform efficacy. Citation Format: Gabriel Dagotto, Alessandro Colarusso, Robert Patio, David Li, Tochi Anioke, Victoria Giffin, Malika Aid, Dan Barouch. Neoantigen adenoviral cancer vaccine generates improved CD8+ T-cell responses compared to adjuvanted peptide vaccine [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Tumor Immunology and Immunotherapy; 2023 Oct 1-4; Toronto, Ontario, Canada. Philadelphia (PA): AACR; Cancer Immunol Res 2023;11(12 Suppl):Abstract nr B004.

The Use of Viral Vectors for Gene Therapy and Vaccination in Tuberculosis.

Tuberculosis (TB), an infection caused by Mycobacterium tuberculosis (Mtb), is one of the primary causes of death globally. The treatment of TB is long and based on several drugs, producing problems in compliance and toxicity, increasing Mtb resistance to first-line antibiotics that result in multidrug-resistant TB and extensively drug-resistant TB. Thus, the need for new anti-TB treatments has increased. Here, we review some model strategies to study gene therapy based on the administration of a recombinant adenovirus that encodes diverse cytokines, such as IFNγ, IL12, GM/CSF, OPN, TNFα, and antimicrobial peptides to enhance the protective immune response against Mtb. These models include a model of progressive pulmonary TB, a model of chronic infection similar to latent TB, and a murine model of pulmonary Mtb transmission to close contacts. We also review new vaccines that deliver Mtb antigens via particle- or virus-based vectors and trigger protective immune responses. The results obtained in this type of research suggest that this is an alternative therapy that has the potential to treat active TB as an adjuvant to conventional antibiotics and a promising preventive treatment for latent TB reactivation and Mtb transmission. Moreover, Ad vector vaccines are adequate for preventing infectious diseases, including TB.