Human Adenovirus Type Research Articles

Infectivity of Human Adenovirus Type 55 to Human Intestinal Cells

To examine the infectivity of human adenovirus type 55 (HAdV-55) in human intestinal cells. Caco-2 cells were cultured in vitro, and infected with HAdV-3, 7, 14 and 55. The expression of viral proteins in infected cells was detected with immunofluorescence method. The intracellular and supernatant viral DNA levels were determined with fluorescent quantitative PCR at different points of time. The level of infectious virus particles in the supernatant of Caco-2 cells was determined with adenovirus sensitive HEp-2 infection assay. Immunofluorescence assay showed positive result for the expression of HAdV-55 virus protein in Caco-2 cells 48 h post infection. HAdV-3, 7, 14, and 55 showed sustained replication and proliferation in Caco-2 cells. The level of viral DNA in infected cells and the supernatant increased with the infection time, and the viral DNA level of HAdV-55 was significantly higher than those of HAdV-3, 7 and 14. The infectious virus particles of HAdV-55 in Caco-2 supernatant were more than those of HAdV-3, 7 and 14, showing statistically significant difference ( P<0.05). Caco-2 cells were infected with low doses of virus (1×TCID 50), and the cytopathic effect (CPE) of HAdV-55 infection wells was more significant than that of HAdV-3, 7 and 14 infection wells. This study found that human intestinal cells were susceptible to HAdV-55, and the infection level was higher than that of other common respiratory infections caused by adenovirus types 3, 7 and 14.

Efficacy of compartmentalization in controlling an adenovirus type 54 keratoconjunctivitis outbreak on Oki Island, Japan.

PurposeTo analyze the epidemiologic characteristics of an outbreak of human adenovirus type 54 (HAdV-54) on Oki Island, Shimane Prefecture, Japan, in 2017 and to assess the effectiveness of a compartmentalization method in controlling the incidence and spread.Study designRetrospective cohort study.MethodsThe infection was diagnosed in 136 individuals, and typing was confirmed by PCR and direct sequencing. The epidemiologic characteristics of the disease including the infection rate, incubation period, and basic reproductive number (R0), ie, number of cases directly infected by an infectious patient during the course of the disease, were investigated. The effectiveness of compartmentalization for infection control was determined by simulating the outbreak using the Susceptible-Exposed-Infectious-Recovered (SEIR) model.ResultsThe majority of the HAdV-54-infected individuals were the children of 3 nursery schools (A, B, and C) and their parents on Oki Island. The infection rates in the 3 schools were 13.2%, 16.9%, and 17.2%, respectively. The one class of school B without the index case was initially compartmentalized, and the infection rate in this compartment was 0%. The incubation period was calculated to be 9.3 ± 3.5 days, and the disease duration, 13.0 ± 5.4 days. The R0 was 1.43. Using these parameters, a SEIR model was constructed. The SEIR model well predicted the daily incidence of infection and indicated that the compartmentalization method provides effective reduction in the incidence of the infection, with much earlier control.ConclusionsThe compartmentalization method is effective to control HAdV-54 outbreaks.Supplementary InformationThe online version contains supplementary material available at 10.1007/s10384-021-00826-8.

Persistent viral shedding of human adenovirus type 7 in children with severe pneumonia.

To understand host-pathogen interactions and develop effective prevention and control strategies for human adenovirus (HAdV), it is essential to explore the characteristics of HAdV shedding. Hospitalized children <14 years who had severe HAdV pneumonia were tested for HAdV DNA by quantitative real-time PCR in nasopharyngeal aspirate (NPA). A total of 132 children were enrolled, including 102 patients with HAdV type 7 (HAdV-7) infection and 12 patients with HAdV type 3 (HAdV-3) infection. A total of 1372 qualified NPA samples were collected. There was a significant negative correlation between the viral load of HAdV and the course of the disease (Spearman r = -0.547, p = .000). HAdV-7 load decreased at a rate of 0.089 log10 copies/mL per day (95% CI: -0.096 to -0.081; R 2 = 0.332), and the duration of viral shedding was predicted to be 96.9 days (y = 8.624-0.089x). However, HAdV-3 load decreased more quickly (95% CI: - 0.229 to - 0.143; R 2 = 0.403), and the duration of viral shedding was 51.4 days (y = 9.558-0.186x). The median viral load of the HAdV-7 group at weeks 2 and3, and more than 3 weeks postinfection was higher than that of the HAdV-3 group. No significant differences in the duration of viral shedding were found in different gender, age (>2 vs. ≤2 years), and with or without underlying diseases groups. Viral shedding in children with severe HAdV pneumonia persisted, among which HAdV-7 lasted longer than 3 months and the viral load decreased slowly than HAdV-3.

Complete Genome Sequences of Two Human Adenovirus Type 55 Isolates from South Korea and the United States.

Here, we report two complete genome sequences of human adenovirus 55 (HAdV-55) isolates, from a patient in Pennsylvania in 2006 and a U.S. military member in South Korea in 2019. The findings demonstrate the continued global transmission of HAdV-55 viruses in both military and civilian populations.

Epidemiology and pathogen study of an outbreak in clusters caused by human adenovirus type 4 in Shenzhen

Objective To analyze the epidemiological and pathogenetic characteristics of a community outbreak of acute respiratory tract infection by Human adenovirus serotype 4 (HAdV-4) at a primary school in Baoan district, Shenzhen, Feb.22-28, 2019. Methods All epidemiological and clinical information of these cases was collected through field interviews and medical records. Throat swabs samples were collected and tested for influenza virus in quantitative fluorescence PCR. Influenza virus negative samples were then PCR tested for 6 other common respiratory virus. HAdV-4 positive samples were further tested using hexon gene sequencing of adenovirus. The sequences were aligned with the GenBank data to determine the genotypes and draw the phylogenetic tree. Results The epidemic occurred in Class 1, Grade 2, with a total of 54 students, including 29 boys and 25 girls. After investigation, there were no cases of similar symptoms in other classes of the school. Totally 13 patients were diagnosed, including 7 boys and 6 girls, the incidence rate was 24.1%(7 / 29) and 24.0% (6/25), respectively. The clinical symptoms included fever (13 cases, 100.0%), sore throat (8, 61.5%), muscular ache (8, 61.5%) and cough (5, 38.5%). All the symptoms were mild, and there were no severe cases. All 5 throat swabs samples were adenovirus positive by PCR, and these positive samples were confirmed to be HAdV-4 subgroups E by DNA sequence analysis. Conclusion The acute respiratory infection outbreak was caused by HAdV-4. The sequence of the strain is highly homologous with sequences from other districts of Shenzhen and Chinese cities. 摘要：目的 分析2019年2月22—28日深圳市宝安区某小学一起急性呼吸道病毒感染聚集性疫情的流行病学及 病原学特点。 方法 采用流行病学个案调査表对疫情进行现场调査, 使用荧光定量 PCR 方法对采集的咽拭子标本进 行流感样病例病原学筛査, 筛査阴性标本进行6种常见呼吸道病毒核酸检测。对腺病毒核酸阳性的标本, 用腺病毒六 邻体基因作为靶基因进行序列扩增及测定, 测序结果在GenBank上进行序列比较, 确定其病毒亚型并进行系统进化分 析。 结果 疫情发生在二年级(1)班, 全班共54名学生, 男29名, 女25名。经调査该学校其他班级其余年级未出现相 同症状病例。该起疫情共发现病例13例, 其中男生7例, 女生6例, 男女学生罹患率分别为24.1%( 7 /29)和24.0% ( 6 /25)。临床特征为发热13例(100.0%), 咽痛8例(61.5%), 全身肌肉酸痛8例(61.5%), 咳嗽5例(38.5%), 症状均较轻, 无重 症病例。共采集5份咽拭子标本 , 经荧光定量PCR检测均为腺病毒核酸阳性 , 5份标本用分型引物检测并分析序列确 定均为腺病毒E亚属4型。 结论 此次急性呼吸道感染聚集性疫情由腺病毒4型引起, 毒株序列与深圳其他区、国内 其他城市分离的腺病毒4型毒株序列具有髙度同源性。

The Fiber Knob Protein of Human Adenovirus Type 49 Mediates Highly Efficient and Promiscuous Infection of Cancer Cell Lines Using a Novel Cell Entry Mechanism.

The human adenovirus (HAdV) phylogenetic tree is diverse, divided across seven species and comprising over 100 individual types. Species D HAdV are rarely isolated with low rates of preexisting immunity, making them appealing for therapeutic applications. Several species D vectors have been developed as vaccines against infectious diseases, where they induce robust immunity in preclinical models and early phase clinical trials. However, many aspects of the basic virology of species D HAdV, including their basic receptor usage and means of cell entry, remain understudied. Here, we investigated HAdV-D49, which previously has been studied for vaccine and vascular gene transfer applications. We generated a pseudotyped HAdV-C5 presenting the HAdV-D49 fiber knob protein (HAdV-C5/D49K). This pseudotyped vector was efficient at infecting cells devoid of all known HAdV receptors, indicating HAdV-D49 uses an unidentified cellular receptor. Conversely, a pseudotyped vector presenting the fiber knob protein of the closely related HAdV-D30 (HAdV-C5/D30K), differing in four amino acids from HAdV-D49, failed to demonstrate the same tropism. These four amino acid changes resulted in a change in isoelectric point of the knob protein, with HAdV-D49K possessing a basic apical region compared to a more acidic region in HAdV-D30K. Structurally and biologically we demonstrate that HAdV-D49 knob protein is unable to engage CD46, while potential interaction with coxsackievirus and adenovirus receptor (CAR) is extremely limited by extension of the DG loop. HAdV-C5/49K efficiently transduced cancer cell lines of pancreatic, breast, lung, esophageal, and ovarian origin, indicating it may have potential for oncolytic virotherapy applications, especially for difficult to transduce tumor types.IMPORTANCE Adenoviruses are powerful tools experimentally and clinically. To maximize efficacy, the development of serotypes with low preexisting levels of immunity in the population is desirable. Consequently, attention has focused on those derived from species D, which have proven robust vaccine platforms. This widespread usage is despite limited knowledge in their basic biology and cellular tropism. We investigated the tropism of HAdV-D49, demonstrating that it uses a novel cell entry mechanism that bypasses all known HAdV receptors. We demonstrate, biologically, that a pseudotyped HAdV-C5/D49K vector efficiently transduces a wide range of cell lines, including those presenting no known adenovirus receptor. Structural investigation suggests that this broad tropism is the result of a highly basic electrostatic surface potential, since a homologous pseudotyped vector with a more acidic surface potential, HAdV-C5/D30K, does not display a similar pantropism. Therefore, HAdV-C5/D49K may form a powerful vector for therapeutic applications capable of infecting difficult to transduce cells.

NRG Oncology NRG-GI007 trial-in-progress: Phase I study of OBP-301 (Telomelysin) and definitive chemoradiation (CRT) for patients with locally advanced esophageal and gastroesophageal adenocarcinoma who are not candidates for surgery.

TPS262 Background: Definitive CRT is a standard-of-care for patients with medically inoperable esophageal cancer (EC, NEJM 326:1593). The NRG/RTOG 0436 study of cisplatin/paclitaxel and RT (+/- cetuximab) as definitive therapy showed that about ½ of patients have locally persistent disease (JAMA Oncol 3:1520). OBP-301 is a conditionally-restricted, replication-competent adenovirus derived from human adenovirus type 5 (Ad-5) that adds a human Telomerase Reverse Transcriptase (hTERT) gene promoter; it replicates only in tumor cells to cause lysis. It may enhance RT and may cause immunogenic cell death. A phase I study with RT in Japanese patients with inoperable EC showed tolerability and activity. Methods: In NRG-GI007, OBP-301 is added to weekly carboplatin/paclitaxel and RT to 50.4 Gy (1.8 Gy/fx ×28 fx) for patients with medically inoperable esophageal or gastroesophageal junction (GEJ) adenocarcinoma. Patients receive intratumoral OBP-301 1×1012 virus particles (vp)/ml via endoscopy (EGD) 3 days prior to CRT, then at days 12 and 26 of CRT, for a total of 3 doses. Restaging with PET and EGD occur 6-8 weeks later. Blood and tumor tissue are collected for immune- and viral-based correlative assays. Patients must be assessed to be medically inoperable and have ECOG performance status &lt;1. The primary endpoint is safety, and clinical complete response (cCR) rate is a secondary endpoint. Initially, 6 patients are enrolled. If protocol-defined dose-limiting toxicity (DLT) occurs in &lt;1 of 6 patients, the dose will be deemed to be safe and 9 more will be enrolled to further assess safety and obtain a preliminary assessment of cCR rate. If &gt;2 of 6 patients have DLT, the dose of OBP-301 is reduced to 1×1011 vp/ml and another 6 patients will be treated. If &lt;1 of 6 patients has a DLT at the lower dose, that dose will be deemed to be safe and 9 more will be enrolled. If &gt;2 of 6 patients have DLT, then neither dose level will have met the safety rule and the trial will be ended. This trial opened to accrual on June 29, 2020. Clinicaltrials.gov NCT04391049. Funding: This project was supported by grants U10CA180868 (NRG Oncology Operations), U10CA180822 (NRG Oncology SDMC), U24CA180803 (IROC), from the National Cancer Institute (NCI) and Oncolys BioPharma. Clinical trial information: NCT04391049.

Diversity of enteric and non-enteric human adenovirus strains in Brazil, 2006-2011.

During 2006-2011, 5035 fecal samples were tested by PCR for human adenovirus (HAdV) and sequenced. HAdV was detected in 198 cases (3.9%), with the highest rate in children ≤5 years. Enteric HAdVs were the most prevalent genotypes (78%; 146/187): HAdV-F41 (63.6%; 119/187), HAdV-F40 (12.3%; 23/187), HAdV-A12 (1.6%; 3/187) and HAdV-A31 (0.5%; 1/187). Non-enteric HAdVs were detected in 22% (41/187): HAdV-C1 (8.0%; 15/187), HAdV-C2 (6.9%; 13/187), HAdV-C5 (4.3%; 8/187), HAdV-D8 (1.3%; 2/187), HAdV-B21 (0.5%; 1/187), HAdV-B3 (0.5%; 1/187) and HAdV-C6 (0.5%; 1/187). This 6-year retrospective study points out a high diversity of HAdV types circulating in Brazil and highlights the need to carry out molecular epidemiological studies of HAdV among patients with acute diarrheal infection on a regular basis.

Structure-Based Modeling of Complement C4 Mediated Neutralization of Adenovirus.

Adenovirus (AdV) infection elicits a strong immune response with the production of neutralizing antibodies and opsonization by complement and coagulation factors. One anti-hexon neutralizing antibody, called 9C12, is known to activate the complement cascade, resulting in the deposition of complement component C4b on the capsid, and the neutralization of the virus. The mechanism of AdV neutralization by C4b is independent of downstream complement proteins and involves the blockage of the release of protein VI, which is required for viral escape from the endosome. To investigate the structural basis underlying how C4b blocks the uncoating of AdV, we built a model for the complex of human adenovirus type-5 (HAdV5) with 9C12, together with complement components C1 and C4b. This model positions C4b near the Arg-Gly-Asp (RGD) loops of the penton base. There are multiple amino acids in the RGD loop that might serve as covalent binding sites for the reactive thioester of C4b. Molecular dynamics simulations with a multimeric penton base and C4b indicated that stabilizing interactions may form between C4b and multiple RGD loops. We propose that C4b deposition on one RGD loop leads to the entanglement of C4b with additional RGD loops on the same penton base multimer and that this entanglement blocks AdV uncoating.

Genetic Analysis of Human Adenovirus Type 7 Strains Circulating in Different Parts of China.

To investigate the molecular epidemiology and genetic variation of human adenovirus type 7 (HAdV-7) in children with acute respiratory infections (ARI) in China. HAdV-7-positive respiratory samples collected from children with ARI in Beijing, Shijiazhuang, Wenzhou and Guangzhou from 2014–2018 were selected for gene amplification and sequence analysis. Fifty-seven HAdV-7 clinical strains with hexon, penton base and fiber gene sequences were obtained. Meanwhile 17 strains were selected randomly from different cities for whole genome sequencing. Phylogenetic and variation analyses were performed based on the obtained sequences, HAdV-7 prototype strain Gomen (AY594255), vaccine strains (AY495969 and AY594256) and representative sequences of strains. The phylogenetic trees constructed based on whole genome sequences, major capsid protein genes (hexon, penton base and fiber) and the early genes (E1, E2, E3 and E4) were not completely consistent. The HAdV-7 strains obtained in this study always clustered with most of the circulating strains worldwide from the 1980s to the present. Compared with the HAdV-7 prototype strain Gomen (AY594255), some amino acid mutations in loop1 and loop2 of hexon and the RGD loop region of the penton base gene were observed. Recombination analysis showed that partial regions of 55 kDa protein and 100 kDa hexon-assembly associated protein genes among all HAdV-7 strains in this study were from HAdV-16 and HAdV-3, respectively. Our study demonstrated the molecular evolution characteristics of HAdV-7 strains circulating in China and provided basic reference data for the prevention, control and vaccine development of HAdV-7.Electronic supplementary materialThe online version of this article (10.1007/s12250-020-00334-y) contains supplementary material, which is available to authorized users.

A bivalent live-attenuated vaccine candidate elicits protective immunity against human adenovirus types 4 and 7

ABSTRACT Human adenovirus types 4 (HAdV4) and 7 (HAdV7) often lead to severe respiratory diseases and occur epidemically in children, adults, immune deficiency patients, and other groups, leading to mild or severe symptoms and even death. However, no licensed adenovirus vaccine has been approved in the market for general use. E3 genes of adenovirus are generally considered nonessential for virulence and replication; however, a few studies have demonstrated that the products of these genes are also functional. In this study, most of the E3 genes were deleted, and two E3-deleted recombinant adenoviruses (ΔE3-rAdVs) were constructed as components of the vaccine. After E3 deletion, the replication efficiencies and cytopathogenicity of ΔE3-rAdVs were reduced, indicating that ΔE3-rAdVs were attenuated after E3 genes deletion. Furthermore, single immunization with live-attenuated bivalent vaccine candidate protects mice against challenge with wild-type human adenovirus types 4 and 7, respectively. Vaccinated mice demonstrated remarkably decreased viral loads in the lungs and less lung pathology compared to the control animals. Taken together, our study confirms the possibility of the two live-attenuated viruses as a vaccine for clinic use and illustrates a novel strategy for the construction of an adenovirus vaccine.

In Silico Designing of a Multi-Epitope Based Vaccine Candidate Against Human Adenovirus Type B3 Respiratory Infections by Utilising Various Immunoinformatics Approaches

Human adenovirus type B3 (HAdV-B3) causes severe respiratory infections, hence an efficient vaccine is required. Unfortunately, the presence of numerous hexon variations makes conventional vaccine designing difficult which warrants an alternative method. Therefore, an in silico multi-epitope vaccine had been constructed against appropriate hexon variants of HAdV-B3. The allergenicity, antigenicity, structure, physicochemical properties along with molecular docking with TLR-3 and TLR-9 had also been predicted. The constructed vaccine had 23 different epitopes. It showed non-allergic but antigenic nature with 30hours of half-life in vitro and exhibited thermostable nature. We anticipate that this will considerably reduce the time and expense of biological work needed for future vaccine development.

Lung Expression of Human Angiotensin-Converting Enzyme 2 Sensitizes the Mouse to SARS-CoV-2 Infection.

Preclinical mouse models that recapitulate some characteristics of coronavirus disease (COVID-19) will facilitate focused study of pathogenesis and virus–host responses. Human agniotensin-converting enzyme 2 (hACE2) serves as an entry receptor for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) to infect people via binding to envelope spike proteins. Herein we report development and characterization of a rapidly deployable COVID-19 mouse model. C57BL/6J (B6) mice expressing hACE2 in the lung were transduced by oropharyngeal delivery of the recombinant human adenovirus type 5 that expresses hACE2 (Ad5-hACE2). Mice were infected with SARS-CoV-2 at Day 4 after transduction and developed interstitial pneumonia associated with perivascular inflammation, accompanied by significantly higher viral load in lungs at Days 3, 6, and 12 after infection compared with Ad5-empty control group. SARS-CoV-2 was detected in pneumocytes in alveolar septa. Transcriptomic analysis of lungs demonstrated that the infected Ad5-hACE mice had a significant increase in IFN-dependent chemokines Cxcl9 and Cxcl10, and genes associated with effector T-cell populations including Cd3 g, Cd8a, and Gzmb. Pathway analysis showed that several Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways were enriched in the data set, including cytokine–cytokine receptor interaction, the chemokine signaling pathway, the NOD-like receptor signaling pathway, the measles pathway, and the IL-17 signaling pathway. This response is correlative to clinical response in lungs of patients with COVID-19. These results demonstrate that expression of hACE2 via adenovirus delivery system sensitized the mouse to SARS-CoV-2 infection and resulted in the development of a mild COVID-19 phenotype, highlighting the immune and inflammatory host responses to SARS-CoV-2 infection. This rapidly deployable COVID-19 mouse model is useful for preclinical and pathogenesis studies of COVID-19.

Epidemiology and Genetic Variabilities of Human Adenovirus Type 55 Reveal Relative Genome Stability Across Time and Geographic Space in China.

After the first outbreak in China in 2006, human adenovirus type 55 (HAdV-B55) has become a common pathogen causing life threatening pneumonia in northern China. However, HAdV-B55 infection has been rarely reported in southern China. Here, we collected throat swabs from 3,192 hospitalized children with acute respiratory disease (ARD) from May 2017 to April 2019 in Guangzhou, southern China, tested them for HAdV-B55 infection. Only one of 1,399 patients from May 2017 to April 2018 was HAdV-B55 positive; HAdV-B55 infections significantly increased with 10 of 1,792 patients testing positive since May 2018. HAdV-B55-267, isolated from a case of death, was sequenced for whole genomic analysis. Three other strains, HAdV-B55-Y16, -TY12, and -TY26, isolated earlier in patients from Shanxi, northern China, were also sequenced and analyzed. The four HAdV-B55 strains formed similar plaques, grew to similar titers, and resulted in similar typical cell pathogenic effects. HAdV-B55-267 formed a subclade with the prototype strain QS-DLL; strains HAdV-B55-Y16, -TY12, and -TY26 were closely related to strain QZ01. HAdV-B55 could be divided into two subtypes (HAdV-B55-a and -b) according to the presence or absence of the insertion of “CCATATCCGTGTT”; all strains isolated from China except for strain BJ01 belong to subtype b. HAdV-B55-267 had only one non-synonymous substitution comparing with strain QS-DLL, and all HAdV-B55 strains had highly conserved capsid proteins and few non-synonymous substitutions. This study suggests that HAdV-B55 is an important pathogen associated with ARD in Guangzhou since 2018, exhibiting the relative genome stability across time and geographic space in China.

A Tumor-Targeted Replicating Oncolytic Adenovirus Ad-TD-nsIL12 as a Promising Therapeutic Agent for Human Esophageal Squamous Cell Carcinoma.

Esophageal squamous cell carcinoma (ESCC) is one of the most lethal cancers in China and existing therapies have been unable to significantly improve prognosis. Oncolytic adenoviruses (OAds) are novel promising anti-tumor drugs and have been evaluated in several cancers including ESCC. However, the antitumour efficacy of the first generation OAds (H101) as single agent is limited. Therefore, more effective OAds are needed. Our previous studies demonstrated that the novel oncolytic adenovirus Ad-TD-nsIL12 (human adenovirus type 5 with E1ACR2, E1B19K, E3gp19K-triple deletions)harboring human non-secretory IL-12 had significant anti-tumor effect, with no toxicity, in a Syrian hamster pancreatic cancer model. In this study, we evaluated the anti-tumor effect of Ad-TD-nsIL12 in human ESCC. The cytotoxicity of Ad-TD-nsIL12, H101 and cisplatin were investigated in two newly established patient-derived tumor cells (PDCs) and a panel of ESCC cell lines in vitro. A novel adenovirus-permissive, immune-deficient Syrian hamster model of PDCs subcutaneous xenograft was established for in vivo analysis of efficacy. The results showed that Ad-TD-nsIL12 was more cytotixic to and replicated more effectively in human ESCC cell lines than H101. Compared with cisplatin and H101, Ad-TD-nsIL12 could significantly inhibit tumor growth and tumor angiogenesis as well as enhance survival rate of animals with no side effects. These findings suggest that Ad-TD-nsIL12 has superior anti-tumor potency against human ESCC with a good safety profile.

Seroprevalence of Neutralizing Antibodies against Six Human Adenovirus Types Indicates the Low Level of Herd Immunity in Young Children from Guangzhou, China.

Human adenoviruses (HAdVs) commonly cause many diseases such as respiratory diseases, gastroenteritis, cystitis worldwide. HAdV-3, -7, -4 and emergent HAdV-55 and HAdV-14 are the most important types causing severe respiratory diseases. There is no effective drug available for clinical treatment, and no vaccine available for the general population. Therefore, it is important to investigate the seroprevalence against HAdV for developing novel vaccines and vectors. In this study, we investigated the seroprevalence and titer levels of neutralizing antibodies (NAb) against HAdV-3, -4, -7, -14, -55, and -11 in total 278 healthy populations between 0 months and 49 years of age (228 children and 50 adults) from Guangzhou. In children under the age of 18 years, the seropositive rates were significantly increased against HAdV-3 at 12.07%, 33.96%, and 64.29% and against HAdV-7 at 0%, 18.87%, and 19.05% in age groups of 1–2, 3–5, and 6–17 years, respectively. The seroprevalence was very low (0% ~ 8.1%) for all other four types. In adults aged between 18 and 49 years, HAdV-3, -4, and -7 (> 50.00%) were the most common types, followed by HAdV-14 (38.00%), -55 (34.00%), and -11 (24.00%). Adults tended to have high NAb titers against HAdV-4 and -55. HAdV-55-seropositive donors tended to be HAdV-11- and HAdV-14-seropositive. These results indicated the low level of herd immunity against all six HAdV types in young children, and HAdV-14, -55, -11 in adults from Guangzhou City. Our findings demonstrate the importance of monitoring HAdV types and developing vaccines against HAdV for children and adults.

Optimized Adenoviral Vector That Enhances the Assembly of FMDV O1 Virus-Like Particles in situ Increases Its Potential as Vaccine for Serotype O Viruses.

Although replication-defective human adenovirus type 5 (Ad5) vectors that express in situ the capsid-encoding region of foot-and-mouth disease virus (FMDV) have been proven to be effective as vaccines in relevant species for several viral strains, the same result was not consistently achieved for the O1/Campos/Brazil/58 strain. In the present study, an optimization of the Ad5 system was explored and was proven to enhance the expression of FMDV capsid proteins and their association into virus-like particles (VLPs). Particularly, we engineered a novel Ad5 vector (Ad5[PVP2]OP) which harbors the foreign transcription unit in a leftward orientation relative to the Ad5 genome, and drives the expression of the FMDV sequences from an optimized cytomegalovirus (CMV) enhancer-promoter as well. The Ad5[PVP2]OP vaccine candidate also contains the amino acid substitutions S93F/Y98F in the VP2 protein coding sequence, predicted to stabilize FMD virus particles. Cells infected with the optimized vector showed an ∼14-fold increase in protein expression as compared to cells infected with an unmodified Ad5 vector tested in previous works. Furthermore, amino acid substitutions in VP2 protein allowed the assembly of FMDV O1/Campos/Brazil/58 VLPs. Evaluation of several serological parameters in inoculated mice with the optimized Ad5[PVP2]OP candidate revealed an enhanced vaccine performance, characterized by significant higher titers of neutralizing antibodies, as compared to our previous unmodified Ad5 vector. Moreover, 94% of the mice vaccinated with the Ad5[PVP2]OP candidate were protected from homologous challenge. These results indicate that both the optimized protein expression and the stabilization of the in situ generated VLPs improved the performance of Ad5-vectored vaccines against the FMDV O1/Campos/Brazil/58 strain and open optimistic expectations to be tested in target animals.

Molecular Detection of Human Enteric Adenoviruses in Water Samples Collected from Lake Victoria Waters Along Homa Bay Town, Homa Bay County, Kenya.

Lake Victoria is the primary source of water for millions of people in the Sub-Saharan Africa region. In recent years, population development around the lake has resulted in compromised sanitation standards resulting in increased faecal pollution of the lake. Consequently, this condition has increased the chances of waterborne enteric viruses, such as adenoviruses' circulation in the community. Adenoviruses can affect health in both humans and animals by causing a myriad of diseases including the gastrointestinal infections. The study aimed to detect contamination of the lake water with pathogenic human adenoviruses along Homa Bay town, Homa Bay County, Kenya. To examine the presence of adenoviral genome, we collected a total of 216 (monthly n = 36) water samples from six different locations marked by high levels of anthropogenic activities along the shoreline. Molecular amplification technique using the nested PCR procedure was used to detect the genomes from the watersamples. Human adenoviruses were detected in 11 samples (5.09%). Statistical analyses indicated a significant correlation between adenovirus presence and the approximate distance from pit latrines and sewage treatment works at the area. The findings indicate that faecal contamination of the lake watersoriginated from thepoint sources. The findings also suggest a possibility of elevated levels of faecal pollution in different surface waters within the lake basin. The findings indicate that some of the enteric viruses circulating in the local community are human adenovirus type 40, and 41. The data may provide a basis for recognizing the need to prioritize environmental monitoring for enteric virus contamination on an on-going basis.

Molecular Epidemiology and Clinical Features Analysis of Respiratory Adenovirus Infections Reveals Correlations between Genotype, Inflammatory Biomarkers, and Disease Severity.

Background Human adenoviruses (HAdVs) are commonly causing respiratory disease. We molecularly genotyped HAdV circulating in Chinese hospitalized children with respiratory infections and summarized the clinical profiles and common inflammatory biomarkers, so as to better determine their associations with disease severity. Method Children with respiratory single HAdV infection cases that occurred from December 2017 to March 2019 were enrolled for a cross-sectional study. Clinical/laboratory features based on the genotypes of respiratory HAdV infection were reviewed for comparative analysis. Results A total of 84 patients were enrolled, and HAdV types were identified from 82 patients. Species B (HAdV-7, 44%; HAdV-3, 43%, and HAdV-14, 5%) was the most common, followed by C (HAdV-2, 4% and HAdV-1, 1%) and E (HAdV-4, 1%). Severe HAdV infection and HAdV-7 infection groups were associated with significantly longer duration of fever and hospitalized days, higher morbidity of tachypnea/dyspnea, more pleural effusion, more respiratory rales, more frequently required mechanical ventilation, and significantly higher fatality rate. The elevated procalcitonin (PCT) and C-reactive protein (CRP) levels were significantly associated with severe HAdV infection. Conclusions HAdV-7 and HAdV-3 were the most common types among children with respiratory adenovirus infection; vaccines against these two genotypes are in urgent need. PCT and CRP are significantly associated with the severity of HAdV infection.

Filociclovir Is a Potent In Vitro and In Vivo Inhibitor of Human Adenoviruses.

Human adenovirus (HAdV) infection is common in the general population and can cause a range of clinical manifestations, among which pneumonia and keratoconjunctivitis are the most common. Although HAdV infections are mostly self-limiting, infections in immunocompromised individuals can be severe. No antiviral drug has been approved for treating adenoviruses. Filociclovir (FCV) is a nucleoside analogue which has successfully completed phase I human clinical safety studies and is now being developed for treatment of human cytomegalovirus (HCMV)-related disease in immunocompromised patients. In this report, we show that FCV is a potent broad-spectrum inhibitor of HAdV types 4 to 8, with 50% effective concentrations (EC50s) ranging between 1.24 and 3.6 μM and a 50% cytotoxic concentration (CC50) of 100 to 150 μM in human foreskin fibroblasts (HFFs). We also show that the prophylactic oral administration of FCV (10 mg/kg of body weight) 1 day prior to virus challenge and then daily for 14 days to immunosuppressed Syrian hamsters infected intravenously with HAdV6 was sufficient to prevent morbidity and mortality. FCV also mitigated tissue damage and inhibited virus replication in the liver. The 10-mg/kg dose had similar effects even when the treatment was started on day 4 after virus challenge. Furthermore, FCV administered at the same dose after intranasal challenge with HAdV6 partially mitigated body weight loss but significantly reduced pathology and virus replication in the lung. These findings suggest that FCV could potentially be developed as a pan-adenoviral inhibitor.