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Parvovirus B19 (B19V) is a human pathogen belonging to the Parvoviridae family. It is widely diffused in the population and responsible for a wide range of diseases, diverse in pathogenetic mechanisms, clinical course, and severity. B19V infects and replicates in erythroid progenitor cells (EPCs) in the bone marrow leading to their apoptosis. Moreover, it can also infect, in an abortive manner, a wide set of different cell types, normally non-permissive, and modify their normal physiology. Differences in the characteristics of virus-cell interaction may translate into different pathogenetic mechanisms and clinical outcomes. Joint involvement is a typical manifestation of B19V infection in adults. Moreover, several reports suggest, that B19V could be involved in the pathogenesis of some autoimmune rheumatologic diseases such as rheumatoid arthritis (RA), juvenile idiopathic arthritis (JIA), systemic sclerosis (SSc), systemic lupus erythematosus (SLE), or vasculitis. This review provides basic information on the B19 virus, highlights characteristics of viral infection in permissive and non-permissive systems, and focuses on recent findings concerning the pathogenic role of B19V in rheumatologic diseases.
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BACKGROUND: Parvovirus B19(B19) is a DNA virus. The most common B19 disease is erythema infectiosum (fifth-disease). PCR and ELISA are sensitive for detecting of acute disease. However, it is not clear which test better and the relationship between laboratory tests and clinical findings. OBJECTIVE: To discuss the clinical and laboratory characteristics of pediatric patients infected with B19. STUDY DESIGN: 236 children were examined. Children with at least one positive molecular or serological test were included. Positive serum B19-DNA and/or B19-IgM was considered an acute B19 infection. RESULTS: B19DNA was detected in 80.8 % of acute cases. Serological tests were less positive. Acute B19 infection was observed in 24 patients. Only 17 patients were positive for B19 DNA, 3 for IgM and 4 for both. The sensitivity of B19 DNA is 87.5 %. However, this rate is 29.2 % for B19 IgM. CONCLUSION: B19-DNA and IgM together provide a better, highly accurate diagnosis.
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Anticuerpos Antivirales , ADN Viral , Eritema Infeccioso , Inmunoglobulina M , Parvovirus B19 Humano , Humanos , Parvovirus B19 Humano/genética , Parvovirus B19 Humano/inmunología , Parvovirus B19 Humano/aislamiento & purificación , Niño , Inmunoglobulina M/sangre , Preescolar , Femenino , Masculino , ADN Viral/sangre , Anticuerpos Antivirales/sangre , Eritema Infeccioso/diagnóstico , Eritema Infeccioso/sangre , Eritema Infeccioso/inmunología , Lactante , Sensibilidad y Especificidad , Adolescente , Reacción en Cadena de la Polimerasa/métodos , Infecciones por Parvoviridae/diagnóstico , Infecciones por Parvoviridae/sangre , Infecciones por Parvoviridae/inmunología , Infecciones por Parvoviridae/virología , Ensayo de Inmunoadsorción Enzimática , Pruebas Serológicas/métodosRESUMEN
Viral infections are major causes of mortality in solid-organ and hematopoietic stem cell transplant recipients. Epstein-Barr virus (EBV) and Parvovirus B19 (B19V) are among the common viral infections after transplantation and were recommended for increased screening in relevant guidelines. Therefore, the development of rapid, specific, and cost-effective diagnostic methods for EBV and B19V is of paramount importance. We applied Fluorescence of Loop Primer Upon Self-Dequenching Loop-mediated Isothermal Amplification (FLOS-LAMP) for the first time to develop a novel multiplex assay for the detection of EBV and B19V; the fluorophore attached to the probe are self-quenched in unbound state. After binding to the dumbbell-shaped DNA target, the fluorophore is dequenched, resulting in fluorescence development. The novel multiplex FLOS-LAMP assay was optimized by testing various ratios of primer sets. This novel assay, with great specificity, did not cross-react with the common virus. For the detection of EBV and B19V, the limits of detection could reach 969 and 798 copies/µL, respectively, and the assay could be completed within 25 min. Applying this novel assay to detect 200 clinical transplant individuals indicated that the novel assay had high specificity and good sensitivity. We developed multiplex FLOS-LAMP assay for the detection of EBV and B19V, which has the potential to become an important tool for clinical transplant patient screening.
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Infecciones por Virus de Epstein-Barr , Herpesvirus Humano 4 , Técnicas de Diagnóstico Molecular , Técnicas de Amplificación de Ácido Nucleico , Parvovirus B19 Humano , Sensibilidad y Especificidad , Humanos , Herpesvirus Humano 4/genética , Herpesvirus Humano 4/aislamiento & purificación , Técnicas de Amplificación de Ácido Nucleico/métodos , Parvovirus B19 Humano/genética , Parvovirus B19 Humano/aislamiento & purificación , Infecciones por Virus de Epstein-Barr/diagnóstico , Infecciones por Virus de Epstein-Barr/virología , Técnicas de Diagnóstico Molecular/métodos , Fluorescencia , Cartilla de ADN/genética , Receptores de Trasplantes , Infecciones por Parvoviridae/diagnóstico , Infecciones por Parvoviridae/virología , ADN Viral/genética , Trasplante de ÓrganosRESUMEN
This is a case report of a 6-year-old girl with relapsed B cell acute lymphoblastic leukemia in which adoptive cell therapy was applied successfully to treat refractory human parvovirus (HPV) B19 infection. Allogenic chimeric antigen receptor (CAR) T-cell therapy (bispecific CD19/CD22) was bridged to hematopoietic stem cell transplantation (HSCT) using a haploidentical paternal donor. However, HPV B19 DNAemia progressed and transfusion-related graft versus host disease occurred. After finding a third-party related donor with a better HLA match, haploidentical HPV B19-seropositive CD45RA+ depleted cells (16.5 × 106/kg) were administered and paternal TCRαß+ depleted stem cell were retransplanted. The HPV B19 DNAemia became negative within 1 week and the reticulocyte, neutrophil, hemoglobin, and platelet counts gradually normalized. The patient remained stable during the 1-year outpatient follow-up period. Thus, our case report highlights that persistent B19 infection can lead to pancytopenia, aplastic crisis, and graft rejection and TCRαß+ depleted haplo-HSCT is an effective means of hematopoiesis recovery. CD45RO memory T-cell therapy is the key to treating and preventing the development of refractory severe HPV B19 infection.
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Trasplante de Células Madre Hematopoyéticas , Infecciones por Parvoviridae , Parvovirus B19 Humano , Receptores de Antígenos de Linfocitos T alfa-beta , Humanos , Femenino , Niño , Parvovirus B19 Humano/inmunología , Infecciones por Parvoviridae/terapia , Infecciones por Parvoviridae/inmunología , Antígenos Comunes de Leucocito/metabolismo , Inmunoterapia Adoptiva/métodos , Anemia Aplásica/terapia , Anemia Aplásica/inmunología , Enfermedad Injerto contra Huésped/terapia , Enfermedad Injerto contra Huésped/inmunología , Resultado del Tratamiento , Leucemia-Linfoma Linfoblástico de Células Precursoras B/terapia , Leucemia-Linfoma Linfoblástico de Células Precursoras B/inmunologíaRESUMEN
This study aimed to estimate the serological status and dynamic changes in the prevalence of Parvovirus B19 (PVB19) antibodies within the general population residing in the northern part of the Republic of Serbia (Province of Vojvodina) during a 16-year period. Serum samples were analyzed for Human PVB19-specific IgM and IgG antibodies using enzyme-linked immunosorbent assay (ELISA). Throughout the study period, the overall seroprevalence was 49.51%. Approximately 10% of patients exhibited a serologic profile positive for PVB19 IgM antibodies. Notably, seroprevalence varied significantly, ranging from 9.12% in the pediatric cohort (ages 1-4 years) to 65.50% in the adult demographic (40-59 years old). Seroprevalence was higher (51.88%) among women compared to men (42.50%). Immunologically naive pregnant women in the age groups 26-36 and 36-45 years had 45% (OR = 0.55, 95% CI: 0.31-1.00) and 52% (OR = 0.48; 95% CI: 0.24-0.94) lower odds of having negative IgM and IgG compared to those in age group 16-25 years old. Improved knowledge of the epidemiology of PVB19 may assist clinicians in the differential diagnosis of PVB19 clinical manifestations. The PVB19 detection is particularly important for monitoring individuals in risk groups such as women of reproductive age, medical staff, patients with hematological disorders, and those with immunodeficiency.
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Eritema Infeccioso , Infecciones por Parvoviridae , Parvovirus B19 Humano , Masculino , Adulto , Humanos , Femenino , Niño , Embarazo , Adolescente , Adulto Joven , Persona de Mediana Edad , Eritema Infeccioso/epidemiología , Estudios Seroepidemiológicos , Yugoslavia , Serbia/epidemiología , Infecciones por Parvoviridae/epidemiología , Infecciones por Parvoviridae/diagnóstico , Anticuerpos Antivirales , Inmunoglobulina G , Inmunoglobulina MRESUMEN
Human parvovirus B19 (B19V) has a wide clinical spectrum, ranging from an asymptomatic infection to a life threatening one. During pregnancy, it can lead to fetal loss and hydrops fetalis. This retrospective study examined the incidence rates of B19V in Israel, analyzing anonymized electronic medical records of 2.7 million individuals between January 2015 and September 2023. A generalized linear model with a Poisson distribution was fit to the data, adjusting for potential confounders. A marked increase in B19V was observed in 2023, with an adjusted incidence rate ratio (IRR) of 6.6 (95% CI 6.33-6.89) when comparing 2023 to previous years. When specifically comparing 2023 to COVID-19 years (2020-2022), adjusted IRR climbs to 9.21 (8.66-9.80). Moreover, in 2023, previously existing seasonality has largely disappeared. High SES characterized most infected individuals with a marked discrepancy in social sectors; the Arab population was significantly less likely to be found B19V positive, even when adjusting for SES. Most infections occurred in school-aged children (6-11 years old). Pregnant women experienced the most significant rise in B19V, with an adjusted IRR of 11.47 (9.44-13.97) in 2023 compared to previous years; most cases were diagnosed in the first trimester. This study demonstrates that Israel is currently experiencing the largest and longest reported outbreak of B19V to date. Policymakers should consider setting screening policies in place, at least for populations at risk, while specifically studying and potentially targeting low socioeconomic populations and specific social sectors to avoid health inequalities.
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Infecciones por Parvoviridae , Parvovirus B19 Humano , Complicaciones Infecciosas del Embarazo , Niño , Embarazo , Humanos , Femenino , Parvovirus B19 Humano/genética , Estudios Retrospectivos , Israel/epidemiología , ADN ViralRESUMEN
Human parvovirus B19 (B19V) is a single-stranded non-enveloped DNA virus of the family Parvoviridae that has been associated with various autoimmune disorders. Systemic sclerosis (SSc) is an autoimmune connective tissue disorder with high mortality and has been linked to B19V infection. However, the precise mechanism underlying the B19V contribution to the development of SSc remains uncertain. This study investigated the impacts of the functional B19V-VP1 unique region (VP1u) in macrophages and bleomycin (BLE)-induced SSc mice. Cell experimental data showed that significantly decreased viability and migration of both B19V-VP1u-treated U937 and THP-1 macrophages are detected in the presence of celastrol. Significantly increased MMP9 activity and elevated NF-kB, MMP9, IL-6, TNF-α, and IL-1ß expressions were detected in both B19V-VP1u-treated U937 and THP-1 macrophages. Conversely, celastrol revealed an inhibitory effect on these molecules. Notably, celastrol intervened in this pathogenic process by suppressing the sPLA2 activity of B19V-VP1u and subsequently reducing the inflammatory response. Notably, the administration of B19V-VP1u exacerbated BLE-induced skin fibrosis in mice, with augmented expressions of TGF-ß, IL-6, IL-17A, IL-18, and TNF-α, ultimately leading to α-SMA and collagen I deposits in the dermal regions of BLE-induced SSc mice. Altogether, this study sheds light on parvovirus B19 VP1u linked to scleroderma and aggravated dermal fibrosis.
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Infecciones por Parvoviridae , Parvovirus B19 Humano , Esclerodermia Sistémica , Animales , Humanos , Ratones , Proteínas de la Cápside/genética , Fibrosis , Interleucina-6/metabolismo , Metaloproteinasa 9 de la Matriz/metabolismo , Infecciones por Parvoviridae/complicaciones , Parvovirus B19 Humano/genética , Esclerodermia Sistémica/inducido químicamente , Factor de Necrosis Tumoral alfa/metabolismo , Proteínas ViralesRESUMEN
Human parvovirus B19 (B19V) has been strongly associated with a variety of inflammatory disorders, such as rheumatoid arthritis (RA), inflammatory bowel disease and systemic lupus erythematosus. Nonstructural protein 1 (NS1) of B19V has been demonstrated to play essential roles in the pathological processes of B19V infection due to its regulatory properties on inflammatory cytokines. Celastrol, a quinone methide isolated from Tripterygium wilfordii, has displayed substantial potential in treating inflammatory diseases, such as psoriasis and RA. However, little is known about the effects of celastrol on B19V NS1induced inflammation. Therefore, cell viability assay, migration assay, phagocytosis analysis, zymography assay, ELISA and immunoblotting were conducted to verify the influences of celastrol on macrophages. The present study reported the attenuating effects of celastrol on B19V NS1induced inflammatory responses in macrophages derived from human acute monocytic leukemia cell lines, U937 and THP1. Although the migration was not significantly decreased by celastrol in both U937 and THP1 macrophages, significantly decreased viability, migration and phagocytosis were detected in both B19V NS1activated U937 and THP1 macrophages in the presence of celastrol. Additionally, celastrol significantly decreased MMP9 activity and the levels of inflammatory cytokines, including IL6, TNFα and IL1ß, in B19V NS1activated U937 and THP1 cells. Notably, significantly decreased levels of NLR family pyrin domaincontaining 3, apoptosisassociated specklike, caspase1 and IL18 proteins were observed in both B19V NS1activated U937 and THP1 cells in the presence of celastrol, indicating the involvement of the inflammasome pathway. To the best of our knowledge, the present study is the first to report on the attenuating effects of celastrol on B19V NS1induced inflammatory responses in macrophages, suggesting a therapeutic role for celastrol in B19V NS1related inflammatory diseases.
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Artritis Reumatoide , Parvovirus B19 Humano , Humanos , Inflamasomas , Proteína con Dominio Pirina 3 de la Familia NLR , Macrófagos , CitocinasRESUMEN
Parvovirus B19 infection is associated with a wide range of clinical manifestations, from asymptomatic to severe neurological disorders. Its major clinical symptoms, fever and rash, are common to multiple viruses, and laboratory tests to detect B19 are frequently not available. Thus, the impact of B19 on public health remains unclear. We report the case of a 38-day old girl admitted to São Paulo Clinical Hospital, Brazil, with an initial diagnosis of bacterial meningitis, seizures, and acute hydrocephalus. Antibiotic therapy was maintained for one week after admission and discontinued after negative laboratory results were obtained. Nine days after symptoms onset, a cerebral spinal fluid (CSF) sample revealed persistent pleocytosis. The complete B19 complete genome was subsequently identified in her CSF by a metagenomic next-generation sequencing approach. This report highlights the possible involvement of B19 in the occurrence of acute neurological manifestations and emphasizes that its possible involvement might be better revealed by the use of metagenomic technology to detect viral agents in clinical situations of unknown or uncertain etiology.
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BACKGROUND: The role of human parvovirus B19 (B19V) infection in malignant and benign lesions such as head and neck squamous cell carcinomas (HNSCCs) and oral mucocele lesions has not been established. Herein, we examined, for the first time, the presence of B19V in HNSCCs from Iranian subjects. METHODS: One hundred and eight HNSCC specimens were analyzed for the presence of B19V using nested polymerase chain reaction (nPCR) and TaqMan quantitative PCR assays. Immunohistochemistry procedures were performed to evaluate the expression of B19V VP1/VP2 proteins, p16INK4a, and NF-κB in tumor tissues and their adjacent non-tumor tissues. In addition, 40 oral mucocele, 30 oral buccal mucosa swabs, and 30 nasopharyngeal swabs obtained from healthy adults were analyzed as controls. RESULTS: B19V DNA was detected in 36.1% of HNSCCs. Further, 23.3% of HNSCC specimens showed immunoreactivity against B19V VP1/VP2 proteins. There was a significant difference in the frequency of B19V DNA-positive cases between the patient and control groups (p < 0.0001). Moreover, comparing tumoral tissues and their adjacent non-tumor tissues in terms of immunoreactivity against B19V structural proteins, a significant association was found between tumor tissues and B19V infection (p < 0.0001). Finally, investigating the simultaneous presence of B19V and high-risk human papillomaviruses (HPV) DNA, we found a significant association between these two viral infections in HNSCCs (p = 0.031). CONCLUSIONS: To sum up, B19V was frequently present in HNSCC tissues of Iranian patients but mostly absent in the adjacent non-tumor tissues as well as oral mucocele lesions, buccal, and nasopharyngeal swabs of healthy subjects. HPV possibly contributes to B19V persistence in HNSCC tissues. Additional research is required to investigate potential etiological or cofactor roles of B19V in the development of HNSCCs.
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Background: Human parvovirus B19 (B19V) is a common contaminant found in plasma pools and plasma derivatives. Previous studies were mainly focused on limited aspects, further assessment of prevalence of B19V DNA and antibodies in plasma donors, the contamination of B19V in pooled plasma and plasma derivatives should be performed in China. Study Design and Methods: Individual plasma donors' samples from four provinces and pooled plasma from four Chinese blood product manufacturers were collected and screened using B19V DNA diagnostic kits between October 2018 and May 2020. The positive samples were investigated for the seroprevalence of B19V antibodies and subjected to sequence analysis and alignment for phylogenetic studies. Moreover, 11 plasma donors who were B19V DNA-positive at their first testing were also followed during the later donation period. Additionally, 400 plasma pools and 20 batches of plasma derivatives produced by pooled plasma with a viral load of B19V DNA exceeding 104IU/mL were also collected and tested for B19V DNA and antibodies. Objectives: To comprehensively and systematically determine the frequency and viral load of B19V DNA in plasma donors, pooled plasma, and plasma derivatives from four Chinese blood product manufacturers. Results: A total of 17,187 plasma donors were analyzed and 44 (0.26%) specimens were found positive for B19V DNA. The quantitative DNA levels ranged from 1.01 × 101 to 5.09 × 1012 IU/mL. Forty-four DNA-positive specimens were also investigated for the seroprevalence of B19V antibodies, 75.0% and 2.3% of which were seropositive for B19V IgG and IgM antibodies, respectively. The phylogenic analyses showed that the prevalent genotypes in the four provinces' plasma donors belonged to B19V Genotype 1. Eleven individual plasma donors who were B19V DNA-positive at the first donation were then followed for a period, and in general, the DNA levels of B19V gradually decreased. Moreover, 64.8% (259/400) of the pooled plasma was contaminated by B19V, with concentrations of 1.05 × 100-3.36 × 109IU/mL. Approximately 72.6% of the DNA-positive plasma pools were only moderately contaminated (<104 IU/mL), while 27.4% contained >104 IU/mL. Twenty batches of plasma derivatives produced by pooled plasma with a viral load of B19V DNA exceeding 104IU/mL were also tested. B19V was detected in 5/5 PCC samples and 5/5 factor VIII samples but was not found in the intravenous immune globulin and albumin samples. Conclusion: The contamination of B19V in pooled plasma and plasma-derived clotting factor concentrates is serious. Whether B19V nucleic acid testing (NAT) screening of plasma and plasma derivatives is launched in China, blood product manufacturers should spontaneously perform B19V NAT screening in plasma donors and mini-pool plasma. These measures can ensure that samples with high titer B19V DNA are discarded in order to prevent and control this transfusion transmitted virus.
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Anticuerpos Antivirales , Donantes de Sangre , ADN Viral , Parvovirus B19 Humano , Humanos , ADN Viral/sangre , Pueblos del Este de Asia , Parvovirus B19 Humano/genética , Filogenia , Reacción en Cadena de la Polimerasa , Estudios Seroepidemiológicos , Anticuerpos Antivirales/sangreRESUMEN
The acquired immunodeficiency syndrome patients with compromised immunity are prone to hemophagocytic syndrome secondary to opportunistic infections.This paper reports a rare case of hemophagocytic syndrome secondary to human parvovirus B19 infection in an acquired immunodeficiency syndrome patient,and analyzes the clinical characteristics,aiming to improve the diagnosis and treatment of the disease and prevent missed diagnosis and misdiagnosis.
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Síndrome de Inmunodeficiencia Adquirida , Eritema Infeccioso , Linfohistiocitosis Hemofagocítica , Infecciones por Parvoviridae , Parvovirus B19 Humano , Humanos , Linfohistiocitosis Hemofagocítica/diagnóstico , Linfohistiocitosis Hemofagocítica/tratamiento farmacológico , Eritema Infeccioso/complicaciones , Síndrome de Inmunodeficiencia Adquirida/complicaciones , Infecciones por Parvoviridae/complicaciones , Infecciones por Parvoviridae/diagnósticoRESUMEN
At present, many infectious pathogens, especially emerging/re-emerging pathogens, exist in the blood of voluntary blood donors and may be transmitted through blood transfusions. However, most of Chinese blood centers only routinely screen for HBV, HCV, HIV, and syphilis. We employed metagenomic next-generation sequencing (mNGS) to investigate the microbiome in healthy voluntary blood donors to help assess blood safety in China by identifying infectious pathogens presented in donations that could lead to transfusion-acquired infections. We collected 10,720 plasma samples from voluntary blood donors from seven blood centers in different cities during 2012-2018 in China. A total of 562 GB of clean data was obtained. By analyzing the sequencing data, it was found that the most commonly identified bacteria found in the healthy blood were Serratia spp. (5.0176%), Pseudomonas spp. (0.6637%), and Burkholderia spp. (0.5544%). The principal eukaryote were Leishmania spp (1.3723%), Toxoplasma gondii (0.6352%), and Candida dubliniensis (0.1848%). Among viruses, Human Parvovirus B19 (B19V) accounts for the highest proportion (0.1490%), followed by Torque teno midi virus (0.0032%) and Torque teno virus (0.0015%). Since that B19V is a non-negligible threat to blood safety, we evaluated the positive samples for B19V tested by mNGS using quantitative polymerase chain reaction, Sanger sequencing, and phylogenetic analysis to achieve a better understanding of B19V in Chinese blood donors. Subsequently, 9 (0.07%) donations were positive for B19V DNA. The quantitative DNA levels ranged from 5.58 × 102 to 7.24 × 104 IU/ml. The phylogenic analyses showed that prevalent genotypes belonged to the B19-1A subtype, which disclosed previously unknown regional variability in the B19V positivity rate. The investigation revealed that many microbes dwell in the blood of healthy donors, including some pathogens that may be dormant in the blood and only cause disease under specific conditions. Thus, investigating the range and nature of potential pathogens in the qualified donations provided a framework for targeted interventions to help prevent emerging and re-emerging infectious diseases.
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Background: Human Parvovirus B19 (PB19) is a single-stranded DNA virus. Septic shock from viremia is rare with PB19; however, this infection can progress to life-threatening conditions. We report the first case of severe septic shock associated with a PB19 infection after cardiac surgery. Case Presentation: A 50-year-old Chinese woman received elective double metal valve replacement, including the aortic valve and the mitral valve, under cardiopulmonary bypass (CPB) and suffered severe septic shock on postoperative day (PD) 30. Through the detection of PB19-specific nucleic acids in blister fluid and serum samples via metagenomic next-generation sequencing (mNGS), positive serum PB19 IgM and no other proven infection, acute PB19 infection was confirmed. After five days of combined treatment, no further fever or abdominal discomfort was noted, and the patient's circulation gradually became stable without vasoactive medications. Conclusion: PB19 may be an unrecognized cause of septic shock, rash, fever of unknown origin or multiple systemic signs and symptoms, especially in immunosuppressed and immunocompetent critically ill patients. Investigations for viral aetiology are needed.
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Procedimientos Quirúrgicos Cardíacos , Eritema Infeccioso , Parvovirus B19 Humano , Choque Séptico , Femenino , Humanos , Persona de Mediana Edad , Eritema Infeccioso/complicaciones , Choque Séptico/etiología , Choque Séptico/complicaciones , Parvovirus B19 Humano/genética , Anticuerpos AntiviralesRESUMEN
B19 virus (B19V) is a pathogenic human parvovirus that infects erythroid progenitor cells. Because there are limited in vitro culture systems to propagate this virus, little is known about the molecular mechanisms by which it propagates in cells. In this study, we introduced a HiBiT peptide tag into various loops of VP2 located on the surface of B19V particles and evaluated their ability to form virus-like particles (VLPs). Three independent sites were identified as permissive sites for peptide tag insertion without affecting VLP formation. When the HiBiT tag was introduced into B19V clones (pB19-M20) and transfected into a semipermissive erythroleukemia cell line (UT7/Epo-S1), HiBiT-dependent luciferase activities (HiBiT activities) increased depending on helicase activity of viral NS1. Furthermore, we used a GFP11 tag-split system to visualize VLPs in the GFP1-10-expressing live cells. Time-lapse imaging of green fluorescent protein (GFP)-labeled VLPs revealed that nuclear VLPs were translocated into the cytoplasm only after cell division, suggesting that the breakdown of the nuclear envelope during mitosis contributes to VLP nuclear export. Moreover, HiBiT activities of culture supernatants were dependent on the presence of a detergent, and the released VLPs were associated with extracellular vesicles, as observed under electron microscopy. Treatment with an antimitotic agent (nocodazole) enhanced the release of VLPs. These results suggest that the virions accumulated in the cytoplasm are constitutively released from the cell as membrane-coated vesicles. These properties are likely responsible for viral escape from host immune responses and enhance membrane fusion-mediated transmission. IMPORTANCE Parvovirus particles are expected to be applied as nanoparticles in drug delivery systems. However, little is known about how nuclear-assembled B19 virus (B19V) virions are released from host cells. This study provides evidence of mitosis-dependent nuclear export of B19V and extracellular vesicle-mediated virion release. Moreover, this study provides methods for modifying particle surfaces with various exogenous factors and contributes to the development of fine nanoparticles with novel valuable functions. The pB19-M20 plasmid expressing HiBiT-tagged VP2 is a novel tool to easily quantify VP2 expression. Furthermore, this system can be applied in high-throughput screening of reagents that affect VP2 expression, which might be associated with viral propagation.
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Infecciones por Parvoviridae , Parvovirus B19 Humano , Humanos , Línea Celular , Proteínas Fluorescentes Verdes/metabolismo , Parvovirus B19 Humano/metabolismo , Péptidos/metabolismo , Partículas Similares a Virus ArtificialesRESUMEN
BACKGROUND: Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is a multifactorial disease with an unexplained aetiology in which viral infections are possible trigger factors. The aim of this study was to determine the involvement of human herpesvirus (HHV)-6A/B, HHV-7, and parvovirus B19 (B19V) in the etiopathogenesis of ME/CFS. METHODS: 200 patients with clinically diagnosed ME/CFS and 150 apparently healthy individuals were enrolled in this study. Single-round, nested, and quantitative real-time polymerase chain reactions (PCR) were used to detect the presence and load of HHV-6A/B, HHV-7, and B19V. HHV-6A and HHV-6B were distinguished by PCR and restriction analysis. Immunoenzymatic assays were applied to estimate the presence of virus-specific antibodies and the level of cytokines. RESULTS: HHV-6A/B, HHV-7, and B19V specific antibodies were detected among patients and healthy individuals in 92.1% and 76.7%, 84.6% and 93.8%, and 78% and 67.4% of cases. HHV-6B had 99% of HHV-6 positive patients. Latent HHV-6A/B, HHV-7, and B19V infection/co-infection was observed in 51.5% of the patients and 76.7% of the healthy individuals, whereas active-45% of the ME/CFS patients and 8.7% of healthy individuals. HHV-6A/B load in patients with a persistent infection/co-infection in a latent and active phase was 262 and 653.2 copies/106 cells, whereas HHV-7 load was 166.5 and 248.5 copies/106 cells, and B19V-96.8 and 250.8 copies/106 cells, respectively. ME/CFS patients with persistent infection in an active phase had a higher level of pro-inflammatory cytokines (interleukin(IL)-6, tumor necrosis factor-alpha(TNF-α) and IL-12) and anti-inflammatory (IL-10) than with a persistent infection in a latent phase. A significant difference was revealed in the levels of TNF-α, IL-12, and IL-10 among the patient groups without infection, with latent infection/co-infection, active single, double and triple co-infection. The levels of TNF-α, IL-12, and IL-10 are significantly higher in patients with severe compared with a moderate course of ME/CFS. CONCLUSIONS: Significantly more persistent HHV-6A/B, HHV-7, and B19V infection/co-infection in an active phase with a higher viral load and elevated levels of pro- and anti-inflammatory cytokines among patients with ME/CFS than healthy individuals indicate the importance of these infections/co-infections in ME/CFS development. The presence of these infections/co-infections influences the ME/CFS clinical course severity.
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Coinfección , Síndrome de Fatiga Crónica , Virosis , Humanos , Interleucina-10 , Factor de Necrosis Tumoral alfa , Infección Persistente , Citocinas , Interleucina-12RESUMEN
The acquired immunodeficiency syndrome patients with compromised immunity are prone to hemophagocytic syndrome secondary to opportunistic infections.This paper reports a rare case of hemophagocytic syndrome secondary to human parvovirus B19 infection in an acquired immunodeficiency syndrome patient,and analyzes the clinical characteristics,aiming to improve the diagnosis and treatment of the disease and prevent missed diagnosis and misdiagnosis.