OBJECTIVETo investigate the expression of IFN-λ1 in respiratory epithelial cells of children with respiratory syncytial virus (RSV) infection and its relationship with RSV load.

METHODSThe nasopharyngeal swabs were collected from the children who were hospitalized with respiratory tract infection from June 2015 to June 2016. A direct immunofluorescence assay was used to detect the antigens of seven common respiratory viruses (including RSV) in the nasopharyngeal swabs. A total of 120 children who were only RSV positive were selected as the RSV infection group. A total of 50 children who had negative results in the detection of all viral antigens were selected as the healthy control group. Fluorescence quantitative real-time PCR was used to determine the RSV load and the expression of IFN-λ1 mRNA in the nasopharyngeal swabs of children in the two groups.

RESULTSThe expression of IFN-λ1 in the RSV infection group was significantly higher than that in the healthy control group (P<0.05). The expression of IFN-λ1 was positively correlated with RSV load (r=0.56, P<0.05).

CONCLUSIONSRSV can induce the expression of IFN-λ1 in respiratory epithelial cells, suggesting that IFN-λ1 may play an important role in anti-RSV infection.

Antigens, Viral ; analysis ; Child, Preschool ; Epithelial Cells ; immunology ; Female ; Humans ; Infant ; Infant, Newborn ; Interleukins ; analysis ; physiology ; Male ; Nasopharynx ; microbiology ; Real-Time Polymerase Chain Reaction ; Respiratory Syncytial Virus Infections ; immunology ; virology ; Viral Load

Human respiratory syncytial virus (RSV) is the leading cause of severe lower respiratory tract infection, such as bronchiolitis, bronchitis, or pneumonia, in both infants and the elderly. Despite the global burden of diseases attributable to RSV infection, no clinically approved vaccine is available, and a humanized monoclonal antibody for prophylaxis is not readily affordable in developing countries. There are several hurdles to the successful development of RSV vaccines: immune-vulnerable target populations such as premature infants, pregnant women, and immunocompromised people; safety concerns associated with vaccine-enhanced diseases; repeated infection; and waning memory. To develop successful strategies for the prevention of RSV infection, it is necessary to understand the protective and pathologic roles of host immune responses to RSV infection. In this review, we will summarize the positive and negative relationship between RSV infection and host immunity and discuss strategies for the development of the first successful RSV vaccine.
Humans ; Immunity ; Immunocompromised Host ; Respiratory Syncytial Virus Infections/immunology/*prevention & control ; *Respiratory Syncytial Virus Vaccines ; Respiratory Syncytial Viruses/*physiology

OBJECTIVE: To explore the mechanisms for an increase in susceptibility of asthma induced by respiratory syncytial virus (RSV), to observe the expression of interleukin-8 (IL-8) in human bronchial epithelial cells (HBECs) after RSV infection and to invesigate the regulatory effect of IL-8 on Th17/Treg differentiation.
 METHODS: HBECs were divided into a control group and a RSV infected group. The RSVE-infected model of HBECs was established and examined. The expression of IL-8 mRNA was detected by real-time PCR, and the levels of IL-8 were measured by ELISA. Peripheral blood lymphocytes in healthy people were extracted and divided into a control group and an IL-8 treatment group. Based on concentration of IL-8 in RSV-infected HBECs, lymphocytes were treated by a matched concentration of human recombinant IL-8 for 24 h. The distribution of Th17 and Treg subsets in lymphocytes were examined by flow cytometry.
 RESULTS: The RSV-infected HBECs model was successfully established. The infected HBECs were still able to split and passage. The RSV could be detected in every passage in the infected cells. Virus particles indicated by bright yellow green fluorescence were seen under fluorescence microscope. Edema of mitochondrias, expansion of endoplasmic reticulum, fissure around nucleus and intracellular virus particles were all observed under electron microscope. The expression IL-8 mRNA were significantly enhanced in the RSV-infected group, and the level of IL-8 in the RSV-infected group was higher than that in the control group (P<0.05). After IL-8 treatment for 24 h, the ratio of Th17 subsets in lymphocytes were dramatically increased compared to the control group (P<0.05), but there was no difference in the ratio of Treg subsets between the 2 groups (P>0.05).
 CONCLUSION Over-secretion of IL-8 by the RSV-infected HBECs may promote the differentiation of Th17 subsets and maintain the Th17/Tred imbalance.
Cell Differentiation ; Cells, Cultured ; Epithelial Cells ; drug effects ; virology ; Flow Cytometry ; Humans ; Interleukin-8 ; immunology ; pharmacology ; Real-Time Polymerase Chain Reaction ; Recombinant Proteins ; pharmacology ; Respiratory Syncytial Virus Infections ; immunology ; Respiratory Syncytial Viruses ; T-Lymphocytes, Regulatory ; cytology ; Th17 Cells ; cytology

The respiratory syncytial virus (RSV) belongs to the family Paramyxoviridae and subfamily Pneumovirinae. The RSV can cause acute infections of the lower respiratory tract in infants. The F gene of the RSV is a conservative gene and varies only slightly in its expression. Few studies focusing on the variability of the F gene have been carried out. F protein (fusion glycoprotein) is a transmembrane glycoprotein that mediates fusion and penetration between the virus and host cells. Neutralizing antibody against the F protein can protect against infection by RSV subtypes A and B. Hence, F protein has become the main target for the development of a monoclonal antibody and vaccine against the RSV. An effective vaccine is not available, so a monoclonal antibody against F protein is now the most important method to reduce the morbidity and severity associated with RSV infection in high-risk children. However, a monoclonal antibody can lead to the production of drug-resistant strains of the RSV. This review focuses on genetic variation of the F gene of the RSV as well as progress in the development of a monoclonal antibody against F protein and a vaccine in the last decade.
Animals ; Antibodies, Monoclonal ; immunology ; Humans ; Respiratory Syncytial Virus Infections ; immunology ; prevention & control ; virology ; Respiratory Syncytial Viruses ; genetics ; immunology ; Viral Fusion Proteins ; genetics ; immunology ; Viral Vaccines ; genetics ; immunology

This investigation enrolled 570 healthy young males gathered from all over the country for military service at the Republic of Korea Air Force boot camp. It confirmed RSV IgG seroprevalence by utilizing the enzyme immunoassay method just prior to undergoing basic training. The mean age of this study was 20.25+/-1.34 yr old. The results of their immunoassay seroprofiles showed that 561 men (98.4%) were positive, 2 (0.4%) were negative and 7 (1.2%) were equivocal belonging to the grey zone. It was confirmed that RSV is a common respiratory virus and RSV infection was encountered by almost all people before reaching adulthood in Korea. Nine basic trainees belonging to the RSV IgG negative and equivocal grey zone categories were prospectively observed for any particular vulnerability to respiratory infection during the training period of two months. However, these nine men completed their basic training without developing any specific respiratory illness.
Adult ; Antibodies, Viral/*blood ; Humans ; Immunoenzyme Techniques ; Immunoglobulin G/*blood ; Male ; Military Personnel ; Respiratory Syncytial Virus Infections/*epidemiology ; Respiratory Syncytial Viruses/*immunology ; Seroepidemiologic Studies ; Young Adult

OBJECTIVEThe present study was designed to explore the practical application of the rapid etiological diagnosis by detecting specific IgM antibody against common respiratory viruses in children with acute lower respiratory infections (ALRI).

METHODClinical specimens including nasopharyngeal aspirates and serum of acute phase from hospitalized children were collected from 207 infants and children with acute lower respiratory infections from March 2009 to September 2010. Seven common respiratory virus antigens were identified from the collected nasopharyngeal aspirates by direct immunofluorescence assay (DFA). ELISA was used to detect specific IgM antibody against RSV, ADV, IFVA, IFVB and PIV, while indirect immunofluorescence assay (IFA) was used to detect specific IgM antibody against RSV, ADV, IFVA, IFVB, PIV1, PIV2 and PIV3 in collected acute phase serum.

RESULTThe overall positive rates to detect viral antigen by using DFA, ELISA and IFA was 67.6%, 57.5% and 39.6%, respectively. The consistent rate of ELISA and IFA versus accepted DFA were 21.7% and 31.4%, respectively. The average days from onset of the symptoms to blood sample collection for those with the consistent results by ELISA and DFA were 12.0 d for ADV, 9.6 d for PIV2, 9.5 d for IFV, and 5.3 d for RSV, respectively, and by IFA and DFA were 15.0 d for PIV3, 9.2 d for ADV, and 7.4 d for RSV, respectively. Among all age groups, the consistent rate of serum viral IgM and antigen detections was highest in children younger than 3 years old.

CONCLUSIONAlthough there were differences between serum IgM antibody and viral antigen detections, specific IgM antibody detection was of value in early and rapid etiological diagnosis of pediatric ALRI, especially for young children. It could provide serologic evidence of respiratory virus infection. The diagnostic rate of pathogen could be improved if it was used in combination with viral antigen diagnostic methods.

Antibodies, Viral ; analysis ; blood ; Antibody Specificity ; Antigens, Viral ; analysis ; Child ; Child, Preschool ; Enzyme-Linked Immunosorbent Assay ; Female ; Fluorescent Antibody Technique ; Humans ; Immunoglobulin M ; analysis ; blood ; Infant ; Male ; Nasopharynx ; virology ; RNA Viruses ; genetics ; isolation & purification ; Respiratory Syncytial Virus Infections ; diagnosis ; virology ; Respiratory Syncytial Viruses ; genetics ; isolation & purification ; Respiratory Tract Infections ; diagnosis ; immunology ; virology ; Sensitivity and Specificity

OBJECTIVETo study the regulation trend of resveratrol on TNF-alpha, IL-1beta, IL-6 expressions in bronchoalveolar layage fluid (BALF) of RSV-infected BALB/c mice at different time points.

METHODRSV-induced BALB/c mice were orally administered with resveratrol. Their BALFs were collected at 24, 72 and 144 h after the first nasal drip with RSV to detect the level of TNF-alpha, IL-1P3, IL-6 by EILSA.

RESULTThe expression of TNF-alpha, IL-1Pf and IL-6 in BALF increased significantly compared with the normal group (P <0. 01) after 24 hours of RSV infection, while the expression of TNF-alpha (P < 0.01), IL-1beta (P < 0.05), IL-6 (P < 0.01) in the resveratrol group decreased notably compared with the model group. After 72 hours of infection with RSV, although the expression of TNF-alpha (P < 0.05), IL-1beta (P < 0.01) and IL-6 (P < 0.01) in BALF in model group were higher than those in the normal group, they were much more lower than at 24 h. The expression of IL-1beta and IL-6 (P < 0.05) in the resveratrol groups were down-regulated significantly, but no difference had been shown in TNF-alpha expression compared with the RSV infection group. After infection with RSV for 144 h, the expression of IL-1beta (P < 0.01) and IL-6 (P < 0.05) in BALF in the model group were higher than those in the normal group, but there was no difference in the secretion of TNF-alpha. The expression of TNF-alpha, IL-1beta and IL-6 showed also no remarkable difference between the resveratrol groups and the RSV infection group.

CONCLUSIONResveratrol can inhibit the over expression of inflammatory factors TNF-alpha, IL-1beta, IL-6 in bronchoalveolar lavage fluid of RSV-induced BALB/c mice and keep them at a low level with the passing of infection time.

Animals ; Bronchoalveolar Lavage Fluid ; immunology ; Female ; Interleukin-1beta ; analysis ; Interleukin-6 ; analysis ; Mice ; Mice, Inbred BALB C ; Respiratory Syncytial Virus Infections ; drug therapy ; immunology ; Stilbenes ; pharmacology ; therapeutic use ; Tumor Necrosis Factor-alpha ; analysis

OBJECTIVETo study the roles of CD4(+)CD25(+) regulatory T cells and Foxp3 mRNA in peripheral blood as well as serum total immunoglobulin E (IgE) in the pathogenesis of bronchiolitis caused by respiratory syncytial virus (RSV).

METHODSThe proportion of CD4(+)CD25(+) regulatory T cells and expression of Foxp3 mRNA in peripheral blood, and total serum IgE level were tested by flow cytometry, RT-PCR and ELISA respectively in 57 children with RSV bronchiolitis (26 atopic patients and 31 nonatopic patients). Twenty five healthy children were used as the control group.

RESULTSThe proportion of CD4(+)CD25(+) regulatory T cells in peripheral blood in children with bronchiolitis, either in the atopic (7.7+/- 1.6%)or the nonatopic group (8.8+/- 2.1%), was significantly lower than that in the control group (10.5+/- 1.6%) (P< 0.01). Foxp3 mRNA expression in peripheral blood was significantly lower in both atopic and nonatopic children with bronchiolitis than that in the control group (P< 0.01). Significantly increased total serum IgE level was noted in both atopic (241.2+/- 102.5 IU/mL) and nonatopic children (125.5+/- 63.2 IU/mL) with bronchiolitis compared with that in the control group (27.2+/- 10.5 IU/ml) (P< 0.01). There were significant differences in the proportion of CD4(+)CD25(+) regulatory T cells and Foxp3 mRNA expression in peripheral blood (P< 0.05) as well as total serum IgE level (P< 0.01) between the atopic and the nonatopic group. The proportion of CD4(+)CD25(+) regulatory T cells (r=-0.70, P< 0.01) and Foxp3 mRNA expression in peripheral blood (r=-0.79, P< 0.01) were closely negatively correlated to total serum IgE level.

CONCLUSIONSBoth the proportion of CD4(+)CD25(+) regulatory T cells and Foxp3 mRNA expression in peripheral blood were reduced, in contrast, the total serum IgE level increased in children with RSV bronchiolitis. This suggested that CD4(+)CD25(+) regulatory T cells and Foxp3 mRNA together with IgE participated in the pathogenesis of RSV bronchiolitis.

Bronchiolitis ; etiology ; immunology ; CD4-Positive T-Lymphocytes ; immunology ; Female ; Forkhead Transcription Factors ; genetics ; Humans ; Immunoglobulin E ; blood ; Infant ; Male ; RNA, Messenger ; blood ; Respiratory Syncytial Virus Infections ; etiology ; immunology ; T-Lymphocytes, Regulatory ; physiology

OBJECTIVETo investigate the effect of respiratory syncytial virus (RSV) infection on the production of thymic stromal lymphopoietin (TSLP) and Th1/Th2 balance in asthmatic mice.

METHODSThirty-two female BALB/c mice were randomly divided into 4 groups, namely the PBS group, ovalbumin (OVA) group, RSV group and OVA/RSV group. The mice were sensitized by OVA and then stimulated with nebulized OVA, and RSV was inoculated into the nasal cavity of the mice. BUXCO noninvasive lung function detection was performed to examine the airway response to metacholine, and enzyme-linked immunosorbent assay (ELISA) was used to detect the serum levels of IL-4, IL-5, IL-13, and IFN-gamma in the mice. The cells in the bronchoalveolar lavage fluid (BALF) were counted and classified, and the supernatants of the BALF were used for the detection of TSLP. Histopathological changes in the lung tissues of the mice were examined using HE staining, and immunohistochemistry using anti-mouse TSLP antibody was performed to examine TSLP expressions in the airway epithelial cells.

RESULTSRSV infection promoted the production of TSLP in the asthmatic mice, and the concentration of TSLP in OVA/RSV group (2.13-/+0.05 ng/ml) was significantly higher than that in the other groups (P<0.01). RSV infection increased the serum levels of IL-4, IL-5, IL-13, and IFN-gamma in the mice. The total BALF cells, eosinophils, lymphocytes and neutrophils in OVA/RSV group were significantly higher than those in the other groups; noninvasive lung function examination showed higher Penh value in OVA/RSV group (318.66-/+50.87) than in the other groups when the inhaled metacholine increased to 6.25 mg/ml (P<0.01). More obvious and extensive airway inflammatory cell infiltration in OVA/RSV group were observed, and immunohistochemical staining also showed higher expression of TSLP in the airway epithelial cells of OVA/RSV group.

CONCLUSIONSRSV infection promotes the production of TSLP in the airway epithelial cells and increases the level of Th2 cytokines in asthmatic mice. Concurrent RSV infection can exacerbate Th2 inflammatory reaction in asthmatic mice.

Animals ; Bronchoalveolar Lavage Fluid ; Cytokines ; biosynthesis ; secretion ; Female ; Immunohistochemistry ; Inflammation ; immunology ; virology ; Interferon-gamma ; blood ; Interleukins ; blood ; Lung ; immunology ; metabolism ; virology ; Mice ; Mice, Inbred BALB C ; Respiratory Syncytial Virus Infections ; blood ; immunology ; metabolism ; Th2 Cells ; cytology ; immunology ; virology

OBJECTIVEA deficient interferon-gamma (IFN-gamma) response has been involved in the pathogenesis of severe respiratory syncytial virus (RSV) infection. Gene polymorphisms in IFN-gamma/A+874T have been associated with the susceptibility to asthma and might be related to disease severity of RSV infection. This study investigated the single nucleotide polymorphisms (SNPs) of IFN-gamma/A+874T in Han children in Wenzhou area and to explore the correlation between gene polymorphisms of IFN-gamma/A+874T and the susceptibility and disease severity of RSV bronchiolitis, as well as the effect of SNPs upon nasopharyngeal secretions (NPS) IFN-gamma and total serum IgE levels.

METHODSOne hundred and fourteen hospitalized children with RSV bronchiolitis and 90 healthy controls were recruited. Sequence analysis was used for detecting the SNPs of IFN-gamma/A+874T. NPS IFN-gamma levels were measured using ELISA. Total serum IgE levels were assayed using the chemiluminescence method.

RESULTSIFN-gamma/A+874T gene polymorphisms were present in both the patient and the control groups. AA and AT genotypes were found in both groups, with a AA frequency of 82.5% vs 77.8% and a AT frequency of 17.5% vs 21.1% (p>0.05). The frequency of allele was 90.4% (A) and 9.6% (T) in the patient group, and 88.3% (A) and 11.7% (T) in the control group, respectively. There were no significant differences in the allele frequency between the two groups. Moreover, no difference was found both in NPS IFN-gamma and total serum IgE levels between AA and AT genotypes in the patient group. There were no significant differences in the variation of IFN-gamma/+874 between mild and moderate to severe cases.

CONCLUSIONSIFN-gamma/A+874T gene polymorphisms were present in Han children in Wenzhou area. Gene variations were not associated with the susceptibility and disease severity of RSV bronchiolitis as well as IFN-gamma and total serum IgE levels.

Bronchiolitis ; genetics ; immunology ; Female ; Genetic Predisposition to Disease ; Humans ; Immunoglobulin E ; blood ; Infant ; Interferon-gamma ; genetics ; Male ; Nasopharynx ; immunology ; Polymorphism, Single Nucleotide ; Respiratory Syncytial Virus Infections ; genetics ; immunology