Child ; Humans ; Respiratory Syncytial Virus Infections ; immunology ; virology ; Respiratory Syncytial Virus, Human ; immunology ; pathogenicity

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

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

OBJECTIVETo probe the epidemiological trend of respiratory syncytial virus (RSV) and cellular immunological change of RSV bronchopneumonia among children in Suzhou in the past five years.

METHODS10,205 children with acute respiratory tract infection from January 2001 to December 2005 were enrolled into the study. Nasopharyngeal aspirates were obtained from the respiratory tract by aseptic vacuum aspiration. Direct immuno-fluorescence assay was employed to detect seven kinds of virus antigens including RSV antigen. CD3, CD4, CD8, CD19, CD16 and CD56 in peripheral blood mononuclear cells of 30 patients with RSV bronchopneumonia (1.5-24.0 months old group) were analyzed by flow cytometry analysis, and 15 normal infants (1.5-24.0 months old group) were enrolled as control group.

RESULTSThe annual positive rate of RSV was 24.94%, 25.83%, 24.05%, 25.39% and 27.30% respectively from 2001 to 2005. It also found that the peak season for RSV infection was spring or winter (January to March or November to December). The positive rate of RSV was significantly higher in 1-12 months old group than that in > 12 months old group (chi2 = 97.320, P < 0.01), as well as the groups between 1-12 months old (chi2 = 7.804, P < 0.05, the highest positive rate was occurred at 3-6 months old group). The positive rate of RSV was significantly higher in boys than that in girls (chi2 = 9.693, P < 0.01). The percentages of CD3+, CD4+, CD8+ and NK (CD16 + 56)+ cells were significantly lower in RSV bronchopneumonia than those in control group (t = 3.199, P < 0.01; t = 2.215, P < 0.05; t = 2.619, P < 0.05 and t = 5.240, P < 0.01, respectively). While the percentage of CD19+ cells was significantly elevated in RSV bronchopneumonia than that in control group (t = 2.875, P < 0.01).

CONCLUSIONRSV infection is of obvious seasonal changes. The younger the patient, the higher positive rates of RSV infection is, while and the cellular immunity function is lower. The effective measures for preventing RSV infection are important, especially for the infants. Further investigation is necessary to understand the causes of the variations for RSV infections between boys and girls.

Adolescent ; Bronchopneumonia ; epidemiology ; immunology ; virology ; Child ; Child, Preschool ; China ; epidemiology ; Female ; Humans ; Infant ; Infant, Newborn ; Male ; Respiratory Syncytial Virus Infections ; epidemiology ; immunology ; Respiratory Syncytial Viruses

Adenoviridae ; immunology ; Antigens, Viral ; analysis ; Child ; Fluorescent Antibody Technique ; Humans ; Respiratory Syncytial Viruses ; immunology ; Respiratory Tract Infections ; immunology ; Respirovirus ; immunology ; Virus Diseases ; 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

AIMTo study the relation between Respiratory Syncytial Virus infection and asthma development by measuring airway responsiveness (AR) and M2R function.

METHODSGuinea pigs (n = 34) were randomly divided into 4 groups: Hep-2/NS group (group A, n = 9), RSV/NS group (group B, n =9), Hep-2/OVA group (group C, n = 8) and RSV/OVA group(group D, n = 8). On day 21 after infection we tested AR and M2R. Then counted eosinophils in BALF and observed pathological change.

RESULTSIntraairway pressure(IP mmH20) of group B had no significant difference with group A(P > 0.01), and the extent of IP decrease also had no difference between groups A and B (P > 0. 05), but IP of C group were much higher than group A (P<0.05), with extent of IP decrease lower than group A (P < 0.05). And IP of group D were higher than group C (P < 0.01), with the extent of IP decrease much lower than group C (P < 0.05).

CONCLUSIONRSV infection could enhance OVA-induced M2R dysfunction, then develop AHR.

Animals ; Asthma ; immunology ; physiopathology ; virology ; Bronchial Hyperreactivity ; immunology ; physiopathology ; virology ; Female ; Guinea Pigs ; Male ; Ovalbumin ; immunology ; Random Allocation ; Receptor, Muscarinic M2 ; physiology ; Respiratory Syncytial Virus Infections ; immunology ; Respiratory Syncytial Viruses ; immunology

Allergens ; immunology ; Animals ; Asthma ; etiology ; Enzyme Activation ; Lung ; pathology ; Matrix Metalloproteinases ; physiology ; Mice ; Respiratory Syncytial Virus Infections ; enzymology ; pathology

To construct plasmid of recombinant protein candidate vaccine of respiratory syncytial virus, express it in E. coli, and to investigate its immunogenicity and protective efficacy. A CD8+ T cell epitope from respiratory syncytial virus (RSV) M2 protein F/M2:81 - 95 and the G:125-225 (G1) gene fragments from RSV-G protein containing B cell epitopes were amplified by PCR method and then inserted into the prokaryotic expression vector pET-DsbA after bonding to a linker. The fusion protein DsbA-G1-Linker-F/M2:81-95 (D-G1LF/M2) was expressed successfully in E. coli BL21 (DE3). The product was proved to be RSV-specific by Western-blot. After purified by affinity chromatography on Ni+ Sepharose and renatured by gradient dialysis. D-G1LF/M2 was used to immune BALB/c mice. D-G1LF/M2 induced high anti-D-G1LF/M2 IgG, anti-RSV IgG and neutralizing antibody titers in serum and lung of BALB/c mice, and elicied RSV-specific CTL responses. The IgG subclass distribution revealed that IgG1/IgG2a ratio was 2.66. Viral titration indicated that D-G1LF/M2 could protect BALB/c mice against RSV challenge in lung.
Animals ; Antibodies, Viral ; blood ; immunology ; Escherichia coli ; genetics ; metabolism ; Humans ; Immunoglobulin G ; blood ; immunology ; Mice ; Mice, Inbred BALB C ; Plasmids ; genetics ; immunology ; Recombinant Fusion Proteins ; biosynthesis ; genetics ; immunology ; Respiratory Syncytial Virus Infections ; prevention & control ; Respiratory Syncytial Virus Vaccines ; biosynthesis ; genetics ; immunology ; Respiratory Syncytial Virus, Human ; genetics ; immunology ; Viral Envelope Proteins ; genetics ; Viral Fusion Proteins ; genetics ; Viral Proteins ; genetics

Bronchiolitis is a risk factor for the development of childhood asthma. Eosinophilic inflammation in airways plays an important role in the pathophysiology of both bronchiolitis and asthma. To investigate this inflammation, we measured the eosinophil cationic protein (ECP), regulated on activation normal T-cell expressed and secreted (RANTES) and eotaxin levels in nasopharyngeal secretions (NPS). Twenty-eight patients with RSV bronchiolitis (RSV group), 11 patients with non-RSV bronchiolitis (non-RSV group) and 7 controls were enrolled in this study. ECP, RANTES, and eotaxin levels were measured by enzyme immunoassays. The ECP level in the NPS of the RSV group was significantly higher than that in the NPS of the non-RSV group and controls. RANTES and eotaxin levels in infants with bronchiolitis were significantly higher than those in the controls, but there was no significant difference between the RSV and non-RSV groups. In conclusion, with regard to eosinophilic airway inflammation, as compared with non-RSV bronchiolitis, RSV bronchiolitis may be more similar to childhood asthma.
Respiratory Syncytial Virus Infections/*immunology ; RANTES/analysis ; Nasopharynx/*immunology/secretion ; Male ; Infant ; Humans ; Female ; Eosinophil Cationic Protein/*analysis ; Chemokines, CC/analysis ; Chemokines/*analysis ; Bronchiolitis/*immunology