scholarly journals The NS2 Protein of Human Respiratory Syncytial Virus Suppresses the Cytotoxic T-Cell Response as a Consequence of Suppressing the Type I Interferon Response

2006 ◽  
Vol 80 (12) ◽  
pp. 5958-5967 ◽  
Author(s):  
Alexander Kotelkin ◽  
Igor M. Belyakov ◽  
Lijuan Yang ◽  
Jay A. Berzofsky ◽  
Peter L. Collins ◽  
...  
Keyword(s):  
Respiratory Syncytial Virus ◽  
Type I Interferon ◽  
Human Respiratory Syncytial Virus ◽  
Interferon Response ◽  
Cytotoxic T Cell ◽  
Type I ◽  
Type I Ifn ◽  
Ifn Γ ◽  
Syncytial Virus

ABSTRACT The NS1 and NS2 proteins of human respiratory syncytial virus (HRSV) have been shown to antagonize the type I interferon (IFN) response, an effect subject to host range constraints. We have now found that the HRSV NS2 protein strongly controls IFN induction in mouse cells in vitro, validating the use of the mouse model to study the consequences of these gene deletions on host immunity. We evaluated the effects of deleting the NS1 and/or NS2 gene on the induction of HRSV-specific pulmonary cytotoxic T lymphocytes (CTL) in BALB/c and 129S6 mice in response to intranasal infection with HRSV lacking the NS1 and/or NS2 gene and subsequent challenge with wild-type (wt) HRSV. In mice infected with HRSV lacking the NS2 gene (ΔNS2) or lacking the NS2 gene in combination with the NS1 gene (ΔNS1/2 HRSV), the magnitude of the pulmonary CTL response was substantially elevated compared to that of mice infected with wt HRSV or the ΔNS1 mutant, whether measured by binding of CD8+ cells to an HRSV-specific major histocompatibility complex class I tetramer, by measurement of CD8+ cells secreting gamma interferon (IFN-γ) in response to specific in vitro stimulation, or by a standard chromium release cell-killing assay. In contrast, in STAT1 knockout mice, which lack responsiveness to type I IFN, the level of IFN-γ-secreting CD8+ cells was not significantly different for HRSV lacking the NS2 gene, suggesting that the increase in CTL observed in IFN-responsive mice is type I IFN dependent. Thus, the NS2 protein of HRSV suppresses the CTL component of the adaptive immune response, and this appears to be a consequence of its suppression of type I IFN.

scholarly journals Lack of Type I Interferon Signaling Ameliorates Respiratory Syncytial Virus-Induced Lung Inflammation and Restores Antioxidant Defenses

Antioxidants ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 67
Author(s):  
Maria Ansar ◽  
Yue Qu ◽  
Teodora Ivanciuc ◽  
Roberto P. Garofalo ◽  
Antonella Casola
Keyword(s):  
Respiratory Syncytial Virus ◽  
Airway Inflammation ◽  
Type I Interferon ◽  
Cell Model ◽  
Antioxidant Defenses ◽  
Related Factor ◽  
Type I ◽  
Type I Ifn ◽  
Rsv Infection ◽  
Syncytial Virus

Respiratory syncytial virus (RSV) infection in mouse and human lung is associated with pathogenic inflammation and oxidative injury. RSV impairs antioxidant responses by increasing the degradation of transcription factor NF-E2-related factor 2 (NRF2), which controls the expression of several antioxidant enzymes (AOEs). In addition to its protective effects, type I IFNs have been increasingly recognized as important mediators of host pathogenic responses during acute respiratory viral infections. We used a mouse model of RSV infection to investigate the effect of lack of type I interferon (IFN) receptor on viral-mediated clinical disease, airway inflammation, NRF2 expression, and antioxidant defenses. In the absence of type I IFN signaling, RSV-infected mice showed significantly less body weight loss and airway obstruction, as well as a significant reduction in cytokine and chemokine secretion and airway inflammation. Lack of type I IFN receptor was associated with greatly reduced virus-induced promyelocytic leukemia lung protein expression, which we showed to be necessary for virus-induced NRF2 degradation in a cell model of infection, resulting in restoration of NRF2 levels, AOE expression, and airway antioxidant capacity. Our data support the concept that modulation of type I IFN production and/or signaling could represent an important therapeutic strategy to ameliorate severity of RSV-induced lung disease.

scholarly journals Respiratory Syncytial Virus NS1 Protein Degrades STAT2 by Using the Elongin-Cullin E3 Ligase

2007 ◽  
Vol 81 (7) ◽  
pp. 3428-3436 ◽  
Author(s):  
Joanne Elliott ◽  
Oonagh T. Lynch ◽  
Yvonne Suessmuth ◽  
Ping Qian ◽  
Caroline R. Boyd ◽  
...  
Keyword(s):  
Respiratory Syncytial Virus ◽  
E3 Ligase ◽  
Interferon Response ◽  
Type I ◽  
Ns1 Protein ◽  
Consensus Sequences ◽  
Ubiquitin Ligase E3 ◽  
Syncytial Virus ◽  
Cullin 2

ABSTRACT Respiratory syncytial virus (RSV) infection causes bronchiolitis and pneumonia in infants. RSV has a linear single-stranded RNA genome encoding 11 proteins, 2 of which are nonstructural (NS1 and NS2). RSV specifically downregulates STAT2 protein expression, thus enabling the virus to evade the host type I interferon response. Degradation of STAT2 requires proteasomal activity and is dependent on the expression of RSV NS1 and NS2 (NS1/2). Here we investigate whether RSV NS proteins can assemble ubiquitin ligase (E3) enzymes to target STAT2 to the proteasome. We demonstrate that NS1 contains elongin C and cullin 2 binding consensus sequences and can interact with elongin C and cullin 2 in vitro; therefore, NS1 has the potential to act as an E3 ligase. By knocking down expression of specific endogenous E3 ligase components using small interfering RNA, NS1/2, or RSV-induced STAT2, degradation is prevented. These results indicate that E3 ligase activity is crucial for the ability of RSV to degrade STAT2. These data may provide the basis for therapeutic intervention against RSV and/or logically designed live attenuated RSV vaccines.

scholarly journals Differential Type I Interferon Induction by Respiratory Syncytial Virus and Influenza A Virus In Vivo

2007 ◽  
Vol 81 (18) ◽  
pp. 9790-9800 ◽  
Author(s):  
Nancy A. Jewell ◽  
Negin Vaghefi ◽  
Sara E. Mertz ◽  
Parvis Akter ◽  
R. Stokes Peebles ◽  
...  
Keyword(s):  
Influenza Virus ◽  
Respiratory Syncytial Virus ◽  
Virus Infection ◽  
Influenza A Virus ◽  
Influenza A ◽  
Type I Interferon ◽  
Type I ◽  
Type I Ifn ◽  
Syncytial Virus

ABSTRACTType I interferon (IFN) induction is an immediate response to virus infection, and very high levels of these cytokines are produced when the Toll-like receptors (TLRs) expressed at high levels by plasmacytoid dendritic cells (pDCs) are triggered by viral nucleic acids. Unlike many RNA viruses, respiratory syncytial virus (RSV) does not appear to activate pDCs through their TLRs and it is not clear how this difference affects IFN-α/β induction in vivo. In this study, we investigated type I IFN production triggered by RSV or influenza A virus infection of BALB/c mice and found that while both viruses induced IFN-α/β production by pDCs in vitro, only influenza virus infection could stimulate type I IFN synthesis by pDCs in vivo. In situ hybridization studies demonstrated that the infected respiratory epithelium was a major source of IFN-α/β in response to either infection, but in pDC-depleted animals only type I IFN induction by influenza virus was impaired.

scholarly journals Evaluation of the Safety and Immune Efficacy of Recombinant Human Respiratory Syncytial Virus Strain Long Live Attenuated Vaccine Candidates

2021 ◽  
Author(s):  
Li-Nan Wang ◽  
Xiang-Lei Peng ◽  
Min Xu ◽  
Yuan-Bo Zheng ◽  
Yue-Ying Jiao ◽  
...  
Keyword(s):  
Respiratory Syncytial Virus ◽  
Gene Deletion ◽  
Human Respiratory Syncytial Virus ◽  
Temperature Sensitive ◽  
T7 Promoter ◽  
Vaccine Candidates ◽  
Rsv Infection ◽  
Syncytial Virus

AbstractHuman respiratory syncytial virus (RSV) infection is the leading cause of lower respiratory tract illness (LRTI), and no vaccine against LRTI has proven to be safe and effective in infants. Our study assessed attenuated recombinant RSVs as vaccine candidates to prevent RSV infection in mice. The constructed recombinant plasmids harbored (5′ to 3′) a T7 promoter, hammerhead ribozyme, RSV Long strain antigenomic cDNA with cold-passaged (cp) mutations or cp combined with temperature-sensitive attenuated mutations from the A2 strain (A2cpts) or further combined with SH gene deletion (A2cptsΔSH), HDV ribozyme (δ), and a T7 terminator. These vectors were subsequently co-transfected with four helper plasmids encoding N, P, L, and M2-1 viral proteins into BHK/T7-9 cells, and the recovered viruses were then passaged in Vero cells. The rescued recombinant RSVs (rRSVs) were named rRSV-Long/A2cp, rRSV-Long/A2cpts, and rRSV-Long/A2cptsΔSH, respectively, and stably passaged in vitro, without reversion to wild type (wt) at sites containing introduced mutations or deletion. Although rRSV-Long/A2cpts and rRSV-Long/A2cptsΔSH displayed  temperature-sensitive (ts) phenotype in vitro and in vivo, all rRSVs were significantly attenuated in vivo. Furthermore, BALB/c mice immunized with rRSVs produced Th1-biased immune response, resisted wtRSV infection, and were free from enhanced respiratory disease. We showed that the combination of ΔSH with attenuation (att) mutations of cpts contributed to improving att phenotype, efficacy, and gene stability of rRSV. By successfully introducing att mutations and SH gene deletion into the RSV Long parent and producing three rRSV strains, we have laid an important foundation for the development of RSV live attenuated vaccines.

scholarly journals The Human Immune Response to Respiratory Syncytial Virus Infection

2017 ◽  
Vol 30 (2) ◽  
pp. 481-502 ◽  
Author(s):  
Clark D. Russell ◽  
Stefan A. Unger ◽  
Marc Walton ◽  
Jürgen Schwarze
Keyword(s):  
Immune Response ◽  
Respiratory Syncytial Virus ◽  
T Cell ◽  
T Cell Response ◽  
Rsv Infection ◽  
Human Immune Response ◽  
Ifn Γ ◽  
Human Immune ◽  
Syncytial Virus

SUMMARY Respiratory syncytial virus (RSV) is an important etiological agent of respiratory infections, particularly in children. Much information regarding the immune response to RSV comes from animal models and in vitro studies. Here, we provide a comprehensive description of the human immune response to RSV infection, based on a systematic literature review of research on infected humans. There is an initial strong neutrophil response to RSV infection in humans, which is positively correlated with disease severity and mediated by interleukin-8 (IL-8). Dendritic cells migrate to the lungs as the primary antigen-presenting cell. An initial systemic T-cell lymphopenia is followed by a pulmonary CD8+ T-cell response, mediating viral clearance. Humoral immunity to reinfection is incomplete, but RSV IgG and IgA are protective. B-cell-stimulating factors derived from airway epithelium play a major role in protective antibody generation. Gamma interferon (IFN-γ) has a strongly protective role, and a Th2-biased response may be deleterious. Other cytokines (particularly IL-17A), chemokines (particularly CCL-5 and CCL-3), and local innate immune factors (including cathelicidins and IFN-λ) contribute to pathogenesis. In summary, neutrophilic inflammation is incriminated as a harmful response, whereas CD8+ T cells and IFN-γ have protective roles. These may represent important therapeutic targets to modulate the immunopathogenesis of RSV infection.

Sign in / Sign up

Export Citation Format

Share Document