scholarly journals B-1 and B-2 Cell–Derived Immunoglobulin M Antibodies Are Nonredundant Components of the Protective Response to Influenza Virus Infection

2000 ◽  
Vol 192 (2) ◽  
pp. 271-280 ◽  
Author(s):  
Nicole Baumgarth ◽  
Ometa C. Herman ◽  
Gina C. Jager ◽  
Lorena E. Brown ◽  
Leonore A. Herzenberg ◽  
...  
Keyword(s):  
Influenza Virus ◽  
Survival Rates ◽  
Influenza Virus Infection ◽  
Serum Levels ◽  
Immunoglobulin M ◽  
Virus Clearance ◽  
Efficient Induction ◽  
Specific Igg ◽  
Natural Igm

We have studied the role of secreted immunoglobulin (Ig)M in protection from infection with influenza virus and delineated the relative contributions of B-1 versus B-2 cell–derived IgM in this process. Mice deficient in secreted IgM but capable of expressing surface IgM and secreting other Ig classes show significantly reduced virus clearance and survival rates compared with wild-type controls. Irradiation chimeras in which only either B-1 or B-2 cells lack the ability to secrete IgM show mortality rates similar to those of mice in which neither B-1 nor B-2 cells secrete IgM. Dependence on both sources of IgM for survival is partially explained by findings in allotype chimeras that broadly cross-reactive B-1 cell–derived natural IgM is present before infection, whereas virus strain–specific, B-2 cell–derived IgM appears only after infection. Furthermore, lack of IgM secreted from one or both sources significantly impairs the antiviral IgG response. Reconstitution of chimeras lacking B-1 cell–derived IgM only with IgM-containing serum from noninfected mice improved both survival rates and serum levels of virus-specific IgG. Thus, virus-induced IgM must be secreted in the presence of natural IgM for efficient induction of specific IgG and for immune protection, identifying B-1 and B-2 cell–derived IgM antibodies as nonredundant components of the antiviral response.

scholarly journals Role of Interleukin-12 in Primary Influenza Virus Infection

1998 ◽  
Vol 72 (6) ◽  
pp. 4825-4831 ◽  
Author(s):  
Juanita M. Monteiro ◽  
Catherine Harvey ◽  
Giorgio Trinchieri
Keyword(s):  
Immune Response ◽  
Influenza Virus ◽  
Virus Infection ◽  
Nk Cell ◽  
Influenza Virus Infection ◽  
Interleukin 12 ◽  
Live Virus ◽  
Virus Clearance ◽  
Ifn Γ

ABSTRACT The effect of endogenous interleukin-12 (IL-12) on the influenza virus immune response in BALB/c mice was evaluated. Following primary influenza virus infection, IL-12 mRNA and protein are detected in the lung, with live virus being required for cytokine induction. Endogenous IL-12 contributes to early NK cell-dependent gamma interferon (IFN-γ) production (days 3 and 5) but not late T-cell-dependent IFN-γ secretion (day 7). IL-12 contributes to the inhibition of early virus replication but is not required for virus clearance. IL-12 also modestly contributes to the activation of cytotoxic T lymphocytes. Thus, in this model of experimental influenza virus infection, endogenous IL-12 contributes primarily to the early development and activation of the innate immune response.

scholarly journals Natural Antibody and Complement Mediate Neutralization of Influenza Virus in the Absence of Prior Immunity

2007 ◽  
Vol 81 (7) ◽  
pp. 3487-3494 ◽  
Author(s):  
Jerome P. Jayasekera ◽  
E. Ashley Moseman ◽  
Michael C. Carroll
Keyword(s):  
Immune Response ◽  
Influenza Virus ◽  
Adaptive Immune Response ◽  
Influenza Virus Infection ◽  
Immunoglobulin M ◽  
Classical Pathway ◽  
Viral Lysis ◽  
Microbial Infections ◽  
Natural Igm ◽  
Deficient Mice

ABSTRACT Early control of virus replication by the innate immune response is essential to allow time for the generation of a more effective adaptive immune response. As an important component of innate immunity, complement has been shown to be necessary for protection against numerous microbial infections. This study was undertaken to investigate the role of complement in neutralizing influenza virus. Results demonstrated that the classical pathway of complement mediated serum neutralization of influenza virus. Although nonimmune serum neutralized influenza virus, the mechanism of virus neutralization (VN) required antibody, as sera from RAG1-deficient mice lacked VN activity; moreover, purified natural immunoglobulin M (IgM) restored VN activity to antibody-deficient sera. The mechanism of VN by natural IgM and complement was associated with virion aggregation and coating of the viral hemagglutinin receptor; however, viral lysis did not significantly contribute to VN. Additionally, reconstitution of RAG1-deficient mice with natural IgM resulted in delayed morbidity during influenza virus infection. Collectively, these results provide evidence that natural IgM and the early components of the classical pathway of complement work in concert to neutralize influenza virus and that this interaction may have a significant impact on the course of influenza viral pneumonia.

scholarly journals Polymerase Acidic Subunit of H9N2 Polymerase Complex Induces Cell Apoptosis by Binding to PDCD 7 in A549 Cells

2020 ◽  
Author(s):  
Shaohua Wang ◽  
Na Li ◽  
Shugang Jin ◽  
Ruihua Zhang ◽  
Tong Xu
Keyword(s):  
Cell Death ◽  
Influenza Virus ◽  
Cell Apoptosis ◽  
Influenza A ◽  
A549 Cells ◽  
Influenza Virus Infection ◽  
Economic Loss ◽  
Poultry Production ◽  
H9n2 Influenza Virus

Abstract Background: H9N2 influenza virus, a subtype of influenza A virus, can spread across different species and induce the respiratory infectious disease in humans, leading to a severe public health risk and a huge economic loss to poultry production. Increasing studies have shown that polymerase acidic (PA) subunit of RNA polymerase in ribonucleoproteins complex of H9N2 involves in crossing the host species barriers, the replication and airborne transmission of H9N2.Methods: Here, to further investigate the role of PA subunit during the infection of H9N2 influenza virus, we employed mass spectrometry (MS) to search the potential binding proteins of PA subunit of H9N2. Our MS results showed that programmed cell death protein 7 (PDCD7) is a binding target of PA subunit. Co-immunoprecipitation and pull-down assays further confirmed the interaction between PDCD7 and PA subunit. Overexpression of PA subunit in A549 lung cells greatly increased the levels of PDCD7 in the nuclear and induced cell death assayed by MTT assay.Results: Flow cytometry analysis and Western blot results showed that PA subunit overexpression significantly increased the expression of pro-apoptotic protein, bax and caspase 3, and induced cell apoptosis. However, knockout of PDCD7 effectively attenuated the effects of PA overexpression in cell apoptosis.Conclusions: In conclusion, the PA subunit of H9N2 bind with PDCD7 and regulated cell apoptosis, which provide new insights in the role of PA subunit during H9N2 influenza virus infection.

scholarly journals Better Response to Influenza Virus Vaccination in Physically Trained Older Adults Is Associated With Reductions of Cytomegalovirus-Specific Immunoglobulins as Well as Improvements in the Inflammatory and CD8+ T-Cell Profiles

2021 ◽  
Vol 12 ◽  
Author(s):  
Eduardo S. Felismino ◽  
Juliana M. B. Santos ◽  
Marcelo Rossi ◽  
Carlos A. F. Santos ◽  
Edison L. Durigon ◽  
...  
Keyword(s):  
Older Adults ◽  
T Cells ◽  
Influenza Virus ◽  
Exercise Training ◽  
Serum Levels ◽  
Specific Antibody Response ◽  
Post Vaccination ◽  
Specific Immunoglobulin ◽  
Specific Igg ◽  
Regular Practice

Chronic cytomegalovirus (CMV) infection is a trigger factor for the development of immunosenescence and negatively impacts the immune response to influenza virus vaccination (IVV) in older adults. However, the role of physical exercise training in this context is unknown. Thus, the aim of this study was to investigate whether the regular practice of combined exercise training can improve the specific antibody response to IVV in CMV-seropositive older adults. Eighty older adults were distributed into two groups—non-practitioners (NP, n = 31, age = 74.06 ± 6.4 years) and practitioners of combined exercise training (CET, n = 49, age = 71.7 ± 5.8 years)—for at least 12 months. Both volunteer groups were submitted to IVV and blood samples were collected before (pre) and 30 days after (post) the vaccination. Concerning the specific antibody response to IVV, higher serum levels of specific immunoglobulin A (IgA) were found in the CET group post- than pre-vaccination (p < 0.01), whereas higher levels of specific immunoglobulin M (IgM) were observed both in the NP (p < 0.05) and CET (p < 0.001) groups post-vaccination as compared to the pre-vaccination values. Serum levels of specific immunoglobulin G (IgG) for IVV and CMV, as well as interleukin 6 (IL-6) and IL-10, were similar between the time points evaluated. However, the IL-10/IL-6 ratio post-vaccination was higher (p < 0.05) in the CET group than that before vaccination. Negative correlations were observed between the specific IgG levels for IVV and CMV only in the CET group, both pre- and post-vaccination. In addition, negative correlations were found between IL-10 and specific IgG for CMV in all volunteer groups pre- and post-vaccination, whereas a positive correlation between IL-10 and specific-IgG for IVV pre- and post-vaccination was observed in the CET group. In addition, with the hemagglutination inhibition (HAI) assay, it was found that 32.2% of the NP group and 32.6% of the CET group were responders to IVV and displayed reductions in the CMV serostatus (p < 0.05 and p < 0.001, respectively) and increases in naive and effector CD8+ T cells post-vaccination (p < 0.01). However, only the responders from the CET group showed significant reductions in the ratio of effector to naive CD8+ T cells (p < 0.05) and increased IL-10 levels post-vaccination (p < 0.001). In summary, this study demonstrates that the improvement in the response to IVV in CMV-seropositive older adults was related to an anti-inflammatory status and enhancement of naive CD8+ T cells, particularly associated with regular practice of CET.

scholarly journals Role of Host Immune Response and Viral Load in the Differential Outcome of Pandemic H1N1 (2009) Influenza Virus Infection in Indian Patients

PLoS ONE ◽  
2010 ◽  
Vol 5 (10) ◽  
pp. e13099 ◽  
Author(s):  
Vidya A. Arankalle ◽  
Kavita S. Lole ◽  
Ravi P. Arya ◽  
Anuradha S. Tripathy ◽  
Ashwini Y. Ramdasi ◽  
...  
Keyword(s):  
Immune Response ◽  
Influenza Virus ◽  
Viral Load ◽  
Virus Infection ◽  
Influenza Virus Infection ◽  
Host Immune Response ◽  
Pandemic H1n1 ◽  
Differential Outcome ◽  
Pandemic H1n1 2009

Role of oxidants in influenza virus-induced gene expression

1998 ◽  
Vol 274 (1) ◽  
pp. L134-L142 ◽  
Author(s):  
Katharine Knobil ◽  
Augustine M. K. Choi ◽  
Gordon W. Weigand ◽  
David B. Jacoby
Keyword(s):  
Gene Expression ◽  
Cell Death ◽  
Influenza Virus ◽  
Virus Infection ◽  
A549 Cells ◽  
Influenza Virus Infection ◽  
Pyrrolidine Dithiocarbamate ◽  
Oxygen Intermediates ◽  
Mrna Induction

Influenza virus-induced epithelial damage may be mediated, in part, by reactive oxygen intermediates (ROIs). In this study, we investigated the role of ROIs in the influenza virus-induced gene expression of antioxidant enzymes and in the activation of nuclear factor-κB (NF-κB), an oxidant-sensitive transcriptional factor. Influenza virus infection increased production of intracellular ROIs in A549 pulmonary epithelial cells. Induction of manganese superoxide dismutase (MnSOD) mRNA correlated with increased MnSOD protein and enzyme activity. Influenza virus infection also activated NF-κB binding as determined by an electrophoretic mobility shift assay. Pretreatment of A549 cells with N-acetyl-l-cysteine attenuated virus-induced NF-κB activation and interleukin (IL)-8 mRNA induction but did not block induction of MnSOD mRNA. In contrast, pyrrolidine dithiocarbamate blocked activation of NF-κB and induction of MnSOD and IL-8 mRNAs. Treatment with pyrrolidine dithiocarbamate also markedly decreased virus-induced cell death. Thus oxidants are involved in influenza virus-induced activation of NF-κB, in the expression of IL-8 and MnSOD, and in virus-induced cell death.

scholarly journals Role of Extracellular Vesicles in Influenza Virus Infection

2020 ◽  
Vol 10 ◽  
Author(s):  
Yuan Jiang ◽  
Xiaowen Cai ◽  
Jiwen Yao ◽  
Huanhuan Guo ◽  
Liangjun Yin ◽  
...  
Keyword(s):  
Influenza Virus ◽  
Virus Infection ◽  
Extracellular Vesicles ◽  
Influenza Virus Infection

scholarly journals Role of CARD Region of MDA5 Gene in Canine Influenza Virus Infection

Viruses ◽  
2020 ◽  
Vol 12 (3) ◽  
pp. 307 ◽  
Author(s):  
Cheng Fu ◽  
Shaotang Ye ◽  
Yongbo Liu ◽  
Shoujun Li
Keyword(s):  
Innate Immunity ◽  
Influenza Virus ◽  
Cytokine Production ◽  
Influenza Virus Infection ◽  
Luciferase Assay ◽  
Canine Influenza Virus ◽  
Card Domain ◽  
Canine Influenza ◽  
Receptor Family

MDA5 belongs to the RIG-I-like receptor family, which is involved in innate immunity. During viral infection, MDA5 generates an antiviral response by recognizing the ligand to activate interferon. However, the role and mechanism of MDA5 in canine influenza virus (CIV) infection are unclear. To understand the mechanism of canine MDA5-mediated innate immunity during CIV infection, we detected the distribution of MDA5 in beagles, and the structural prediction showed that MDA5 was mainly composed of a CARD domain, RD domain, and DExD/H helix structure. Moreover, we found that MDA5 inhibits CIV replication. Furthermore, in the dual luciferase assay, we revealed that the CARD region of MDA5 strongly activated the IFN-β promoter and mainly transmitted signals through the CARD region. Overexpression of the CARD region of MDA5 revealed that the MDA5-mediated signaling pathway could transmit signals by activating the IRF3/NF-κB and IRF3 promoters, promoting the expression of antiviral proteins and cytokine release, thereby inhibiting CIV replication. Upon silencing of MDA5, cytokine production decreased, while the replication ability of CIV was increased. Thus, this study revealed a novel mechanism by which MDA5 mediated CIV infection and provided new avenues for the development of antiviral strategies.

Sign in / Sign up

Export Citation Format

Share Document