Pulmonary immunity to viruses

2017 ◽  
Vol 131 (14) ◽  
pp. 1737-1762 ◽  
Author(s):  
S. Rameeza Allie ◽  
Troy D. Randall
Keyword(s):  
Immune Responses ◽  
Respiratory Tract ◽  
Viral Infection ◽  
Viral Infections ◽  
Inflammatory Responses ◽  
Lung Damage ◽  
Immune Memory ◽  
Chronic Obstructive ◽  
Adaptive Immune ◽  
Respiratory Viral Infections

Mucosal surfaces, such as the respiratory epithelium, are directly exposed to the external environment and therefore, are highly susceptible to viral infection. As a result, the respiratory tract has evolved a variety of innate and adaptive immune defenses in order to prevent viral infection or promote the rapid destruction of infected cells and facilitate the clearance of the infecting virus. Successful adaptive immune responses often lead to a functional state of immune memory, in which memory lymphocytes and circulating antibodies entirely prevent or lessen the severity of subsequent infections with the same virus. This is also the goal of vaccination, although it is difficult to vaccinate in a way that mimics respiratory infection. Consequently, some vaccines lead to robust systemic immune responses, but relatively poor mucosal immune responses that protect the respiratory tract. In addition, adaptive immunity is not without its drawbacks, as overly robust inflammatory responses may lead to lung damage and impair gas exchange or exacerbate other conditions, such as asthma or chronic obstructive pulmonary disease (COPD). Thus, immune responses to respiratory viral infections must be strong enough to eliminate infection, but also have mechanisms to limit damage and promote tissue repair in order to maintain pulmonary homeostasis. Here, we will discuss the components of the adaptive immune system that defend the host against respiratory viral infections.

scholarly journals Mast Cell Responses to Viruses and Pathogen Products

2019 ◽  
Vol 20 (17) ◽  
pp. 4241 ◽  
Author(s):  
Jean S. Marshall ◽  
Liliana Portales-Cervantes ◽  
Edwin Leong
Keyword(s):  
Mast Cell ◽  
Mast Cells ◽  
Immune Responses ◽  
Viral Infection ◽  
Viral Infections ◽  
Inflammatory Responses ◽  
Local Source ◽  
Type I ◽  
Viral Challenge ◽  
Cell Responses

Mast cells are well accepted as important sentinel cells for host defence against selected pathogens. Their location at mucosal surfaces and ability to mobilize multiple aspects of early immune responses makes them critical contributors to effective immunity in several experimental settings. However, the interactions of mast cells with viruses and pathogen products are complex and can have both detrimental and positive impacts. There is substantial evidence for mast cell mobilization and activation of effector cells and mobilization of dendritic cells following viral challenge. These cells are a major and under-appreciated local source of type I and III interferons following viral challenge. However, mast cells have also been implicated in inappropriate inflammatory responses, long term fibrosis, and vascular leakage associated with viral infections. Progress in combating infection and boosting effective immunity requires a better understanding of mast cell responses to viral infection and the pathogen products and receptors we can employ to modify such responses. In this review, we outline some of the key known responses of mast cells to viral infection and their major responses to pathogen products. We have placed an emphasis on data obtained from human mast cells and aim to provide a framework for considering the complex interactions between mast cells and pathogens with a view to exploiting this knowledge therapeutically. Long-lived resident mast cells and their responses to viruses and pathogen products provide excellent opportunities to modify local immune responses that remain to be fully exploited in cancer immunotherapy, vaccination, and treatment of infectious diseases.

scholarly journals SP-A and SP-D: Dual Functioning Immune Molecules With Antiviral and Immunomodulatory Properties

2021 ◽  
Vol 11 ◽  
Author(s):  
Alastair Watson ◽  
Jens Madsen ◽  
Howard William Clark
Keyword(s):  
Viral Infection ◽  
Influenza A ◽  
Viral Infections ◽  
Inflammatory Responses ◽  
Therapeutic Potential ◽  
Inflammatory Diseases ◽  
Chronic Obstructive ◽  
Cell Functions ◽  
Increased Risk ◽  
Syncytial Virus

Surfactant proteins A (SP-A) and D (SP-D) are soluble innate immune molecules which maintain lung homeostasis through their dual roles as anti-infectious and immunomodulatory agents. SP-A and SP-D bind numerous viruses including influenza A virus, respiratory syncytial virus (RSV) and human immunodeficiency virus (HIV), enhancing their clearance from mucosal points of entry and modulating the inflammatory response. They also have diverse roles in mediating innate and adaptive cell functions and in clearing apoptotic cells, allergens and other noxious particles. Here, we review how the properties of these first line defense molecules modulate inflammatory responses, as well as host-mediated immunopathology in response to viral infections. Since SP-A and SP-D are known to offer protection from viral and other infections, if their levels are decreased in some disease states as they are in severe asthma and chronic obstructive pulmonary disease (COPD), this may confer an increased risk of viral infection and exacerbations of disease. Recombinant molecules of SP-A and SP-D could be useful in both blocking respiratory viral infection while also modulating the immune system to prevent excessive inflammatory responses seen in, for example, RSV or coronavirus disease 2019 (COVID-19). Recombinant SP-A and SP-D could have therapeutic potential in neutralizing both current and future strains of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) virus as well as modulating the inflammation-mediated pathology associated with COVID-19. A recombinant fragment of human (rfh)SP-D has recently been shown to neutralize SARS-CoV-2. Further work investigating the potential therapeutic role of SP-A and SP-D in COVID-19 and other infectious and inflammatory diseases is indicated.

scholarly journals Time-course of upper respiratory tract viral infection and COPD exacerbation

2019 ◽  
Vol 54 (4) ◽  
pp. 1900407 ◽  
Author(s):  
Daiana Stolz ◽  
Eleni Papakonstantinou ◽  
Leticia Grize ◽  
Daniel Schilter ◽  
Werner Strobel ◽  
...  
Keyword(s):  
Respiratory Tract ◽  
Viral Infection ◽  
Respiratory Tract Infections ◽  
Viral Infections ◽  
Nucleic Acid Amplification ◽  
Chronic Obstructive ◽  
Upper Respiratory Tract ◽  
Stable Period ◽  
Upper Respiratory ◽  
Tract Infections

Viral respiratory tract infections have been implicated as the predominant risk factor for acute exacerbations of chronic obstructive pulmonary disease (AECOPD). We aimed to evaluate, longitudinally, the association between upper respiratory tract infections (URTI) caused by viruses and AECOPD.Detection of 18 viruses was performed in naso- and orοpharyngeal swabs from 450 COPD patients (Global Initiative for Chronic Obstructive Lung Disease stages 2–4) who were followed for a mean of 27 months. Swabs were taken during stable periods (n=1909), at URTI onset (n=391), 10 days after the URTI (n=356) and during an AECOPD (n=177) and tested using a multiplex nucleic acid amplification test.Evidence of at least one respiratory virus was significantly higher at URTI onset (52.7%), 10 days after the URTI (15.2%) and during an AECOPD (38.4%), compared with the stable period (5.3%, p<0.001). During stable visits, rhinovirus accounted for 54.2% of all viral infections, followed by coronavirus (20.5%). None of the viruses were identified in two consecutive stable visits. Patients with a viral infection at URTI onset did not have a higher incidence of exacerbation than patients without viral infection (p=0.993). Τhe incidence of any viral infection during an AECOPD was similar between URTI-related AECOPD and non-URTI-related AECOPD (p=0.359). Only 24% of the patients that had a URTI-related AECOPD had the same virus at URTI onset and during an AECOPD. Detection of parainfluenza 3 at URTI onset was associated with a higher risk of an AECOPD (p=0.003). Rhinovirus and coronavirus were the most frequently detected viruses during AECOPD visits, accounting for 35.7% and 25.9% of all viral infections, respectively.The prevalence of viral infection during the stable period of COPD was low. The risk of exacerbation following the onset of URTI symptoms depends on the particular virus associated with the event and was significant only for parainfluenza 3.

scholarly journals Regulation of Antiviral Immune Response by N6-Methyladenosine of mRNA

2021 ◽  
Vol 12 ◽  
Author(s):  
Baoxin Zhao ◽  
Weijie Wang ◽  
Yan Zhao ◽  
Hongxiu Qiao ◽  
Zhiyun Gao ◽  
...  
Keyword(s):  
Immune Responses ◽  
Viral Infection ◽  
Viral Infections ◽  
Immune Cell ◽  
Vital Role ◽  
Immune Defense ◽  
Interferon Response ◽  
Adaptive Immune Responses ◽  
Antiviral Immune Response ◽  
Adaptive Immune

Host innate and adaptive immune responses play a vital role in clearing infected viruses. Meanwhile, viruses also evolve a series of mechanisms to weaken the host immune responses and evade immune defense. Recently, N6-methyladenosine (m6A), the most prevalent mRNA modification, has been revealed to regulate multiple steps of RNA metabolism, such as mRNA splicing, localization, stabilization, and translation, thus participating in many biological phenomena, including viral infection. In the process of virus–host interaction, the m6A modification that presents on the virus RNA impedes capture by the pattern recognition receptors, and the m6A modification appearing on the host immune-related molecules regulate interferon response, immune cell differentiation, inflammatory cytokine production, and other immune responses induced by viral infection. This review summarizes the research advances about the regulatory role of m6A modification in the innate and adaptive immune responses during viral infections.

scholarly journals Eosinophils and Bacteria, the Beginning of a Story

2021 ◽  
Vol 22 (15) ◽  
pp. 8004
Author(s):  
Edna Ondari ◽  
Esther Calvino-Sanles ◽  
Nicholas J. First ◽  
Monica C. Gestal
Keyword(s):  
Immune Responses ◽  
Respiratory Tract ◽  
Bacterial Infections ◽  
Viral Infections ◽  
Inflammatory Responses ◽  
Current Knowledge ◽  
Parasitic Infections ◽  
Th2 Responses ◽  
A Cell ◽  
Anti Inflammatory

Eosinophils are granulocytes primarily associated with TH2 responses to parasites or immune hyper-reactive states, such as asthma, allergies, or eosinophilic esophagitis. However, it does not make sense from an evolutionary standpoint to maintain a cell type that is only specific for parasitic infections and that otherwise is somehow harmful to the host. In recent years, there has been a shift in the perception of these cells. Eosinophils have recently been recognized as regulators of immune homeostasis and suppressors of over-reactive pro-inflammatory responses by secreting specific molecules that dampen the immune response. Their role during parasitic infections has been well investigated, and their versatility during immune responses to helminths includes antigen presentation as well as modulation of T cell responses. Although it is known that eosinophils can present antigens during viral infections, there are still many mechanistic aspects of the involvement of eosinophils during viral infections that remain to be elucidated. However, are eosinophils able to respond to bacterial infections? Recent literature indicates that Helicobacter pylori triggers TH2 responses mediated by eosinophils; this promotes anti-inflammatory responses that might be involved in the long-term persistent infection caused by this pathogen. Apparently and on the contrary, in the respiratory tract, eosinophils promote TH17 pro-inflammatory responses during Bordetella bronchiseptica infection, and they are, in fact, critical for early clearance of bacteria from the respiratory tract. However, eosinophils are also intertwined with microbiota, and up to now, it is not clear if microbiota regulates eosinophils or vice versa, or how this connection influences immune responses. In this review, we highlight the current knowledge of eosinophils as regulators of pro and anti-inflammatory responses in the context of both infection and naïve conditions. We propose questions and future directions that might open novel research avenues in the future.

Indicators of the kinin blood system in severe forms of acute respiratory viral infections in children

1982 ◽  
Vol 63 (2) ◽  
pp. 51-52
Author(s):  
V. A. Anokhin ◽  
A. D. Tsaregorodtsev
Keyword(s):  
Viral Infection ◽  
Viral Infections ◽  
Severe Form ◽  
Blood System ◽  
Control Group ◽  
Healthy Children ◽  
Respiratory Viral Infection ◽  
Respiratory Viral Infections ◽  
Acute Respiratory Viral Infection ◽  
Apparently Healthy

The aim of this work was to study the parameters of the components of the kinin blood system in children with severe forms of acute respiratory viral infections (ARVI) with neurotoxicosis syndrome. 55 children with ARVI (aged from 1 to 6 months - 14, from 6 months to 1 year - 18, from 1 to 3 years - 11, from 3 to 7 years - 12). 38 patients were admitted in the first three days of illness, 12 - on 4-5 days and 5 - at a later date. 30 children had a severe form of acute respiratory viral infection and 25 - moderate. Adenovirus infection was diagnosed in 14 patients, influenza - in 16, parainfluenza - in 7, MS-viral infection in 5, mixed viral infection - in 13. The control group consisted of 10 apparently healthy children.

scholarly journals New prospects for local etiotropic treatment of acute respiratory viral infections

2019 ◽  
pp. 105-108
Author(s):  
A. A. Krivopalov ◽  
V. A. Shatalov ◽  
S. V. Shervashidze
Keyword(s):  
Respiratory Tract ◽  
Respiratory System ◽  
Safety Profile ◽  
Viral Infections ◽  
Inflammatory Diseases ◽  
Upper Respiratory Tract ◽  
Positive Experience ◽  
High Efficacy ◽  
Upper Respiratory ◽  
Respiratory Viral Infections

According to WHO, the respiratory system diseases are currently inside the ten most common pathologies. The modern strategy for treating influenza and ARVI gives priority to the antiviral and immunostimulating agents, but the symptomatic drugs, which include preparations based on silver and its compounds, also play an important role. The large positive experience in using silver preparations supported by numerous clinical studies shows their high efficacy and satisfactory safety profile in the treatment of infectious and inflammatory diseases of the nose and upper respiratory tract in children and adults.

scholarly journals A functional spleen contributes to afucosylated IgG in humans

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Iwona Wojcik ◽  
David E. Schmidt ◽  
Lisa A. de Neef ◽  
Minke A. E. Rab ◽  
Bob Meek ◽  
...  
Keyword(s):  
Immune Responses ◽  
Viral Infections ◽  
Immune Cell ◽  
Lymphoid Organ ◽  
Immune Effector ◽  
Adaptive Immune ◽  
Wide Range ◽  
Humoral Responses ◽  
First Time

AbstractAs a lymphoid organ, the spleen hosts a wide range of immune cell populations, which not only remove blood-borne antigens, but also generate and regulate antigen-specific immune responses. In particular, the splenic microenvironment has been demonstrated to play a prominent role in adaptive immune responses to enveloped viral infections and alloantigens. During both types of immunizations, antigen-specific immunoglobulins G (IgGs) have been characterized by the reduced amount of fucose present on N-linked glycans of the fragment crystallizable (Fc) region. These glycans are essential for mediating the induction of immune effector functions. Therefore, we hypothesized that a spleen may modulate humoral responses and serve as a preferential site for afucosylated IgG responses, which potentially play a role in immune thrombocytopenia (ITP) pathogenesis. To determine the role of the spleen in IgG-Fc glycosylation, we performed IgG subclass-specific liquid chromatography–mass spectrometry (LC–MS) analysis of Fc glycosylation in a large cohort of individuals splenectomized due to trauma, due to ITP, or spherocytosis. IgG-Fc fucosylation was consistently increased after splenectomy, while no effects for IgG-Fc galactosylation and sialylation were observed. An increase in IgG1- and IgG2/3-Fc fucosylation level upon splenectomy has been reported here for the first time, suggesting that immune responses occurring in the spleen may be particularly prone to generate afucosylated IgG responses. Surprisingly, the level of total IgG-Fc fucosylation was decreased in ITP patients compared to healthy controls. Overall, our results suggest a yet unrecognized role of the spleen in either the induction or maintenance of afucosylated IgG responses by B cells.

scholarly journals Innate Immune Responses to Highly Pathogenic Coronaviruses and Other Significant Respiratory Viral Infections

2020 ◽  
Vol 11 ◽  
Author(s):  
Hanaa Ahmed-Hassan ◽  
Brianna Sisson ◽  
Rajni Kant Shukla ◽  
Yasasvi Wijewantha ◽  
Nicholas T. Funderburg ◽  
...  
Keyword(s):  
Immune Responses ◽  
Viral Infections ◽  
Innate Immune ◽  
Innate Immune Responses ◽  
Highly Pathogenic ◽  
Respiratory Viral Infections
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