The Immune Response to Respiratory Viruses: From Start to Memory

2021 ◽  
Vol 42 (06) ◽  
pp. 759-770
Author(s):  
Tom D.Y. Reijnders ◽  
Alex R. Schuurman ◽  
Tom van der Poll

AbstractBiomedical research has long strived to improve our understanding of the immune response to respiratory viral infections, an effort that has become all the more important as we live through the consequences of a pandemic. The disease course of these infections is shaped in large part by the actions of various cells of the innate and adaptive immune systems. While these cells are crucial in clearing viral pathogens and establishing long-term immunity, their effector mechanisms may also escalate into excessive, tissue-destructive inflammation detrimental to the host. In this review, we describe the breadth of the immune response to infection with respiratory viruses such as influenza and respiratory syncytial virus. Throughout, we focus on the host rather than the pathogen and try to describe shared patterns in the host response to different viruses. We start with the local cells of the airways, onto the recruitment and activation of innate and adaptive immune cells, followed by the establishment of local and systemic memory cells key in protection against reinfection. We end by exploring how respiratory viral infections can predispose to bacterial superinfection.

2011 ◽  
Vol 18 (1) ◽  
pp. 179-189 ◽  
Author(s):  
Paul M Fitch ◽  
Paul Henderson ◽  
Jürgen Schwarze

Respiratory and enteric viral infections cause significant morbidity and mortality world-wide and represent a major socio-economic burden. Many of these viruses have received unprecedented public and media interest in recent years. A popular public misconception is that viruses are a threat to which the human body has only limited defences. However, the majority of primary and secondary exposures to virus are asymptomatic or induce only minor symptoms. The mucosal epithelial surfaces are the main portal of entry for viral pathogens and are centrally involved in the initiation, maintenance and polarisation of the innate and adaptive immune response to infection. This review describes the defences employed by the epithelium of the respiratory and gastrointestinal tracts during viral infections with focus on epithelial modulation of the immune response at the innate/adaptive interface.


2012 ◽  
Vol 54 (5) ◽  
pp. 249-255 ◽  
Author(s):  
Maria Carolina M. Albuquerque ◽  
Rafael B. Varella ◽  
Norma Santos

The frequency of viral pathogens causing respiratory infections in children in the cities of Rio de Janeiro and Teresópolis was investigated. Nasal swabs from children with acute respiratory illnesses were collected between March 2006 and October 2007. Specimens were tested for viral detection by conventional (RT)-PCR and/or real time PCR. Of the 205 nasal swabs tested, 64 (31.2%) were positive for at least one of the viral pathogens. Single infections were detected in 56 samples, 50 of those were caused by RNA viruses: 33 samples tested positive for rhinovirus, five for influenza A, five for metapneumovirus, four for coronavirus and, three for respiratory syncytial virus. For the DNA viruses, five samples were positive for bocavirus and one for adenovirus. Co-infections with these viruses were detected in eight samples. Our data demonstrate a high frequency of viral respiratory infections, emphasizing the need for a more accurate diagnosis particularly for the emerging respiratory viruses. The fact that the emerging respiratory viruses were present in 9.2% of the tested samples suggests that these viruses could be important respiratory pathogens in the country.


2021 ◽  
Author(s):  
Vijay Kumar

The COVID-19 pandemic that started in December 2019 in Wuhan city, China has created chaos all over the world with over 185 million infection cases and 4 million deaths world-wide. The pathogen behind COVID-19 has been identified as severe acute respiratory syndrome Coronavirus 2 (SARS-CoV-2) that is more close to the previous SARS-CoV responsible for SARS epidemic 2002–2003. Although, SARS-CoV-2 also differs from SARS-CoV in many aspects as indicated by genetic studies. For example, SARS-CoV does not have a furin binding domain or site, whereas its presence in SARS-CoV-2 spike (S) protein increases its potential for infectivity. The horseshoe bats (Rhinolphus species) from China are considered as primary animal reservoirs for SARS-CoV and SARS-CoV-2. However, along with CoVs, bats also harbor many other viral pathogens (Ebola, Nipah, and Hendra viruses) without having serious infections. The bat physiology plays a crucial role in harboring these viruses along with adaptations to longevity and slow aging process. The immune system plays a crucial role in the clearance or establishment of the infection. Present chapter discusses different immunological aspects (innate immune response comprising the virus recognizing pattern recognition receptors (PRRs), type 1 interferon production, pro- and anti-inflammatory immune response, and adaptive immune response) that help bats to control viral infection without getting a severe infection as compared to other mammals, including humans.


2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Jonathan M. Read ◽  
Shanta Zimmer ◽  
Charles Vukotich ◽  
Mary Lou Schweizer ◽  
David Galloway ◽  
...  

Abstract Background Information on the etiology and age-specific burden of respiratory viral infections among school-aged children remains limited. Though school aged children are often recognized as driving the transmission of influenza as well as other respiratory viruses, little detailed information is available on the distribution of respiratory infections among children of different ages within this group. Factors other than age including gender and time spent in school may also be important in determining risk of infection but have been little studied in this age group. Methods We conducted a cohort study to determine the etiology of influenza like illness (ILI) among 2519 K–12 students during the 2012–13 influenza season. We obtained nasal swabs from students with ILI-related absences. Generalized linear mixed-effect regressions determined associations of outcomes, including ILI and laboratory-confirmed respiratory virus infection, with school grade and other covariates. Results Overall, 459 swabs were obtained from 552 ILI–related absences. Respiratory viruses were found in 292 (63.6%) samples. Influenza was found in 189 (41.2%) samples. With influenza B found in 134 (70.9%). Rates of influenza B were significantly higher in grades 1 (10.1, 95% CI 6.8–14.4%), 2 (9.7, 6.6–13.6%), 3 (9.3, 6.3–13.2%), and 4 (9.9, 6.8–13.8%) than in kindergarteners (3.2, 1.5–6.0%). After accounting for grade, sex and self-reported vaccination status, influenza B infection risk was lower among kindergarteners in half-day programs compared to kindergarteners in full-day programs (OR = 0.19; 95% CI 0.08–0.45). Conclusions ILI and influenza infection is concentrated in younger schoolchildren. Reduced infection by respiratory viruses is associated with a truncated school day for kindergarteners but this finding requires further investigation in other grades and populations.


2021 ◽  
Vol 15 ◽  
pp. 175346662199505
Author(s):  
Alastair Watson ◽  
Tom M. A. Wilkinson

With the global over 60-year-old population predicted to more than double over the next 35 years, caring for this aging population has become a major global healthcare challenge. In 2016 there were over 1 million deaths in >70 year olds due to lower respiratory tract infections; 13–31% of these have been reported to be caused by viruses. Since then, there has been a global COVID-19 pandemic, which has caused over 2.3 million deaths so far; increased age has been shown to be the biggest risk factor for morbidity and mortality. Thus, the burden of respiratory viral infections in the elderly is becoming an increasing unmet clinical need. Particular challenges are faced due to the interplay of a variety of factors including complex multimorbidities, decreased physiological reserve and an aging immune system. Moreover, their atypical presentation of symptoms may lead to delayed necessary care, prescription of additional drugs and prolonged hospital stay. This leads to morbidity and mortality and further nosocomial spread. Clinicians currently have limited access to sensitive detection methods. Furthermore, a lack of effective antiviral treatments means there is little incentive to diagnose and record specific non-COVID-19 viral infections. To meet this unmet clinical need, it is first essential to fully understand the burden of respiratory viruses in the elderly. Doing this through prospective screening research studies for all respiratory viruses will help guide preventative policies and clinical trials for emerging therapeutics. The implementation of multiplex point-of-care diagnostics as a mainstay in all healthcare settings will be essential to understand the burden of respiratory viruses, diagnose patients and monitor outbreaks. The further development of novel targeted vaccinations as well as anti-viral therapeutics and new ways to augment the aging immune system is now also essential. The reviews of this paper are available via the supplemental material section.


2015 ◽  
Vol 2015 ◽  
pp. 1-7 ◽  
Author(s):  
Ma. Del Rocío Baños-Lara ◽  
Boyang Piao ◽  
Antonieta Guerrero-Plata

Mucins (MUC) constitute an important component of the inflammatory and innate immune response. However, the expression of these molecules by respiratory viral infections is still largely unknown. Respiratory syncytial virus (RSV) and human metapneumovirus (hMPV) are two close-related paramyxoviruses that can cause severe low respiratory tract disease in infants and young children worldwide. Currently, there is not vaccine available for neither virus. In this work, we explored the differential expression of MUC by RSV and hMPV in human epithelial cells. Our data indicate that the MUC expression by RSV and hMPV differs significantly, as we observed a stronger induction of MUC8, MUC15, MUC20, MUC21, and MUC22 by RSV infection while the expression of MUC1, MUC2, and MUC5B was dominated by the infection with hMPV. These results may contribute to the different immune response induced by these two respiratory viruses.


2019 ◽  
Vol 11 (3) ◽  
pp. 38-45
Author(s):  
S. A. Khmilevskaya ◽  
N. I. Zryachkin ◽  
V. E. Mikhailova

The aim: to study the etiological structure of acute respiratory infections in children aged 3 to 12 hospitalized in the early stages of the disease in the department of respiratory infections of the children’s hospital, and to reveal the features of their clinical course and the timing of DNA / RNA elimination of respiratory viruses from nasal secretions, depending on the method of therapy. Materials and methods: 100 children with acute respiratory infections aged 3 to 12 years were monitored. The nasal secrets on the DNA / RNA of respiratory viruses were studied by PCR. Depending on the method of therapy, patients were divided into 2 groups: patients of group 1 (comparison) received basic treatment (without the use of antiviral drugs), in patients of the 2nd group (main), along with basal therapy, the drug was used umifenovir in a 5-day course at the ageappropriate dosage. Results: In the etiologic structure of ARVI in children from 3 to 12 years, the leading place was taken by rhinovirus, influenza and metapneumovirus infections (isolated – 18%, 19% and 20% respectively, in the form of a mixed infection – 11%). The main syndromic diagnosis at the height of the disease was rhinopharyngitis. Complications were observed in 42% of cases, as often as possible with flu – 53% of cases. Features of metapneumovirus infection in children of this age group were: predominance of non-severe forms of the disease in the form of acute fever with symptoms of rhinopharyngitis, as well as a small incidence of lower respiratory tract infections. The use of the drug umiphenovir in children with acute respiratory viral infections of various etiologies contributed to significantly faster elimination of viral DNA / RNA from the nasal secretion, which was accompanied by a ecrease in the duration of the main clinical and hematological symptoms of the disease, a decrease in the incidence of complications, and reduced the duration of stay in hospital. Conclusion: application of modern molecular genetic methods of diagnostics made it possible to identify the leading role of influenza, metapneumovirus and rhinovirus infections in the etiology of acute respiratory viral infection in patients aged 3 to 12 years, and to determine a number of clinical features characteristic of this age group. The results of the study testify to the effectiveness of umiphenovir in the treatment of children with acute respiratory viral infections of various etiologies and allow us to recommend this drug as an effective and safe etiotropic agent.


Viruses ◽  
2022 ◽  
Vol 14 (1) ◽  
pp. 150
Author(s):  
Wan Rong Sia ◽  
Yichao Zheng ◽  
Fei Han ◽  
Shiwei Chen ◽  
Shaohua Ma ◽  
...  

Bats are reservoirs of a large number of viruses of global public health significance, including the ancestral virus for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and the causative agent of coronavirus disease 2019 (COVID-19). Although bats are natural carriers of multiple pathogenic viruses, they rarely display signs of disease. Recent insights suggest that bats have a more balanced host defense and tolerance system to viral infections that may be linked to the evolutionary adaptation to powered flight. Therefore, a deeper understanding of bat immune system may provide intervention strategies to prevent zoonotic disease transmission and to identify new therapeutic targets. Similar to other eutherian mammals, bats have both innate and adaptive immune systems that have evolved to detect and respond to invading pathogens. Bridging these two systems are innate lymphocytes, which are highly abundant within circulation and barrier tissues. These cells share the characteristics of both innate and adaptive immune cells and are poised to mount rapid effector responses. They are ideally suited as the first line of defense against early stages of viral infections. Here, we will focus on the current knowledge of innate lymphocytes in bats, their function, and their potential role in host–pathogen interactions. Moreover, given that studies into bat immune systems are often hindered by a lack of bat-specific research tools, we will discuss strategies that may aid future research in bat immunity, including the potential use of organoid models to delineate the interplay between innate lymphocytes, bat viruses, and host tolerance.


2016 ◽  
Vol 21 (5) ◽  
pp. 268-273
Author(s):  
Aleksandr F. Popov ◽  
S. L Kolpakov ◽  
A. I Simakova ◽  
K. A Dmitrenko

For etiological diagnosis of acute respiratory viral infections the improvement of clinical semiotics and searchfor epidemiological consistent patterns are advantageous. Aim the establishment of consistent patterns of the clinical picture of etiologically AIRS decoded by PCR method and validities of epidemiological signs in the Primorsky Krai in the recent period. The material of the study were medical history cases on 276 patients admitted to the infectious department of Primorye Regional Clinical Hospital №2 in the city of Vladivostok in 2014 with a diagnosis of AIRS. Results. In the etiological structure of patients there was dominated influenza (48.2%). Hereafter there were: rhinovirus infection (13.0%), parainfluenza (11.2%), metapneumovirus infection (9,8,5%), adenovirus infection (8.0%). The minimum share was presented by bocavirus (HBoV)) infection (5.16%) and the respiratory syncytial virus, (HRSV) infection (4.7%). There were established the most sensitive and specific symptoms of considered infections. There were revealed features of the seasonality and the age structure of the patients, affecting on the efficiency of diagnosis.


Pathogens ◽  
2020 ◽  
Vol 9 (12) ◽  
pp. 989
Author(s):  
Alexey A. Lozhkov ◽  
Sergey A. Klotchenko ◽  
Edward S. Ramsay ◽  
Herman D. Moshkoff ◽  
Dmitry A. Moshkoff ◽  
...  

Interferons (IFN) are crucial for the innate immune response. Slightly more than two decades ago, a new type of IFN was discovered: the lambda IFN (type III IFN). Like other IFN, the type III IFN display antiviral activity against a wide variety of infections, they induce expression of antiviral, interferon-stimulated genes (MX1, OAS, IFITM1), and they have immuno-modulatory activities that shape adaptive immune responses. Unlike other IFN, the type III IFN signal through distinct receptors is limited to a few cell types, primarily mucosal epithelial cells. As a consequence of their greater and more durable production in nasal and respiratory tissues, they can determine the outcome of respiratory infections. This review is focused on the role of IFN-λ in the pathogenesis of respiratory viral infections, with influenza as a prime example. The influenza virus is a major public health problem, causing up to half a million lethal infections annually. Moreover, the virus has been the cause of four pandemics over the last century. Although IFN-λ are increasingly being tested in antiviral therapy, they can have a negative influence on epithelial tissue recovery and increase the risk of secondary bacterial infections. Therefore, IFN-λ expression deserves increased scrutiny as a key factor in the host immune response to infection.


Sign in / Sign up

Export Citation Format

Share Document