Role of IgA versus IgG in the Control of Influenza Viral Infection in the Murine Respiratory Tract

Abstract Background Viruses are the main infectious agents of acute respiratory infections in children. We aim to describe the epidemiological characteristics of viral pathogens of acute respiratory tract infections in outpatient children. Methods From April 2018 to March 2019, the results of viral detection using oral pharyngeal swabs from 103,210 children with acute respiratory tract infection in the outpatient department of the Children’s Hospital, Zhejiang University School of Medicine, were retrospectively analyzed. Viral antigens, including adenovirus (ADV), influenza A (FLUA), influenza B (FLUB) and respiratory syncytial virus (RSV), were detected by the colloidal gold method. Results At least one virus was detected in 38,355 cases; the positivity rate was 37.2%. A total of 1910 cases of mixed infection with two or more viruses were detected, and the positivity rate of multiple infection was 1.9%. The ADV positivity rate was highest in the 3–6-year-old group (18.7%), the FLUA positivity rate was highest in the > 6-year-old group (21.6%), the FLUB positivity rate was highest in the > 6-year-old group (6.6%), and the RSV positivity rate was highest in the < 1-year-old group (10.6%). There was a significant difference in the positivity rate of viral infection among different age groups (χ2 = 1280.7, P < 0.001). The rate of positive viral infection was highest in winter (47.1%). The ADV infection rate was highest in spring (18.2%). The rates of FLUA and FLUB positivity were highest in winter (28.8% and 3.6%, respectively). The rate of RSV positivity was highest in autumn (17.4%). The rate of positive viral infection in different seasons was significantly different (χ2 = 6459.1, P < 0.001). Conclusions Viral infection rates in children differ for different ages and seasons. The positivity rate of ADV is highest in the preschool period and that of RSV is highest in infants; that of FLU increases with age. The total positive rate of viral infection in different seasons is highest in winter, as is the rate of FLU positivity.

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Role of Alternative Splicing in Regulating Host Response to Viral Infection

Cells ◽

10.3390/cells10071720 ◽

2021 ◽

Vol 10 (7) ◽

pp. 1720

Author(s):

Kuo-Chieh Liao ◽

Mariano A. Garcia-Blanco

Keyword(s):

Innate Immunity ◽

Alternative Splicing ◽

Immune Responses ◽

Viral Infection ◽

Rna Splicing ◽

Type I ◽

Host Immune Responses ◽

Transcriptional Regulatory Mechanisms ◽

Host Virus Interactions

The importance of transcriptional regulation of host genes in innate immunity against viral infection has been widely recognized. More recently, post-transcriptional regulatory mechanisms have gained appreciation as an additional and important layer of regulation to fine-tune host immune responses. Here, we review the functional significance of alternative splicing in innate immune responses to viral infection. We describe how several central components of the Type I and III interferon pathways encode spliced isoforms to regulate IFN activation and function. Additionally, the functional roles of splicing factors and modulators in antiviral immunity are discussed. Lastly, we discuss how cell death pathways are regulated by alternative splicing as well as the potential role of this regulation on host immunity and viral infection. Altogether, these studies highlight the importance of RNA splicing in regulating host–virus interactions and suggest a role in downregulating antiviral innate immunity; this may be critical to prevent pathological inflammation.

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The lung microbiota in Korean patients with non-tuberculous mycobacterial pulmonary disease

BMC Microbiology ◽

10.1186/s12866-021-02141-1 ◽

2021 ◽

Vol 21 (1) ◽

Author(s):

Sung-Yoon Kang ◽

Hyojung Kim ◽

Sungwon Jung ◽

Sang Min Lee ◽

Sang Pyo Lee

Keyword(s):

Principal Component Analysis ◽

Respiratory Tract ◽

Pulmonary Disease ◽

Beta Diversity ◽

Lower Respiratory Tract ◽

Principal Component ◽

Control Group ◽

Flexible Bronchoscope ◽

Bronchial Washing

Abstract Background The microbiota of the lower respiratory tract in patients with non-tuberculous mycobacterial pulmonary disease (NTM-PD) has not been fully evaluated. We explored the role of the lung microbiota in NTM-PD by analyzing protected specimen brushing (PSB) and bronchial washing samples from patients with NTM-PD obtained using a flexible bronchoscope. Results Bronchial washing and PSB samples from the NTM-PD group tended to have fewer OTUs and lower Chao1 richness values compared with those from the control group. In both bronchial washing and PSB samples, beta diversity was significantly lower in the NTM-PD group than in the control group (P = 2.25E-6 and P = 4.13E-4, respectively). Principal component analysis showed that the PSBs and bronchial washings exhibited similar patterns within each group but differed between the two groups. The volcano plots indicated differences in several phyla and genera between the two groups. Conclusions The lower respiratory tract of patients with NTM-PD has a unique microbiota distribution that is low in richness/diversity.

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COVID-19 and nutritional deficiency: a review of existing knowledge

Hormone Molecular Biology and Clinical Investigation ◽

10.1515/hmbci-2020-0074 ◽

2021 ◽

Vol 42 (1) ◽

pp. 77-85

Author(s):

Meghana Muthuvattur Pallath ◽

Ashok Kumar Ahirwar ◽

Satyendra Chandra Tripathi ◽

Priyanka Asia ◽

Apurva Sakarde ◽

...

Keyword(s):

Immune Responses ◽

Viral Infection ◽

Close Contact ◽

Omega 3 Fatty Acids ◽

Omega 3 ◽

Antibody Affinity ◽

Global Pandemic ◽

Underlying Diseases ◽

Pro Inflammatory Cytokines

Abstract COVID-19 has resulted in an ongoing global pandemic, which spread largely among people who have had close contact with the infected person. The immunopathology of the SARS-CoV-2 virus includes the production of an excess amount of pro-inflammatory cytokines “a cytokine-storm”. The respiratory system (main), cardiovascular system and the gastrointestinal tract are the most affected body systems during viral infection. It has been found that most of the patients who require admission to hospital are elderly or have chronic underlying diseases. Higher cases of malnutrition and co-morbidities like diabetes mellitus and cardiovascular diseases are reported in elderly patients due to which, the immune system weakens and hence, the response to the virus is diminished in magnitude. A deficiency of micronutrients results in impaired immune responses leading to improper secretion of cytokines, alterations in secretory antibody response and antibody affinity which increases susceptibility to viral infection. The deficiency of various micronutrients in COVID-19 patient can be treated by appropriate nutritional supplements, prescribed after evaluating the patients’ nutritional status. Here we aim to highlight the role of a few particular nutrients namely Vitamin D, Vitamin C, Omega-3 fatty acids, Zinc and Magnesium along with the synergistic roles they play in enhancing immunity and thus, maintaining homeostasis.

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Toll-Like Receptors: Expression and Roles in Otitis Media

International Journal of Molecular Sciences ◽

10.3390/ijms22157868 ◽

2021 ◽

Vol 22 (15) ◽

pp. 7868

Author(s):

Su Young Jung ◽

Dokyoung Kim ◽

Dong Choon Park ◽

Sung Soo Kim ◽

Tong In Oh ◽

...

Keyword(s):

Tract Infection ◽

Respiratory Tract ◽

Respiratory Tract Infection ◽

Otitis Media ◽

Middle Ear ◽

Upper Respiratory Tract Infection ◽

Upper Respiratory Tract ◽

Toll Like Receptors ◽

Upper Respiratory

Otitis media is mainly caused by upper respiratory tract infection and eustachian tube dysfunction. If external upper respiratory tract infection is not detected early in the middle ear, or an appropriate immune response does not occur, otitis media can become a chronic state or complications may occur. Therefore, given the important role of Toll-like receptors (TLRs) in the early response to external antigens, we surveyed the role of TLRs in otitis media. To summarize the role of TLR in otitis media, we reviewed articles on the expression of TLRs in acute otitis media (AOM), otitis media with effusion (OME), chronic otitis media (COM) with cholesteatoma, and COM without cholesteatoma. Many studies showed that TLRs 1–10 are expressed in AOM, OME, COM with cholesteatoma, and COM without cholesteatoma. TLR expression in the normal middle ear mucosa is absent or weak, but is increased in inflammatory fluid of AOM, effusion of OME, and granulation tissue and cholesteatoma of COM. In addition, TLRs show increased or decreased expression depending on the presence or absence of bacteria, recurrence of disease, tissue type, and repeated surgery. In conclusion, expression of TLRs is associated with otitis media. Inappropriate TLR expression, or delayed or absent induction, are associated with the occurrence, recurrence, chronicization, and complications of otitis media. Therefore, TLRs are very important in otitis media and closely related to its etiology.

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