Research

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11 pages, 1723 KiB

Open AccessArticle

IFN-γ Attenuates Eosinophilic Inflammation but Is Not Essential for Protection against RSV-Enhanced Asthmatic Comorbidity in Adult Mice

by Abenaya Muralidharan, Md Bashir Uddin, Christopher Bauer, Wenzhe Wu, Xiaoyong Bao and Keer Sun

Viruses 2022, 14(1), 147; https://0-doi-org.brum.beds.ac.uk/10.3390/v14010147 - 14 Jan 2022

Cited by 2 | Viewed by 1988

Abstract

The susceptibility to respiratory syncytial virus (RSV) infection in early life has been associated with a deficient T-helper cell type 1 (Th1) response. Conversely, healthy adults generally do not exhibit severe illness from RSV infection. In the current study, we investigated whether Th1 [...] Read more.

The susceptibility to respiratory syncytial virus (RSV) infection in early life has been associated with a deficient T-helper cell type 1 (Th1) response. Conversely, healthy adults generally do not exhibit severe illness from RSV infection. In the current study, we investigated whether Th1 cytokine IFN-γ is essential for protection against RSV and RSV-associated comorbidities in adult mice. We found that, distinct from influenza virus, prior RSV infection does not induce significant IFN-γ production and susceptibility to secondary Streptococcus pneumoniae infection in adult wild-type (WT) mice. In ovalbumin (OVA)-induced asthmatic mice, RSV super-infection increases airway neutrophil recruitment and inflammatory lung damage but has no significant effect on OVA-induced eosinophilia. Compared with WT controls, RSV infection of asthmatic Ifng^−/− mice results in increased airway eosinophil accumulation. However, a comparable increase in eosinophilia was detected in house dust mite (HDM)-induced asthmatic Ifng^−/− mice in the absence of RSV infection. Furthermore, neither WT nor Ifng^−/− mice exhibit apparent eosinophil infiltration during RSV infection alone. Together, these findings indicate that, despite its critical role in limiting eosinophilic inflammation during asthma, IFN-γ is not essential for protection against RSV-induced exacerbation of asthmatic inflammation in adult mice. Full article

(This article belongs to the Special Issue Post-viral Superinfection: Revising the Role of Pathogens and the Host)

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20 pages, 2882 KiB

Open AccessArticle

Successive Inoculations of Pigs with Porcine Reproductive and Respiratory Syndrome Virus 1 (PRRSV-1) and Swine H1N2 Influenza Virus Suggest a Mutual Interference between the Two Viral Infections

by Juliette Bougon, Céline Deblanc, Patricia Renson, Stéphane Quéguiner, Stéphane Gorin, Sophie Mahé, Mireille Le Dimna, Nicolas Barbier, Frédéric Paboeuf, Gaëlle Simon and Olivier Bourry

Viruses 2021, 13(11), 2169; https://0-doi-org.brum.beds.ac.uk/10.3390/v13112169 - 27 Oct 2021

Cited by 4 | Viewed by 1956

Abstract

Porcine reproductive and respiratory syndrome virus (PRRSV) and swine influenza A virus (swIAV) are major pathogens of the porcine respiratory disease complex, but little is known on their interaction in super-infected pigs. In this study, we investigated clinical, virological and immunological outcomes of [...] Read more.

Porcine reproductive and respiratory syndrome virus (PRRSV) and swine influenza A virus (swIAV) are major pathogens of the porcine respiratory disease complex, but little is known on their interaction in super-infected pigs. In this study, we investigated clinical, virological and immunological outcomes of successive infections with PRRSV-1 and H1N2 swIAV. Twenty-four specific pathogen-free piglets were distributed into four groups and inoculated either with PRRSV at study day (SD) 0, or with swIAV at SD8, or with PRRSV and swIAV one week apart at SD0 and SD8, respectively, or mock-inoculated. In PRRSV/swIAV group, the clinical signs usually observed after swIAV infection were attenuated while higher levels of anti-swIAV antibodies were measured in lungs. Concurrently, PRRSV multiplication in lungs was significantly affected by swIAV infection, whereas the cell-mediated immune response specific to PRRSV was detected earlier in blood, as compared to PRRSV group. Moreover, levels of interferon (IFN)-α measured from SD9 in the blood of super-infected pigs were lower than those measured in the swIAV group, but higher than in the PRRSV group at the same time. Correlation analyses suggested an important role of IFN-α in the two-way interference highlighted between both viral infections. Full article

(This article belongs to the Special Issue Post-viral Superinfection: Revising the Role of Pathogens and the Host)

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Review

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15 pages, 862 KiB

Open AccessReview

Disease Tolerance during Viral-Bacterial Co-Infections

by Tarani Kanta Barman and Dennis W. Metzger

Viruses 2021, 13(12), 2362; https://0-doi-org.brum.beds.ac.uk/10.3390/v13122362 - 25 Nov 2021

Cited by 5 | Viewed by 4097

Abstract

Disease tolerance has emerged as an alternative way, in addition to host resistance, to survive viral-bacterial co-infections. Disease tolerance plays an important role not in reducing pathogen burden, but in maintaining tissue integrity and controlling organ damage. A common co-infection is the synergy [...] Read more.

Disease tolerance has emerged as an alternative way, in addition to host resistance, to survive viral-bacterial co-infections. Disease tolerance plays an important role not in reducing pathogen burden, but in maintaining tissue integrity and controlling organ damage. A common co-infection is the synergy observed between influenza virus and Streptococcus pneumoniae that results in superinfection and lethality. Several host cytokines and cells have shown promise in promoting tissue protection and damage control while others induce severe immunopathology leading to high levels of morbidity and mortality. The focus of this review is to describe the host cytokines and innate immune cells that mediate disease tolerance and lead to a return to host homeostasis and ultimately, survival during viral-bacterial co-infection. Full article

(This article belongs to the Special Issue Post-viral Superinfection: Revising the Role of Pathogens and the Host)

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