Too young to die? How aging affects cellular innate immune responses to influenza virus and disease severity

Abstract

Influenza is a respiratory viral infection that causes significant morbidity and mortality worldwide. The innate immune cell response elicited during influenza A virus (IAV) infection forms the critical first line of defense, which typically is impaired as we age. As such, elderly individuals more commonly succumb to influenza-associated complications, which is reflected in most aged animal models of IAV infection. Here, we review the important roles of several major innate immune cell populations in influenza pathogenesis, some of which being deleterious to the host, and the current knowledge of how age-associated numerical, phenotypic and functional cell changes impact disease development. Further investigation into age-related modulation of innate immune cell responses, using appropriate animal models, will help reveal how immunity to IAV may be compromised by aging and inform the development of novel therapies, tailored for use in this vulnerable group.

The Impact of Aging on the Lung Alveolar Environment, Predetermining Susceptibility to Respiratory Infections

“…ALF contains innate soluble components with the primary role of maintaining proper pulmonary function ( Notter, 2000 ; Fronius et al, 2012 ; Torrelles and Schlesinger, 2017 ). Our studies and others indicate that lung tissue in the elderly (in humans and mice) has a high basal inflammation and oxidative stress that leads to dysfunction of critical innate soluble and cellular components that could drive host susceptibility to respiratory infections and diseases [e.g., influenza, pneumonia, tuberculosis (TB)] ( Toapanta and Ross, 2009 ; Shivshankar et al, 2011 ; Canan et al, 2014 ; Moliva et al, 2014 ; Piergallini and Turner, 2018a ; Keilich et al, 2019 ; Bulut et al, 2020 ; Harpur et al, 2021 ). Thus, defining when and how these changes occur at the cellular and molecular level is critical to understand age-associated lung-specific pathologies and aging in general.…”

Highly pathogenic avian influenza (HPAI A H5N1) outbreak in Spain: its mitigation through the One Health approach – a short communication

“…In recent times, studies have shown that many countries, especially the Sub-Saharan countries and some parts of Europe, including Spain, lack knowledge of the One Health approach to tackle zoonotic infections, which leads to greater vulnerability in the spread of infections and outbreaks, for example, avian influenza A, and setbacks in reducing the spread of these diseases among community members and in the ecological system at large. Using a One Health approach, zoonotic diseases can be prevented from occurring, and if they do occur, the administration of good treatment to both the infected animals and human beings can promote health in animals, humans, and environmental life 8 .…”