Influenza Virus Infection and Bacterial Clearance in Young Adult and Aged Mice

Wyde, Philip R.; Six, Howard R.; Ambrose, Mark; Throop, Bethany J

doi:10.1093/geronj/44.5.b118

Cited by 13 publications

(3 citation statements)

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“…The present findings are consistent with previous reports demonstrating no differences in bacterial clearance between otherwise healthy young and aged mice (Wyde et al, 1989). Conversely, bacterial clearance deficits have been reported in aged rats, but it is important to note that in these cases, the endotoxin dose was extremely high (approximately one order of magnitude or more higher than in our model), and caused 100% mortality (Horan et al, 1991).…”

Section: Discussionsupporting

confidence: 94%

The role of hepatic and splenic macrophages in E. coli-induced memory impairments in aged rats

Barrientos¹,

Thompson²,

Arnold³

et al. 2015

Brain, Behavior, and Immunity

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Bi-directional communication between the peripheral and central nervous systems has been extensively demonstrated. Aged rats exhibit a prolonged proinflammatory response in the hippocampus region of the brain following a peripheral bacterial infection, and this response in turn causes robust memory declines. Here we aimed to determine whether hepatic or splenic macrophages play a role in the maintenance of this central response. Proinflammatory cytokines measured in liver and spleen four days following an E. coli infection revealed a potentiated proinflammatory response in liver, and to a lesser extent in spleen, in aged relative to young rats. To determine whether this potentiated response was caused by impaired bacterial clearance in these organs, E. coli colony forming units in liver and spleen were measured 4 days after infection, and there were no difference between young and aged rats in either organ. No E. coli was detected in the hippocampus, eliminating the possibility that the aged blood brain barrier allowed E. coli to enter the brain. Depletion of hepatic and splenic macrophages with clodronate-encapsulated liposomes effectively eliminated the proinflammatory response to E. coli at four days in both organs. However, this treatment failed to reduce the proinflammatory response in the hippocampus. Moreover, depletion of peripheral macrophages from liver and spleen did not prevent E. coli-induced memory impairment. These data strongly suggest that hepatic and splenic macrophages do not play a major role in the long-lasting maintenance of the proinflammatory response in the hippocampus of aged rats following a bacterial infection, or the memory declines that this response produces.

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Section: Discussionsupporting

confidence: 94%

The role of hepatic and splenic macrophages in E. coli-induced memory impairments in aged rats

Barrientos¹,

Thompson²,

Arnold³

et al. 2015

Brain, Behavior, and Immunity

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“…Viral induced immunosuppression can allow for a bacterial super infection, as host immune responses can be suppressed when immunologic cells are impaired during influenza infection and immune cell dysfunction can reduce the host’s ability to fight bacteria (Peltola and McCullers, 2004; Brundage, 2006; Wu et al, 2011). Many studies involving animal models have shown that influenza infection increases and prolongs bacterial growth, due to reduced macrophage accumulation and decreased bacterial clearance due to reduced phagocytic activity (Kleinerman et al, 1976; Wyde et al, 1989; Sun and Metzger, 2008). Additionally it has recently been shown that S. pneumoniae and influenza co-infection results in a reduction in the number of local alveolar macrophages, this due to increased death of these macrophages by apoptosis and necrosis (Sharma-Chawla et al, 2016).…”

Section: Factors Affecting the Severity Of Bacterial Co/secondary Infmentioning

confidence: 99%

Secondary Bacterial Infections Associated with Influenza Pandemics

2017

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Lower and upper respiratory infections are the fourth highest cause of global mortality (Lozano et al., 2012). Epidemic and pandemic outbreaks of respiratory infection are a major medical concern, often causing considerable disease and a high death toll, typically over a relatively short period of time. Influenza is a major cause of epidemic and pandemic infection. Bacterial co/secondary infection further increases morbidity and mortality of influenza infection, with Streptococcus pneumoniae, Haemophilus influenzae, and Staphylococcus aureus reported as the most common causes. With increased antibiotic resistance and vaccine evasion it is important to monitor the epidemiology of pathogens in circulation to inform clinical treatment and development, particularly in the setting of an influenza epidemic/pandemic.

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“…Staphylococcus aureus, Staphylococcus pneumoniae and Haemophilus influenza are the most common pathogens involved in influenza-associated bacterial pneumonia. The increased susceptibility to secondary bacterial invasion following influenza infection is attributed to decreased mucociliary clearance by the airways, enhanced bacterial adherence to influenza-infected cells, immunosuppression caused by virus infection, and decreased bacterial clearance by phagocytes (Rouse & Horohov, 1986;Wyde et al 1989;Leigh et al 1991). On the other hand, S. aureus has been shown to secrete a protease capable of activating haemagglutinin by proteolytic cleavage in vitro.…”

Section: Effects Of Influenza Infection On the Hostmentioning

confidence: 99%

Vitamin E and infectious diseases in the aged

Han

Meydani

1999

Proc. Nutr. Soc.

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The incidence of infectious diseases, particularly respiratory diseases, increases with age. Age-associated decline in immune function contributes to the increased susceptibility of the aged to infections. Vitamin E supplementation has been shown to improve some aspects of immune function in aged animals and human subjects. The protective effect of vitamin E against viral or bacterial infections in experimentally-challenged young animals has been reported. We investigated the effects of supplementation with vitamin E and other antioxidants on resistance to influenza infection in young and old animals. While vitamin E-supplemented young mice showed only a modest reduction in lung viral titre, vitamin E-supplemented old mice exhibited a highly significant (P< 0.05) reduction in viral lung titre. In subsequent studies, we focused on the mechanism of vitamin E-induced reduction of influenza viral titre. The results of these studies as well as those reported by other investigators on the relationship between vitamin E and infectious diseases will be reviewed.

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Influenza Virus Infection and Bacterial Clearance in Young Adult and Aged Mice

Cited by 13 publications

References 0 publications

The role of hepatic and splenic macrophages in E. coli-induced memory impairments in aged rats

The role of hepatic and splenic macrophages in E. coli-induced memory impairments in aged rats

Secondary Bacterial Infections Associated with Influenza Pandemics

Vitamin E and infectious diseases in the aged

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