Low-dose arsenic compromises the immune response to influenza A infection in vivo.
BACKGROUND
Arsenic exposure is a significant worldwide environmental health concern. We recently reported that 5-week exposure to environmentally relevant levels (10 and 100 ppb) of As in drinking water significantly altered components of the innate immune response in mouse lung, which we hypothesize is an important contributor to the increased risk of lung disease in exposed human populations.


OBJECTIVE
We investigated the effects of As exposure on respiratory influenza A (H1N1) virus infection, a common and potentially fatal disease.


METHODS
In this study, we exposed C57BL/6J mice to 100 ppb As in drinking water for 5 weeks, followed by intranasal inoculation with a sub lethal dose of influenza A/PuertoRico/8/34 (H1N1) virus. Multiple end points were assessed postinfection.


RESULTS
Arsenic was associated with a number of significant changes in response to influenza, including an increase in morbidity and higher pulmonary influenza virus titers on day 7 post-infection. We also found many alterations in the immune response relative to As-unexposed controls, including a decrease in the number of dendritic cells in the mediastinal lymph nodes early in the course of infection.


CONCLUSIONS
Our data indicate that chronic As exposure significantly compromises the immune response to infection. Alterations in response to repeated lung infection may also contribute to other chronic illnesses, such as bronchiectasis, which is elevated by As exposure in epidemiology studies.
Kozul
Courtney D
CD
Department of Pharmacology and Toxicology, Dartmouth Medical School, Hanover, New Hampshire, USA.
Ely
Kenneth H
KH
Enelow
Richard I
RI
Hamilton
Joshua W
JW
D000818:Animals; D001151:Arsenic / Q000633:toxicity*; D001992:Bronchoalveolar Lavage Fluid; D004305:Dose-Response Relationship, Drug; D009980:Influenza A virus / Q000302:isolation & purification*; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D009976:Orthomyxoviridae Infections / Q000276:immunology*
D001151:Arsenic