title: Exercise Improves Host Response to Influenza Viral Infection in Obese and Non-Obese Mice through Different Mechanisms.
abstract: Obesity has been associated with greater severity of influenza virus infection and impaired host defense. Exercise may confer health benefits even when weight loss is not achieved, but it has not been determined if regular exercise improves immune defense against influenza A virus (IAV) in the obese condition. In this study, diet-induced obese mice and lean control mice exercised for eight weeks followed by influenza viral infection. Exercise reduced disease severity in both obese and non-obese mice, but the mechanisms differed. Exercise reversed the obesity-associated delay in bronchoalveolar-lavage (BAL) cell infiltration, restored BAL cytokine and chemokine production, and increased ciliary beat frequency and IFNα-related gene expression. In non-obese mice, exercise treatment reduced lung viral load, increased Type-I-IFN-related gene expression early during infection, but reduced BAL inflammatory cytokines and chemokines. In both obese and non-obese mice, exercise increased serum anti-influenza virus specific IgG2c antibody, increased CD8+ T cell percentage in BAL, and reduced TNFα by influenza viral NP-peptide-responding CD8+ T cells. Overall, the results suggest that exercise "restores" the immune response of obese mice to a phenotype similar to non-obese mice by improving the delay in immune activation. In contrast, in non-obese mice exercise treatment results in an early reduction in lung viral load and limited inflammatory response.
authors.affiliation: Immunobiology Program, Iowa State University, Ames, IA, United States of America.
authors.forename: Kristi J
authors.initials: KJ
authors.lastname: Warren
authors.affiliation: Department of Kinesiology, College of Human Sciences, Iowa State University, Ames, IA, United States of America.
authors.forename: Molly M
authors.initials: MM
authors.lastname: Olson
authors.affiliation: Department of Kinesiology, College of Human Sciences, Iowa State University, Ames, IA, United States of America.
authors.forename: Nicholas J
authors.initials: NJ
authors.lastname: Thompson
authors.affiliation: Department of Kinesiology, College of Human Sciences, Iowa State University, Ames, IA, United States of America.
authors.forename: Mackenzie L
authors.initials: ML
authors.lastname: Cahill
authors.affiliation: VA Nebraska-Western Iowa Health Care System Research Service, Department of Veterans Affairs Medical Center, Omaha, NE, United States of America; Pulmonary, Critical Care, Sleep & Allergy Division, University of Nebraska Medical Center, Nebraska Medical Center, Omaha, NE, United States of America.
authors.forename: Todd A
authors.initials: TA
authors.lastname: Wyatt
authors.affiliation: Immunobiology Program, Iowa State University, Ames, IA, United States of America; Department of Veterinary Diagnostic and Production Animal Medicine, Iowa State University, Ames, IA, United States of America.
authors.forename: Kyoungjin J
authors.initials: KJ
authors.lastname: Yoon
authors.affiliation: National Veterinary Services Laboratories, USDA, APHIS, Ames, IA, United States of America.
authors.forename: Christina M
authors.initials: CM
authors.lastname: Loiacono
authors.affiliation: Immunobiology Program, Iowa State University, Ames, IA, United States of America; Department of Kinesiology, College of Human Sciences, Iowa State University, Ames, IA, United States of America.
authors.forename: Marian L
authors.initials: ML
authors.lastname: Kohut
mesh_terms: D000818:Animals; D001992:Bronchoalveolar Lavage Fluid / Q000821:virology*; D018925:Chemokines / Q000378:metabolism; D016207:Cytokines / Q000378:metabolism; D009980:Influenza A virus; D008168:Lung / Q000378:metabolism / Q000821:virology; D051379:Mice; D008820:Mice, Obese; D009765:Obesity / Q000378:metabolism*; D009976:Orthomyxoviridae Infections / Q000378:metabolism / Q000821:virology*; D010805:Physical Conditioning, Animal / Q000502:physiology*
chemical_list: D018925:Chemokines; D016207:Cytokines