[HTML][HTML] Altered Treg and cytokine responses in RSV-infected infants

AF Christiaansen, MA Syed, PP Ten Eyck… - Pediatric …, 2016 - nature.com
AF Christiaansen, MA Syed, PP Ten Eyck, SM Hartwig, L Durairaj, SS Kamath, SM Varga
Pediatric research, 2016nature.com
Background: Respiratory syncytial virus (RSV) is the leading cause of bronchiolitis and
pneumonia in children under 1 y of age in the USA. The host immune response is believed
to contribute to RSV-induced disease. We hypothesize that severe RSV infection in infants is
mediated by insufficient regulation of the host immune response of regulatory T cells (Tregs)
resulting in immunopathology. Methods: Blood and nasal aspirates from 23 RSV-infected
and 17 control infants under 1 y of age were collected. Treg frequencies were determined by …
Abstract
Background:
Respiratory syncytial virus (RSV) is the leading cause of bronchiolitis and pneumonia in children under 1 y of age in the USA. The host immune response is believed to contribute to RSV-induced disease. We hypothesize that severe RSV infection in infants is mediated by insufficient regulation of the host immune response of regulatory T cells (Tregs) resulting in immunopathology.
Methods:
Blood and nasal aspirates from 23 RSV-infected and 17 control infants under 1 y of age were collected. Treg frequencies were determined by flow cytometry from peripheral blood mononuclear cells. Analysis of 24 cytokines was measured by multiplex assay on nasal aspirates.
Results:
We demonstrate that the frequency of activated Tregs is significantly reduced in the peripheral blood of RSV-infected infants compared with age-matched controls. Surprisingly, T helper (Th) 17 related cytokines including interleukin (IL)-1β, IL-17A, and IL-23 were associated with a reduction in clinical symptoms of respiratory distress. In addition, the amount of IL-33 protein in nasal washes, a cytokine important in maintaining Treg homeostasis in mucosal tissues, was decreased in RSV-infected children.
Conclusion:
These results suggest that decreased Treg numbers and an inability to properly control the host inflammatory response results in severe RSV infection.
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