RT Journal Article
SR Electronic
T1 Distal respiratory tract viral infections in young children trigger a marked increase in alveolar mast cells
JF ERJ Open Research
JO erjor
FD European Respiratory Society
SP 00038-2018
DO 10.1183/23120541.00038-2018
VO 4
IS 4
A1 Andersson, Cecilia K.
A1 Shikhagaie, Medya
A1 Mori, Michiko
A1 Al-Garawi, Amal
A1 Reed, Jennifer L.
A1 Humbles, Alison A.
A1 Welliver, Robert
A1 Mauad, Thais
A1 Bjermer, Leif
A1 Jordana, Manel
A1 Erjefält, Jonas S.
YR 2018
UL http://openres.ersjournals.com/content/4/4/00038-2018.abstract
AB Viral infections predispose to the development of childhood asthma, a disease associated with increased lung mast cells (MCs). This study investigated whether viral lower respiratory tract infections (LRTIs) can already evoke a MC response during childhood.Lung tissue from young children who died following LRTIs were processed for immunohistochemical identification of MCs. Children who died from nonrespiratory causes served as controls. MCs were examined in relation to sensitisation in infant mice exposed to allergen during influenza A infection.Increased numbers of MCs were observed in the alveolar parenchyma of children infected with LRTIs (median (range) 12.5 (0–78) MCs per mm2) compared to controls (0.63 (0–4) MCs per mm2, p=0.0005). The alveolar MC expansion was associated with a higher proportion of CD34+ tryptase+ progenitors (controls: 0% (0–1%); LRTIs: 0.9% (0–3%) CD34+ MCs (p=0.01)) and an increased expression of the vascular cell adhesion molecule (VCAM)-1 (controls: 0.2 (0.07–0.3); LRTIs: 0.3 (0.02–2) VCAM-1 per mm2 (p=0.04)). Similarly, infant mice infected with H1N1 alone or together with house dust mite (HDM) developed an increase in alveolar MCs (saline: 0.4 (0.3–0.5); HDM: 0.6 (0.4–0.9); H1N1: 1.4 (0.4–2.0); HDM+H1N1: 2.2 (1.2–4.4) MCs per mm2 (p<0.0001)). Alveolar MCs continued to increase and remained significantly higher into adulthood when exposed to H1N1+HDM (day 36: 2.2 (1.2–4.4); day 57: 4.6 (1.6–15) MCs per mm2 (p=0.01)) but not when infected with H1N1 alone.Our data demonstrate that distal viral infections in young children evoke a rapid accumulation of alveolar MCs. Apart from revealing a novel immune response to distal infections, our data may have important implications for the link between viral infections during early childhood and subsequent asthma development.Viral infections in children evokes a rapid recruitment and accumulation of mast cells in the alveolar parenchyma http://ow.ly/i9eN30meNM7