House Dust Protein Worsens Allergic AsthmaLast Updated: October 19, 2012. A bacterial protein found in house dust can promote the development of allergic asthma in response to indoor allergens, according to a letter published online Oct. 14 in Nature Medicine.
FRIDAY, Oct. 19 (HealthDay News) -- A bacterial protein found in house dust can promote the development of allergic asthma in response to indoor allergens, according to a letter published online Oct. 14 in Nature Medicine.
Rhonda H. Wilson, Ph.D., from the National Institutes of Health in Research Triangle Park, N.C., and colleagues examined whether bacterial components of household dust could act as allergic adjuvants in mice, and examined allergic responses in wild-type mice or mice lacking the Tlr4 or Tlr5 gene (receptors of the innate immune response that recognize common features of pathogens) exposed to household dust extracts.
The researchers found that the bacterial flagellin protein could stimulate strong allergic airway responses to innocuous proteins. Wild-type mice and mice lacking Tlr4 had similar strong allergic responses to household dust, while mice lacking Tlr5, the mammalian receptor for flagellin, had markedly lower allergic responses to dust. People with asthma also had higher levels of anti-flagellin antibodies than those without asthma.
"Together, these findings suggest that household flagellin promotes the development of allergic asthma by TLR5-dependent priming of allergic responses to indoor allergens," Wilson and colleagues conclude.