EFFECT OF THERMONEUTRAL HOUSING ON FUNGAL‐INDUCED RESPIRATORY ALLERGIC DISEASE IN MICE.

Climate change is projected to increase the number of fungal agents and may become a significant health impact. It is important to consider how respiratory allergic responses could be altered with global warming. Core temperature (Tc) was monitored by telemetry in female, BALB/c mice while acclimated for one week to ambient temperatures (Ta) of 22 or 30 °C. Exposure to 30 °C led to small increase in Tc that recovered in ~3 d. Mice were exposed to house dust mite (HDM) allergen that was administered by intratracheal aspiration 4X over a 4 week period at doses ranging from 1.25 to 20 ug. Airway responses to methacholine challenge were assessed 1 day following the last exposure to HDM and suggest a trend toward more elevated responses in higher dose mice housed at 30 °C. Bronchoalveolar lavage fluid (BALF) and blood were collected 2 days after the final exposure. BALF total cell counts increased at 10 and 20 ug in mice acclimated to 22 C. Allergic responses were manifested at lower doses of HDM in mice acclimated to 30 °C. Tc appeared to be unaffected by HDM exposure at 22 and 30 °C. The data suggest that housing in a thermoneutral environment of 30 °C may exacerbate the respiratory response to allergic agents compared to housing at a Ta of 22 °C that is a mild cold stress in mice. Future studies will address how higher Ta that elevate Tc will affect respiratory allergic responses. (Abstract does not represent USEPA policy).