ed into the esophageal lumen of mice, travels to • Corresponding author. Mailing address: Division of Allergy. Im- munology and Infectious Diseases. The Children's Hospital of Phila- delphia. 34th St. and Civic Center Blvd.. Philadelphia. PA 19104. Phone: (215) 590-4492. Fax: (215) 590-2025. Electronic mail address: ge