Induced Tolerogenic Dendritic Cells as Modulators of Allergic Asthma

Summary

Despite advances in medications, allergic diseases, including allergic asthma continue to rise in prevalence. For this reason, there is a need for a better understanding of the mechanisms of allergic diseases and novel insights into modulating allergic inflammation. The investigators hypothesize that much remains to be learned about the behavior of T effector and T regulatory cells in allergic disease. Furthermore, the investigators hypothesize that novel mechanisms of allergic tolerance may exist, and elucidation of these mechanisms may provide insights into novel therapeutic strategies to control allergic diseases. The investigators will investigate the capacity for T cell tolerance induction in allergic subjects by a novel type of immune tolerizing dendritic cell (it-DC). The investigators will assess whether in vitro generated it-DCs have the capacity to induce antigen-specific T regulatory cells and suppress allergen-specific T effector cell function in vitro.

Standardized Cat Allergen extract and Dust Mite Allergens will be used to generate changes in the airways that occur during exposure to allergen. For this investigation, the route of administration will be topical application of the titrated allergen to a bronchoscopically isolated subsegment of one lobe of one lung. The dose of biologic will be determined from prior skin-prick testing.

Conditions

• Asthma
• Allergies

Interventions

BIOLOGICAL

Bronchoscopy, Segmental Allergen Challenge and Bronchoalveolar Lavage

On the first bronchoscopy day,BAL will first be performed in the lingual without instillation of diluent or allergen. A 2ml aliquot of isotonic diluent is instilled into the right upper lobe.The procedure is repeated in the right middle lobe with instillation of 2ml of standardized cat or mite allergen solution. A test dose concentration of allergen is administered first consisting of 2 ml of allergen at 1/10th(Cat,D.farinae)or 1/30th(D.pteronyssinus)the threshold concentration.If on visual inspection through the bronchoscope there is no evidence of mucosal inflammation after 2 minutes a second segmental allergen challenge will be done in the right middle lobe using 2ml of full-dose allergen at the threshold concentration(Cat,D.farinae)or 1/3 the threshold concentration(D.pteronyssinus). This dose will be predetermined by quantitative skin prick testing.A second bronchoscopy is performed 24 hours after delivery of allergen extract and diluent to obtain BAL fluid from the RUL and RML.

PROCEDURE

Phlebotomy

200 (40 teaspoons) ml of blood will be obtained from the subjects to collect different leukocyte populations. A second 200 ml of blood will be obtained from the Track 2 subjects 4 weeks later for isolation of T lymphocytes for functional studies.

Sponsors & Collaborators

• National Institute of Allergy and Infectious Diseases (NIAID)

  collaborator NIH

• Andrew D. Luster, M.D.,Ph.D.

  lead OTHER

Principal Investigators

• Andrew D Luster, M.D., Ph.D. · Massachusetts General Hospital

Study Design

Allocation

NA

Purpose

BASIC_SCIENCE

Masking

NONE

Model

SINGLE_GROUP

Eligibility

Min Age

18 Years

Max Age

50 Years

Sex

ALL

Healthy Volunteers

Yes

Timeline & Regulatory

Start

2013-01-31

Primary Completion

2016-09-30

Completion

2016-09-30

Countries

• United States

Study Locations