B Cell Mobilization, Dissemination, Fine Tuning of Local Antigen Specificity and Isotype Selection in Asthma.

In order to better understand how the immune system interacts with environmental triggers to produce organ-specific disease, we here address the hypothesis that B and plasma cells are free to migrate through the mucosal surfaces of the upper and lower respiratory tracts, and that their total antibody repertoire is modified in a common respiratory tract disease, in this case atopic asthma. Using Adaptive Immune Receptor Repertoire sequencing (AIRR-seq) we have catalogued the antibody repertoires of B cell clones retrieved near contemporaneously from multiple sites in the upper and lower respiratory tract mucosa of adult volunteers with atopic asthma and non-atopic controls and traced their migration. We show that the lower and upper respiratory tracts are immunologically connected, with trafficking of B cells directionally biased from the upper to the lower respiratory tract and points of selection when migrating from the nasal mucosa and into the bronchial mucosa. The repertoires are characterized by both IgD-only B cells and others undergoing class switch recombination, with restriction of the antibody repertoire distinct in asthmatics compared with controls. We conclude that B cells and plasma cells migrate freely throughout the respiratory tract and exhibit distinct antibody repertoires in health and disease.

Isolation and Characterization of Lymphocytes from Human Mucosal Biopsies.

The important role of the local mucosal environment in both the initiation and progression of allergic disease is well established. Analysis of tissue-resident lymphocyte subsets by flow cytometry requires isolation of viable cells from mucosal samples.Here we describe an advanced method to dissociate lymphocytes from human mucosal (e.g., nasal, bronchial) biopsies. Single-cell suspensions are obtained through a combination of gentle mechanical disruption and incubation of tissue with proteolytic enzymes. This method fully utilizes limited clinical samples and is amenable to a variety of downstream applications for phenotypic, single-cell analysis of tissue lymphocytes or pooled lymphocyte subsets.