Fig. 3: Cigarette smoke exposure reduces nasal OVA-IgA avidity during the acute post-immunization period while augmenting mutational load in the cognate nasal Igha repertoire.

Mice exposed to room air (RA) or cigarette smoke (CS) for one week were intranasally immunized with LPS/OVA as described in Fig. 1, and metrics of antibody antigen-binding affinity and somatic hypermutation were assessed. A Median fluorescence intensity (MFI) of IgA and OVA was quantified within OVA-IgA ASCs in the nasal mucosa at 3dpb. Data represent n = 11–12 mice per group from two independent experiments. B OVA:IgA MFI ratio at various timepoints. Data represent n = 11–12 mice per group from two independent experiments (3dpb) and n = 5 mice per group (7dpb and 14dpb independently). C Avidity indices were derived for NALF OVA-IgA by chaotropic urea ELISA. Data represent 13–15 animals per group from two independent experiments at each timepoint. D Nasal Igha mRNA transcripts were analyzed at 3dpb by high-throughput immunoglobulin sequencing. Replacement mutations were quantified in CDRs 1/2 and FWRs 1/2/3 on a per-clone basis. Data represent n = 3–9 mice per group. A.U. arbitrary units. A–C Student’s unpaired t-tests, D Mann-Whitney test with Bonferroni correction. Mean ± SEM. *p < 0.05.