Type I interferon signaling shapes B cell phenotype and pathogenicity in the nonobese diabetic (NOD) mouse model of Sjögren’s disease

Abstract

Purpose : Type I interferon (IFN) signaling is required for the development of lacrimal gland (LG) autoimmunity, but the cellular targets and pathogenic mechanisms have not been defined. We tested the hypothesis that lymphocytes require IFNAR1 to perpetuate LG inflammation using experimental mouse models of LG disease.

Methods : Wild-type (WT) NOD and NOD-SCID mice were purchased from The Jackson Laboratory. Ifnar1-deficient NOD mice generated by CRISPR/Cas9. Differential gene expression was determined using the Mouse Autoimmune Profiling panel, Nanostring nCounter analysis system, and Rosalind online analysis platform to compare whole-tissue RNA from LGs of 6- and 10-week-old NOD mice. Bulk or magnetically sorted cells were adoptively transferred from WT and/or KO donor mice to NOD-SCID recipients. LG were fixed in buffered formalin, processed, embedded in paraffin, sectioned, and stained with H&E. Inflammation was quantified by standard focus scoring. Flow cytometry was used to characterize lymphocytic infiltrates of the LG. Statistics were calculated with Prism 9.0.1. Two-group comparisons were performed by Mann-Whitney tests. Log2ratios of the frequencies of WT/KO for populations in co-adoptive transfer studies were analyzed via single sample T tests. P-values < 0.05 were considered significant.

Results : WT or KO NOD cervical lymph node cells were adoptively transferred into NOD-SCID mice. KO recipients developed significantly less LG disease (P=0.0398). T cells isolated from WT or KO donors were transferred to NOD-SCID mice, but no significant difference in LG disease severity was found in recipients (P=0.8968). NanoString studies found that B cell genes and pathways were upregulated early in LG disease, and many of these genes were downstream of type I IFN signaling. CD45.2 WT and CD45.1 KO NOD splenocytes were co-transferred into NOD-SCID mice. Significantly more WT B cells than KO B cells infiltrated the LG (P<0.0001) and these WT B cells in the LG expressed high levels of CD11c and TLR7. These studies also found that age-associated B cells (CD21/35^lowCD23^low) required intrinsic type I IFN signaling to infiltrate the LG (P=0.0002).

Conclusions : We found that there is a lymphocyte-intrinsic role for type I IFN signaling in LG disease. We also found that type I IFN signaling modulates B cell infiltration of the LG and shapes their phenotype.

This abstract was presented at the 2024 ARVO Annual Meeting, held in Seattle, WA, May 5-9, 2024.