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bioRxiv · 10.64898/2026.07.10.737835

ARID3a-Expressing Naive B Cells in SLE have an Activated Phenotype and Transiently Express Surface CD68

Garton, J.·Hocker, J. R. S.·Garman, L.·Zhong, H.·Zimmerman, K.·Guthridge, J. M.·James, J. A.·Webb, C. F.
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Abstract

Numbers of ARID3a (AT-Rich Interaction Domain 3a) -expressing B lymphocytes from patients with systemic lupus erythematosus (SLE) are associated with increased disease activity. Normally, ARID3a-expressing circulating naive B cells are rare, but in SLE naive B cells dramatically increase ARID3a expression. We found that in vitro stimulation of B lymphocytes from healthy individuals with a cocktail of cytokines and agonists induced ARID3a in a subset of activated naive B cells and in IgD-CD27- double negative B cells previously associated with autoimmunity. Single cell RNA-seq of isolated naive B cells from ten SLE patients, with varying frequencies of ARID3a-expressing cells, revealed that ARID3a-associated genes included activation markers. Moreover, our data revealed the unexpected co-expression of the scavenger receptor CD68 with ARID3a, at both the transcript and protein level, in activated subsets of naive B cells. Inhibition of ARID3a in stimulated B cell cultures blocked naive B cell activation and CD68 expression. Together, these data identify ARID3a and CD68 as markers of naive B cell precursors associated with autoimmunity in SLE.

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Garton, J., Hocker, J. R. S., Garman, L., Zhong, H., Zimmerman, K., Guthridge, J. M., James, J. A., Webb, C. F.. 2026-07-16. ARID3a-Expressing Naive B Cells in SLE have an Activated Phenotype and Transiently Express Surface CD68. https://doi.org/10.64898/2026.07.10.737835

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