Atypical B cells in chronic infectious diseases and systemic autoimmunity: puzzles with many missing pieces

Curr Opin Immunol. 2022 Jun 17;77:102227. doi: 10.1016/j.coi.2022.102227. Online ahead of print.ABSTRACTThe world's struggle to contain the SARS-CoV-2 epidemic, primarily through vaccination, has highlighted the importance of better understanding the biology of B cells that participate in defense against infectious diseases, both acute and chronic. Here, we focus on a population of human B cells, termed atypical B cells (ABCs), that comprise a distinct B-cell lineage that differentiates from naive B cells in an interferon-γ-driven process, and are infrequent in healthy individuals but significantly expanded in chronic infectious diseases, including malaria, as well as in systemic autoimmune diseases such as systemic lupus erythematosus (SLE). Recent comparisons of ABCs by single-cell RNAseq provided evidence that ABCs in diverse chronic infectious diseases and in systemic autoimmune diseases are highly related and share common drivers of differentiation and expansion. However, ABCs in different diseases are not identical and also show discrete disease-specific features. Here, we compare and contrast key features of two ABC populations, namely those that are expanded in individuals living in malaria-endemic areas of the world versus those in SLE patients. This comparison is of interest as it appears that unique features of these two diseases result in participation of autoreactive ABCs in parasite-specific responses in malaria but in pathogenic autoimmune responses in SLE. A ...
Source: Current Opinion in Immunology - Category: Allergy & Immunology Authors: Source Type: research