J Infect Dis . Propagation of activated B cells by in vitro SFTSV infection of human peripheral blood mononuclear cells

[tetano]

J Infect Dis


. 2021 Jul 5;jiab343.
doi: 10.1093/infdis/jiab343. Online ahead of print.
Propagation of activated B cells by in vitro SFTSV infection of human peripheral blood mononuclear cells


Yuji Wada ¹ , Sho Miyamoto ¹ , Shun Iida ^{1 2} , Kaori Sano ^{1 2} , Yuko Sato ¹ , Akira Ainai ¹ , Kumpei Saito ¹ , Harutaka Katano ¹ , Hideki Hasegawa ^{1 2 3} , Tadaki Suzuki ¹



Affiliations

• PMID: 34223910
• DOI: 10.1093/infdis/jiab343

Abstract

Severe fever with thrombocytopenia syndrome (SFTS) is an emerging, life-threatening tick-borne viral hemorrhagic fever (VHF) caused by SFTS virus (SFTSV). Transient appearance of plasmablastic lymphocytes in the peripheral blood of SFTS cases has been reported; however, the pathological significance of this transient burst in peripheral blood plasmablastic lymphocytes is unclear. Here, we show that SFTSV infection of human peripheral blood mononuclear cells (PBMCs) in vitro induced propagation of atypical lymphocytes. These atypical lymphocytes were activated B cells, which were induced by secretory factors other than viral particles; these factors were secreted by SFTSV-infected B cells. Activated B cells shared morphological and immunophenotypic characteristics with B cells of plasmablast lineage observed in peripheral blood and autopsy tissues of SFTS cases. This suggests that SFTSV-infected B cells secrete factors that induce B cell differentiation to plasmablasts, which may play an important role in pathogenesis of SFTS through the SFTSV-B cell axis.

Keywords: B cell; SFTSV; activated B cells; atypical lymphocytes; peripheral blood mononuclear cells; plasmablasts.