Decreased perforin- producing B cells correlate with systemic lupus erythematosus

Objective It has been proved that B cells play indispensable roles in immunity via producing cytokines and secreting antibodies. Aberrant B cells are considered as the major participants in the pathogenesis of systemic lupus erythematosus (SLE). Recently, perforin (PFP)-producing B cell has been identified, serving as a new type of potential anti-tumour effector cells. However, the roles and characteristics of the PFP-producing B cells in SLE remain unclear. Methods The frequencies of PFP-producing B cells in peripheral blood of heathy controls (HC) and SLE patients were detected by flow cytometry, and their correlation with the patient clinical and immunological features were analysed. The capacities of these cells in producing PFP were also compared between HC and SLE by RT-qPCR and ELISpot analyses. Results In this study, we demonstrated that B cells could produce PFP and was further enhanced upon anti-BCR and IL-21 stimulation. In patients with SLE, the frequencies of these PFP-producing B cells were decreased and negatively correlated with the clinical characteristics. Further analysis revealed that SLE patients with vasculitis and pleurisy showed even lower frequencies of PFP-producing B cells. Conclusion These findings revealed that B cells could produce PFP, and a decrease in these cells was associated with SLE pathogenesis.