ObjectivesA population of atypical memory B cells (AtMs) are greatly expanded in patients with active lupus, but their generation and pathophysiological roles are poorly defined. The aim of this study was to comprehensively characterise lupus AtMs with a purpose to identify therapeutic clues to target this B cell population in lupus.MethodsPeripheral B cell subsets were measured by flow cytometry. Sorting-purified B cell subsets were subject to RNA sequencing and functional studies. Plasma cytokines and secreted immunoglobulins were detected by Luminex or ELISA. In situ renal B cells were detected by multiplexed immunohistochemistry.ResultsCD24−CD20hi AtMs were strongly increased in two Chinese cohorts of patients with treatment-naïve lupus. Gene expression profile indicated that B cell signalling and activation, lipid/saccharide metabolism and endocytosis pathways were abnormally upregulated in lupus AtMs. In addition, the mammalian target of rapamycin complex 1 (mTORC1) pathway was remarkably activated in lupus AtMs, and blocking mTORC1 signalling by rapamycin abolished the generation of T-bet+ B cells and terminal differentiation of lupus AtMs. Furthermore, lupus AtMs displayed a dysfunctional phenotype, underwent accelerated apoptosis, poorly co-stimulated T cells and produced proinflammatory cytokines. Interestingly, lupus AtMs were in a paradoxically differentiated status with markers pro and against terminal differentiation and enriched with antinucleosome reactivity. Finally, AtMs were accumulated in the kidneys of patients with lupus nephritis and associated with disease severity.ConclusionsThese findings demonstrated that mTORC1-overactivated lupus AtMs are abnormally differentiated with metabolic and functional dysregulations. Inhibiting mTORC1 signalling might be an attractive option to target AtMs and to improve therapeutic effectiveness in patients with lupus.

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A hallmark of systemic lupus erythematosus (SLE) is the breaking of B-cell tolerance with the generation of high-affinity autoantibodies; however, the antibody-independent features of the B-cell compartment in SLE are less understood. In this study, we performed an extensive examination of B-cell subsets and their proinflammatory properties in a Chinese cohort of new-onset SLE patients. We observed that SLE patients exhibited an increased frequency of transitional B cells compared with healthy donors and rheumatoid arthritis patients. Plasma from SLE patients potently promoted the survival of transitional B cells in a type I IFN-dependent manner, which can be recapitulated by direct IFN-α treatment. Furthermore, the effect of IFN-α on enhanced survival of transitional B cells was associated with NF-κB pathway activation and reduced expression of the pro-apoptotic molecule Bax. Transitional B cells from SLE patients harbored a higher capacity to produce proinflammatory cytokine IL-6, which was also linked to the overactivated type I IFN pathway. In addition, the frequency of IL-6-producing transitional B cells was positively correlated with disease activity in SLE patients, and these cells were significantly reduced after short-term standard therapies. Thus, the current study provides a direct link between type I IFN pathway overactivation and the abnormally high frequency and proinflammatory properties of transitional B cells in active SLE patients, which contributes to the understanding of the roles of type I IFNs and B cells in the pathogenesis of SLE.

Background: Breast carcinoma (BC) is a cancer with a high morbidity rate, but the mechanisms by which it develops are never clear. There has been speculation regarding the potential relationships between breast cancer and local HPV infections for some time, and although much clinical research supports this hypothesis, some research results disprove the association. Therefore, the association is still inconclusive.Methods: We performed the data collection by searching the database PubMed, Embase, Cochrane Library and Web of science. In addition, 22 sites were added manually. After carefully selection, the pooled odds rate of 37 included case control studies was calculated. Subgroup analysis, publication bias and trim & fill analysis were conducted to make the result more reliable.Results: The analysis of 37 case control studies containing 3,607 BC cases and 1,728 controls showed obviously increase of BC risk with human papillomavirus (HPV) positive [summary odds ratio (SOR) =6.22, 95% confidence interval 4.25 to 9.12; P=0.0002]. Subgroup analysis proved three high risk HPV types (HPV16, 18 and 33) were positively correlated to BC.Conclusions: This systemic review and meta-analysis provide the evidence for HPV infection as a potential risk factor in BC, while the mechanism of this hypothesis still needs further evaluation.